Applying STF to HT

[astropixel]

Hi. I am attempting to apply STF parameters to HT and get the following results (never tried this before). These are my concerns.

I've played around with various settings but always come back to the process below. Am I on the right track? Should I expect the result shown in the top image and post process to improve the histogram distribution, as in the second image. Is there a better method?

Three images below - post BatchPreprocessing, ABE and ColourCalibration. 

1. STF applied to HT - The STF parameters suppress the histogram and clip the black point severely.

2. STF applied to HT+HMT+SCNR (green average)- seems to partly recover the histogram (if I can think of it like that)

3. Normal HT stretch - contrast is low.

BTW - I love the way BatchPreprocessing crops stacking artifacts for you - wonderful - think of everything.

[mschuster]

I think in 2) your noise reduction is brightening the darkest pixels, so hence there is less shadow clipping than in 1).

Ctrl-click the STF dialog's "A" auto button. This will bring up a dialog letting you set "default" STF parameters. This is one way to quickly adjust shadow clipping point and target background value.

I would also like to learn better methods to address this shadow clipping.

Thanks,
Mike

[astropixel]

Thanks Mike. Second time round the results improved without any changes from me. I can't explain that - finger trouble . I followed your suggestion as well and see how that works...

...the results are significantly better with less effort during post processing. I seem to have been doing it the hard way, afraid to alter settings too much.

The final image lit up with saturation - finished with curves and local histogram equalisation and noise reduction using ATWT.