Greenscreen example
 

I found this post at DVXUSER.
http://www.dvxuser.com/V3/showpost.p...2&postcount=12

Steve

I have to say that I am very dissappointed in the actual resolution of this camera. The blocking from undersampling is easily noticable, and there is just a general lack of detail. That said, it keys relatively well considering.

I thought it looked soft too.

It's hard to know, since we don't know the settings selected.

Well, we'll know a lot more once the rez comparison test comes soon.

Steve

Look around. Rez charts have been shot, and the results are not encouraging. They confirm what we've been seeing in test shots ... the "true" resolving power of the camera (CCD, lens, et. all) is pretty poor ... almost half what 1080 is capabable of.

Maybe one of you (or someone else) could post a reference to a greenscreen example so we can compare how the HVX200 still compares to how it "should" look. I'd like to see a nice example of " 'true' resolving power," an image that does not look "too soft," and one that you feel does not exhibit:
I'm planning on doing greenscreen work with the HVX200, so this topic is very important to me. If there is a camera out there that may provide a better solution (and none of the problems that were mentioned above) that is within the $6,000 to $10,000 range, I'd like to know about it before I buy the HVX.

Thanks.

Well, I must say this is much easier than DV. Big Time.

http://www.holyzoo.com/content/hvx20...s_Keylight.mov

And that's not delving deeper in Keylight at all. With DV, I had to Color Smooth in FCP, export Uncompressed, tweak for a long time in Keylight, then do more custom matte work with Tinderbox.

Anyone still majorly disappointed? Sure, maybe if you're used to HDCAM, uncompressed capture or film scans. ;)

It does key cleanly ... that isn't my problem. The problem is with the lack of real detail in the shot, and the obvious color sub-sampling (especially around the edges) that seems to be exacerbated by the interpolation of the real resolution to the recorded resolution.

I clicked on your "Public Profile" to see the type of camera that you were using, as I was thinking that may be a good solution. It just says N/A. Do you mind letting me know the camera you have found and are using that does not have the problems above?

Heh heh.. man, if I tried to explain to any average viewer that this doesn't look good because it has a lack of real detail and color subsampling issues exacerbated by interpolation of real resolution to recorded resolution, they would put their hand up in my face, shake their head, and say, "Dude step away from the computer for awhile, it looks awesome."

I see what you're disappointed by, but is it going to hinder your ability to create what you want to create?

-steev

If someone gave me the camera ... I wouldn't complain! ;-)

But since it's my $10,000 that I have to spend, if what I wanted was a camera in that price range for studio work, well the Canon XL H1 via the SDI outputs is the clear winner. The CCD has appreciably more real resolution and going out via SDI eliminates compression artifacts.

Well, Joseph - right there is the nut.
Studio - no choice.
But for other situations ? ... think this is where the HVX will make a lot of sales.

How much would one need to spend to edit in "uncompressed" and then store that footage?

Rob,
We are discussing keying, which doesn't seem to be done in the field too much! ;-)

Derek,
I assume that you don't want a real answer and are just trying to make a point? (It's very easy to compute how much storage you need.) Regardless, capturing to a codec like Cineform (or using Apple's AIC after the fact) are very viable solutions for even low budget NLE's.

Joseph, I'm sorry if you see it that way. I just sold my XL2 and related gear last Saturday, so I have no camera and no loyalty to one brand over the other. The H1 is available and the HVX soon will be. I've read all kinds of posts with a varrying range of price tags associated with what you would need to shoot and store uncompressed. Most of those prices would prevent me from being able to afford shooting in that format. I have to consider how everything will work together and the overall workflow from shooting to distributing, not just the camera price.

Can you just let me know a price range of what would need to be spent to do so? It sounds like you've done your homework on the subject.

Even a low price range would be fine, as I'm not making documentary's or anything like that. Or, if there's a recent link within this forum that might be a good reference on the subject, no need to re-explain it if it's already been covered elsewhere. That's one of the great things about this forum - the huge archive of information it stores. Thank you Joseph.

