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Author Topic: Canon 5D Mark III @ ISO 25,600  (Read 9515 times)

Ellis Vener

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Re: Canon 5D Mark III @ ISO 25,600
« Reply #40 on: March 13, 2012, 03:28:20 PM »

Quote
"further analog gain is only useful if it improves the S/N ratio in the output signal"

yep.
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Ellis Vener
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John MacLean

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Re: Canon 5D Mark III @ ISO 25,600
« Reply #41 on: March 13, 2012, 05:31:20 PM »

Hi Ellis,

Aside from the banter here, I would like to see a test at a smaller aperture. Say f8 with a longer exposure, to see the lens at its maximum potential. But maybe the noise was the main reason for the test, and you're not as concerned with the resolving detail?

Thanks,
John
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Ellis Vener

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Re: Canon 5D Mark III @ ISO 25,600
« Reply #42 on: March 13, 2012, 07:38:14 PM »

Hi Ellis,

Aside from the banter here, I would like to see a test at a smaller aperture. Say f8 with a longer exposure, to see the lens at its maximum potential. But maybe the noise was the main reason for the test, and you're not as concerned with the resolving detail?

Thanks,
John
http://www.johnmaclean.com/
https://www.facebook.com/JohnScottMacLean

Thank you John for your contribution. I can definitely do that but of course that might compound long exposure
noise with high sensitivity setting noise. That's a different kind of worst case scenario!
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Ellis Vener
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PierreVandevenne

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Re: Canon 5D Mark III @ ISO 25,600
« Reply #43 on: March 13, 2012, 07:42:58 PM »

An even deeper look at the question you raise Andrew is to see that  what you essentially propose  is that for my (or anyone else's)  review to be fair I need to look at this every possible combination of a camera's ISO settings put through every possible permutation of raw processing (Lightroom v4 /ACR 7; Capture One, Capture One pro, DPP,  etc.) , sharpening, and noise reduction software. And maybe we should throw interpolation software in there as well. I have no

No, that would be a more superficial look. Andrew's question is fairly simple to answer once you have the camera in hand (for example with the IRIS freeware). If you can't use IRIS (for example because you have no adequate RAW decoder at this point) changing a slider on a relatively under-exposed image is just a shortcut, an approximation. There's no need to test dozens of approximations. One will probably be enough to get a good idea.

And remember that the interesting camera reviews are the ones that go a bit further than the standard ones. We all know that there will be hundreds of reviews of that camera, most of them written in the very same mold that was used for the D30.

No need to let this discussion evolve into ad-hominems.
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John MacLean

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Re: Canon 5D Mark III @ ISO 25,600
« Reply #44 on: March 13, 2012, 07:51:08 PM »

Thank you John for your contribution. I can definitely do that but of course that might compound long exposure
noise with high sensitivity setting noise. That's a different kind of worst case scenario!

Yes when I did the math I got 6 seconds @ f8. WOW that is a low light room shot!

Ellis Vener

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Re: Canon 5D Mark III @ ISO 25,600
« Reply #45 on: March 13, 2012, 08:11:35 PM »

Is it me, or is this some thermal amplificator noise in the lower right corner (red+blue)?

Sorry to not get back to this sooner. I am pretty sure it is flare from light reflecting off the glass door on the bookcase , not thermal noise. If the camera is producing that much thermal noise at only 1/6th second that would be a really bad problem. I will check for that tonight.

Edit 11:21PM 03/13/2012
I cannot get it to replicate,  so I am tentatively going with my hypothesis that what we are seeing is flare or glare.

Edit 3:26PM 03/14/2012
I absolutely cannot get the effect to replicate after trying several times at even longer exposures. As this is a pre-production camera body it could be a transient effect but most likely is just flare.
« Last Edit: March 14, 2012, 03:30:14 PM by Ellis Vener »
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Ellis Vener
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NikoJorj

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Re: Canon 5D Mark III @ ISO 25,600
« Reply #46 on: March 15, 2012, 11:16:26 AM »

I absolutely cannot get the effect to replicate after trying several times at even longer exposures. As this is a pre-production camera body it could be a transient effect but most likely is just flare.
OK, many thanks for testing my dumb hypothesis!
The contrary would have been bad news, indeed.
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Nicolas from Grenoble
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