In spite of the above limitations, I still use V2.4.2 for slide processing but haven't updated in spite of frequent nag screens as the price isn't attractive enough for a minor upgrade. If it decides film grain = noise it will totally remove it, if not it may leave 'mottled' areas, so it takes a bit of tuning to see what works. So I tend to use Topaz on a duplicate layer and then blend at 50% with the original. I find that it can remove all noise (which then looks unnatural) and it tends to over-sharpen edges (even on the lowest sharpening setting).

I also use Topaz on a separate layer so I can reduce the effect if needed. I therefore use the Topaz plugin within PS after conversion from RAW in ACR. In my experience Topaz Denoise AI doesn't work well on RAWs. grain in B&W negative scans or is that a no no?

Also do either satisfactorily help in reducing p.m. I’m also interested in which application is the biggest resource hog, as I believe both use AI, as well as making the best job of minimising digital noise. When I get a spare moment I’ll search for reviews.

Dxo deep prime review