Why do I get noisy results when converting from raw to jpeg?

Question

I am using ACDSee Photo Studio Professional 2019 and shooting with a Canon 80D (storing raw+jpeg files from the camera). In the past I've shot mostly jpeg files and fine-tuned them in ACDSee with fairly good results. More recently I started experimenting with the raw files workflow and I have have a hard time getting good results when exporting my final files to jpeg.

I included a very simple example below where I started with this original raw. I think here the grain is normal since according to my understanding this is how raw files are captured:

Next I edited the exposure, light and added some noise reduction that brought me to something like this result, which still looks noisy to me but when adding more noise reduction it seems to decrease quality even more:

Finally I exported to jpeg and below I'm comparing the original jpeg from the camera on the left side (which is slightly too dark but not noisy at all) with the jpeg I generated from my tuned raw image on the right side.

As shown the original jpeg from the camera is smooth and not grainy at all while the final tuned jpeg has all sorts of glitches introduced to it.

At this point I'm not too sure what I'm doing wrong. I think the top answer from the following post gives a nice overview of the raw file processing workflow Why do RAW images look worse than JPEGs in editing programs?

Using that information I tried to play with sharpness and noise reduction in different ways but I cannot seem to get better results than what is shown above.

Thanks for your help.

Answer 1

The noise level is not actually all that much different, it is just that your exposure correction also corrected the exposure of the noise. With digital cameras, it is better to expose brighter than you want, then dial down in post-production than the other way round. The more light you work with, the lower the noise levels of the result will end up. In a similar vein, it appears like you increased contrast and/or local contrast. Again, this comes at the cost of amplifying noise. So does sharpening. Admitting more light (via longer exposure or wider aperture) can be accommodated by lowering your ISO setting to avoid blown highlights.

Answer 2

On your RAW image after noise reduction applied, there is still too much color (or chromatic) noise. You have basically 2 main kind of noise: luminance noise and color noise (also named chromatic noise). (more details about the 2 kind of noise here). I am not familiar with ACDSee but according to their website, you can indeed fine tune both noise reductions (like for the other software I am used to). you can find here how to do this fine tuning. So, I suggest you trim differently the sliders to add more chromatic noise reduction. Last but not least, it is based on Lightroom, but this article gives good examples of what it means to add too few or too much luminance or chromatic noise.

Answer 3

If you reduce the brightness of the raw image you processed yourself to match the jpeg image processed by the camera, the noise will probably be very similar. Another way of looking at it is that if you increase the brightness of the camera produced jpeg image to match the brightness of the raw file you processed, it will show just as much noise as the raw file.

Anytime you amplify a signal after it has already been converted from analog to digital, you also equally amplify the noise.

Answer 4

You need to apply noise reduction algorithms. Please note that not all RAW programs can replicate what the camera does: How to reproduce camera noise reduction using open source software?

Almost(?) all RAW programs have at least some form of noise reduction, but it may not exactly match the camera's noise reduction. YMMV.

I recommend trying at least RawTherapee, as suggested in the linked question/answer. I have found its noise reduction algorithms very capable.