35mm Adapter Static Aldu35 - Page 66 at DVinfo.net

Go Back   DV Info Net > Special Interest Areas > Alternative Imaging Methods

Alternative Imaging Methods
DV Info Net is the birthplace of all 35mm adapters.


Reply
 
Thread Tools Search this Thread
Old July 20th, 2004, 08:52 AM   #976
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
Cool -- thanks for the response.

One more question -- where'd you get your grit? Is AO5 the same as 1500 grit?

Incidentally, I think today's my acid etching day...

- jim
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply With Quote
Old July 20th, 2004, 02:49 PM   #977
New Boot
 
Join Date: Nov 2002
Location: Skellefteå, Västerbotten, Sverige (Sweden)
Posts: 23
Jim
Could you post a full res. pic from your Aldu35 (static adapter), I'ven seen the pics from it at ideaspora.net but it would be great if I could see some in full screen (I'd prefer that street w/ computer scene..)

Just want to have a closer look at the grain as I just ordered that Aluminium Oxide 1000 grit to make one of my own.

I've been working with a cd-mini35-adapter (agus35)? but I want to have 2 adapters, one static and one cd.

THANKS in advance
/ Eric
Eric Ohman is offline   Reply With Quote
Old July 20th, 2004, 09:37 PM   #978
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
Eric,

I'd be happy to -- just give me a day or two.

Incidentally, the reason I ask about 1500 grit is that I know that, as my adapter is currently, the grain is evident, particularly under certain conditions -- low light, especially.

So, I'm interested in seeking out finer grit, or moving to acid etching -- I've got the acid cream here and plan to endeavor the etching tonight -- and this might be especially relevant if you've got a higher res cam than my lowly GL-1.

Not that I need to have the grain disappear completely, but I would like to achieve finer results than those gotten with 1000 grit.

- jim
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply With Quote
Old July 21st, 2004, 01:32 AM   #979
New Boot
 
Join Date: Jul 2004
Posts: 19
Ok. Just thought I'd post something to make myself known. I just stumbled on this stuff a couple of days ago so it's a bit of a learning curve. I've only managed to get through about half of the material here so I'm probably jumping the gun somewhat.

I thought I'd share my experiments so far anyway. Describing them as rough would be an understatement but I just wanted as quickly as possible to get an idea of how this all worked. I'd experimented a bit previously with just a lens and obviously ran into troubles. So, here I am. This is my short journey so far.

After some examination I put together a baking paper and toilet roll screen and spacer. As far as the flange focus length goes, I wasn't suer becacue I had an old lens lying around and I wasn't sure what camera it came from. Some trial and error and I had an image.

I then stepped the technology up a notch and cut up a plastic vitamin bottle and pulled a plastic freezer bag across the opening and pressed the lid on top. I found that the plastic was too transparent so I could see the light directly through rather than just the image on the screen. I tried it with a couple of layers and found that this was better but I could still see the light from the apeture opening behind the screen.

I've got an old Sharp MiniDV camera which has macro abilities but only at fully wide. It focuses on the screen fine when the camera is pressed right up against the screen.

Unfortunately, as you might expect, it didn't really work. Basically I have a very faint image in the centre of the screen but nothing else. The image projects perfectly on the whole screen which is approximately 40mm diameter. Not sure reading the thread if 'hotspot' and 'vignetting' is the same thing in this context but I have some thoughts.

Firstly, I think one problem is that the light from the apeture opening can be seen through the screen so the camera is adjusting based on the brightest point of light. I don't think this bit is related directly to the physics of light per se.

The next problem is the physics of light. The light from the back of the lens comes out in a cone like this

35mm lens ()><|<()< CCD

|=screen
()=video lens

where light would normally come into the camera like this

\
..()>CCD
/

So when the light from the lens goes into the video camera the light on the outside misses the CCD entirely. This is where the fresnel/condenser comes in, yes???

In the current versions, you use the fresnel to make the light go like this -

35mm lens ()><|=()> CCD

Basically, without the fresnel, only the light that is going straight or an angle cloese to straight that allows it to reach the CCD gets picked up.

Does that sound about right?

I'm going to read more. I know this stuff is all pretty obvious but I thought I'd share anyway.

On a side note. About the flipping in post, for PC users, it might be worth looking at some software called avisynth. It's a frame serving program which is mainly used in DVD ripping but basically you write basic scripts which can be used instead of avi files and add some fairly sophisticated effects. Flipping, deinterlacing and the like are easy and it allows you to use the original file, virtually filtered so you don't need to render the flipped file first. If this sounds interesting to anyone I'll give you some other info to get it working for you.

Cheers for reading. This wo'nt be the last you'll hear from me.

Raavin (AKA Jason Keenan)
Jason Keenan is offline   Reply With Quote
Old July 21st, 2004, 01:35 AM   #980
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
acid etching can kiss my grit

I followed his instructions METICULOUSLY this evening and found acid etching to produce terrible results. What a shame -- or is it sham?

