I was using the Screen Transfer Function in PixInsight yesterday, applying it to the histogram and then saving the image as a 16bit TIFF file to process further in Adobe Photoshop.
For some reason, when doing the same thing today, when I save the image from PixInsight I get a massively underexposed TIFF file, as if the STF didn't apply to the image properly.
The only thing I can't work out is why this is happening as I'm doing nothing different to what I did yesterday.
The first attached screenshot shows what the image looks like in PixInsight after I've applied the STF to the histogram. The second screenshot shows what the image looks like once I've saved it as a 16bit TIF.
Screen transfer function does what it says. It only applies the stretch to what you see in screen, not the original image.
You'll have to apply the histogram transformation to the image. Either adjust the stretch directly in that function, or you can drag the instance from STF on the histogram function then apply it.
Exactly what ChrisV said.
Use histogram transformation.
I generally stretch over 3-4 iterations for better fine tuning. Use the preview function before applying to your main image.
