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Author Topic: 5D Mark II noise analysis  (Read 4163 times)

james_elliot

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5D Mark II noise analysis
« on: December 29, 2008, 11:23:27 am »

I have received a 5D Mark II this morning and I ran my usual tests on it (see here).
The 5D Mark II noise is  astonishing low, and quite above what I was hoping for.
The 5D Mark II dark noise at 12800 ISO is on par with the 1Ds MarkII at 1600 ISO (4 bits remaining), and ISO 25600 is on par with the 1Ds Mark II at 3200 ISO
Compared with the 40D, 12800 ISO on the 5D Mark II is equivalent to 3200 ISO on the 40D.

I don't have access to Nikon cameras, so if anyone has a D3 and/or a D3X and wishes to follow my testing procedure, I would be very happy to see and post the results.

PS: Caveat: these measurement only deal with "dark noise", which is only one component of noise.
« Last Edit: December 29, 2008, 11:25:43 am by james_elliot »
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Panopeeper

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5D Mark II noise analysis
« Reply #1 on: December 29, 2008, 02:22:22 pm »

What is the point of measuring the read noise with ISOs, which are numerically derived? The 5D2's read noise @ 6400 is exactly the double of that @ 3200, four times as high at ISO 12800 and eight times higher @ ISO 25600. The 40D's read noise is exactly twice as high @ ISO 3200 as @ ISO 1600.

I assume you aren't using the fake ISOs in astronomy, are you?
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Gabor

Paul Roark

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5D Mark II noise analysis
« Reply #2 on: December 29, 2008, 02:41:00 pm »

This may be an OT question, but is there is difference in noise level when in Live View mode?

Paul
www.PaulRoark.com
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james_elliot

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5D Mark II noise analysis
« Reply #3 on: December 29, 2008, 04:27:18 pm »

Quote from: Panopeeper
What is the point of measuring the read noise with ISOs, which are numerically derived? The 5D2's read noise @ 6400 is exactly the double of that @ 3200, four times as high at ISO 12800 and eight times higher @ ISO 25600. The 40D's read noise is exactly twice as high @ ISO 3200 as @ ISO 1600.
Just watch the following curves (which are real measurements of the 40D noise for a 10s shot with NR off) and you will realize that noise processing is not linear when you raise ISO. Watch the other curves on my site and you will see how complex the subject is. Manufacturers are putting a lot of intelligence in noise processing and that's what is interesting.

[attachment=10598:speed_104000n.png]
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yoni

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5D Mark II noise analysis
« Reply #4 on: December 29, 2008, 05:06:41 pm »

Check out the comparison at http://www.dxomark.com/index.php/eng/Image-Quality-Database between the two. If you accept there cutoff of 30db diff is around 1/4 stop.
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james_elliot

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5D Mark II noise analysis
« Reply #5 on: December 29, 2008, 05:10:49 pm »

Quote from: Paul Roark
This may be an OT question, but is there is difference in noise level when in Live View mode?
Good question. I just did the test. As expected, the answer is yes, especially after quite a long time. The probable cause is the heating of the sensor and the IC boards in live view mode.
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james_elliot

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5D Mark II noise analysis
« Reply #6 on: December 29, 2008, 05:18:27 pm »

Quote from: yoni
Check out the comparison at http://www.dxomark.com/index.php/eng/Image-Quality-Database between the two. If you accept there cutoff of 30db diff is around 1/4 stop.
Yes, but they are measuring noise at 18% reflectance (grey), not on a completely dark frame. This is a different from pure dark noise and it levels results between cameras (but it is extremely useful also!).
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Panopeeper

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5D Mark II noise analysis
« Reply #7 on: December 29, 2008, 05:53:03 pm »

Quote from: james_elliot
Just watch the following curves (which are real measurements of the 40D noise for a 10s shot with NR off) and you will realize that noise processing is not linear when you raise ISO. Watch the other curves on my site and you will see how complex the subject is
The noise with the fake ISOs *is* linear related to the ISO from which they are derived. There is no point of researching the noise characteristics of those ISOs, and shooting with such ISOs in raw is not only useless but counterproductive.

See List of read noise per ISO
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Gabor

james_elliot

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5D Mark II noise analysis
« Reply #8 on: December 29, 2008, 06:32:38 pm »

Quote from: Panopeeper
The noise with the fake ISOs *is* linear related to the ISO from which they are derived. There is no point of researching the noise characteristics of those ISOs, and shooting with such ISOs in raw is not only useless but counterproductive.

See List of read noise per ISO
Interesting, but your measurements are only about means and deviations which are quite a reduction of noise distribution.
Actual distribution measurements show that, for example, the curves at 12800 and 25600 for the 5D Mark II don't have exactly the same shape, and that the differences depend on the shutter speed.
This may be the result of a variation in the readings (the sensor temperature might have changed), but can also be the result of a more subtle way of handling the problem of the so called "fake ISOs".

Of course I agree that the "ISO H1 and H2 extensions" (to use the Canon words) are probably mainly generated by multiplicating the values of ISO 6400, while regular ISO  are made by using different gain in the analog/digital conversion process. However, displaying the curves is a way to check this, and doesn't cost lot of time.

Shooting in real life with "fake ISO" in RAW is a convenient way to avoid the problem of having to think about under-exposing when shooting and then later on  boost the levels in post-processing... Of course, some highlights might get lost in the process.

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