View Full Version : 7D for chroma Keying??? or 5D or get another brand for this
kingsta
09-23-2009, 04:15 PM
I will be doing heavy green screening and I'm delaying to buy because I keep getting told to wait for the newest Dslr... I'm now down to 30 more days to decide and thinking about just preordering the 7D now.... What is my best solution for green screening in the 3000$ price range.... I want clean Keys with the sharpest edges for under 3000$. Does anything out there do uncompressed recording and out put in my price range??
Is the 7D compression and color space good enough??
Should I just stick with the 7D for the bang for buck or what do you guys recommend for under 3000???
manglerBMX
09-23-2009, 04:44 PM
for doing chroma keying, the hvx200a or hpx170 are the best prosumer cameras for pulling a key due to its 4:2:2 color space in the dvcproHD codec. but i have seen good keys pulled with 5d footage. but majority of a good key depends on good lighting and a solid green background. so if you've got a good lighitng/screen setup, then pulling the key shouldn't be that much of an issue. then it comes down to software. after effects with the keylight plugin is one of the best next to shake.
ydgmdlu
09-23-2009, 04:45 PM
Well, the codec is at least as good as HDV, and the chroma subsampling is 4:2:0 just like HDV. If you want HD, you can't get anything better for under $3000.
Michael Olsen
09-23-2009, 04:57 PM
The $3000 price range is really the limitation here. Without stepping up to about $7000, the 5D and the 7D would be the best bet, I think, basically because they make up the whole market.
turdtoothless
09-23-2009, 05:04 PM
For chromakeying which would rule?
a)canon HV40 - capturing uncompressed through Blackmagic Intensity card @ 4:2:2
OR
b)canon 7D - with its higher resolution but only 4:2:0 chroma
ydgmdlu
09-23-2009, 05:14 PM
For chroma-keying ALONE, I'd say option (a). But there are so many other factors...
Matthew Bennett
09-23-2009, 05:34 PM
The ultimate for chroma keying is an Andromeda modded DVX100A - uncompressed 10bit 4:4:4.
If there's one avail soon on ebay, etc, you could probably get it for under 3K.
http://www.hostingphpbb.com/forum/andromeda.html
Barry_Green
09-23-2009, 07:50 PM
For chromakeying which would rule?
a)canon HV40 - capturing uncompressed through Blackmagic Intensity card @ 4:2:2
OR
b)canon 7D - with its higher resolution but only 4:2:0 chroma
Why do you think the 7D would have higher resolution than an HV40?
And if I was choosing between those two, strictly for keying, I'd say the uncompressed HV40 would probably be the better bet. 4:2:2 is way better than 4:2:0 for keying.
NoahK
09-23-2009, 07:55 PM
Got a pretty convincing argument for the 5D here:
http://www.dslr-cinematography.com/tutorials/2009/9/21/eos-5d-mark-ii-vs-green-screen.html
-Noah
astigmatic
09-23-2009, 08:01 PM
Why do you think the 7D would have higher resolution than an HV40?
And if I was choosing between those two, strictly for keying, I'd say the uncompressed HV40 would probably be the better bet. 4:2:2 is way better than 4:2:0 for keying.
better yet, blackmagic or nanoflash with the canon hf-s100 will get you around 800-900 lines of resolution, 4.2.2
Barry_Green
09-23-2009, 08:11 PM
Got a pretty convincing argument for the 5D here:
Yeah, but... I mean, come on... that guy's test had to be the easiest key test on earth. He had no hair and clean edges everywhere. Put up a blonde with hair blowing in the wind, with some lace and glass, and I think the disadvantages of an inefficiently-compressed artifact-potential 4:2:0 system are going to become obvious as versus an uncompressed 4:2:2...
NoahK
09-23-2009, 08:31 PM
I dunno- those are pretty tack sharp lenses. Sure I'd love to have both that and a RAW codec for $2700 but maybe it's just a little more fun to try something new.
