DV Info Net

DV Info Net (https://www.dvinfo.net/forum/)
-   Canon EOS Crop Sensor for HD (https://www.dvinfo.net/forum/canon-eos-crop-sensor-hd/)
-   -   What ISO for your 7D??? (https://www.dvinfo.net/forum/canon-eos-crop-sensor-hd/469830-what-iso-your-7d.html)

Jerry Porter December 21st, 2009 09:38 PM

What ISO for your 7D???
 
I have found that anything over about 1200 ISO on my 7D produces unacceptable noise levels that basically render the footage worthless. I mean more noise than my JVC HD110 at +9 gain. What ISO do you get with yours that produces visible noise? I'm shooting with a Tamron f2.8 17-50 - Marvels Cine settings - 1920X1080 30fps (60 shutter)- M for all the settings - White balance @ K - auto light optimizer off and noise suppression at standard. How about you?? I see people all the time posting that they shot something at 6400 and it looks great, how is this being accomplished?? Post? If so with what? Right now I'm not that impressed with the low light on this camera. It takes great shots it just needs light like any other camera. Does the noise suppression even matter in video mode? I'm pretty sure that it's not the camera specifically as I took a friends out and it looked the same at all ISO settings with the same set ups and lenses. Am I missing something in my set up that is giving me the noise?

Brian Luce December 21st, 2009 10:28 PM

The conventional wisdom (Daniel Browning) is that 2.8 is just starting to get to territory that beats 1/3" HDV cams. Around 1.8 and you should be blowing them away.

1250 is my max too.

Dror Levi December 22nd, 2009 12:02 AM

but when using F1.8 wouldn't it make everything blurry and only small portion of the picture in focus?

Brian Luce December 22nd, 2009 02:02 AM

Quote:

Originally Posted by Dror Levi (Post 1463243)
but when using F1.8 wouldn't it make everything blurry and only small portion of the picture in focus?

Well, yeah. But people go beyond 1.8 (to 1.4 etc) all the time. You could spend 5 grand to RENT a pimped Genesis for a day and have the same issue.

Liam Hall December 22nd, 2009 03:27 AM

I shot a camera test on Sunday using ISOs between 200 and 1600. The 1600 held up remarkably well.

There are five shots at 1600 ISO in this sequence:


Regis Hervagault December 22nd, 2009 05:52 AM

160-320-640-1250 are supposed to be the cleanest iso on the 5D and supposedly the 7D too.
shooting wide apertures brings so much more light it is the best solution albeit selective focusing issues.
for best results in low light, i'd open up and use the closest ISO from the above list.
when there's enough light, fine tune exposure with a variable ND filter if needed.

Jerry Porter December 22nd, 2009 07:07 AM

Thanks, that 1250 mark seems to be the break point?? Liam, nice piece I enjoyed it. I seem to be to get away with a little higher (1600) when shooting abstract, but if I put a shiny solid darker surface any where near the shot and it gets bad quickly, also with a face in the shot 1250 seems to be pushing it.

Keith Moreau December 22nd, 2009 09:32 PM

I agree with you Jerry that the low-light capabilities of the 7D seem to be overrated or over-hyped. My EX1, with it's 1/2" sensor (about 1/3 the size of the APC-C) blows the 7D away in terms of low light vs noise, at least in my unscientific anecdotal experience.

My theory is that, while the sensor is bigger, the way that the HD image is created on the 7D is to 'line skip' to produce the image. If every 3rd line is skipped, then the light from that line isn't part of the signal, so it's 1/3 as sensitive (or however many lines are skipped).

I think in something like a RED, where it's made to record and process all the light that hits the sensor, the light gathering specs correlate to sensor size. And in still mode on the 7D, you do get that sensitivity (in my theory).

I still love it for the shallow DOF and organic, beautiful images that are just not possible with any camcorder under 30K (RED), but for the low light - jury's out for me.

Of course I could be horribly wrong, but yes, just like you, I'm not impressed with the low light noise levels. Anybody want to weigh in on my theory?

David Chapman December 22nd, 2009 09:52 PM

I do some things differently from what has been posted thus far and may solve your problem. We talked about some of this here: http://www.dvinfo.net/forum/canon-eo...ing-video.html

I decided 3 things:
1. Turn Highlight Tone Priority off
2. Stick with whole/non-clipping ISO values:100, 200, 400, 800, 1000, 1600, 2000, etc
3. Manually select white balance

The ISO values you mentioned are cleaner with a "lens cap on" test, but actually clip highlights or crush blacks. HTP underexposes and then shifts—overexposing blacks creating more visible noise. Auto white balance also adds to the noise mix (but not shooting stills in RAW mode).

With all of these under my control, my footage was far less noisy.

