Cinema vs. Smooth

[Joshua Csehak]

I'm finding that Cinema is actually a more useful setting than Smooth. Thought I'd share my results with you guys and get your take on things.

First, I did a pure dynamic range test, and Smooth seemed to come out a stop or two ahead (as did Nostalgic). But then, after a couple test shots, it seemed like light-colored objects looked more natural in Cinema, though the gamma crushed the blacks too much for my taste. So I shot a direct comparison.

The first attachment is on Cinema, the second on Smooth. No surprises there. But I adjusted the gamma of the Cinema clip (this is all in Color, btw) to match the overall brightness of the Smooth clip, which is the third attachment. Looks to me like there's no extra noise in the lows -- everything looks the exact same there -- and a lot more detail and range in the highs. The adjusted Cinema image looks flatter to my eye, and more natural. The Smooth image looks as if I took the adjusted Cinema image and applied some contrast. As we all know, you can always add contrast, but you can't really take it away, so I'm thinking, Cinema is actually the best choice for maximum image quality.

Of course, this depends on your application. If I was shooting stuff that wasn't going to go to a colorist, but straight to the web (or broadcast), I'd use Smooth for sure.

Thoughts?

[Joshua Csehak]

smooth

[Joshua Csehak]

cinema adjusted

[Andrew Reid]

Cinema just underexposes basically, to protect highlights. But the way it does so reduces tonality and dynamic range. You are far better off using Smooth with a lower ISO. The GH2 has trouble enough with crushed blacks and the Cinema film mode makes that worse.

[Sara]

Andrew is right and I (and hundreds of others on personalview) have tested this extensively.

You never want to run any gamma/color profile that underexposes a digital sensor for the sake of a "look."  Adobe produced this PDF warning people about the problems associated with underexposure and how digital sensors are different than film. 

Also remember that exposure is heavily related to color depth as well - ie "raising shadows" not only introduces digital noise, but also increase the rate of false color and image posterization.  Ugly and makes productions reek of "cheap video."

http://wwwimages.adobe.com/www.adobe.com/content/dam/Adobe/en/products/photoshop/pdfs/linear_gamma.pdf

From what we can tell, smooth and nostalgic (lots of warmth however) give the most dynamic range - very important because that is "somewhat" a small weakness of the GH2's sensor. 

I am not arguing with your results - it does indeed look like your cinema shot after editing is flatter, but again I think that editing the smooth would produce a similar or better result.

Also remember that all these settings have adjustments you can make as well - Nearly all the GH2 "pros" shooting little productions I know of shoot Smooth -2,-2,0,-2 (leaving color alone because we need color information due to the 4:2:0 nature of the GH2 output)

[Joshua Csehak]

I hear what you guys are saying, and I agree with you in theory. I understand about ETTR and stuff (thanks for the pdf link though, Sara -- they put it really well!). But it looks to me that in some cases, Cinema simply looks better than Smooth/Nostalgic, and I'm trying to figure out a) why, and b) if that means I should be using Cinema in spite of the fact that it technically has less dynamic range. After all, if it looks better, it is better, right?

Here are my dynamic range tests. They are with the Roadrunner hack. I used my "DR650" http://www.magicgoggles.com/blog/?p=5, which is just a bunch of 1-stop NDs on top of each other. They probably don't show anything you don't already know, but maybe you'll find them useful. They are NOT shot at the same aperture. What I did was open the aperture until the brightest spot on the bulb blew out just a bit. So they're all normalized for the top end of the highlights. I feel like this accurately represents real-world situations, b/c when ETTR, oftentimes what you might do is open it up all the way, and close it down till the highlights (or at least, the highlights you care about) aren't blown out.

The first thing you can see is that -- just as you said -- out of the camera, cinema has about a stop less dynamic range on the low end.

[Joshua Csehak]

smooth

[Joshua Csehak]

cinema

[Joshua Csehak]

from my 60D, for reference (picture style Neutral, everything as flat as I could make it)

[Joshua Csehak]

But now what if I take the Cinema shot and grade it with +1.33 to the gamma (and bring the lift down -0.04 to bring the blacks back to black). Now the darks match, the highlights blow out exactly the same, but the lights are much darker. Smooth is indeed smoother, but the lights, before they hit 100%, are much lighter and have less color information. It seems like, if you can keep your highlights from blowing out, cinema is the way to go, b/c you retain more information in the 2-3 stops below 100%.

But is it noisier in the darks? Not that I can tell. Playing the footage, the grain looks about the same to my eye.

[Joshua Csehak]

But that's my subjective opinion. Let's look at what's really going on in those darks. Cranking them all up by +2.7 gamma (and -0.05 lift so we can see what we're working with) reveals the bits at the lowest end. Here's nostalgic:

[Joshua Csehak]

and here's smooth. This is interesting -- nostalgic seems to have a half stop or so extra DR on the low end!

[Joshua Csehak]

Here's cinema. No surprises here, I don't think. It falls apart much more than the other two, with another half-stop less information.

[Joshua Csehak]

And here's the 60D, for reference. It's about as noisy as smooth/nostalgic, and it looks like it actually has a half-stop less DR than nostalgic. So much for the idea that the GH2 has less DR than Canon!

[Joshua Csehak]

Here's something else interesting. Nostalgic is actually not warmer, it's less cooler! To get it to true gray, I have to further bring down the blue channel. Here it is with that: