Re: D700 sample photos up to 25,600 ISO

From: floyd@xxxxxxxxxx (Floyd L. Davidson)
Date: Tue, 05 Aug 2008 05:55:57 -0800

"Wilba" <usenet@xxxxxxxxxxxxxxxxxxx> wrote:

Floyd L. Davidson wrote:

What we are doing is replacing all of the individual values with
that average value. The average will be lower than the highest
values, and thus the visual effect of the noise will be reduced.

Describing it in words isn't working. Would you show us images that
illustrate the idea?

Demonstrating results is fairly easy to do.
(Illustrating the concept is obviously not easy. It is
explained in many other places and I have no interest in
wasting time arguing with the others here over
nonsense.)

I've made 8 images, using a tripod mounted Nikon D3, and
have uploaded them to my webpage.

They were made with the following configurations:

Image /-------- Camera Settings --------\
Number ISO Shutter Aperture Exposures

7880 1600 1/20 f/5.0 1
7881 3200 1/40 f/5.0 1
7882 6400 1/80 f/5.0 1
7883 12800 1/160 f/5.0 1
7884 25600 1/320 f/5.0 1
7885 25600 1/320 f/5.0 8 (Averaged)
7886 3200 1/320 f/5.0 8 (Additive)
7887 25600 1/640 f/10.0 8 (Additive)

Note that the last two are underexposed by 3 f/stops
for the camera ISO. Image 7886, with the camera ISO
setting at 3200 is exposed correctly for ISO 25,600.
Image 7887, with the camera ISO set for 25,600, is
exposed correctly for an ISO of 204,800.

The raw data was converted using UFRAW. No sharpening
or noise reduction was done. Each image was adjusted to
have identical values for the highlights. The variation
in exposure ranged from +0.18 to -0.53. (It appears
that 9 exposures, rather than 8, for the multi-exposure
images would have produced better result.)

From these images I've cropped out a 600x600 portion,

Follow-Ups:
- Re: D700 sample photos up to 25,600 ISO
  - From: John P Sheehy

References:
- Re: D700 sample photos up to 25,600 ISO
  - From: Jennifer Usher
- Re: D700 sample photos up to 25,600 ISO
  - From: Bill Lang
- Re: D700 sample photos up to 25,600 ISO
  - From: Floyd L. Davidson
- Re: D700 sample photos up to 25,600 ISO
  - From: John Sheehy
- Re: D700 sample photos up to 25,600 ISO
  - From: Floyd L. Davidson
- Re: D700 sample photos up to 25,600 ISO
  - From: Wolfgang Weisselberg
- Re: D700 sample photos up to 25,600 ISO
  - From: Floyd L. Davidson
- Re: D700 sample photos up to 25,600 ISO
  - From: Wolfgang Weisselberg
- Re: D700 sample photos up to 25,600 ISO
  - From: Floyd L. Davidson
- Re: D700 sample photos up to 25,600 ISO
  - From: Wolfgang Weisselberg
- Re: D700 sample photos up to 25,600 ISO
  - From: Floyd L. Davidson
- Re: D700 sample photos up to 25,600 ISO
  - From: Wilba

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