> Read this, then tell us. :-)
> <http://www.dpreview.com/articles/8189925268/what-s-that-noise-shedding-some-light-on-the-sources-of-noise>
>
> Oh So Quiet Moose
First of all, that is one horribly written article. (both of them,
including part 2). Secondly, the author continues to buy into the old
saw about sensor size.
I'm not going to go screaming like I have in the past, but this author
is under the same misguided thinking that says that a sheet of Tri-X
in 4x5 is going to be less grainy than Tri-X in 35mm roll film. The
SIZE DOES NOT MATTER!!!! ENLARGEMENT RATIO IS WHAT MATTERS!!!!
Sorry, I screamed.
Secondly, the flow-through diagrams are hokey, at best. It took me a
while to interpret that amplification stage and while it is
effectively correct, it is unlike anything I've ever seen before.
Honestly, there is absolutely nothing new here, it's just Ansel Adams'
Zone System for the digital age. But unlike Ansel Adams, this guy has
no clue what he's mumbling on about. He stumbled into the right answer
but through incorrect steps getting there.
To paraphrase the article, there are just a couple points worth knowing:
1. To keep noise down in ANY type of amplified "system", always have
your source as loud or bright as possible without clipping. This means
that you expose up to the maximum point where you won't clip the
important highlights. The goal here is to always keep system gain to a
minimum. An old adage I learned 35 years ago in sound system
engineering is to maximize your outputs, minimize your inputs.
2. Boosting the ISO settings in almost all cameras results in reduced
dynamic range. Keep the boost as low as possible and combined with
maximum exposure will give you the most dynamic range. The author
spent 500 words trying to say this but never quite got there.
A third point, which I would suggest is that noise and dynamic range
are not synonymous. You can have noise in your images that don't
affect the maximum dynamic range of the subject. It will affect how
the roll-off occurs in the shadows, but doesn't clip the shadows.
Boosting your ISO settings will clip part of the maximum range of the
image. A lower ISO will keep the maximum range of the image, but will
induce a greater amount of noise across the image. If you have the
means of cleaning the noise out of the image, you'll end up with a
greater dynamic range in the final image than if you achieved a
cleaner in-camera image.
--
Ken Norton
ken@xxxxxxxxxxx
http://www.zone-10.com
--
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/
|