Feature film shooting with jvc and mini 35 adaptor/congrats + questions 4 charles
 

Hi guys
Thanks to charles and team for the test info. on the jvc cam and mini 35 adaptor from P+S Technik. I am a co-producer/writer/director of an independent film called Spoon that is in pre-production at the moment. We are based in cape town, south africa. We are planning to use the JVC cam and mini 35 lenses to shoot the film and have purchased two of each unit for testing. We are working with a company called cineform and capturing direct to disk using the new cineform codec which is amazing. We are presently shooting tests and found Charles + teams' test footage and results most helpful.

Here are a couple of questions for Charles+team (and anybody else who has any ideas) interwoven with some info from our tests so far:
1. FOCUS- in your opinion, does the "softness" that one gets with the mini-35 give the same kind of softness drop as one could expect with 35mm film or is it more? Obviously we want a softer film look but we seem to be too soft on our tests. We have been struggling to get sharp focus through the mini 35 lens. On our first tests our ground glass focus went out very slightly. Its very very sensitive and seems to be something that one needs to check regularly. We've been doing some technical tests but your stuff seems to be sharper than anything we've gotten to date. We did a bunch of exterior night stuff with rain etc. which I'm going to try and post up. We just started shooting the day stuff.
2. We have noticed that the focus assist doesn't seem to work if there is not enough light. Did you guys find that as well?
3. What setting was your sharpness on when you guys shot the tests?
4. Your gamma was on +3 for the night shots – where there any other settings you used on your day shots that might help us (master blacks etc.)
5. Which lens did you guys use for the shot called AR_walking hands?
6. What stop loss do you think you were getting? The mini 35 guys say that we should loose about 1.5 stops - we have done several technical tests which confirm that we are getting something a lot closer to just over a 3 stop loss. ie. F4 on the fujinon = T1.3 on a carl zeiss 25mm

We now have some interesting results so far from the day test shots that literally just came in:
a. as one would imagine, we found that it helped the focus hugely to shoot with detail on - we had originally wanted to avoid this as we understand its a digital process so we wanted to shoot the "cleanist" image possible and then rather try and sharpen in post. (we own a big post facility) We want to try and avoid any digital mess that might appear when we blow the footage up to a 35m print. However so far it seems that it's better to use the camera's detail settings. Do you guys have any thoughts on the detail setting issue?
b. We found that when shooting daytime ext. city shots, we got the most detailed and clean image by stopping down on the relay lens and shooting wide open on the prime lens. ie: our prime lens was wide open and we used the relay lens to get correct exposure. We had originally heard that it should be the other way around so this was a surprise.

We have a lot of night ext. and int. shots in the film so our biggest concern is likely to be the stop that we are loosing. We need serious light power. Basically on all our interiors and night exteriors we are having to shoot with relay and prime lens wide open. The fact that it appears that we get a cleaner image if we can stop down on the relay lens is frustrating and we're a bit in the dark at the moment if you pardon the expression.

you can keep updated with our progress on the capture side (we're using brand new codec technology in partnership with cineform) at http://indiefilmlive.blogspot.com/

ABOUT OUR PROJECT
Spoon is a supernatural thriller with a lot of visual effects. My partner Simon Hansen and I aim to help pioneer a new genre of film that we're calling "commercial independent". Basically films that have large scale production values produced on indie budgets. To see the kind of stuff we've done with no money in the past visit www.thesas.com and download the shortfilms on the viral page. One features a space shuttle landing in cape town and the other a digital artist training boot camp. We also recently co-produced a short film directed by our friend Neill Blomkamp. Its called Alive in Jo'burg and features aliens living in a south african township. www.ratel.ca
Our vfx company is www.atomic-vfx.com

Hi Sharlto, howzit?! Glad you found the footage useful.

1). "Sharpness" is a complicated term when used to compare film and video. I think that the slight softness that the Mini35 creates is part of what makes it look more pleasing to the eye; I find straight HD in general to sometimes be overally sharp in appearance (which is why I'm not a resolution-hound, only gravitating towards the most number of lines or resolution charts). Many have noted that the shot in our tests of the female model in front of the flowerbed is noticeably softer with the Mini35 than the straight-up version, but I can't say for sure since this was the first images we shot that day that we had dialed in the back focus (or even the front focus) perfectly.

2). Focus assist issue--Hadn't noticed that. I can well imagine that if there isn't enough contrast in the image it would have problems. Our night photography was fairly contrasty with highlights throughout.

3, 4, 5) Here are the notes that I had on the shots (I don't have anything on the detail, but I believe it was at unity (0):

All clips were 720/24p, 1/48 shutter, motion smoothing OFF unless noted. 0 db gain. All Mini35 clips shot with Cooke S4 lenses at T2, Mini35 set at speed 6.

Static test with Amy and flowerbed:
Mini35, 50mm
WB set at location
Cinema Mode ON
Color gain: 6
White clip: 100
Knee: 90%

Rack through greenery:
Mini35, 100mm,
Cinema Mode OFF
color matrix standard
cinema gamma : 3
color gain: 6

Greenery with Amy and Robert walking
Same settings as above

Amy and Robert walking, ends on holding hands
Same settings as above

Amy closeup
Mini35, 100mm
Settings otherwise same

Rob closeup
Same settings as above

Night exterior: Nicolette walks right to left
Mini35, 27mm
Color matrix: Cinema
Gamma: standard
Gamma level: 3
Color gain: 3

6) Stop loss issue: I would say that this probably has more to do with the markings on the Fujinon than anything else--it has been surmised that they are probably not all that accurate. Bear in mind that you are comparing T stops on the Zeiss (actual measured transmission) vs f-stops on the Fujinon (theoretical transmission). I personally feel that the Mini sucks up between 1.5 and 2 stops of light.

