C 300 footage for commercial

Alister Chapman · January 3rd, 2012, 11:21 AM

Well now Canon have posted their white papers, I've been able to look at a graph of the C-Log curve, although all the published charts come with a strong "this is a representation" disclaimer and no real scales, so no idea how accurate they are.

From what I've seen in the white papers the compression starts around 30-40% which was is lower than I had observed. The range is restricted to 12 stops (compared to the F3's 13) which will help the image look more natural compared to s-Log. 12 stops is only half a stop increase over what is typically achieved with a cinegamma or other semi-log gamma, but this still makes a lot of sense with the C300 as trying to squeeze more into 8 bits would in my opinion be a step too far. 12 Stops is a very respectable range.

With a log type curve as the gamma gain decreases (compared to a standard gamma) with brightness there can be a perceived reduction of noise in the mid to high range when you compare standard and log gammas side by side. But I would still expect a higher ISO to produce a noisier image. It may be that when the C300 is locked in to CP Cinema mode that there is a reduction in detail correction and this may reduce the appearance of noise.

Argh..... I'm so eager to get my hands on a C300 to put it through it's paces!

Jim Martin · January 3rd, 2012, 02:50 PM

Thanks Alister for the great post! Canon is doing a big event here on Saturday so I'll, as always, fish around and see what I can find out.

Happy New Year!

Jim Martin
Filmtools.com

Sanjin Svajger · January 5th, 2012, 09:12 AM

Quote:

Originally Posted by Alister Chapman

there can be a perceived reduction of noise in the mid to high range when you compare standard and log gammas side by side.

The noise goes up in the blacks - not the mids or highs...

Alister Chapman · January 6th, 2012, 07:57 AM

That's what I am implying. Is that when you compare Log and standard gamma there may appear to be more noise in the blacks with a standard gamma than log for the same exposure as there is less gain and thus noise in the mid and high range with log.

Remember that if you have a higher dynamic range, you can open the iris up more before you over expose so your whole shot, including the mid range is also exposed brighter and the whole shot will look brighter. OR you can open the iris up a bit more but can use less gain and as a result the noise looks reduced as as well.

That's the theory at least... I will hopefully be able to confirm all this once my C300 is delivered.

January 3rd, 2012, 11:21 AM	#16
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Re: C 300 footage for commercial Well now Canon have posted their white papers, I've been able to look at a graph of the C-Log curve, although all the published charts come with a strong "this is a representation" disclaimer and no real scales, so no idea how accurate they are. From what I've seen in the white papers the compression starts around 30-40% which was is lower than I had observed. The range is restricted to 12 stops (compared to the F3's 13) which will help the image look more natural compared to s-Log. 12 stops is only half a stop increase over what is typically achieved with a cinegamma or other semi-log gamma, but this still makes a lot of sense with the C300 as trying to squeeze more into 8 bits would in my opinion be a step too far. 12 Stops is a very respectable range. With a log type curve as the gamma gain decreases (compared to a standard gamma) with brightness there can be a perceived reduction of noise in the mid to high range when you compare standard and log gammas side by side. But I would still expect a higher ISO to produce a noisier image. It may be that when the C300 is locked in to CP Cinema mode that there is a reduction in detail correction and this may reduce the appearance of noise. Argh..... I'm so eager to get my hands on a C300 to put it through it's paces! __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com Last edited by Alister Chapman; January 3rd, 2012 at 01:08 PM.

January 3rd, 2012, 02:50 PM	#17
Jim Martin Major Player Join Date: Jul 2004 Location: Burbank, CA 91502 Posts: 949	Re: C 300 footage for commercial Thanks Alister for the great post! Canon is doing a big event here on Saturday so I'll, as always, fish around and see what I can find out. Happy New Year! Jim Martin Filmtools.com

January 6th, 2012, 07:57 AM	#19
Alister Chapman Inner Circle Join Date: Dec 2005 Location: Bracknell, Berkshire, UK Posts: 4,957	Re: C 300 footage for commercial That's what I am implying. Is that when you compare Log and standard gamma there may appear to be more noise in the blacks with a standard gamma than log for the same exposure as there is less gain and thus noise in the mid and high range with log. Remember that if you have a higher dynamic range, you can open the iris up more before you over expose so your whole shot, including the mid range is also exposed brighter and the whole shot will look brighter. OR you can open the iris up a bit more but can use less gain and as a result the noise looks reduced as as well. That's the theory at least... I will hopefully be able to confirm all this once my C300 is delivered. __________________ Alister Chapman, Film-Maker/Stormchaser http://www.xdcam-user.com/alisters-blog/ My XDCAM site and blog. http://www.hurricane-rig.com