Noah
cjwolff
09-23-2009, 08:50 PM
Yeah, but... I mean, come on... that guy's test had to be the easiest key test on earth. He had no hair and clean edges everywhere. Put up a blonde with hair blowing in the wind, with some lace and glass, and I think the disadvantages of an inefficiently-compressed artifact-potential 4:2:0 system are going to become obvious as versus an uncompressed 4:2:2...
Ditto that Barry. I've been pulling a lot of keys lately and they have been exactly what you've described-platinum blonde models dancing with fans blowing and ghostly pale skin that will reflect green no matter how you light it. This guy's test is too easy.
With that said, you can pull a key off of a pretty lousy camera. Last footage I've worked with was off of an A1U which I consider crap. The secret is preparation. You have to learn how to use a lightmeter and/or waveform monitor. Then you have to direct your models and be careful with wardrobe.
If you're new to keying you won't learn this unless you get out there and shoot and try to key footage.
Windjammer
09-23-2009, 09:14 PM
I've heard that Cineform Neo will interpolate the 4:2:0 footage into 4:2:2. Would this make a difference in pulling a better key?
cjwolff
09-23-2009, 09:46 PM
From http://www.adamwilt.com/DV-FAQ-tech.html#colorSampling
Can I chroma-key with 4:1:1 / 4:2:0?
Yes indeed. Many early DVEs were 4:1:1 internally; plenty of digital boxes out there still are (such as the Panasonic WJ-MX50 and Sony FXE-series vision mixers, both of which chroma-key). As previously mentioned, BetaSP could be considered a 3:1:1 format in terms of component bandwidth, and BetaSP is used for chroma-key applications all the time. With some care, DV25 keys at least as well as BetaSP; read on... Part of the standard JVC sales pitch for D-9 is the superiority of 4:2:2 (which is true), and the utter doom and degradation that awaits you should you try to do anything -- including chroma-key -- with a 4:1:1 format (which is, shall we say, a wee bit exaggerated). But that doesn't mean that you can't do very satisfactory work in 4:1:1.
JVC had an excellent D-9 demo tape showing multigeneration performance comparisons of DV, D-9, and Digital Betacam; watch it if you can. Just be sure you take the hype with a grain of salt.
True, the chroma performance of 4:2:2 formats is superior to 4:1:1 formats, especially in multigeneration analog dubbing. But by the same token, 4:4:4 is as superior to 4:2:2 as 4:2:2 is to 4:1:1 or 4:2:0.
Where DV can get into trouble is that the coarse resolution of the chroma signal (only 180 samples per scanline in 4:1:1) leads to a very regular, "steppy" key signal, most noticeable on near-vertical edges or vertical edges where motion is present, especially if the codec's decompression simply replicates the chroma sample across the intervening pixels instead of low-pass filtering or interpolating between samples. The 4:2:0 sampling in 625 DV/DVCAM is somewhat better in this regard, but it has its own problems vertically, so there's always a tradeoff.
The single most important factor in good DV chroma-keying is low-pass filtering or interpolating the chroma prior to applying the keyer, so that the “steppy edges” are knocked off. Some codecs do a pretty good job of this by default (Avid DV); some can be set up for it (Matrox: Control Panel > Sounds and Multimedia > Hardware > Video Codecs > Properties > Matrox VFW Software Codecs > Settings... > Chroma Interpolation (YUV -> RGB)); with others you can add a filter (I have filters for FCP here (http://www.adamwilt.com/SteppyEdges.html)).
Some people capture DV for chroma keying using an analog Y/C feed, since the analog connection prefilters and smooths the chroma.
The Matrox RTX.100 DV NLE board uses multi-tap resampling of DV's chroma to generate astoundingly good, crisp, finely-detailed keys in real time – so there is certainly enough information on DV's chroma for most keying purposes; the only tricky bit is recovering it intelligently!
