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-   -   CineGama curves (https://www.dvinfo.net/forum/sony-xdcam-ex-pro-handhelds/112088-cinegama-curves.html)

Craig Seeman January 10th, 2008 10:57 AM

CineGama curves
 
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I believe a few people have been looking for graphic representation of the EX1 CineGamma curves. While they aren't in the manual, they are in the brochure. Here's the screen shot for easy reference.

Now if one could see what the Matrix settings where all about. . . .

Piotr Wozniacki January 10th, 2008 11:10 AM

Thanks Craig, but this picture we've all seen... What would be of interest is a graphical comparison with the 4 STD curves, though!

Craig Seeman January 10th, 2008 11:35 AM

Sadly Sony doesn't provide examples of STD gamma profiles . . . nor even detailed descriptions of Matrix settings anywhere I look including their various websites.

In fact I find the manual description of CINE1 (the final line of the description) one of the most humorously meaningless things I've seen in any technical manual.

"CINE1 . . . for a calm and quiet effect." - HUH?
Great for meditation films but bad for action/adventure?
Where's the "highly disturbing and abrasive" gamma setting?

Steven Thomas January 10th, 2008 11:39 AM

Looking at that image gives me an overall idea of what to expect from each curve.
You really can't tie it together until you've actually tried each one under a certain condition.

Eric Pascarelli January 10th, 2008 11:40 AM

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Here's a chart I did when I first got the camera. It is f/stop (on the camera) vs IRE (from a grey card) so it's not a direct response curve, but shows the relationship between some of the curves.

Cine 4 is my favorite because it gives more shadow detail and rolls off the highlights. The Standard 4 has the same shadow detail as Cine 4 but has more linear highlights. I am not sure what's going on the top of the standard curves - it's a bit weird and might be an error on my part, but that's what I measured.

What I am looking for is a pleasing image that's reasonably flat and gives the most options in post.

Take this all with a grain of salt - I did it hastily on my kitchen counter so I could find a "favorite." Hardly scientific.

Bill Ravens January 10th, 2008 11:44 AM

cool, Eric. Thanx

Piotr Wozniacki January 10th, 2008 12:06 PM

Thanks Eric!

And Steven - of course experimenting is the best thing, but even with the great LCD screen of EX1, you'll only really know the results while on your NLE timeline - sometimes too late :).

Steven Thomas January 10th, 2008 12:14 PM

Yes, that's why I use a large live monitor. Also, always experiment and determine "your" ideal settings for the camera before any important shoot.

Mike Barber January 12th, 2008 10:44 PM

how would YOU describe the different profiles?
 
I am curious to know -- considering the sparse and vague (at best) descriptions in the manual -- how would YOU describe the different profiles?

Craig Seeman January 12th, 2008 10:47 PM

I spoke to Juan Martinez about the lack of detailed information about Cine Gamma and Standard Gamma curves as well as the Matrixes. He said he hopped to get that info up on Sony's site.

Simon Hunt January 13th, 2008 03:47 AM

I've done work with the F-900 (panavision) for some TV Series and MOW's. Always controlled by an MSU for full adjustment. The way I've learned to think of gammas are as adjusting the "mid tones" or "greys". Knee controls whites and Black adjustment controls just that, black levels. You need to experiment to understand it, but while adjusting gammas watch the mid tone values or 30 to 80 IRE range on a scope. Black gammas are at the bottom end of that... between black and grey. The preset curves of the EX1 should be interesting to play with but I agree the info in the pamphlet needs some improving. How about identifying the 2 sides of the graph!

Eric, good job with your graph. The 2 STD curves "clip" off at the top probably on purpose. Most broadcasters require a standard of "white clip" set at 100 IRE. Some allow up to 108 IRE. That appears to be in the ball park of what you found, so I'd say you were pretty close.

Matrix on the other hand can be a dangerous thing. It can adjust the color of the image and unless you have a means of resetting it you can get very lost (on the F-900) If you want to play with this, do it when you have plenty of time! I'm not familiar with the way the EX1 uses Matrix adjustment but my opinion is based on my work with the F-900. It can be handy to create a "look" in camera, but most often productions would rather shoot it "normal" and adjust the "look" in post, for full flexibility. Some effects are hard to recover from in post.

Does that help or confuse more?

Michael H. Stevens January 13th, 2008 04:53 AM

Quote:

Originally Posted by Steven Thomas (Post 806258)
Yes, that's why I use a large live monitor. Also, always experiment and determine "your" ideal settings for the camera before any important shoot.

How "large" and how good to dothe job? Do you mean an On Camera monitor because that's all I could use being in remote desert places. I'm looking to "see" my gamma curves WYSIWYG

Piotr Wozniacki January 13th, 2008 05:10 AM

Quote:

Originally Posted by Michael H. Stevens (Post 807545)
How "large" and how good to dothe job? Do you mean an On Camera monitor because that's all I could use being in remote desert places. I'm looking to "see" my gamma curves WYSIWYG

I'm not Steven:) but the answer is obvious; the larger/higher resolution the better. On the other hand, when switching between curves that really differ, you can see the effect on the camera LCD; even though my V1E has a much lower quality LCD, I can clearly see when I engage cine 1 / cine 2, crush or stretch blacks etc. The only thing a bit more difficult to observe are knee settings, as they are not that obvious - you really need to know where to look (using zebras may help with this a lot).

However, for playing with color matrix one really need a good monitor! also - unlike the V1 - the EX1 has 8 curves available, which makes the things much more complicated; therefore if Mr. Martinez kept his promise we would all benefit from having some reference graphs indeed.


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