How does the D3 achieve such high ISO?

Started Feb 17, 2008 | Discussions thread
ejmartin Veteran Member • Posts: 6,274
Re: Who doesn't get it

Amin Sabet wrote:

ejmartin wrote:

So if one is not fixated on the pixel (which corresponds to a
different spatial scale depending on the pixel size) but rather looks
at a fixed scale, pixel size is essentially irrelevant within a wide
range, its major effect is on resolution, not noise. Unless of
course you print images based on pixel size and so different sizes
for different cameras, rather than some standard size where smaller
pixels are a smaller percentage of the image.

Emil, what you say here makes sense, and I've seen you post this
before. In practice, I don't think it works out quite right. There
is no doubt that the apparent noise advantage of large pixel cameras
based on evaluation at the pixel level is highly misleading.
However, even when compared at the same overall print size, the large
pixel cameras enjoy a noise advantage in my experience. Low light
1Ds II files against 5D files, both ISO 1600 pushed to ISO 3200 and
printed at 12 x 18" - the 5D files have better detail/noise from the
examples I have seen. Same goes for pocket cameras, eg Fuji F30 vs
Canon G7 (granted the Fuji sensor is a touch larger) when compared at
ISO 800 and up at any given same print size. Same for low light high
ISO D3 vs 1Ds Mk III examples I have seen on the web and printed for
my own evaluation at equal output sizes. I don't know why practice
should deviate from the theory you are putting forth, but this is
what I am seeing in the prints.

The quantitative point being made is that the 5D and 1Ds2 are collecting about the same number of photons per unit area, and both have about 4 electrons of read noise per pixel at high ISO (so there is a slight advantage to the 5D, but very slight). So there won't be a difference in the noise properties of raw, out to the limits of resolution of the larger pixel camera (after that, the two can't be compared, of course).

So when you see a difference in the printed result, it has to be a difference in the processing -- for instance, raw conversion, sharpening, or resampling to the final print resolution. Any of these could introduce a difference in the noise spectrum and sharpness that would favor one camera over the other. But you bring up a good point, and I don't know what the best method is to ensure that the equal quality that is available in the raw data is maintained through to the final result.

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