Unbiased noise test.

Started Feb 28, 2009 | Discussions thread
natureman Veteran Member • Posts: 3,979
Re: not very accurate

sidelight wrote:

natureman wrote:

[[snip]
And don't blame him for any camera company's failure to match their
camera ISO settings to the actual correct ISO. That is something the
camera companies should have figured out a long time ago.

Uhh... I think it was Iliah who pointed out the exposure differences
in the Imaging Resource files used for the comparison here. I
followed the posts and Iliah was very polite and even encouraging to
the OP, even if offering critique of the methodology. Pointing out
how large exposure variations can significantly influence noise
conclusions is a good thing. The OP was not blamed.

Iliah Borg said "You can't really compare even noise from the shots you used - those shots are underexposed to different degrees. Pretty much each camera model has its ISO calibrated differently. The raw levels at middle gray sometimes differ as much as 2+ times, that is more than 1 stop. If you take this into account you should compare, say, D3X at ISO 400 to 5D MkII at slightly more than ISO 200."

He also said that the OP was mislead by IR (unknowningly) and that the OPs comparison was incomplete and inconclusive. Actually, it's complete and conclusive, based on the parameters the OP stated.

I haven't checked again, but there's a good chance that IR used the camera's ISO settings and matched them from camera to camera regarding their exposure settings. If they did so, and the exposures are noticably different, then it's the camera maker's fault.

I didn't say the OPs comparison is perfect, but some people here are condemning it simply because it doesn't show what they want it to.

As far as converters goes, the main point some have made, is that
certain converters may be more appropriate for certain cameras.

That's obvious.

Some
people have argued that in doing these kind of comparsions, it might
be better to use the "best" converter for each camera, to show the
best that can be achieved by a user. I have no idea if differences
would be significant or not, but that idea is worth exploring.

Anyone here is free to explore it and post the results here for all to see. Expecting the OP to do that, or to conform to any variable anyone might suggest is ridiculous. The guy already did a lot of work. If someone isn't happy with the results, let them do a different comparison. I'm not saying that no one has the right to criticize the comparison, but expecting the OP to redo it is way too much.

Anyone here should know that there can be variables in any test like this. Even if the results were different in another comparison, they aren't likely to be way different. All the cameras are capable of nice images. The strengths or weaknesses of each camera depends on a lot of factors. Nitpicking this comparison, just to try to prove that one camera is better than all the others is an exercise in fanboyism.

Regards

-- hide signature --

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