Additionally, use the matte choker and/or matte feathering and smoothing controls of your keyer to round off the edges a hard-cut key signal gives you. I've had excellent results with After Effects Production Bundle's Color Difference key, and superb results also using the Chroma Keyer in Final Cut Pro 3. Using these tools I can make very clean and acceptable keys, certainly for hard-edged keying. Spill supressors (or “edge enhance” in FCP 3's Chroma Keyer) are essential in cleaning up any remaining chroma spill in the foreground video.
You may also find that layering different key signals gives you excellent results. I've used a heavily-choked chroma key to cut my main matte, but then add one or two luma, extract, or difference keys to define the edge detail that the chroma key can't get. Each luma key may only work for a small part of the image; it may lose the greenscreen background but also lose the interior of a similarly-bright face. However, it usually is able to get edge detail, because the edges of a person fall off in shadow or are picked out brightly by the rimlight, and the chroma key holds the interior matte that the luma key won't provide.
DV-aware keyers like dvGarage's (http://www.dvgarage.com/) DV Matte Pro (for After Effects or Final Cut Pro) do a great job of keying DV; if you're frustrated by the standard software keyers provided with your NLE or effects package, try an add-on keyer. I used to struggle with FCP's chroma key, even with my add-on chroma smoothing filter (or the ones Apple supplied starting in FCP 4.0), but DV Matte Pro is so much better (and easier to use) I almost can't compare it. I simply kick myself for not trying it out sooner!
John Jackman has some good examples (http://www.greatdv.com/post/bluescreendv3.htm) of DV keying on his post-production pages (http://www.greatdv.com/post/post.htm) at greatdv.com (http://www.greatdv.com/).
filmfan222
09-27-2009, 02:13 PM
here are some tests Ive done with the 5D mark II.
Barry, if you thought the C47 guys test was easy...I raise you one ANIMATRONIC CAT.
I was blown away with its quality. It blew my old HVX200 out of the water even considering the H264 codec
I would assume that if the 7D's noise pattern is a little worse, but the bitrate of the H264 codec is higher than the 5D your looking at some very similiar results.
http://extranet.modea.com/hasbro/furreal/tests/ball_test.mov
(user is hasbro...pass is pawtucket)
(around 27mb, so let it load)
Chaz
Michael Olsen
09-27-2009, 02:24 PM
Though off topic, I have to say:
That cat is absolutely terrifying.
cjwolff
09-27-2009, 02:34 PM
here are some tests Ive done with the 5D mark II.
Barry, if you thought the C47 guys test was easy...I raise you one ANIMATRONIC CAT.
Wow, I'm sold. That's almost as good a test as an iron-deficient platinum blonde.
Eddy Robinson
09-27-2009, 04:44 PM
The ultimate for chroma keying is an Andromeda modded DVX100A (...)
Until you want HD resolution, that is. I guess the easiest way to find out would be to rent/borry a 5D or 7D for a day and stick something fluffy in front of a cheap screen. Software tools that have been developed to give fairly good results even to ugly mini-DV footage can only ease matters.
grifter09
09-27-2009, 05:51 PM
Good post Cjwolf.
Just to add to it, i used to do quite a bit of keying dv footage professionally about 10 years ago and definately found layering to be effective, especially in conjunction with masks in AE.
Also, i found with the horrible edges DV footage had. It was always better to key with a very loose feather to the edges. Spill supress the green and choose suitable (dark) background footage to key onto. I was lucky enough to be able to give input into what backgrounds could be used.
In all the keying i did with AE i was never as impressed as what a big box in the studio did with a live feed. It was really impressive. It was called Trinity. I used to run both feeds of footage through it and capture the footage out of it, it was that good.
Im now looking forward to pushing 7d footage.
ChosenPredator
09-27-2009, 05:54 PM
here are some tests Ive done with the 5D mark II.
Barry, if you thought the C47 guys test was easy...I raise you one ANIMATRONIC CAT.