Regarding detail, I prefer not boost it in the camera as I think it adds a video "look" to the results.

Regarding which lens to adjust exposure, it is standard practice to set the cine lens at the desired aperture for depth of field purposes and adjust exposure via the relay. You should not see an optical difference with the relay wide open vs stopped down. When you say that the image was cleaner when the relay was stopped down, in what way? If the backfocus of the Mini35 is not properly adjusted, you will see a focus shift as you stop down the relay (it will improve), so remember that backfocus should be adjusted with the relay wide open and the cine lens stopped down to make the groundglass texture more apparent (Mini35 motor off, of course).

Good luck with your ventures!

My hats off to you Charles. Only a select few BOLD Cinematographers are confident enough DP's to give up their camera settings for the goodness of indie-kind. You're a scholar & a gentleman.

- ShannonRawls.com

Thanks for the kudos Shannon, but honestly I believe that lighting and composition are far more important factors for creating one's individual look than camera settings--I prefer to do more of the manipulation in post-production anyway, when you can judge the image more accurately and aren't under-the-gun.

Here here.
 

Hi Charles. Just another thank you. I am also involved in Spoon and we all greatly appreciate your assistance.

Simon

Hmm- no problems with diffraction then from the relay lens being stopped down too far? Not just a question for Charles as I realise he only had this rig for a short time to play with.

I think we discussed elsewhere that anything stopped down further than F8 on the stock lens caused diffraction issues for all those pixels they crammed in on the sensor. Maybe it's not an issue on the relay lens?

I'm going to hazard a guess on this, but I believe that because the light rays going through the relay are more parallel (due to the nature of the projected image on the ground glass) than one would encounter in a normal lens situation, diffraction and refraction are not as much of an issue. Probably there is a point in which stopping down the relay could be a problem. I've always tried to keep it around the middle position and use ND accordingly (on the camera or on the cine lens) to be safe.

relay lens vs prime lens
 

thanks for all your feedback charles. thats my co-producer/director simon posting above. We have been doing extensive tests and i'm still trying to get permission to post up the files with results but we have discovered the following:
1. we are definatley getting a difference between having the relay lens wide open and stopping down on it. when the relay lens is wide open, we can see the texture of the groundglass a lot more clearly and this messes up the image and results in a loss of detail. (when its stopped down, we find that the "spinning" groundglass grain gives a nice filmic look) With the relay wide open, the image also goes slightly yellow- overall it somewhat resembles the kind of thing one might see on a bad lens. my dop thought that perhaps this was because of the relatively poor quality of the mini 35 relay lens
2. we seemed to get a slightly more focused image as we stopped down on the relay lens, even when we set the backfocus with the relay wide open as you suggested.
3. john we haven't noticed any problems stopping down on the relay lens
4. at this point it looks like shooting with detail on normal is getting the best results.

It seems that the results are good as long as the relay lens is not wide open. This is a problem for us because we have a lot of night and low light shoots, but we're still testing and trying to see if we can make it work.

Charles a quick question - we're still waiting for our HD res monitor. I'm thinking we can't trust the camera's monitor/computer monitors for things like focus/detail. When you guys shot did you find yourselves relying heavily on the HD monitor as you were working?

Sharlto, welcome to the world of relay lenses, or in my case the HD dvx100a with it's built in "relay" lens. They suck, that is my feeling after playing with every sort of 35 adapter I could get my hands on, even building one from scratch.

It's very true that the relay lens will make your images softer when it's open, the reason? as far as I can tell a 1/3rd inch ccd is so small in size that your almost at the OPTICAL limit of glass to get above a 720x480 3ccd image, with the dvx100a and it's pixel offsetting we are getting 1540x984 HD frames from the camera, you can see shots here:www.reel-stream.com they look great, however when you open the dvx lens all the way IN HD ONLY it's lens goes soft, not so with SD, that looks great...not enough resolution to show the softness.

WIth your camera setup, your getting 1280x720 3ccd images from a 1/3rd inch chip! Far more resolution is needed from your glass then the dvx pixel for pixel. I'm sure your pixel sizes are smaller(they must be to fit them on a 1/3rd inch ccd) and this creates the need for cleaner glass. If you think about it, the 35mm glass on the front of a ground glass system does not need to resolve as much because it's image area is 24mm x 36mm approx. so your "limit" is the relay, or in my case the dvx lens..then ontop of that your dealing with the issues of focusing 2 lens systems, A feature I would hate to deal with on a "real" production outside studio test images. I have a feeling that your dealing on a level that many people don't have a need for, feature work from a relay system, I have been doing the same thing. I think the ONLY way to see what you think is a 35mm test print, I have not done this yet as we decided to shoot on the VariCam instead of the relay system, I'm not that blown away by the varicam but, it does have one lens system that is SHARP!!!

here is a SD spot we shot with the relay and the 4:4:4 from the dvx:
http://www.reel-stream.com/gallery_i...1&image_id=174

and a test comp using lightwave:http://www.reel-stream.com/gallery_i...1&image_id=173
building and ground are the plate

and yet a 2nd 30sec spot, not using relay system, just the uncompressed footage of the kid and his leg breaking the surface
http://www.reel-stream.com/gallery_i...1&image_id=183

-Obin
www.dv3productions.com

Obin, so what are you saying?

- Shannon

IMHO, the relay system is not up to spec for feature work, anything above an HDTV set I don't think they work well for, maybe the pro35 has better glass and would work well. I have never used the pro35.

does this answer your question?

