Aperture and noise

Does the aperture selected affect noise that is generated when using a high ISO (specifically the D600)? When I shot the theater photos Friday night, I used ISO 1250. Since they had an extra spotlight that isn't normally used, I was able to shoot at @f/6.3 to f/7.1 instead of f/4.5 or wider. Would the aperture have any adverse effect on the amount of noise generated?

There seems to be more noise at ISO 1250 than I've had with this camera at 1600, but since its sensor was replaced, I do question whether the noise is from the change in sensor or the change in aperture. This is the first time I've used a smaller aperture at a higher ISO so I don't have any direct comparisons to make. Thanks for any info!

I can't think of any way aperture could affect the quantity of noise directly. However, a smaller aperture will require a longer exposure and a longer exposure will result in more noise. So aperture does affect the level of noise indirectly but I think it would be more appropriate to blame exposure length rather than aperture.

My understanding of this from articles I have seen is that this is due to the way the signal is processed. Partial (or intermediate) iso values like 1250 require the A/D converter to apply digital multiplication to the signal. I am not sure how partial iso values are implemented on the D600 but it may be that the sensor is actually being exposed at 1600 and then the A/D converter is modifying the signal. Some people argue that you should avoid using intermediate iso values due to the extra signal processing applied.

Dave_W, since there was an extra spotlight, I chose to use the same ISO as I've used in the past. Even though I went with apertures between f/6.3-f/7.1 my shutter speeds were even slightly faster than what I used in the spring with this camera. I'm guessing it's the replaced sensor.... Just another reason why I'm glad Nikon will be issuing a refund.

Steve B said:

My understanding of this from articles I have seen is that this is due to the way the signal is processed. Partial (or intermediate) iso values like 1250 require the A/D converter to apply digital multiplication to the signal. I am not sure how partial iso values are implemented on the D600 but it may be that the sensor is actually being exposed at 1600 and then the A/D converter is modifying the signal. Some people argue that you should avoid using intermediate iso values due to the extra signal processing applied.

Click to expand...

Not sure where, but I seem to remember reading that using full steps in ISO (100, 200, 400, 800, 1600, 3200) gives cleaner results that the intermediate values...