There are multiple ways to approach this.
First off, try to shoot in better light.
If the light is poor (like dark overcast winter days), even the biggest sensor with the best lens will struggle to produce good shots.
Second, check how you use the AI Denoise.
I find that using it at full 100 setting leads to overly aggressive NR and a plasticky look to images. Dial it down to less values.
Also, I'm finding that for many images the classic NR works quite well if the ISO < 3200.
Third, check other NR tools.
For example DXOs Pure Raw 3 integrates with Lightroom as a plug-in these days and can output some decent results, in some cases better than Adobe's AI Denoise.
Fourth, look at a better, faster lens.
After all, the AI Denoise is just a piece of software so the better the input, the better the output, right?
And, while not a bad lens, the Olympus 100-400 is not the greatest lens ever, and at f6.3 is would be considered a slow lens for FF cameras...
As others have said above, the Olympus/OMDS 300mm f4 is the prime choice. Not only it will be much sharper than your 100-400 but it's 1.3 stops faster, so you'll go from ISO 3200 to ISO1250 for the same shutter speed.
Btw, here's how an OM1 with the 300mm f4 @ f4, ISO3200, 1/750s looks like, before and after Adobe AI Denoise at 50%:
View attachment 75950
Also, same shot denoised with DXO PureRAW 3 (left) vs Adobe AI Denoise (right)
View attachment 75951
Finally, there is the option to moving to a larger sensor.
Be it APS-C from Fuji, Sony or Canon or FF from Nikon, Sony or Canon.
The issue here is that depending on what camera and
Thanks so much for this feedback and photo examples! Do you find the 300mm gets you close enough? The way I shoot now, I’m uncertain if it would be. That may be a goal.
I’m considering moving to a larger sensor if it doesn’t, as you suggest, fail to move the needle in a positive direction for me. I am in the process of looking up the specs:
I own OM-1, 20 MP. 100-400mm f5-6.3
I own Tamron 150-600 G2 (Would buying a Canon R7 be an upgrade or not be redundant to the OM-1 system?) My Nikon D500 eventually malfunctioned.
Z8 46 MP, 2lbs $3656
180-600mm f5.6-6.3 $1696
Total $5352
Canon R7 33 MP
100-500mm f4.5-7.1 $2,399.
200-800mm 4.5lbs $1,899 f6.3-9. Pre-order
3lbs
Total $3248