Sadly, yes.

Maybe P&S will make some upgrades to their stuff to handle HD for the Mini35.

I wonder if this problem persists with using the Mini35 & the Sony Z1U. and I wonder if Nate Weaver experienced any of this when making his Music Video.

- ShannonRawls.com

Thing is, they KICK MAJOR BUTT for anything BUT full on bigscreen, so I think 99% of projects are great with the 35mm units..I can't shoot anything without one now days, looks like cheap video without it! LOL.. dunno if you have seen it but here is a spot I just shot and cut, using nothing more then dv tape!!!

www.dv3productions.com/work/teletexas.wmv
the girl has no adapter

on a standard TV that spot looks great

make sure you use IE to view it, FireFox has a lameass plugin that resizes work to full screen, even if it's native 320x240!

here is the first test output from the dvx100a HD with the new 4:4:4 hardware and the micro35 with a nikon 105mm lens...
www.cineform.com/video/ama_cineform2.avi
a bit short for internet downloading, but I think you can get the idea of what this could look like, used one hard light for this "test" shot..
gota get the cineform codec to view this file at www.cineform.com

guys how does this cineform file compare to your 1280x720 mini35 captures?
BTW this has been into AE so the dark edges are a mask, FYI ;)

Hello Sharlto,

You say:

“We found that when shooting daytime ext. city shots, we got the most detailed and clean image by stopping down on the relay lens and shooting wide open on the prime lens. ie: our prime lens was wide open and we used the relay lens to get correct exposure. We had originally heard that it should be the other way around so this was a surprise.”

In theory if the relay is set optimally, there should not be a significant change of sharpness when the iris on the relay is closed.
I did setup a JVC GY HD100 on the Mini35 and focused the relay wide open using a chart. Then I closed the relay iris to see if I get a change in sharpness. At first, on the monitor I had available, (not a HD one) I did see a small improvement in sharpness and contrast between position 1 and 4 on the relay’s iris. But the monitor was displaying two images with very different intensity and I found that the higher intensity did not render as good an image. (I wonder if you were under similar conditions)
To avoid this problem I adjusted the light on my chart as well as the aperture of the relay to keep the display even in intensity and under those conditions I could not see any change in sharpness of the image.
I suspect you are not able to see the best position of you relay when it is wide open.

Let me know if you are still testing the system.

Best regards,

Sharlto and Simon,

I located here in Canada and have been running a mini35 unit since late 2003. I originally ran it with a PAL version of the XL1se (I used 25fps/50i to achieve 24p in post for NTSC) and since last year have been using the XL2 upon it's release. Now that the Canon HD XLH1 is out I'm kicking myself but oh well.... ;)

My experience with the mini35 unfortunately is limited to 16:9 SD (864x480) but of my 2 years experience using the mini35 I have noticed the best images came from my system with a slightly stopped lens (f2 to f4) and a slightly stopped relay lens. Scientifically I have no idea why although some of the posts here seem to indicate some reasons. When I shoot I also periodically check the back focus once the f-stop of the lens is set so you might want to try this as well until you find the sharpest point of focus.

Another tip, I'm not sure about other users of the mini35 but I have noticed vignetting if you stop down the relay lens past say "5". So as a rule of thumb I never go past this when shooting outdoors and if necessary throw on a Neutral Density filter.

Your problem however seems to be the opposite of all of this and having shot in night interiors and exteriors all I can say is shooting wide open (f1.2 or f2) on a 35mm lens poses some extremely challenging focus issues. For me mainly finding focus but also pulling focus if necessary for the shot. When directors want to dolly in or out under low light I cringe since usually I pull my own focus, an experienced focus puller would obviously help the situation but my point anyway is that you will get a wider depth of field with a lens that is stopped down to f3.5 or f4 which could make for some easier focusing but of course require more light. :(

In these night interior shots http://www.starcentral.ca/acorns.htm, with the lighting used on set it seemed as though the SUN was there with us - but through the mini35/XL2 proper exposure was obtained. In fact slight under exposure.

It might not make a lot of sense at first, but I've often suggested on some productions not to use the mini35 adapter for low light shots. Often depth can be achieved through good lighting and placement so perhaps consider that as an alternative option.

Lastly I've seen much of the work from you and Simon on the site www.thesas.com and can't wait to start seeing more from your project "Spoons" and the use of the mini35 and JVC on it. I also watched "Alive in Jo'burg" and think it's absolutely brillant! Would you mind sharing what 3D modelling programs and/or other software packages are used for your work(s)?

Cheers and best of luck in the New Year on all your projects!

Dennis

part 1
 

Hi one and all.

It is a bit of a long posting so I'm having to do it in two parts...

It is about time I broke the seal and made a posting on this site. It has been and continues to be my pleasure to be working with Simon Hansen and Sharlto Copley as DoP on ‘Spoon’. We are all taking a bit of time off for Christmas readying ourselves for the ‘Big Push’ come Jan 6th - I’m off doing a bit of R and R out here in the slopes in Switzerland yet my dreams are all still filled by Spoonic imagery. It’s funny how this industry gets under your skin; she’s always there tugging at your elbow or beckoning your thoughts away from level living. A strangely unrequited love affair in which we all find ourselves vying for the attentions of a beautiful yet slightly aloof mistress. Ah but I find myself wandering off on a euphemistic tangent – it is probably something to do with all the Charles Dickens and Oscar Wild that the BBC love to show at this time of year…

Anyway, back to the point.

Firstly a thank you. Thank you to all who have so kindly responded to our questions and taken the time to share their knowledge. You are a generous bunch that’s for sure.