Sorry, Derek, I thought you were being facetious. My apologies.

it is true that an "end-to-end" uncompressed workflow is going to be fairly expensive. (Check out http://www.hdforindies.com for good info.)

The reality is that the bulk of the average project doesn't need to be handled this way, though. In my experience you can use a very high quality an "intermediate" codec for the bulk of your work.

My day-to-day is on the Mac. I know that I can do simple (mostly just cuts) edits on even a PowerBook. My main machine is a dual G5, and it performs well under almost any condition.

On the Windows side, many people are very happy with the performance of Cineform based systems.

Either way, you should be able to get into either for under $5k, and then add storage as needed.

I know that in theory the HVX should have the advantage with the DVCPROHD codec, but real world images are revealing that the imaging chain (lens, ccd, processing) isn't using a fraction of that potential. My guess is you could pull a better key from the XL H1 even using HDV recording.

Hey, no apologies necessary, this is a great forum with great forum members. I could understand how you could read my questions that way. That's one problem with things being written in forums (and emails for that matter). I looked at some of your previous posts, and you are in a similar situation that I am in two ways. First, it looks like you are looking for a good HD/HDV solution - and the best camera for your money. Second, you're a Mac G5 user.

I had planned on purchasing a ReflecMedia studio set up for a few ideas I had, but postponed that to divert the money to towards a HD/HDV camera. I will be doing some greenscreen work, but I don't know how much. If I had to break it down into a percentage, it would probably only be about 25%.

I'll just have to continue to weigh the pro's & con's of the current camera's along with all the various ways it will be used (from greenscreen to mounting it in a car) and make my decisions from there. I appreciate the info you supplied. I'm sure I'll see you around since we have some common interests.

"Rob,
We are discussing keying, which doesn't seem to be done in the field too much! ;-)"

Rotflmao - errr, yeah you got a point there.

Sorry - I'm looking at them all from the angle of what's going to be most useful/general purpose cam.

Raid
 

http://www.lafcpug.org/Tutorials/bas...age_soltz.html
http://www.barefeats.com/
http://homepage.mac.com/comeback/iblog/Work/B787268209/
http://www.blackmagic-design.com/products/sd/

these are a few links to get you headed in the right direction. I have been looking into this option as well.

Under $3000 for the raid (8 x sataII 500g) plus box not including the card($300) and decklink($600)

Raids come in all different flavors, the SATA raid has quickly developed into a low cost option for editing uncompressed 8bit HD, the jury is still out on 10bit HD but technically it is getting possible.

I am waiting for a few more months until I get closer to the due date of my project because the technology is advancing fast, specifically the raid cards.
You would need the latest mac loaded with ram and FCP, that is what I am using so that cost could range from $4000 to $10,000 depending on what you wanted.

i was able to pull a key from this in keylight nicely, better than dv. With just a few tweaks, I got a good key. Normally with DV it took LOTS of tweaking.
http://rileyharmon.com/temp/comp.tif

Green in the field.
I've been doing that since 1990. Shooting corporate video with an exec in their office. Bring it back home and key in the appropriate marketing material in back.

Moving video.
You simply can't change the quality of a key from a still frame. All sorts of problems can expose themselves when you play back a key that you won't see in a still frame. I'd love to see a link to such a demo.

Codec can be an issue.
My eyes see softening on fast action with HDV codec. Try shooting a bouncing basketball in front of a green screen using HDV vs DVCProHD for example (maybe a bicycle tire with spokes spinning). For corporate video how about shooting a fast moving piece of machinery in front of a green screen. Yes to can upsample HDV to DVProHD (or uncompressed) but HDV may have already done it's damage to a fast moving subject.

I would love to see HVX source video (moving subject if possible) shot in front of green screen so I can try keying myself.