Quote:
Quality Statement:
I have made gg numerous times with mechanical abrasives up to 1000 grit AO. I consider myself somewhat good at this. The Acid etched gg is far easier to produce, costs less for materials and I feel is of far superior quality to mechanically produced gg.
-- James "The Chemist"

Macro of my acid-etched filter:

http://ideaspora.net/acid.jpg

I'd love to be proven wrong...

- jim
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply With Quote
Old July 21st, 2004, 01:46 AM   #981
New Boot
 
Join Date: Jul 2004
Posts: 19
I also just downloaded the freeware OSLO from http://www.sinopt.com/

It's supposed to be lens design software. I haven't had much of a chance to play but it might be useful for illustrations and hopefully useful for testing lenses virtually before you purchase.

Raavin :)
Jason Keenan is offline   Reply With Quote
Old July 21st, 2004, 04:55 AM   #982
New Boot
 
Join Date: Nov 2002
Location: Skellefteå, Västerbotten, Sverige (Sweden)
Posts: 23
whooo... that acid etching didn't look any goot at all. It looks just like my pre-frosted cd look, terrible.

- Jim
(100% res frame with the static adapter footage..)
Yeah please do that. Take your time
Eric Ohman is offline   Reply With Quote
Old July 21st, 2004, 10:36 AM   #983
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
Eric,

I hope you're on broadband and like over-achieving:

Here's a link to a zipped 12.2mb NTSC DV .avi from the source footage -- it's the computer shot in question, a simple rack focus from the computer to passers-by.

And, for the truly adventurous, a link to a 50mb zipped bit of shallow DOF business that I like quite a bit. I'll keep this second clip up for a day or two and then take it down.

Now, I've got some apologies for the footage:

1) There's plenty of dust on one of the three glass elements in my setup in this footage -- the macro lens, the GG and the Nikon -- or all three, in fact. I didn't have proper cleaning stuff on me at the time, so it is what it is.

2) Scratches -- I reground this glass last night and they persist -- my worry now is that others have been right about the quality of Rockshed grit -- every time I grind away old scratches, new ones appear. I've ordered WAO 5 from Got Grit hoping to eventually solve this problem

3) Shakiness/Color -- none of this has been deshaked or color corrected.

edit: wow, I'm getting 77k upstream -- most I'd ever get in Philly was 20.

- jim
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply With Quote
Old July 21st, 2004, 03:33 PM   #984
Major Player
 
Join Date: Oct 2003
Location: Southern Cal-ee-for-Ni-ya
Posts: 608
How to evaluate GG DOF grain troubles

Nice clips!

For those looking to have usable footage without the 'stuck grain' look that less than perfect GG gives, please review the excerpt below from my post on the "Mini35 Oscillating Ground Glass Idea " thread.
It appears that many people have been disappointed by the video they get because they were a little mislead by some samples they saw.


---- Tips and Info on GG grain evaluations below : --------

1) Posting still images of a GG video is WORTHLESS for evaluating the grain. Period. You need to see a slow panning shot of the GG in use, preferably with some of the scene out of focus a bit and shadows and highlights. Only then do you have a chance to see the grain pattern because it remains in the same place on your monitor while the image moves past it.
So you shouldn't ask for frame grabs of the GG for evaluating it for grain.

2) Posting TINY video,or some highly compressed format is also worthless for seeing grain effects. The first thing that a compression codec throws away is the grain pattern! The poster should use a 7 megabit/sec mpeg4 or Media9 video to show the details. Then you can see possible fixed pattern grain effects.

-Les
Les Dit is offline   Reply With Quote
Old July 21st, 2004, 04:40 PM   #985
Regular Crew
 
Join Date: Feb 2004
Location: Austin, TX
Posts: 182
Stuck Grain -

I agree with Les re 'stuck grain'. Has anyone really removed the stuck grain in the static approach? Like Les says, static frames don't cut it for evaluation. The second a slow pan happens, and that grain, regardless of how fine, doesn't move - it's immediately apparent and obvious... yuck! Frankly, I'm not convinced that it can be removed without moving the ground glass using traditional grinding. I think the only way would be to have a truly grainless diffusion surface (which catches enough image to be fixable with a condensor AND doesn't kill you with so much light loss that you have to bake the talent with 18k's). Seems like the bossscreen or something like opal glass are the only things that even get close to this.

It just seems (to me) like the second you can buy into moving the ground glass, everything gets easier... don't worry quite so much about the 'coarseness' of the grain - giving you better diffusion and light transferrance, and there is no problem with any dust on the ground glass because its moving.