Brian Luce December 22nd, 2009 10:20 PM

Quote:

Originally Posted by Keith Moreau (Post 1463625)
I agree with you Jerry that the low-light capabilities of the 7D seem to be overrated or over-hyped. My EX1, with it's 1/2" sensor (about 1/3 the size of the APC-C) blows the 7D away in terms of low light vs noise, at least in my unscientific anecdotal experience.

Keith, are you using fast lenses?

Jad Meouchy December 22nd, 2009 10:51 PM

If you want low light performance, try a 55mm f/1.2 with ISO 600, the crossover where I've started to notice noise. But I've found that it doesn't start to affect perception until ISO 1000. The bottom line is that your lens choice is rather important when shooting at night.

Khoi Pham December 22nd, 2009 11:30 PM

Quote:

Originally Posted by Keith Moreau (Post 1463625)
I agree with you Jerry that the low-light capabilities of the 7D seem to be overrated or over-hyped. My EX1, with it's 1/2" sensor (about 1/3 the size of the APC-C) blows the 7D away in terms of low light vs noise, at least in my unscientific anecdotal experience.

My theory is that, while the sensor is bigger, the way that the HD image is created on the 7D is to 'line skip' to produce the image. If every 3rd line is skipped, then the light from that line isn't part of the signal, so it's 1/3 as sensitive (or however many lines are skipped).

I think in something like a RED, where it's made to record and process all the light that hits the sensor, the light gathering specs correlate to sensor size. And in still mode on the 7D, you do get that sensitivity (in my theory).

I still love it for the shallow DOF and organic, beautiful images that are just not possible with any camcorder under 30K (RED), but for the low light - jury's out for me.

Of course I could be horribly wrong, but yes, just like you, I'm not impressed with the low light noise levels. Anybody want to weigh in on my theory?

You must have a very slow lens, use any F1.4 or F1.6 lens will blow away your EX1, you probably compared your EX1 at F1.6 to a stock F3.5 lens on the 7D, how fair is that?

Keith Moreau December 23rd, 2009 12:52 AM

I am using primarily 2.8 zooms. I have a f1.4 and f1.8 primes but haven't used them much yet.

I guess what I'm saying is that I can shoot pretty usable EX footage with some substantial gain (+6 or more) in darker than ideal conditions without a lot of noise. With my f2.8 zooms (Canon 17-55, 70-200 L) it seems like I often need more light or I'm on the edge, and I know if I go past ISO 640 it's going to start getting noisy in the blacks.

As someone mentioned before, as we start getting lower than 2.8, the shallow DOF limits the versatility of what you can capture, so this limits us to wider lenses for those situations if you want less noise.

If people are happy with the low light performance, that's wonderful, I want to be happy with it too, and perhaps I haven't yet found the right combination of settings.

Anyway, as I said, I'm just agreeing with Jerry on the low light/noise performance of the 7D, but I'd love to be proven wrong, I want to be able to use this wonderful little camera in as many adverse conditions as it will allow.

This is a great forum and I appreciate all the knowledge here.

Jerry Porter December 23rd, 2009 07:10 AM

Quote:

Originally Posted by David Chapman (Post 1463634)
I do some things differently from what has been posted thus far and may solve your problem. We talked about some of this here: http://www.dvinfo.net/forum/canon-eo...ing-video.html

I decided 3 things:
1. Turn Highlight Tone Priority off
2. Stick with whole/non-clipping ISO values:100, 200, 400, 800, 1000, 1600, 2000, etc
3. Manually select white balance

The ISO values you mentioned are cleaner with a "lens cap on" test, but actually clip highlights or crush blacks. HTP underexposes and then shifts—overexposing blacks creating more visible noise. Auto white balance also adds to the noise mix (but not shooting stills in RAW mode).

With all of these under my control, my footage was far less noisy.

Hi Dave,
Thanks for chiming in here as you and I have talked several times before about the 7D, all those things you listed I do as well except on the ISO values, but I will definitely give it a try. Where are you finding the noise levels getting unacceptable for you?

Jean-Philippe Archibald December 23rd, 2009 09:30 AM

Quote:

Originally Posted by Keith Moreau (Post 1463695)
I guess what I'm saying is that I can shoot pretty usable EX footage with some substantial gain (+6 or more) in darker than ideal conditions without a lot of noise. With my f2.8 zooms (Canon 17-55, 70-200 L) it seems like I often need more light or I'm on the edge, and I know if I go past ISO 640 it's going to start getting noisy in the blacks.

This lens is 1 2/3 stop slower than the one on your EX1. You are comparing apple and orange.


All times are GMT -6. The time now is 05:12 PM.

DV Info Net -- Real Names, Real People, Real Info!
1998-2024 The Digital Video Information Network