I'd like to see the DVCPro50 greenscreen from an HVX as well.

Just by chance, have you tried to key a 480p60 HDV clip sourced from the HD-100?

Point taken. My head is always in the narrative film world and it's easy to forget the other side. ;-)

In theory at least, well lit green screen should be MPEG2 and hence HDV friendly as large parts of the image never change and contain little detail so the codec dosn't have to work too hard. However the 4:2:0 subsampling isn't good. It may be that if you use a good intermediary that resamples at 4:2:2 and does some chroma restoration, such as Cineform, you could get a half decent key. Need to try this out to see.

Alister,
I agree. The codec isn't much of a factor here. It's the subsampling that can be killer. That's why I'd give the nod to the H1's SDI output.

If you compare the raw green screen image and the final composite you can see that the key cut-out has been shrunk to mask any keying artifacts, there are also background rocks visible through the left side of the guys face by his eye. Trying to key hair like that is a nightmare with any setup, but if you compare the clean image and the composite you will see large amounts of hair is completely missing. Shrinking the key matt by a few pixels is a good (and often used) way of hiding a less than perfect key and this has clearly been done with this image.

Still the final result looks good although the background is somewhat sharper then the foreground.

My own experiments with the foregound image have shown that it keys reasonably well, but would take a lot of work and a fair bit of fiddling to get a final result as good as the one posted. I would love to see the image moving as that would really show how much the matt has been shrunk and what is really going on with the hair.

Joseph,
Just to be clear, SDI out of the H1 gets it out of the camera and into a better codec than the HDV that would damage it. That's obvious. Unfortunately most shoots with a $6-$9,000 camera in the field won't have the budget to handle SDI on location (for me at least). Studio shoots are another story but most of my shoots are in the field and lugging the equipment or possible extra crew for SDI is not practical. Heck, if the budget were that high one might start to look at 2/3" cameras, at least as a rental, for shoots that also budget for an SDI video path on location.

HDV compession may simply make a green screen key problematic if the object in front of the screen has significant motion. Going into 4:2:2 or even 4:4:4 color space can't improve the softening if you're coming from the file already recorded in HDV on tape.

I want to shoot a decent green screen in an exec's office and I want to be able to shoot fast moving products, whether a tennis racket in motion or a piece of high tech manufacturing gear without the image softening if it's going to a portable record medium.

All things being equal I'd like the bitrate of DVCPRO, but alas, all things are not equal, and I'd rather key a sharp HDV shot than a soft DVCPRO shot.

So far, the images from both the H1 and the HD100 are showing very little MPEG artifacting ... far less than expected.

I haven't seen a green screen shot from the H1 yet, but I wouldn't dismiss it sight unseen simply because you think HDV "should" perform worse.

Interlaced or Progressive
 

I was just wondering....which format would be better for pulling a cleaner key, progressive or interlaced. Thanks.

Progressive rules, big time. Interlaced video is a nightmare for post process work such as keying, rotoscoping, masking, compositing, and speed manipulation.

Converting from HDV's 4:2:0 colour space to 4:2:2 can and does significantly improve both final image quality and keying if done correctly. Normal playback of HDV simply creates a 4:2:0 colour space image, however if the codec or conversion to 4:2:2 process is smart it can fill in much of the missing data. Admittedly the codec is "guessing" as to what should be there but if on one sample you have green, then at the next sample you have is green then it is probably safe to say that the missing sample in between is green. Due to limitations of lenses and optics you will almost never see a pixel to pixel change from say red to green, there are likely to be several shades in between so well executed sub sampling and conversion can work very well.

I use the cineform codec a lot and it really does clean up the chroma removing many of the 4:2:0 colour space artifacts.

Besides which there are new keying algorithyms and vector based keying which work very well with both 4:2:0 and 4:2:2. Most modern keys are not derived just from the chroma information, luma is also very important to getting a good key. But if the image is soft, it will always be soft. The sample being looked at here looks soft, the final composited image does not look right, yes it might look clean (apart from all the cropping) but the foreground is soooo much softer than the background, maybe it's out of focus?

