I used a Canon 350D for a couple of years then changed to a Nikon D200 last July.  Snapped away quite happily and thought nothing more until my snaps got rejected by the microstocks (SS and IS).  Not quite sure why they wer rejected, by the rejection made me concentrate hard on getting the best results possible from my D200.

Many people elsewhere complain about noise from the D200.  Many people on these threads have commented on noise, using Neat Image etc in an effort to get through the inspectors.

One of the things I have discovered with my D200 is that correct exposure eliminates all the noise.  And I mean exactly correct, not approximate.

I spent many days experimenting.  And I started doing something I had never done before - using the histogram.  I discovered that 'correct' exposure could be obtained only when the white highlights were edging on the histogram upper limit (edging, not touching).  Automatic exposure never achieved that.  As a result, all of the fifty odd pictures I have taken in the last week have been manual exposure only.

Using manual exposure with the histogram as a guide prodices simply excellent results on my D200, using RAW.

Here is a picture of a prawn I took last weekend using exactly this technique.  All I have done is convert to 100% quality jpeg in ACR.  No other changes have been made in ACR.  Then, I have applied a very small amount of additional contrast and saturation simply to compensate for the softness of the filter in the camera.  Lastly, a miniscule amount of USM (and I mean miniscule).

No other processing.  No noise reduction needed.  There is simply no noise.

Here's the file:

http://www.pbase.com/hatman/image/74432460/original

Anyway, it works for me and my D200.  Perhaps others can try this approach with their cameras.

Well I should have known that you would already have been up to speed on this technique leaf, but at least I can have the satisfaction of knowing that I discovered it for myself.

Yes, I've noticed that blues are a problem, and noise can quickly become apparent when upping the blue level.  Presumably the answer is to have a histogram in camera that can show the blue channel?

I don't use Nikon but I'll add to conversation that you have the right technique down (and you can probably adjust that contrast and saturation in the camera) but it also depends on the sensor.

The noise will increase on my Canon 20d when the environment around the camera gets warm.  In the heat of the summer, when the camera has been sitting out (like on a car seat or on a tripod) there will be more noise recorded.

This is also true if you are shooting multiple images.  The sensor tends to heat up and it adds noise.

I haven't noticed it as much on my 30d but then I haven't gone through a hot summer with the 30d yet.

My understanding is that it isn't as much of an issue on full frame sensors.

Here's a technique I use eliminate those ever-present dust spots. I make two passes at the image, first going up and down in columns, then inverting the image (i.e. making it a negative) and going back and forth in rows - this works particularly well on blue and gray areas such as skies.

Can you explain this part a little more?  I don't understand what you are doing in each "pass".  Are you using some tool from the toolbar?

I found another way to get rid of the dust spot problem: I bought an Olympus E-1 a couple of months ago. Fantastic camera, weather sealed body as well as lenses, and no dust whatsoever   

To get rid of dust spots i clean my sensor. 

LOL
great thread!

shoot it the best you can and only get rid of noise for shutterstock...and only after they reject it for noise!