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wulfie
02-05-2005, 10:15 PM
I am getting ready to make a video...which hopefully later can be transfered to film, which is going to be 85% CG background (ala Sky Captain and Lightwave) and includes many CD characters. My cinematographer is leaning towards HD. For HD we are looking at the Sony FX1 and Pro Z brother. I was told by a reseller that the Sony 24p is interlaced and consequently not going to be as good for compositing as say the Panasonic 24p which is true progressive. What are the thoughts here. All will be very very greatly appreciated!!!

Thanks ahead of time!

Bev

michaeljr
02-06-2005, 02:36 AM
If you are going to go to film, I would go with the Sony, be it interlaced, you will get full 1920x1080 and that will most definately look better on film than 1280x720, a quarter more res. you can always run a deinterlacer before you add your CG, or after before it goes to film. check out this good book on digital filmaking and convernting to film.

http://www.dvfilm.com/book.htm

also their dvfilmaker now supports the Sony HD cameras http://www.dvfilm.com/fx1/index.htm

Also, if you decided HD, make sure to have plenty of hard drives. A typcial filled frame of 720x480 is about 1meg, and HD frame is going to be 3 to 5 times bigger, PER LAYER. If you have 10 layer, you could be looking at 40megs per frame, times 24... That's a lot of gigs, maybe even terrabytes in the end. Depending on how long the short is.

I guess I wouldn't worry to much about if it's TRUE Progressive or not since you can deinterlace it and create a progressive image anyway. Take a look at the fillm 24 Days, that was all done with Canon XL1 Pal units and those cameras only offer a quasi progressive mode. It is not true progressive but pixel shifting, and it looked pretty darn good to me.

just my two bits

michael JR.
www.mjrworld.com (http://www.mjrworld.com/)

Good luck, hope to see some stuff this spring and summer.

DorkmanScott
02-06-2005, 02:37 AM
I am getting ready to make a video...which hopefully later can be transfered to film, which is going to be 85% CG background (ala Sky Captain and Lightwave) and includes many CD characters. My cinematographer is leaning towards HD. For HD we are looking at the Sony FX1 and Pro Z brother. I was told by a reseller that the Sony 24p is interlaced and consequently not going to be as good for compositing as say the Panasonic 24p which is true progressive. What are the thoughts here. All will be very very greatly appreciated!!!

Thanks ahead of time!

Bev

The Panasonic will also be "interlaced" in, if I'm not mistaken, the same way as the Sony, which is to say that the 24 unique fps will be converted to 29.97 NTSC using an advanced 3:2 pulldown in the camera.

The bigger problem for you would be pulling a key on the FX1 footage. They use an MPEG-2 compression scheme on the frames to get them to fit onto the same bandwidth as regular DV, since both record to standard miniDV tapes. MPEG-2 is the same compression as used on standard DVDs, and have you EVER tried keying footage from a DVD? It's worse than DV, and that's saying something. Be prepared to do some hard work to get a clean key.

M. Scott

michaeljr
02-06-2005, 04:45 AM
Good point Dorkman, ya, the MPEG2 compression will be 4:1:1 unlike pro HD film stuff which is either 4:2:2 or now they are doing things in 4:4:4 if you have a fiberwire setup in a trailer behind your studio.

I've been able to pull pretty good keys in DV lately without a lot of extra work. Ramping up the color saturation while filming to seperate the green and actor, then desaturating it a bit in post. I'm wondering with the higher resolution of the HDV format, even though it's compressed, will be as easy to pull a key since there will more pixel information to work with?

crew of two was able to do some nice stuff with DV for Duel.

here is a whole forum on the new HDV format cameras. I'm sure someone has already tried to key green screen with them.

http://www.dvinfo.net/conf/forumdisplay.php?forumid=62

I don't know what your budget is, but it sounds pretty high considering you are looking at a Sony FX camera that cost around 4500$ and that doesn't include extra batteries, bag, wide angle lens (which you will need if you are in a small studio) tripod, lights, green screen, computer for onset monitoring, microphones, etc. etc. (unless you already have all this that is.)