Yeah, vector based keying in Serious Magic's Ultra is outstanding. It seems not to mind the lower color space and creates great composites. Ultimatte's Advantedge is great as well.

Eesh
 

I thought it's quite obvious but if some don't seem to make a note of it... Both cameras feature the same sized CCD. So, it becomes sort of obvious, that when it comes to the resolution and sharpness one can expect approximately equal results from all the cameras. Here we are talking about the 1/3" chips which are producing a 1920x1080 image. Can you really expect the 60+ grand camera sharpness here? And besides, we indeed don't know the settings that were used to shoot the test. There is a big chance the sharpness setting was set to a low value.

Overall, you've got to be very spoiled to not notice how juicy in terms of colour the output from the camera is. And that is at 100mbit. Keying indeed becomes a breeze, so people, don't whine. A year ago the news of a camera to offer 1080P for 6 grand was like getting a Civic with a rocket engine.

2Jason - progressive is better for you each frame of the video clip you are working one is one full "picture". With interlaced footage you will be working with strips of the image, which indeed becomes a nightmare when it comes to rotoscoping, keying, trackibg, and pretty much any other post-production work.

They're all the same size chip but the Canon seems to pack more picture elements into it giving better sharpness although it's lens is less than great IMHO. Another thing that matters is how good the processing is inside the camera. With either one of these cameras you should be able to dial in the settings you wish regarding color matrix and enhancement. Also, when it comes to sharpness, the only sharpness that matters is the camera and lense's own sharpness without electronic enchancement (detail at 0). Less electronic sharpening = better keying.

screen shot
 

Thought I'd tack this onto an existing thread, its a screen grab from the latest round of green screen footage. This was a 720P clip. This was with AE and Keylight and was with very little tweaking. There's no matte softening or choking either. For how incredibly fast I keyed this I have to say I'm pretty impressed.

http://www.onlinecheckregister.com/green.jpg

(note that this is a highly compressed JPG file!)

Nice! I didn't get as much detail as you did on the hair, but very easy to key in general. :)

http://www.holyzoo.com/content/hvx20...0_Key2_02.tiff

http://www.holyzoo.com/content/hvx20...0_Key2_03.tiff

Well - I just tried a key right in fcp with an old copy of dv matte pro. Not too good - horsing around.

Then tried with dft z matte - which I've never had much luck with before - heh very quick, not perrrfect perfect but good enough.

Like you guys - normally I'd go to AE for this - but I was impressed and it was fast on the render too. Good stuff ...

Not good with DV Matte?!... You've got to be kidding me.
I have got good (or acceptable, depending on your scale) results with DV Matte when shooting against green poster paper on a $700 consumer camera.

Yes, I know - with dv yes. Easy.

Maybe it's the codec or 720p that it is stuggling with - I don't know. It seemed to be a lot of work ... maybe it's just me. z matte pulled the key easier ...

try it for yourself - what can I say.

Here is the key I pulled tonight in Shake:
http://www.gleb.zerobrains.com/dmitr...HVX_key_1.tiff
The screen wasn't lit evenly, the left side is darker, and realistically I would pull two different keys with Keylight along with Primatte for the base matte. Also, there was a bit of white outlining on the right side around the ear, I'm not sure if that's PNG or the sharpness setting set higher on the camera, but I had to chew in slightly on the ear with eroding (yum, lol). Other than that this is great footage, really. I'm quite impressed with HVX.

Hey Dmitry - did you try in fcp with dv matte ?
Not wanting to put you on the spot at all, don't get me wrong ... I'm interested.

It's a workflow thing as far as I'm concerned, as I said above I'd normally go out to AE - for me dv matte was a hassle in fcp, z matte was easier.

Anyone else as well, please chime in ....