4K : 4096 x ????

[jolle]

Hi everyone, newbie here with a basic question: what size is most common in making matte paintings?
I've been reading up on the subject and it's pretty clear that the smart thing is to make them twice the size you need them to be, which would basically mean you make them in a 4K size. However, that's just the width. With a little bit of research and calculation, you end up with the following heights:

full ap - 4096 x 3112
1.78 - 4096 x 2304
1.85 - 4096 x 2214
2.35 - 4096 x 1743

Yet there are quite a few places online where 4K is defined as 4096x2160, which is 1:1.9, and it also seems that Dylan Cole uses this size often. I don't understand where that size comes from, it's not the 1.78 ratio for television, nor is it the 1.85/2.35 ratio for film. What is the idea behind this 4096x2160 size, could someone please tell me?

[Xdreamer79]

Hmm I don't get the whole point of this resolution thing. I mean if you don't use the mattes for films why to care about the resolution? I use alwayas as big as possible resolutions for my artworks (common @300dpi) since I want to print em out or so....

[jolle]

Well, my problem is not really about the resolution, it's more about the correct aspect ratio. As small as the difference may be between for instance 2160 and 2214 pixels in height, I'd rather get it right than having to crop a canvas after the painting is done, only because it turns out I've been working in the wrong aspect ratio.

[Speculart]

Its funny that you pst this now as I was just thinking about it tonight. In photoshop cs2 when you open a new file you can pick from a whole heap of sizes under the preset dropdown. Film 2K is down the bottom and that gives you a 2048x1536 file. Thats 1.33 aspect ratio.
check this out
The standard analogue television screen ratio today is 1.33:1. The Aspect Ratio is the relationship between the width and height. A Ratio of 1.33:1 or 4:3 means that for every 4 units wide it is 3 units high (4 / 3 = 1.33).
No I know that didnt sound like my voice at all. It was actually whoever wrote its voice and he knows all about this stuff! Here
http://www.dvdaust.com/aspect.htm

Now have a read of that and then answer me this. When you film with an anamorphic lens the film you capture is squashed (like the titles on old movies) so that when it is projected onto the screen (through an anamorphic lens again) it comes out at an aspect ratio of 2.35. So (this is what is bugging me) if I do a matte painting at 1.33 as Dylan does shouldnt I be doing like a squashed version of it so that it will project properly at 2.35?

[jolle]

I don't reckon you need worry about camera recording and projection methods, as as far as I know the recorded film is scanned in and processed further in post-production for special effects and editing anyway. As soon as the film is scanned and in the computer, you just work very straightforward in square pixels. In the 'digital realm' there's nothing but square pixels, really, at least that's what I thought. Photoshop also offers an option to change Image › Pixel Aspect Ratio, I have no idea what the idea behing all this is either.

[Speculart]

yeah you can change your pixels to anamorphic too!! Theres something thats used by less than 1% of photoshop users.

[dstipes]

Hello Speculart,

There is a lot of confusion between “Anamorphic Squeeze Ratio” and “Aspect Ratio”

Anamorphic lenses squeeze or compress the image horizontally at a ratio of 2:1. (In truth, it can vary a bit ... see attached article links.) The height is not affected, only the width. A round ball photographed with an anamorphic lens will produce an ellipse that is taller than it is wide (i.e. a squeezed ball.)

The aspect ratio (“relationship between the width and height”) is the proportions of the image extracted from the negative after it is unsqueezed by the anamorphic projection lens. In essence, what we see projected on the screen. The typical aspect ratio is 2.35:1


Non squeezing lenses (aka “spherical” lenses) will have aspect rations extracted from their negative but without use of any anamorphic taking or projecting lenses. Typically you could see aspect ratios of: 1.85:1, 1.66:1 or 1.33:1

The squeezing and then unsqueezing of the image allows the projected image to be wider than a regular lens can capture or project.

As a side note, many of these early anamorphic lenses were relatively moderate to poor quality and could not be focused to close ranges. There were only a few lenses available and only for production. These lenses were not available or suitable for matte compositing. Matte painters like Matthew Yuricich were forced to paint “squeezed” and had to be careful of the kinds of paint strokes they used. Every paint stroke was stretched out horizontally 2:1.

