Having installed Windows (developer edition Virtual Box image) in a VM, so as to see the viability of shooting my Nikon Z9 in high-efficiency raw mode (darktable cannot decode these files, and probably never will, as IntoPix do not make a development kit for linux, nor specify how to decode these files), and coming to a satisfactory conclusion, I thought I’d next try downloading Topaz photo AI, to assess what it could do in demo mode.
I found some difficulties in making the comparison - I resorted taking a screen snapshot of the topaz screen, importing that into darktable, and taking a snapshot of it. But I couldn’t work out how to get the snapshot and the darktable-processed photo at the same size in the snapshot comparison.
Still I was able to make some tentative conclusions:
Topaz Photo AI is exteremly slow - too slow for me to consider using it on a routine basis
Topaz Photo AI does an amazing job on really high ISO photos, but
At the ISO level (800) I prefer for the shots I really care about (flying dragonflies), it doesn’t do much better than I am able to do with denoise profile (and likewise it’s sharpening is not signifcantly better than I get with Diffuse and Sharpen, lens deblur.
So I am disinclined to go out and purchase it, at least at present. But I will re-asses later in the year. I usually have to resort to flash for shooting at ISO 800 (1/4000 second, f/8 are my normal settings) except in very favourable conditions. I would prefer not to use flash as I could then shoot at 20fps rather than 10fps. So I shall try taking some shots at ISO 6400 without flash, and re-assess.
Darktable has numerous denoise options. I find that the denoise (profiled) works well for most images, however, when it is a very noisy image sometimes changing strength to 1.5 helps. There is also the raw denoise module, but beware that it can often soften details. Astrophoto denoise for some very noisy images can really help. Contrast equalizer facilitates creative noise reduction based on wavelets. Diffuse and sharpen module is another option. I would be surprised if there are not more options I have overlooked. With your great dragonfly pictures you could limit some denoising modules to just the blurry background using masks and this would protect the detail of the dragonfly.
When I have a difficult case, I usually mask the dragonfly, apply sharpening and a low-strength profiled denoise on it. Then invert the mask and apply a very strong surface blur.
But mostly I don’t feel the need to do that these days.
No need to be. The denoise (profiled) does a great job straight out of the box. However, there are some really advanced and innovative options if you have a difficult image. I just experiment with them and see which one does the best job for the specific image. Also there is the hot pixels module, which may technically not be denoising but often is needed with long exposures.
As a new owner of an OM-1 I looked into a few denoise packages/applications and found some enlightening results.
Aeons ago (at least 3 years!) I tried Topaz Denoise and found that it was okay, and like you, Colin, a bit slow. It also did a very poor job on some of my photos. Certainly no better than DT (3.-something? Maybe 2.-something?) did. And today, I agree with the view that DT’s denoise tools are very good indeed.
More recently I looked at DxO Photolab and ON1 for my OM-1 photos - specifically a pelican in flight that was noisy because I bumped the ISO up.
I was unable to easily get satisfactory results with DT: I had converted my *.ORF files into *.DNG files with DigiKam. (This might be of interest to you, with you Z9 files.)
Long story short, I tried quite a few images in ON1 and DxO, and concluded that DxO did a cracking job, but ON1 seemed a touch better in resolving detail in the examples I used. In the end, I purchased ON1 and have been happy with it so far, although I prefer the DxO UI a little more. I am certain that in most instances I could not look at an image processed in either and say with certainty which application was used.
Around YT, there are multiple reviews of both of these and I think that Robin Whalley compared noise reduction in ON1 v DxO and preferred the latter.
My preference is to work in DT whenever I can - I’m familiar with it, and with particular thanks to Boris Hadjukovic for his wonderful series on YT - although it lacks the panorama and photostacking facilities of ON1 (and Affinity Photo, which I also have, nad I think its denoise tools are inferior to DT).
Of course, ON1 now has its own NoNoise AI application which is supposed to operate stand alone or as a plug-in to some of the commercial editors. I’m really getting into overload with all these different add-on applications, and I don’t even own any of them. I understand these are all companies jockeying for market share, but its nearly impossible to wade through the choices to try to determine which is the best, let alone if the additional cost is worth what I already have with darktable.
I tend to agree with you, re everyone having an AI denoise nowadays. Personally, I have to wonder is everyone is using the same algorithms, or if they’re all unique.
As far as assessing their efficacy, I just downloaded their free trials and decided by testing this part of the software. Based on my experience, I found the outlay worthwhile.
A dragonfly is a winged insect of the order odonata.
I set the mask in the denoise profiled module, so I can reuse it in higher modules
I apply sharpening with the Diffuse and Sharpen module
I do something similar with birds when I have a more difficult photo. I was curious if you’ve used the details threshold slider to emphasize or avoid areas for denoise or sharpening
Hi Colin, I am now exploring the use of the diffuse and sharpen modules presets for lens deblur as an alternative to sharpening. I feel it achieves a similar effect without the artefacts that can come from sharpening.