We’ve been testing the hell out of the JVC GY 100 pushing and pulling it in all sorts of direction but it has been all a bit different to the kind of testing I am used to. I suppose there has probably been some sort of perverse desire to find a magical combination of settings that will give us ‘that look’, some as yet untried combination of menu tweaks that will to pull us out of the quagmire that is video and bring us nicely into the realm of film making. Perhaps ultimately it is all a bit ego driven but I have to be honest in saying that I have found this testing very testing. What I have found so particularly taxing is the almost infinite number of menu permutations that could potentially be employed to some how maximise the image capture. I have always had a somewhat discomforting feeling that those techy chaps at the video camera factories don’t actually know very much about film making and so this testing has been about confirmation that the tech-heads that made the cameras know what they are doing; to be satisfied that the factory standard settings are not just set up for John Doe making his crappy family holiday video.


So far this is what we have decided upon;

Master Black.
In some situations it can be useful to boost this above 0 or normal. Naturally the image comes out looking very flat as there are no true blacks and so it has to be graded but by crushing the backs back in the grade the effects are pretty much indistinguishable from shooting with master black at the normal setting. I’m not too sure why this is and was rather hoping the final results would be similar to shooting film with a Varicon. I have even tested a Panasonic Varicam and a Canon XL1 with a Varicon against simply adjusting the master black and found the results to be so similar that the extra effort and cost of using the low con filter system seemed to be unworthy of the effort. There was a qualitative difference to the way the Varicon treated the shadows as compared to pushing the master black but the results always seemed to come back to parity in the grade. Which ever way I tried to get more info from the shadow areas of the scene I would always end up with a graded image that was over run with pixel noise. One idea we have had is to shoot a very flat image and grade the blacks when we go to film print. We are waiting for our first set of test to come back from the labs and who knows maybe there will be some lovely combination of digital capture and chemical grading that will get us away from those ugly chunks of pixelated shadow detail we all hate so much.

My personal goal with all these low con tests was not to find a way to mimic the contrasty and de-saturated look of a bleach bypass or ENR grade as that is very easy to do in a digital grade. Rather it was to find some way of eeking out an extra stop at the top end by being able to underexpose the image more. But so far I don’t seem to have come up with the goods. Bah.

Black Stretch.
All this seems to do is push up the gain in the shadow areas. Useful but only at the expense of a noise increase.

Detail.
At one point we thought we had found something really interesting were we could really make a difference. Turing the detail function off gives us a true native image of what the CCD chip is actually reading. This somehow seemed to be a good thing. The detail function applies some sort of algorithm to the image before it is captured artificially increasing the contrast between individual pixels to create an image that ‘appears’ to be sharper. Since it is effectively a post effect we figured we would by-pass that process in camera and apply our own sharpening to the image during the post process that way gaining full control. Theoretically a cool plan but we have yet to find a plug-in for either Combustion, After Effects or Premiere that increases the apparent sharpness as well as the in camera detail function. Our first series of test with the Mini 35 converter were all shot with the detail function off and the results were far too soft.

It may seem like a slightly long winded way of trying to achieve sharpness but there was another reason for trying this route. We have been working very closely with Cineform in trying to get the most out of their wavelet compression algorithm and one of the things we discovered was that shooting with the detail off reduced the data rate of the encoded files. Whilst the CineForm codec is effectively visually lossless we were finding odd artefacts appearing when the detail was on. It seems now though that CineForm have solved this issue by offering higher bit rates to which the codec can write.

The other aspect that bothered us about the detail function was that it increases the level of the background CCD chip noise levels. All chips produce a certain amount of noise – if you shoot a plain coloured wall and zoom in on the image you can see the attributes of the digital noise. It is around these areas that I have always felt video really falls down. There is a truly chaotic randomness to the type of noise (grain) that you see when you examine a film negative that is not present in a video image. CCD pixels are always in exactly the same place conforming to a grid pattern which is why we get problems with aliasing and jagged diagonals. It is this fact that has largely given rise to the need for artificially boosting apparent sharpness, problems that are especially noticeable in static wide shots. Turn detail off and all the fine detail has a soft edging to it. Turn detail on and the apparent sharpness is increased but there is a latent ghosting to all aspects of the image. We are essentially down to choosing between the lesser of two evils still and this really bothers me.

So at the moment we are back to that standard solution of turning the detail function down by a couple of clicks but living with the standard results obtained by all and sundry unless anybody is aware of a post process that replicates the in camera detail function.


In terms of using the P & S mini 35 I would have to say that in general I am off a similar mind to Charles Papert who wrote:

1). "Sharpness" is a complicated term when used to compare film and video. I think that the slight softness that the Mini35 creates is part of what makes it look more pleasing to the eye; I find straight HD in general to sometimes be overally sharp in appearance…

The Random nature of the ‘noise’ we are getting from the ground glass of the mini 35 is going a long way to eradicating those problems I have just mentioned. There are however a whole ton of other problems thrown up by using the Adaptor.


Again I quote you Charles:
“Regarding which lens to adjust exposure, it is standard practice to set the cine lens at the desired aperture for depth of field purposes and adjust exposure via the relay. You should not see an optical difference with the relay wide open vs stopped down. When you say that the image was cleaner when the relay was stopped down, in what way? If the backfocus of the Mini35 is not properly adjusted, you will see a focus shift as you stop down the relay (it will improve), so remember that backfocus should be adjusted with the relay wide open and the cine lens stopped down to make the groundglass texture more apparent (Mini35 motor off, of course).”

