Unbiased noise test.

Started Feb 28, 2009 | Discussions thread
sidelight Senior Member • Posts: 1,013
Re: simple...

Rcihardc wrote:

Even in your crops 5DII has the lowest noise compared to D3X, 1DSIII
and a900. at the same print size, 5DII has the lowest noise of any
DSLR available today. There has been at 10 different posts that have
confirmed this and yours is the last one. Nikon D3X is close to older
Canon 1DSIII with Sony being far behind from either one.

I posted this in an earlier thread about the D3X and the 5DII sensor. If you can accept DxO's testing, then their results show the 5DII to have similar noise performance at base ISO to the D3X but not in the deepest shadows. Their test protocols are described on their site. I think Iliah has said color temp influences noise as well and this is not varied. The data below is just one aspect of performance of course.

"I pulled this sensor data from DxOMark using the Full SNR tabs and the log plots. The table below compares the signal to noise vs very low gray levels at base ISO. Essentially it shows that the D3X has about half the noise as the 5DII and A900 at 0.1% gray. At 1% and 10% gray, the D3X and 5DII are equal, but about one stop better (3dB) than the A900. The improvement of the D3X over the similar Sony sensor at base ISO indicates significant, if small, design differences.

The second table shows the lowest gray level for each camera at a signal to noise of 5dB (Rose's criterion - defined below). The D3X is able to show recognizable detail (distinguishable from noise) at a deeper black level. Given that this performance also beats the medium format backs recently tested, I think it shows the D3X meets it's design goals of best in class low ISO performance for 35mm format. Differences are obviously getting pretty small now when looking at overall performance.

Signal to Noise (dB) vs Gray Level

0.1% 1% 10% Gray

D3X_ 14_ 26 37

5DII_ 7 25 37

A900_ 7_ 22 33

Leaf75S_ 8_ 25 37 (ISO50)

3dB = 1 stop and +6dB is equivalent to doubling the noise.

Lowest Gray Level Above Rose Criterion *

@S/N=5dB

D3X_ 0.027%

5DII_ 0.078%

A900_ 0.078%

Leaf75S_0.08% (ISO50)

The Rose criterion (named after Albert Rose) states that an SNR of at least 5 is needed to be able to distinguish image features at 100% certainty. An SNR less than 5 means less than 100% certainty in identifying image details.[2]

[2]^ Bushberg, J. T., et al., The Essential Physics of Medical Imaging, (2e). Philadelphia: Lippincott Williams & Wilkins, 2006, p.280"
--
David

Post (hide subjects) Posted by
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
(unknown member)
Keyboard shortcuts:
FForum PPrevious NNext WNext unread UUpvote SSubscribe RReply QQuote BBookmark MMy threads
Color scheme? Blue / Yellow