Have you thought about just using high end DV, being able to buy 2 or 3 cameras for the price of one, or a NLE editing setup, or a nice set or two of lights?

If you use cheap flourescant lights for your green screen be ready for a voice session to replace the onset recorded voices cause those things hum like a chain saw

Also have you decided how to track your green screen footage? when you work in HD resolutions you may have to buy the pro versions of tracking software like I think PFTrack supports HD res.

http://www.thepixelfarm.co.uk/products/products.aspx?PID=3

It cost a couple grand compared to their DV res PFHoe that's about 100$

http://www.thepixelfarm.co.uk/contentfull.aspx?content=pfhoe.htm

just some food for thought.

mJR

Ravix
02-06-2005, 07:02 PM
mmhh those are good points just to add some , wehn u use the panasoni 24p it behaves good and esay on composinting the only problem i found is that camera have a very cheap lenses and the grainy footage is always there ,, i wouldnt mind go for an hd and have those problems for better quality on image..

:hmm: :hmm:

wulfie
02-06-2005, 07:17 PM
I can't thank you guys enough for your thoughts! And no I haven't tried to pull a key from DVD footage Dorkman. My camera man was thinking HD therefore crisp picture. Youv'e given us pause on that one! I have Ultra from Serious Magic, which claims to operate on MPEG formats. I have also used Adobe After Effects with DV footage. What do you use to pull keys?

Thanks for your input mJR. I appreciate the tips on how to get a good key. And no I don't have a large budget for this project. I do have a lot of the other stuff already. I started as a sound studio. I was led down this path of thinking because I thought it would be good to have a second camera for this fiilm. My cinematographer has a JVC GY500. What kind of camera or cameras did you use on Duel? What kind of software for the chroma keying? Are there any chroma key forums out there?

Again thank you so much!!

Bev Standish
Wolfsong Studios

scotttygett
02-06-2005, 08:29 PM
I never do it, but I also think about it way too much, so here's my two cents on green screen : polaroid on the lens and lights (a little pricey) may help you cut down on the surface reflectivity problem, but this is really a consideration of the wardrobe and make-up departments. I keep reading about keeping the actors away from the background, but I don't understand why the hyperfocal distance isn't mentioned? What is out of focus is going to bleed onto what is in focus, so the background is going to have to be in focus as well as the foreground. My feeling is if the guys selling the buckets of green paint won't tell this to you, screw 'em, so ask what you need to know. Narrow spectrum green and blue are pricey compared to black, white or red, but apparently save on headaches, as all the software expects them, I've been told. Hyperfocal charts are still in the ASC Manuals I bet, though it doesn't hurt to test a lens yourself and see its muscle.

michaeljr
02-07-2005, 02:08 AM
I didn't work on Duel, but if you goto their web site http://www.crewoftwo.com/ they show you all the details. I believe they used a Canon XL and GL camera and After Effects for keying, maybe Commotion also on MACs.

I use Combustion 3 from Discreet.com. It has keying tools based on Flint / Flame system and can pull keys quite easy if you have enough good light. To save money, I built my own green screen from wood panels on a 2x2 frame. I used the same cheap 7$ panels on the floor, so I can move these panels around on the ground to make longer walk ways or wider ones. The panels are cheap, but it did require more work to build. For 100$ I have a 24 foot wide, 12 foot tall corner with a full floor. Now I realized after testing that I could have just used a 20$ 12x9 canvas drop cloth (Home Depot has them in the painting isle) hung from a simple PVC pipe which would have given me a smoother corner, but I wasn't sure about painting them. Once I started working on it I found it would have worked. So you could go to Home Depot, buy the drop cloth, 2 panels, green paint, and a brush (or roller), $60 you have 12x9 screen with a floor. A real screen that size would cost over 200$ just for the screen. Buy two drop cloths and that's a 24 foot wide wall!

I took real Roscoe chroma paint, sampled it at Home Depot and got color matched flat paint. The paint is NEARLY identical, rember it's just color, there is no special metals or anything in chroma paint. The only slight difference was the the FLAT MATTE Glidden from HD was slightly more shiny than the 60$ a gallon Roscoe paint. 10 years ago you couldn't go to a store and have colors matched, now you can.