Yet our ground glass was very carefully set – I even recorded the process to tape in order to be able to review the results again. Yet by stopping down on the relay lens we were in fact getting a sharper image. Actually a difference of only 2 full clicks on the relay lens made a very marked difference to the quality of the image. As well as the increase in sharpness there was a very noticeable change in colour cast. There was a warm yellow hue when shooting wide open that disappeared when the lens was shut down.

part 2
 

So now I turn to Obin Olson who I think has hit the nail on the head:

“It's very true that the relay lens will make your images softer when it's open, the reason? as far as I can tell a 1/3rd inch ccd is so small in size that your almost at the OPTICAL limit of glass to get above a 720x480 3ccd image, with the dvx100a and it's pixel offsetting we are getting 1540x984 HD frames from the camera, It's very true that the relay lens will make your images softer when it's open, the reason? as far as I can tell a 1/3rd inch ccd is so small in size that your almost at the OPTICAL limit of glass to get above a 720x480 3ccd image, with the dvx100a and it's pixel offsetting we are getting 1540x984 HD frames from the camera, however when you open the dvx lens all the way IN HD ONLY it's lens goes soft, not so with SD, that looks great...not enough resolution to show the softness.”

The hardest part of lens grinding is tending to the outer most regions which is why it is always advisable to stop down by at least one stop from wide open. It is nearly always the ‘thin bits at the edges’ that give aberrations and soft focus issues. A cheap fast lens will usually be thin at its edges as compared with a higher quality lens which in effect is just the central part of a much bigger lens. Take a look at the relay lens as provided by P & S and it just looks too small. I really don’t know much about lens making but there just does not seem to be enough glass there. And as such it is not surprising that when used wide open we are getting focus issues.

Under ordinary situations the solution would be to simply stop down and deal with it but ‘Spoon’ is a dark film and with the mini 35 we are so starved for light at the CCD that it isn’t really an option for us.

There is also the issue of nasty blue chromatic aberrations around any high lights that are probably as a result of poor achromatic lens coating. (I am guessing here). The Fujinon lens that comes with the camera also has nasty green/violet aberrations. Since the image is split by a prism and captured on three separate CCDs (red, green and blue) digital lenses have to be very carefully coated to ensure that there are no aberrations. I can only assume that this is probably a lengthy and expensive trial and error process to calibrate each lens to the specific attributes of each digital camera. As far as I know the relay lens used to connect the mini 35 to the JVC GY 100 is exactly the same glass that it used to connect the Cannon cameras and maybe it needs to be coated differently.

Anyway, putting aside any light loss issues of using a min 35 my feelings at the moment are that the relay lens really is a weak link in what is other wise a very finely engineered piece of kit.

I now turn to Dennis Hingsberg’s posting;

“Your problem however seems to be the opposite of all of this and having shot in night interiors and exteriors all I can say is shooting wide open (f1.2 or f2) on a 35mm lens poses some extremely challenging focus issues. For me mainly finding focus but also pulling focus if necessary for the shot. When directors want to dolly in or out under low light I cringe since usually I pull my own focus, an experienced focus puller would obviously help the situation but my point anyway is that you will get a wider depth of field with a lens that is stopped down to f3.5 or f4 which could make for some easier focusing but of course require more light. :


Bang on mister. On set focus is one of my biggest fears at the moment. In fact it makes my bum go funny just thinking about it. We will have to shoot a lot of the film wide open T1.3 with a lot of work being done on tighter lenses such as 60mm and 85mm. Even a set hardened seasoned veteran focus puller would think twice about taking on this gig. Add to that fact the very low quality of the eye piece view finder and I see clouds on the horizon. My first reaction to this was to find some way of taking a split from the eye piece monitor and sending a signal to a small HD monitor which my focus puller could use but this would almost certainly need a remote focus assist for which we simply don’t have the money. If anybody out there has some good suggestions…

Dennis, you also wrote;
“It might not make a lot of sense at first, but I've often suggested on some productions not to use the mini35 adapter for low light shots. Often depth can be achieved through good lighting and placement so perhaps consider that as an alternative option.”

We have some pretty big night exterior set ups to get through and we have discussed using the native Fujinon lens. I completely agree that we could create depth in the lighting and so I am slightly less worried about the massive disparity between the 35mm DoF and that of the 1/3 inch CCD with it’s native lens. However the Fujion lens has a very different look to it, for one any bright spots at night give off a star effect which looks very video like where as the mini 35 has a look somewhere between old black and white films before the introduction of anti halation backing and a rather heavy handed use of white pro mists and low con filters. If we can find some way of treating the image to match it to the mini 35 this is still a path we might pursue.


It is late now and it is new years eve and I have to go out and cause some mischief. But before I do I just want add a quick note to something I have only just touched upon. We have been working closely with David Newman, David Taylor and Jeff Yuel from CineForm to really get the most out of their Prospect codec and I can only say that it has been a real privilege and honour to work with such a dedicated and helpful team. Thanks guys. They have set up a blog site for us that deals with the specific issues we have encountered in working with their truly excellent coded. Either visit www.blogger.com and search for a blog called ‘Indie Film Live’ or try opening this link. http://www.blogger.com/posts.g?blogID=18325093 I’m not really very good with this inter-web thingy so it might not work. Let me know if it doesn’t.

And now I am off to watch the fireworks and take stock of another years worth of life lessons. We grow old so quickly yet I wonder when I might be able to call my self a grown-up.

Cheers!

Excellent posts, Joe. Thanks for going into detail on your findings.

