I shoot a lot of wildlife which forces me into higher ISOs. Darktable’s own denoising works very well up a point, but I need more help with my camera above ISO 2000.
Is it better to apply Topaz on the raw file and export to TIFF or DNG, or to denoise the exported JPEG?
And if I should denoise at the start, is there any performance penalty in terms of exposure, white balance, etc by working with TIFF as opposed to the original raw format?
Thanks!
So, I did try out several images with Topaz Denoise and I have to admit, I’m not that impressed. More often I disliked the kinda artificial look on the subject. Might be against the stream, but yeah 
Wildlife often means selective editing with masks, in my workflow at least. And if I have a mask anyway, it’s often easy to sharpen the subject and smooth out the environment.
Maybe submit a play raw and evaluate the results?
Topaz also isn’t very automatable via command line, as far as my research did show (it’s just not flexible enough to just let it run over, say, 100 import images).
To integrate Topaz into your workflow, you would probably need to edit each picture with Topaz one by one and export Tiffs. Sounds time and space consuming to me.
But I’m happy to hear success stories, if you manage to reach your goal.
I don’t have topaz but I do have ON1 and it has its AI denoise elements as well… its not that impressive (to me anyway) and more often than not creates artifacts that only go away if you drop most of the detail enhancing and then you are left with a luma and color noise slider that also you often need to tweak… so for the most part its not great…same with the tack sharp bit… usually full of artifacts
Yeah, that describes exactly my experience with topaz.
IIRC, we resolved any incompatibilities w/ Topaz DNGs from dt 4.4, so you should be ok using that workflow as well.
I can make no valid comment about Topaz. However, in DT I use denoised profile module and it is generally is sufficient. With a really noisy image I set the strength to 1.5 instead of 1. I also use the diffuse or sharpen module to apply initial sharpening using the demosaicing preset. Extra noise reduction can also be done in the diffuse or sharpen module. I may then use the details threshold slider found in the drawn masks option for these modules. A positive value for the details threshold slider can limit sharpening to the edge details which avoids sharpening noise in the smoother areas. A negative value for the details threshold slider denoises the smoother areas without softening the edge details. This user controlled denoising and sharpening produces very good results that may rival or exceed AI (I just don’t know).
BTW, I am surprised that 2000 ISO for wildlife images is presenting any problems. I am using a Canon R7 and am editing images today of wildlife with 4000 ISO and am not needing to take any special precautions as the default denoise (profile) is handling it just fine. But I guess it depends on the age of your camera.
Dxo DeepPRIME seems to be a good choice for AI denoising, and from the demos I’ve seen, it’s probably the best out of all of them.
Thanks all, I knew that I could be walking into a bit of a lion’s den with the question and I appreciate the helpful comments.
For background, I’m shooting with a Canon R7 and with the crop sensor and higher ISOs I find that I have a bit too much noise for my liking after some modest cropping. I do think that DT has awesome noise reduction, but I feel like the profiled denoise leaves a bit of “salt and pepper” even if I take the precaution of masking the subject for noise and sharpening.
Yes, I do agree with the comments and I have a love/hate relation with some of these denoise programs. I find that Topaz can leave an over-smoothed and plastic look that’s pretty obvious to me when other people go overboard with it.
I prefer the denoise that ON1 provides a bit more. It has controls for color, luminescence, detail, and micro-sharpening that gives me a much more reasonable result than Topaz. But yes, @priort , that tack-sharp slider for motion blur is next to useless and I usually have it dialed way back.
Since folks seem interested, I’ll set up a play raw with a moderately noisey photo along with DNG outputs from Topaz and ON1, so see what we come up with.
BTW, could someone answer one of my main questions, if in editing a TIFF is there any performance penalty in terms of exposure, white balance, etc by working with TIFF as opposed to the original raw format?
Many thanks.
As for the TIFF I suppose if you save them as 16 bit maybe a little …
As for the denoise I find that 2 of the defaults in denoise profiled can make a difference…
The preserve shadows if lowered helps a lot and also for your salt and pepper be careful with D&S module it can quickly add lots of that and moving to rgb vs the newer (Y0U0V0 or whatever it is)
and dropping the strength can help with that salt and pepper… But its a dance back and forth to just dial it right so that the noise is just handled and not any more so that you lose detail…
Yes, that would be interesting. The RT users could also join. Would be nice to compare different software with respect to denoising.
I just added the Play Raw!
Since we are both shooting with Canon R7 I can confidently say that AI denoising is not needed at the ISO settings you mention. Maybe share one of your noisy images as a playraw and see what people can do with it.
Why are you asking him to do what he already did?
My bad. You had already posted the picture. I am travelling with my R7 in Sri Lanka at the moment and can’t download and edit your posted image. I am interested in looking at your noise issue when I get back home.
Enjoy your travels :). Look forward to seeing some of your journey
You have posted a 7D image if I am not mistaken in the play raw category. That is a 2014 camera. Do you have a R7 image that you feel is too noisy. I am shooting high ISO images on my R7 and not batting an eyelid at 4000 ISO. The camera is still new to me so I am not really sure of its capabilities with noise.
@Terry - I’ll see if I can dig up a good example, or I can take one 
Bear in mind that the point where noise is intolerable is often an individual perception. Also, sometimes the correction might be worse than the problem.
I’ll follow up. Thanks!
It turns out he put a Canon 7D image not a R7 image in play raw so I would still like to see an R7 image that he is having problems with. I have been shooting at 4000 ISO and the default settings for denoise profiled seem fine from my R7, but I am only looking on laptop while travelling. My 43 inch screen may reveal a different story when I get home.
I really didn’t have a problem with the comment,
I just figured you hadn’t caught up with the thread when you made the request
The 7DII photo was a good example of the process I’m trying to address, and I suspect you want to compare what you and I are seeing because we both use the same camera body.
I’m away from my computer, but I’ll be glad to share a photo when I can. It’s sort of a busy day today for a lot of us. 
Turns out there is hardly any difference between the two cameras at higher ISOs: Photographic Dynamic Range versus ISO Setting