For lights I use CRAPPY cheap Menards 4$ work lamps and cheap $2 bulbs to light my screen. They have one downfall, they are noisy, but that doesn't matter, you can't record good audio in a garage anyway, so I can dub all that later back in. Some say, how can you use flourescant bulbs, they have weird colors? Well it doesn't matter, this isnt' film, it's a DV camera, you can just adjust the white balance and all is fine. No different than beind inside with cool blue light or warm red light of outdoors. Video is great. I have nice halogens for the actors shadows, but the flourescants are so bright and soft, they are great for the green screen and fill light. Not to mention they take little power and no heat. I did some test comparing halogen and flourescants, no comparison.

(take a look at original film footage on the Lord of the Rings box set and see how much color finessing is done before it goes out to the theater. you can see how much color temp is changed in post, you can do the same in post.)

The pros use flourescant all the time, but those things cost 1000$ per lamp set, not 10$. Sure they don't hum, have remote control power, and fold up into a box, but man 1k per set, ouch.

I have a few photos of my screen setup, pretty basic.

http://www.mjrworld.com/newwork/newwork.html#Green Screen 2

You know I learned a lot doing this and watching a lot behind the scenes, from say Star Wars or Sky Captain. You can see that their blue / green screens aren't really setup PERFECT anymore. Digital is very acceptable of defeacts, like the edges between my panels. DV isn't clear enough to even catch those, so they key pulls just fine.

I have never heard of hyperfocus distance. I haven't seen any issues like that with my Sony camera. I guess since the distance between the lens and CCD is so small, there is no depth of field. I have a wide angle lens that gets me out around 18mm or so, at around 16 feet away from the actor and the screen, everything is in focus. I would have to be out in the driveway, 30 plus feet away zoomed in to the actor before I would see a blurring of the green screen.

Doesn't sound like you are that far behind me. I'm still testing ideas and ways to do things. I would suggest the same. Get some paint, paint some card board, get a light, stick a stuffed animal in front of it, and take some footage. Track it, pull a key, stick in on a CG desk, etc. etc. Write it all down and get it working before wasting a lot of time building something big.

Also I don't know of that many sites or forums with good greenscreen stuff because it's so diverese. It was one thing back in the day of film processing, only really one way to do it. Now you have dozen of video formats, dozens of sofware and keying programs. It's really just trial and error in my eyes. Then when you get something that works, you just do it.

mJR
www.mjrworld.com (http://www.mjrworld.com/)

michaeljr
02-07-2005, 04:03 AM
ok, if you want it, here is the label you can print out and take to a Home Depot or any other store that carries Glidden paint.

http://www.mjrworld.com/newwork/Green_screen_2/pages/Glidden_flat_chromagreen_HomeDepot_quart.html
for about $20 you can get a gallon of color match Chroma paint.

this label is for a quart, which is about 8$, just make sure they know if you want a gallon then they will make the appropriate changes for the colors.

enjoy

mJR
www.mjrworld.com (http://www.mjrworld.com/)

DorkmanScott
02-07-2005, 07:25 AM
I didn't work on Duel, but if you goto their web site http://www.crewoftwo.com/ they show you all the details. I believe they used a Canon XL and GL camera and After Effects for keying, maybe Commotion also on MACs.

I know Dave (one of the crew), and you're pretty much right.

A couple things though. He only used Commotion for the rotoscoping of the lightsaber blades, and they used the somewhat pricey Primatte plug-in to pull many of the keys, as well as color difference, luminance, and other forms of keying. He had a lot of trouble battling the 4:1:1 color compression.

This was almost four years ago, though, and many companies have seen the expanding prosumer market worth pursuing. I highly recommend checking out http://www.dvgarage.com and in particular the Composite Toolkit. It'll get you up to speed on bluescreen compositing if you're not already a whiz at it (and even if you are, I recommend it anyway), and also comes with dvMatte, a robust AE plugin specifically written to work around 4:1:1 color compression, which has found its use since in HD and I believe even some film-scanned projects.

M. Scott

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