In the past I've used the Mini35 extensively with the Canon cameras and the DVX and not experienced the loss of focus with the relay opened; it does stand to reason that the added resolution of HDV presents an additional challenge in this area. At the beginning of shooting those tests which were published here, I rolled off resolution charts with both the Fujinon and the Mini35, and under magnifaction Barry Green discovered that the Mini35 version showed CA while the Fujinon was clean. Because I wasn't 100% positive that the footage was mislabeled, I chose not to include those charts in the article. I hadn't noted if the relay was wide open at the time (as it had not been an issue in the past) so again there was not enough documentation to understand where the problem was coming from. This is certainly something that deserves further testing.

If you were able to post still images that demonstrate your results (the softness and color cast shift), that would be interesting.

There is always the possibility that you have a faulty unit...? Were you able to test more than one Mini35? Note Guy's inability to duplicate the problem...

Regarding the focus pulling issue, glad you are being "realistic" about the difficulties of managing T1.3 with longer lenses, this is something that I have been warning many folks here about for a while. Those that come from the film world such as yourself have usually experienced the heartbreak of soft dailies. It's also an excellent reason to have an operator on an HD show--the DP can keep an eye out for focus concerns in a controlled environment (video village).

Detail and Focus issues
 

Joe:

Thanks for the great posts relating your experience on your film.

I have shot HD for nearly 4 years now, 3 years or so with an HDCAM, and the last three months with my new HD100U.

Regarding detail settings, I never used any in camera detail enhancement with the HDCAM (1080i60), and the picture was more than sharp enough; actually looked more pleasing with the detail turned off. Also, when we did any downconverting to SD, the downconvert process added a selectable amount of detail to the SD picture; if we had any turned on in the HD original, the resulting SD downconvert was not as clean.

However, I also did some testing with detail settings on the HD100, and found, like you, that a detail setting between normal and -2 was about the most we could reduce it without ending up with a very soft picture. Not sure why this is, because resolution tests I've done indicate the lens (the stock lens) is resolving the full 1280 x 720, at least in the center of the frame (not near the edges where CA reigns supreme). Perhaps the MPEG-2 compression is a factor, or perhaps the lower pixel count of 720 vs 1080 makes the raw image more apparent.

In the HDCAM, the sweet spot for sharpness was f4 to f5.6; you could open the lens, or go the other way to f8 with very little degradation of image, but those were the absolute limits. Has to do with the pixel size on the CCD imager, and the ability of the lens to resolve to the size of that imager. Stopping down too much causes the wavelengths of different colors of light to spread, and exceed the CCD pixel size, thus softening the image. (the Airy Disk theory). Quite different from larger image film, where we could routinely go to f16 or wide open if we wanted a larger/shorter depth of field, or had to deal with light level issues.

In the HD100, however, due to its 1/3 inch CCD's with even smaller "pixels", the sweet spot is f4. You can just kiss the lower end of f5.6, but stop down no further. Even on my 14" multi-format monitor, I can see a distince difference in focus at f5.6 and smaller, and anything more open than f4. So, this is a camera that you shoot only at f4 (with the stock lens; your mini-35 may vary; I have not had any experience with that), and use ND, shutter speed or lighting to compensate. Fact of life, or you'll end up with a soft image.

I might note here, that consumer HDTV type monitors usually have a certain amount of their own detail enhancement, and often will mask a slightly out of focus shot. To check focus, you must use a broadcast evaluation type monitor without such enhancement.

Now, for focusing in HD, with an ENG type lens:

The only way to pull focus directly on the set is to have at least a 24" evaluation monitor there. You cannot see HD focus on an 8" field monitor, or a 14" or 20" multi-format monitor. Of course, this isn't usually practical or affordable, so the way I was taught, by some very well known and skilled DP's, is as follows:

You must set your back focus, and know it is bang on. For that, you must use a star chart designed for HD (mine is from DSC Labs in Toronto), or use a lens colimator. The resolution of an SD star chart is not good enough.

Back focus will change as the camera warms up, or changes temperature; just the sun coming out will heat the camera body and change it. On some cameras, selecting a different iternal filter will change it. Even long, unsupported heavy lenses will change it with a different tilt angle. Actually, all of this was true with SD cameras, but the image was so soft, and with so much detail enhancement, we didn't notice it much.

So, you must first warm up the camera in the environment you will be shooting in, that is, allow the temp to stabilize. Then, go through the back focus routine, using the focus assist feature. Have the camera at f4, and the star chart about 4-5 feet away, so you can see the focus point best when you are at wide angle. Check it two or three times.

Now, when focusing a scene, zoom all the way in to your focus point, pull focus (using focus assist; focus assist doesn't work well at wide agles), then widen back to your frame. If the back focus is correct, your focus will rack to your frame. But watch for temp changes, or anything that might change it.

During the two year shooting of a documentary with the HDCAM, after loosing too many shots to focus problems (which I didn't discover until back in post), I finally went to the proceedure of leaving the camera on all day, and checking back focus before virtually every shot. You'd be surprised how many times it had gone out.

I've found the HD100 better in this respect than the HDCAM (it actually ran hotter), but you still have to check it.

Regarding the Mini-35, it is my understanding you first have to set the camera back focus, then fiddle with the 35's back focus as well; but if you are aware of the limitations of the HD100 in this area (true of any HD camera by the way; welcome to the world of HD), perhaps this will help you in solving your focus problems.

I've done some testing of black levels with an 11 step crossover chart, and I'll try to post those findings next week. I've probably stirred up enough trouble for a while with this post!

Happy New Year to all!

Gary Morris McBeath
SaltAire Cinema Productions

Good info Gary!

It's probably worth noting that certain rental houses like Clairmont and Panavision have upgraded their F900's with improved fronts and mounts to eliminate the back focus drift due to temperature change, and of course the Digiprime lens series were designed to be used wide open without optical issues.