I was blown away with its quality. It blew my old HVX200 out of the water even considering the H264 codec
I would assume that if the 7D's noise pattern is a little worse, but the bitrate of the H264 codec is higher than the 5D your looking at some very similiar results.
http://extranet.modea.com/hasbro/furreal/tests/ball_test.mov
(user is hasbro...pass is pawtucket)
(around 27mb, so let it load)
Chaz
you win. that was very nice
Martti Ekstrand
09-28-2009, 02:13 AM
Well, one thing to consider beside codec limitations is that often in a green-screen set-up a shallow DOF is not desirable, rather the opposite. So a small sensor camera can actually have a advantage over a vDSLR here as you don't need to pump up the light levels as much to step down the aperture for a deeper DOF. For example hair strands slightly out of focus are a bitch to key even at 4:4:4, they tend to pulse in and out of the matte with a life of their own.
Ted Ramasola
09-28-2009, 03:16 AM
here are some tests Ive done with the 5D mark II.
Barry, if you thought the C47 guys test was easy...I raise you one ANIMATRONIC CAT.
I was blown away with its quality. It blew my old HVX200 out of the water even considering the H264 codec
I would assume that if the 7D's noise pattern is a little worse, but the bitrate of the H264 codec is higher than the 5D your looking at some very similiar results.
http://extranet.modea.com/hasbro/furreal/tests/ball_test.mov
(user is hasbro...pass is pawtucket)
(around 27mb, so let it load)
Chaz
most of my work involved compositing, and even though i ordered the 7d I had my fears. seeing this totally erased those fears.
Thanks for posting.
Sumfun
09-28-2009, 09:59 AM
here are some tests Ive done with the 5D mark II.
Barry, if you thought the C47 guys test was easy...I raise you one ANIMATRONIC CAT.
I was blown away with its quality. It blew my old HVX200 out of the water even considering the H264 codec
Fur looks nice, but I couldn't help but notice artifacts on the whiskers. Now most blondes don't have whiskers, but they do have stray hairs. I guess you can always choke the stray hairs out.
filmfan222
09-28-2009, 11:49 AM
Fur looks nice, but I couldn't help but notice artifacts on the whiskers. Now most blondes don't have whiskers, but they do have stray hairs. I guess you can always choke the stray hairs out.
two schools of thought here:
if by artifacting you mean the aliasing and brief reflections, then yes its a little funny.
if by the fact that you can actually see the whiskers, I would consider that a plus.
DV and even DVCProHD used to just produced one huge blurry pixel where that whisker would be.
(joke)
Ill post more stuff soon.
Scott F
09-28-2009, 01:15 PM
I raise you one ANIMATRONIC CAT.
OMG, I've seen it all now. :cheesy::cheesy::cheesy:
Animaitor
09-28-2009, 07:16 PM
Seen some cats like that in several shops here in Tokyo... scarry as hell >_< Good job on the green screen though!
Lucian
09-28-2009, 07:22 PM
Can some of the technoid types explain why the 7d might be better for keying than hdv?
I can think of one: Better codec. I believe it's something like double the data rate than HDV.
Sumfun
09-29-2009, 09:42 AM
two schools of thought here:
if by artifacting you mean the aliasing and brief reflections, then yes its a little funny.
if by the fact that you can actually see the whiskers, I would consider that a plus.
DV and even DVCProHD used to just produced one huge blurry pixel where that whisker would be.
(joke)
Ill post more stuff soon.
I don't know the term for it, but sometimes parts of the whiskers become big white blocks. This is distracting, and it shows that you've manipulated the image. I'm not saying that DVCPro HD can do better, but for me, I would mask out the whiskers rather than show the flashing.
So I agree that it is a plus that you can see the whiskers, but until you can see it correctly, it is not an advantage.
I don't know the term for it, but sometimes parts of the whiskers become big white blocks. This is distracting, and it shows that you've manipulated the image. I'm not saying that DVCPro HD can do better, but for me, I would mask out the whiskers rather than show the flashing.
So I agree that it is a plus that you can see the whiskers, but until you can see it correctly, it is not an advantage.
I thought the flashing was from the whiskers getting a little shine from the lights, i.e. the whiskers are molded plastic and are reflecting the lights back at the camera, which creates the white blocks for a moment. At least that what it looks like to me. It doesn't look like the codec is failing.
