HDR Merge to Eliminate High ISO Noise

I've been using Affinity Photo 2 to do focus stacks with my macro lens, but I just realized it can do other kinds of stacking as well.

I've been playing around with taking high speed image sequences and using the "HDR Merge" feature as a means of high ISO noise reduction, and the results are pretty impressive.

I'm not using a tripod; these are all hand held, and the software does a great job of auto aligning everything for the stack.

The stack of photos after an HDR merge will look pretty contrasty and saturated and garish, but if you turn "Tone Mapping" all the way down, it will return to normal.

Note: merging 2 images is not a one stop improvement in ISO performance, it takes 4 images to get a one stop ISO improvement, 8 photos for 2 stops, 16 photos for 3 stops, etc. It makes a huge improvement in bright areas, but shadow areas are still pretty noisy, so I like to run a curves adjustment on the image to darken those shadows and hide the noise.

The images can end up looking soft after a merge. I think much of the fine detail is lost in the high ISO noise, and doing a photo stack cleans the noise but doesn't restore the detail. I ran the image though Topaz AI to sharpen it up a bit.

http://kyleclements.com ... https://www.youtube.com/watch?v=PxGmc7exL4s