Dont let PI's STF function fool you with flats!

[UlteriorModem]

I shot a new set of flats and flat darks last night. Things went just fine.

Went to put together the master flat tonight. After calibrating then integrated the calibrated flats. Hit the resulting image with the STF and looked really closely. Yea some gradients showed but wheres all the crud, dust bunnies?

Stretch 1 by Tom Whit, on Flickr

Save the gradients that thing is smooth as glass!

Surely I am doing something wrong. So I tried again and again with different calibration and integration settings. Each time the same 'smooth' results!








I then started to play with the STF settings and found if I moved things around a good deal it revealed the truth!

Stretch 2 by Tom Whit, on Flickr


So even the first results looked like it was not good, it was indeed a good flat!

That is all

[STEVE333]

Nice catch Tom. Thanks for sharing your discovery.

Flats can really be a pain!

Steve

[Graeme1858]

Glad you got to the bottom of it Tom.

Regards

Graeme

[ram]

The PI's STF function is weak I find and just a starting point - did you try the boosted version?