Please tell me if my testing method to determine PureRaw settings is flawed

DxO PureRAW
1

I’m testing out Pure Raw with my Fuji X-T5. To test what settings I want in order to create some presets, I took a shot with the lens cap on at every ISO level (based on the ISO dial on the Fuji), 21 shots in total from 125 - 12,800. I loaded them all in PureRaw and went through one by one looking at them at 800% zoom to see the noise detail. At the higher ISOs what I assume is the sensor noise shows up against the black of the image as splotches of color (mostly reddish). From what I can see, ISOs 125 through about 1250 do not need denoising. I can leave the slider at 0 and the images. From 1600 - 12,800 they need at most 10 points of XD3. Heck, even 5 points and all the noise was gone.

Is the way I went about this incorrect? Was taking black frames at different ISO levels not the best way to determine how much sensor noise there is? Is it fine but just one method and I should do other tests?

I’m asking this because my workflow, especially when I travel, is to load images to an iCloud folder via my iPad Pro, then on the iPad remote access my desktop computer (Mac Mini) to batch run those images through Pure Raw based on their ISO. Then I can load the images in Lightroom on the iPad and work on them. I don’t have a laptop and have no plans to get one.

2

Correct or incorrect? Does not matter.

The method you chose to determine noise of your capture pipeline works for you and therefore suits your needs. What more can you possibly want?

One or more things you might consider: Light itself is noisy and the lower it gets, the more noise will show up in your photos, no matter what iso you set. As temperatures rise, noise will increase in your capture pipeline (sensor, amplifiers, A/D conversion etc.) and your measurements will not be applicable without adjustments. And temperature is not only determined by ambient conditions, but by heat produced while you shoot.

If you really want to see what your gear does, you’d need to repeat the tests with the camera being cold and being hot….in order to find whether there is a difference worth speaking of.

Note that cameras record temperatures in each file’s metadata.

And as always, there’s more: It’s the old “noise vs. details” game. DxO is fairly good at playing this game and you might simply trust PureRAW’s default settings.