Great posts Joe. Thanks for sharing your experiences.
Have you guys tested the HD100/mini35 set up projecting it on a big screen? How soft was it? What I heard is that projected HD with a mini35 is barely sharper than projected SD shot without a mini35. It's sharper, but not buy much. How do you feel about that?

Joe De, good info! Are you feeling like the JVC will not be the camera of choice? will you finish the film with it?

What about using an f900 Sony with a an f1.4 prime set? I would think this would solve your issues....?

The site Joe is referring to is indiefilmlive.blogspot.com. Joe, please post some of this cool info there also.

BtW, Joe, have you tested the Pro35 instead of the mini35? I wonder if they use better glass in it...

BTW I would ask P & S if they know about the issues you are talking about with the softness at wide open...

David, that link is not working for me, could you check it please? Great products BTW, we are also using JVC's HD100 with Aspect HD.

Joe de Kadt, thank you for sharing all your findings and keeping us up to date. I hope that by "reading" more, I'll save time and hassle with our process & workflow around the JVC.

Actually the link is www.indiefilmlive.blogspot.com not blogger.

Thanks Jipsi & Daniel,

Yes, blogspot not blogger.

opening files
 

Hi Guys,

Could anyone spare a minute? I've downloaded Tim's zip and extracted the files but I can't seem to open them into anything that makes any sense, what am I doing wrong?

Thanks again amogos, Greg C.

p.s
 

The above posted in the wrong place for some reason, apologies.

It warms my cockles to be a part of such a sanguine and helpful community. The trouble to which you have gone in your replies goes well beyond that which can be expected during the shakes and fears of new years day. A few more days gone by and I have returned back to the prerequisite level of sobriety needed to stand firm and face the future.

I have, perhaps unnecessarily, been suffering the restless nights of a guilty man. Yet when issues from this mortal coil permeate their way into the usually nebulous realm of my dreams I tend to cock an ear in that direction so that I might properly listen to the ramblings of my subconscious. Of late my nights have been troubled and my nerves jagged and weak as I fear the discovery by all that I am not the Earthly God that my mother assures me I am but merely another utterly fallible mortal. In answer to your question Obin as to whether or not the JVC would be my camera of choice I can only say that I have literally been worried sick by the thought of shooting with it and the mini 35.

There are two aspects of using the converter that really worry me both of which are compounded by the inexperience of our technical crew. We really are a low budget affair an do not have the money to hire a fully experienced and technically savvy crew. We are trading largely on eagerness which goes a long way but…

The loss of light sensitivity that we are experiencing is taking away the ability to shoot with available light. In essence this means that everything has to be lit and not simply augmented. The difference that this will create in on-set lighting practice is quite massive and it comes down to being able to shoot a film with a small lighting rig and novice gaffer or not. A loss of two stops of light is equivalent to using film technology that was availably 30 years ago and improved film sensitivity is one of the main reason why films look so different today. Loosing two stops of light literally means having to use lights that are four times as big. An experienced gaffer and lighting crew would be able to handle the necessary rig but I’m just not sure that we will have that kind of ability especially when you consider the shooting schedule that we are looking at.

Focus issues.
At T2 on a 75mm lens if the subject is 2m from the lens the difference between sharp and out of focus is only 8.8cm. I don’t have the exact data for a lens with a stop of T1.3 but it will be somewhere around 5cm. Keeping sharp on an actor under these conditions is no mean feat. As I will almost certainly be doing most of the operating using the JVC view finder I will not be able to tell if the image is sharp. We almost certainly don’t have the money for a remote focus assist so the focus puller will be having to work off the lens with marks and not off a high deff monitor. This is a job for a very experienced focus puller. As you well know loosing shots because of sharps issues is one of the most depressing things that can happen.

On this note thank you so much Gary Moris McBeath for your incredibly illuminating piece on focus. You have a clarity of understanding that is tangible. We have been doing the vast majority of out testing by capturing straight to disc using a visually lossless wavlet codec (CineForm’s Prospect HD) and find the softness of the image in 720p mode to be as bad whether we shoot to tape (Mpeg2) or to disk. I’m pretty sure that in most cases 1280 x 720 resolution is just to low to get away without detail enhancement. Is your airy disc theory related in any way to circles of confusion? You make a lot of sense in your reasoning for the way the image is treated by the individual pixels yet it throws up the problem of having to stop down on a lens where DoF is already so precious. If I had to use the native lens on the JVC I would do my very best to shoot everything as wide open as possible and use a set of decent ND filters to set exposure. This comes down to making those artistic decisions that so often fly in the face of pure technical reasoning.

If you think logically about what the mini 35 does you wouldn’t even give it a second thought. It’s basic function is to put a phuqued up piece of glass between the world and the chip taking the resolution down probable below that of SD. There is a part of me that finds it very difficult to accept the rationale of using one but we have to remember who the audience are and whether or not they will actually notice. Or rather which of the effects is more noticeable, uncontrollable DoF or soft detail?

I don’t know the answers and wonder sometimes if I am putting the cart before the horse and focusing too much on the technical and too little on the artistic rules of portrayal that we must create in order to define our visions. So often these rules come from a place of necessity in dealing with limitations that they may seem to be merely justification but they will define the decisions that are made on set as the shit sails across the room towards that film noir fan that has just started working…

There are other issues I have with the JVC and the mini 35mm converter including the fiddly back focus, the visible difference in the quality of the relay lens when it is stopped down, the complicated nature of the relay lens, the prime stop and ND relationship that exists in order to control light, the unknown nature of the ground glass on a film out, and the fact that even though they have been around for a few years now I still can’t find any references to feature films that have been shot using one. There is also a horrible split screen problem with the JVC chip that becomes very apparent in low light conditions when the gain is anything above 9db. Taken individually any one of these issues it surmountable. Taken together I feel we might be letting ourselves into a world of pain.