David Stipes



Matthew Yuricich: http://www.imdb.com/name/nm0951046/


Anamorphic articles:

http://www.jkor.com/peter/briefscope.html
“WHAT YOU ALWAYS WANTED TO KNOW ABOUT CinemaScope, BUT WERE AFRAID TO ASK ..... the secrets of CinemaScope from a more technical perspective”
By Peter Gray, Director of Photography


http://www.theasc.com/magazine/sept03/sub/index.html


“Golden Years
20th Century Fox introduced CinemaScope 50 years ago with The Robe. Shortly thereafter, Panavision was born.” by David W. Samuelson

[Speculart]

Thanks David thats great stuff, and read avidly. Can you answer one question please? Matthew Yuricich DID paint squeezed so it would turn out in cinemascope. (MINDBOGGLING) Why dont we? Is the image that we so laboriously paint at 1.33 going to be chopped at top and bottom in the end?
Should the size worked at be dependant on the medium that it will be shown on? (if the project is for film, should we work at 2.35)
Thanks again David
Ps hope you dont think I have taken over your thread Jolle

[dstipes]

Matthew had to paint squeezed because he did not have lenses that would work for his compositing. It was the only solution and as far as I know he was one of the few artists that could pull that off. (Years later Mathew figured how to do matte painting directly to IP stock with distorted colors, but that’s another story.)

Modern digital artist don’t have to paint squeezed (thankfully!). Do you really want to? :shock:

In a professional setting you should expect to have the aspect ratio (or ratios) info provided to you. In other words, you need to know what the format and potential markets or mediums will be for the project.

I can certainly see a situation where you might have to paint to fill or “protect’ an Academy frame (1.33:1 aspect ratio) but know that the primary painted information has to be in a wide screen format like 1.85:1. I ran into that with TV shows that were released as features in Europe or elsewhere.

David

[jolle]

No problem, Speculart, though I still do hope someone has an answer to my question :wink:

[Speculart]

The question has been answered. Read the links provided.

[dstipes]

Also look at thread:


http://www.mattepainting.org/forum/view ... os&start=0 (http://www.mattepainting.org/forum/viewtopic.php?t=208&postdays=0&postorder=asc&highlight=scanning+ratios&start=0)

[dstipes]

It appears that the mysterious 2160 number may be from the Digital Cinema Initiatives, LLC created by a group of seven studios: Disney, Fox, Metro-Goldwyn-Mayer, Paramount Pictures, Sony Pictures Entertainment, Universal Studios, and Warner Bros. Studios to establish uniform specifications for Digital Cinema.

One of their specs is: 4096 Horizontal pixels x 2160 Vertical pixels with square pixels giving an aspect ratio of 1.892.

http://www.dcimovies.com/DCI_Digital_Ci ... pec_v1.pdf (http://www.dcimovies.com/DCI_Digital_Cinema_System_Spec_v1.pdf)


I suspect what is causing confusion is that there are different standards being used, different scanners being used and different resolutions being used.

What is important is to understand what aspect ratios are being used at the studio you are doing your work for. Understand what scanners, what color depth and file formats are being used.

I sure hope this helps in some way …… Maybe some of the working matte artists will jump in here.

David

[jolle]

Great links and tips, David, thanks so much for your help. I think your DCI explanation is it, it seems clear that 2160 is a standard that came from them. This is just for personal use, no studio in their right mind would hire me to do a matte painting :) but even if it's just for me I'd rather get things right straightaway. I think I'll stick to 2160 now that I know where it's coming from, I'd rather paint too wide than having to crop in the height of the image, but in my Photoshop file I'll add some guidelines to indicate the smaller widths of 1.85 and 1.78 aspect ratios.

[dstipes]

jolle,

Let's see some of your work now that this is somewhat resolved.

David

[jolle]

Nice one David, but I'm really just starting out in matte painting. How about I post something here in this thread again in about a month or so? I'm a fairly decent illustrator so I'm not exactly starting from scratch here, but matte painting is quite a bit different and more advanced than what I usually make. Once I'm up and running a bit and I don't feel too shy about how it turns out to look, I'll definately post some work here!

[Speculart]

pussy :D

[jolle]

:roll:
Tell you what, I'll start posting work in a month, no matter how crappy it looks!

[Speculart]

You will be suprised how quickly it will stop looking crappy at all!