For what its worth, I've completely dismantled my static adapter (which worked fairly well) and used the parts to build a 'spinner' - it's good enough for me that I've actually _stopped_ working on it, which is saying something in our little group of addicts.
Jonathon Wilson is offline   Reply With Quote
Old July 21st, 2004, 08:18 PM   #986
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
Would anyone kindly point me in the direction of the proper PCX lens setup I should be using? Any relevant info like where I could buy two cheap close to 58mm would be great, as well.

Thanks!

- jim
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply With Quote
Old July 22nd, 2004, 07:33 AM   #987
New Boot
 
Join Date: Nov 2002
Location: Skellefteå, Västerbotten, Sverige (Sweden)
Posts: 23
- jim

thanks for uploading the clip and very nice shooting on "bottle.avi"

i also need some kind of pcx or fresnel lens cause i get vignetting. please take the time and download this file and tell me what you think.

the zip-file contains a videoclip and a picture of my temporary rig that i use now for testing.... =)

this is the +10 macro lens i use:
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=30045&item=3826338236

when i zoom in i get blurry corners... but hopefully a fresnel lens or pcx lens will help me so that i don't need to zoom that much with my vx1k...

btw, what is the difference between the pcx and fresnel, do you always need both?

THANKS
Eric
Eric Ohman is offline   Reply With Quote
Old July 22nd, 2004, 03:40 PM   #988
Major Player
 
Join Date: Aug 2003
Location: Poplarville, MS
Posts: 453
Microcrystalline wax beats using AO ground glass, no doubt about it. I have posted stills of my progression through different ground glasses and eventually microcrystalline (even shots with the iris near closed, with no sign of grain).

http://www.frankladner.com/m_001.jpg
http://www.frankladner.com/m_002.jpg
http://www.frankladner.com/m_003.jpg

Yeah, I know you can't tell as much with just stills, but after you've looked at so much footage shot with these adapters, it becomes easier to spot, even in stills (esp. on out of focus parts). With me being on a dialup connection at home, it takes a while to upload big video files. However, i'd be willing to upload an uncompressed 720x480 clip of a quick pan or something that you guys can look at in an NLE. That way you have some frames to scrub through and see if you can spot any grain.

It has been mentioned in the microcrystalline wax thread that it may not be fine enough for HD. I don't have an HD camera to test it on, so I don't know if that's true, but I will say that I haven't found a better static solution for SD.

,Frank
Frank Ladner is offline   Reply With Quote
Old July 22nd, 2004, 04:43 PM   #989
New Boot
 
Join Date: Jul 2004
Location: Boise, ID * Orange, CA
Posts: 9
DVX100

I first read about the agus35 last night and I have been reading about all the variations and trying to catch up for hours now.

I'm starting a short film Saturday night. I have access to a GL1 and a DVX100. I'd love to use the DVX100 but am having trouble figuring out exactly what I need.

In a short thread on here someone gave this diagram:

(SLR) - (PCX condenser) - (gg) - (+10 macro) - (+10 macro) - (DVX)

Is that still the best way to do it? If so, which PCX condenser do I need exactly? I have various camera lenses I'd like to be able to use if possible, if I can only use one then probably a Nikon 50mm f1.4.

Also, is there any possible way to get the macro filters I need by Saturday night? I willing to get the poorer single-element right now. Would it be possible to use 2 +1+2+4 kits? A local store has those.

If I were to use it on a GL1, what's the cheapest macro filter I could get away with?

-----

I realize that having this done by Saturday night is pretty unrealistic, but I'd love to try, and that's just the first night of shooting so maybe we could use it for the other days, though I would worry about continuity.

Any help would be appreciated, thanks.
__________________
-Brandon
Brandon Adams is offline   Reply With Quote
Old July 22nd, 2004, 05:23 PM   #990
Major Player
 
Join Date: Dec 2003
Location: Brooklyn, NY
Posts: 636
Frank,

Can you post some shots that are actual full, well-lit frames from your adapter? Where'd you get ahold of the micro-crystalline wax/glass?

- jim
__________________
Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G
Jim Lafferty is offline   Reply
Reply

DV Info Net refers all where-to-buy and where-to-rent questions exclusively to these trusted full line dealers and rental houses...

Professional Video
(800) 833-4801
Portland, OR

B&H Photo Video
(866) 521-7381
New York, NY

Z.G.C.
(973) 335-4460
Mountain Lakes, NJ

Abel Cine Tech
(888) 700-4416
N.Y. NY & L.A. CA

Precision Camera
(800) 677-1023
Austin, TX

DV Info Net also encourages you to support local businesses and buy from an authorized dealer in your neighborhood.
  You are here: DV Info Net > Special Interest Areas > Alternative Imaging Methods

Thread Tools Search this Thread
Search this Thread:

Advanced Search

 



Google
 

All times are GMT -6. The time now is 02:09 AM.


DV Info Net -- Real Names, Real People, Real Info!
1998-2017 The Digital Video Information Network