High ISO noise reduction

[fjrabon]

Well, that's partly the same issue, or at least the same cause, because high ISO + f/16 will drastically cut contrast.

Why would that be? Provided that the shutter speed is compensated, the same amount of light would accumulate at sensor elements, and thus the same signal to the amplifier. I don't quite see how aperture would affect image quality any more at higher ISO than lower, assuming that the exposure is equivalent.

---

I agree with others though. Noise isn't that terrible of a thing provided that it's managed well. If you happen to be using a Mac, Raw Photo Processor renders noise very nicely.

For b/w, you can try inverting a duplicate of the background, set to "overlay" or "soft light" mode and apply an highpass filter with a radius such that the edges are minimal, leaving only the noise profile slightly visible. This will not eliminate noise, but it will give it a more gentle, film-like quality.

I've never gotten this to work in Color, and generally makes a giant mess out of things.

high ISO has always lowered contrast, some cameras are better or worse at dealing with high ISO contrast and color issues, some are worse. It has to do with the way the computer amplifies the signal I believe. It's the same reason high ISO tends to desaturate things a bit. Then add in diffraction from the very stopped down aperture, which lowers sharpness and contrast.

It's not that higher ISO impacts image quality more at stopped down apertures, it's that two things are both working in the same direction of degraded IQ, diffraction + high ISO

 

[Wichipic]

I always use auto-iso for candid shots, I would rather have a bit of image noise than a blurred photo, if you can control the subject then use manual iso and keep it as low as possible, A shutter speed of 1/125 stop most motion blur caused by people moving, animals or sports will need to be a bit higher.

John.

I use Noiseware Professional in CC, try the trial it`s worth it in my opinion, I auto adjusts the noise reduction level, also you can use presets, I used portrait for your photo as it does not smooth out the detail so much.

Noiseware - the Better way to remove Noise

John.

Wow, thanks very much, John!

 

[unpopular]

high ISO has always lowered contrast, some cameras are better or worse at dealing with high ISO contrast and color issues, some are worse. It has to do with the way the computer amplifies the signal I believe. It's the same reason high ISO tends to desaturate things a bit. Then add in diffraction from the very stopped down aperture, which lowers sharpness and contrast.

It's not that higher ISO impacts image quality more at stopped down apertures, it's that two things are both working in the same direction of degraded IQ, diffraction + high ISO

I see what you're saying now. The way you put it made it sound like you were saying that small aperture somehow affects low IQ in high ISO images - rather than it being a compounding effect.