Charles Papert – The blue chromatic aberrations we were getting are definitely from the relay lens. We actually have 2 mini 35s and yes, the C.A.s are present in both units. I return back to Cape town tomorrow and when time permits I will attempt to post some images of our tests.

Michael Maier, you asked if we had done any film out tests. We haven’t yet but we will soon and we will hopefully be posting these results onto the www.indiefilmlive.blogspot.com site. I imagine the results to be somewhere in the realm of SD but I’m hoping that the nature of the oscillating ground glass will go most of the way to resolving that issue. It is usually aliasing and jagged edged diagonals that give the feeling of low detail combined with regular nature of noise in flat areas of colour that most bother me about SD. With luck the loss of definition will be more akin to shooting with a high speed film stock and as such much more easily discarded as noise by the brain. Incidentally does anybody know of a feature that has been shot using a 35mm lens converter? Or any drama for that matter?

Back to Obin. I haven’t had a chance to do a comparative against the pro 35. One of the major issues we faced was that there are no adaptors of any sort out in South Africa. We even built our own basic adaptor using an old CD drive and a finely ground disc to see what kind of results we could expect. Eventually we decided to buy two adaptors from P & S Techinic which only arrived on the Dec 15th. We really haven’t had time to test them properly yet. Yes, an F900 with a set of digi primes would go a long way to solving a lot of our problems. Even better would be a Varicam as we could still use our Wafian boxes to capture true 48 and 60FPS 720p images. This is one of the main reasons we chose to test the JVC as it is the first HDV camera to offer a true 720p 60FPS component output. However it seems that for the cost of 2 month hire of a single Varicam we were able to buy A JVC GY 100 and a mini 35mm converter.

In making a film there are so many decisions that go beyond the merely artistic. And in this vein I remember the severe technical limitations faced by so many film makers over so many years some of which have given birth to entire genres. Film noir came about inpart as a result of a lack of money for big lighting rigs. The Nouvelle Vague also was a result of film makers desire to tell stories using the limited resources they had. Dogma is all about creating limitations. Make your enemies your friends, your weaknesses your strengths, and as Master Sun says in the Art of War “…good warriors cause others to come to them, and do not go to others.”

Spoon Test Files Available
 

Hi All

We've uploaded some files and info from our earlier tests. For the link and info info on the files, please goto:

http://indiefilmlive.blogspot.com/

David we use lightwave 3d, combustion and premiere pro for our cg work. Neill did all the effects on alive on his own - he also uses lightwave but not sure what he's comping and editing on at the moment.

ciao
sharlto copley

Shots look nice. Did you use any filtration? It looks considerably softer than what I get with my HD100. Sometimes it looks almost out of focus. Is it part of your look?
Are you also using the F750 in the film?

out of focus
 

hi michael

I did explain in the text on the blog sight that has the footage that the focus is soft because we were still shooting with detail off at this point, hoping to be able to sharpen in post - but to date we have not been able to do this. Our later tests were sharp when we used "detail on" at zero. We didn't use any filters and the footage has not been graded in any way. Both the prime lens and relay lens were wide open which was hairy, but we realised that we actually had enough lighting power to stop down a fraction.

ciao
sharlto

Yep, sorry, I missed that and also missed the part you say it was shot with the Mini35, which also softens the image. What was I thinking.
Unlike SD, HD needs some detail enhancement. They use it even in the F900/Cinealta. When you see F900 in movies like Star Wars, it's shot with detail on. HD just benefits from it a great deal. I'm sure the shots with detail on look much sharper.

Hi Shartlo,

Any plans to post footage shot with the detail on for the JVC/mini35 combo?

I too found the jvc footage soft for HD so I'd love to see some sharp JVC/mini35 footage. Also be sure to check the mini35 back focus adjustment ring as even a millimeter of adjustment can make a huge difference in your focus.

The 750 footage looks amazing by the way. Have you decided what Spoons will ultimately be shot with yet?

Any news from Spoon shooting ?
 

Just finish reading Spoon shooting blog and its very interesting... any news from thoses guys recently ? almost 2 months that they didnt update their blog...

want to know more about the JVC, Mini35 and film blowup of their movie test

thanks

Battery for mini35 - how long does it last?
 

Hi Guys,

Since a lot of you have been workign with the mini35 on the HD100, can you tell me how long a JVC battery will last on the rig that powers the mini35 only. NOT the camera, just the mini35. Also, if using Canons or Panasonics may be better as my rental dude can swap out the battery mount on the rig to those if needed. I know there are different sizes of batteries even, so if you could let me know the specific batteries you used with model numbers and how long they lasted in a normal shooting day (10 Hours). Thanks,

Miklos, if you mean the stock battery provided with the camera, then forget it. No way that thing can power the Mini35. You need something like the AB mount with compatible battery. On a recent shoot I worked on we used 2 AB Dionic batteries a day.

"yawn" - is this post still around? My last post seems ages old... still waiting for mini35 XL2 footage and results from actual film blow up test.

Anyone read of any other threads with some results worth checking out? Still contemplating my mini35/XL2 or getting into HD and mini35.

Thank all

and you are of course talking about just the mini35, right Paolo? It seems that the 2 AB Dionics would power the camera for a day - surely the mini35 does not draw that much power.