Is the animatronic cat footage anywhere? It doesn't seem to be up anymore.
visugeek
11-07-2009, 04:01 PM
If you are going to be chroma keying in a studio, I would recommend a camcorder with an uncompressed HDMI out and capture with the Black Magic card. You aren't going to get much cleaner than that, and you want the BG to be in focus for tracking markers when necessary.
One of the Canons like the HV-20, 30, or 40 would be a good choice. I think the HVX-200, 170 are uncompressed out of the HDMI as well.
You'll get the fine detail of smoke and hair better with these than anything else in the price range.
killacam
11-07-2009, 05:11 PM
I don't think the 7d would be ideal since you wouldn't need a shallow depth of field for green screening or compositing. And its 4:2:0 color space and aliasing could be issues. However, it'd still be miles better than standard def mini-dv, which is a nightmare even with something as great as dvmatte.
Ian-T
11-07-2009, 05:42 PM
I don't know which post it was but I seen someone using the HDMI out of the 7D for keying. That output is supposed to be 4:2:2. FYI
J. Odoms
11-07-2009, 05:54 PM
I don't know which post it was but I seen someone using the HDMI out of the 7D for keying. That output is supposed to be 4:2:2. FYI
Yeah it was the guys over at the Syndicate, the same fellas who make the Prime Lens mount for the 7D. here is their blog, as well as the info regarding the Maxtor HDMI capture setup.
3rd or 4th post down
http://www.syndicate.se/Default.aspx?Id=294
http://www.syndicate.se/Files/Misc/7D_greenscreen.jpg
Its the best sharpness 7D can do or something is not right wit the lens?
Looks like upscaled SD
Ian-T
11-07-2009, 07:53 PM
http://www.syndicate.se/Files/Misc/7D_greenscreen.jpg
Its the best sharpness 7D can do or something is not right wit the lens?
Looks like upscaled SD
I think it was you who asked this in another post. It's kind of misleading because that's not the actual image size... If in doubt download the commercial they shot that's on their site. The commercial is rendered at 1024x576 but looks pretty sharp to my eyes. But I still need to see an HD version.
can you extract frame from it and post here in png (HD version)?
Ian-T
11-07-2009, 08:37 PM
How do I upload a .PNG file? I see that the allowed file types are :
jpg jpeg tif gif wmv mov avi txt zip at the member upload center.
Ian-T
11-07-2009, 08:59 PM
Not sure if it's such a great difference but anyways....this first capture is from a Prores render straight from the camera's HDMI.
http://hv20.info/yopu/7D HDMI.png
These next frames are from the commercial they posted. Remember this is from a compressed 1024x576 Quicktime file. Not sure what the original looks like. But you can still get an idea from these shots.
http://hv20.info/yopu/7D HDMI 2.png
http://hv20.info/yopu/7D HDMI 3.png
http://hv20.info/yopu/7D HDMI 4.png
Edit: (there...fixed the links)
killacam
11-07-2009, 09:50 PM
I couldn't find the footage from the greenscreen test? I did see the slot car racing one which was nice but not sure if it had any greenscreen (although it did seem to have some nice VFX compositing). I tried looking all over for it- is it one of the Svenska Spel ads (just going by his shirt)?
Ouch, you could edit your post and post links without embeding pics.Nobody will visit this page again,its so slooow.
I think sharpness is similar to the greenscreen,yeah real resolution of 7D is visible ,its not that HD in video mode.
Ian-T
11-08-2009, 07:26 AM
But at the already high bit rate of the 7D I don't expect there to be much difference in resolution. The benefits are "no compression artifacts" and better color scheme especialy for tracking or visual effects. I would also think a notch in dynamic range (since the codec is not present to wash it out) which should result in deeper blacks and maybe even better highlights. I think that it's worth it.
dcloud
11-08-2009, 07:40 AM
ive done greenscreen work with the 7D. It's not bad at all.
dcloud, any samples? thanks!