Greenscreen & Matte Panting in Photoshop

[RiKToR]

Resolution recommendation is about 2 to 3 times the res of the final shot. DPI still 72 unless you want to print one later. I would use 3 times is I were doing a NTSC/PAL Standard Definition and 2-3 times if its in HD depending on what you think you can handle.

[Elementalchaos]

ok, but what about the size of the canvas?....How exactly does the green screen
interpret size?

[JJASSO]

I second Riktor's comment about the resolution, it would be nice that you can share your work in progress

[RiKToR]

Its not green screen size its final shot size. Say if your shooting in DV NTSC then your final output will be 720 x 480 (486 if your using D1) then you make your matte 3 times that final output at the minimum. HD is a whole lot bigger a 1920 x 1080 (near film rez). Also you need to keep in mind the context of your shot, is it a pan up or down, you need to accomodate for those shots and add more matte to either direction for the camera move. Last just because your matte is triple rez doesnt mean you output it that way. See the reason why you make it high rez is so when you scale it down to the needed size it compresses alot of the painted strokes into a more randomized pixel detail making it difficult to see whats painted.
Lastly if you talking about 3 seperate camera positions for your shot then your talking about 3 different mattes from the perspective of each camera shot.

I hope that helps.

[darumon]

Interesting info - is there a good resource (link) which goes into these kinds of details? Particularly for film?

[RiKToR]

not really a link but some of the Gnomon Workshop DVDs on matte painting, Chris Stoski and Dylan Cole's in particular, have a bit of this information. Unless your asking about resolution then standard 35mm film is 2048 x 1556, this is for the 1.85 ratio and 2.35 is what is called anamorphic which is a type of lens the squishes the horizontal aspect, to do mattes for this you can either work squised or you can change the pixel aspect of your matte since the resolution doesnt really change. Anamorphic is a way of getting a 70mm aspect of film onto a 35mm film stock so in essence its the same but the image will be unsqueezed during theatrical projection in reverse of the initial filming lens. Either way photoshop has some presets for you when you create a new document under film and video and I believe there is a number of default resolution types there and you can just increase your image size by 200 to 300% depending on what you need.

[thenextside]

You can find a very complete explanation of all of the formates and lenses in the American Cinematographer Manual. I think it costs about $80.00 US. It is a handy remorse though.
As far as DPI goes... you should only be concerned with the pixel dimension. Like RiKToR says, 72dpi. You can see in PS that if you turn off resampling and change your DPI the pixel dimension remains the same. It is solely for print purposes.
Personally I work 2x the size of final unless there is a push in. I know some guys use less and I worked with a guy a few years ago who worked 1:1. It comes down to what you feel comfortable with and what it looks like at 1:1. If you can pull it off at 1:1 you will be able to work a lot faster. Especially if the studio you are at demands that you work 16bit. 3x at 16bit could be a bit grueling.
For personal work I keep it to 2048 x 1556 and like to have a 2:35 crop. So working size with the crop is 4096 x 1742 and final is 2048 x 871. Hopefully all my math is right there ;)

How exactly does the green screen
interpret size?

I'm not sure what you mean by this. Can you clarify?

Hope that is of some help.
Cheers,
Tim

[Elementalchaos]

Wow! - You all really know your stuff!

I've actually already bought the Dylan Cole Tutorials (all 3) & hopefully I'll
be able to put them to good use over the next week or so.

Thank you for all the help, If I have any more questions I'll post'em here.
Cory. B

[RiKToR]

thenextsideyes you can work cropped in 2.35 and after re reading my post it made it sound that absolutely there was only squshed or pixel correction which is not true. It just has to be squashed back to Anamorphic by the end of compositing.

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.