HDRComposition problem

[headdown]

Hi from Canada,

I have been using HDR Composition with good results for over a year now, usually using 3 integrated images to make up the final HDR image.  Recently I have begun having a problem when I try to do my usual procedure.  See attached image of an integrated 5s, 30s, and 300s image.  I don't know why I get this result recently, since I don't think my settings or procedures have changed.  If I only use 2 integrated images, the problem is gone.  Any help appreciated.

Dean

[pfile]

see if a 24-bit STF LUT helps things... it might just be a display issue.

rob

[headdown]

Hi Rob,

Can you elaborate on that advice please?  I am still fairly new to Pixinsight, and I don't know how to change those parameters, or what LUT stands for.  Thanks!

Dean

[Geoff]

Right click in the picture. From the context menu that occurs, select
Screen Tansfer Functios > Use 24-bit STF LUTs

[pfile]

thanks Geoff.

LUT stands for LookUp Table and the idea is that the since the display is 8-bits per channel per pixel, you need a lookup table to translate any file that has greater bit depth than 8 bits per channel to screen colors. for 64-bit files (which can be generated by some PI processes) the standard lookup table may map too many colors to the same display color and the result is posterization. the 24-bit LUT solves this problem.

juan has a writeup here: https://pixinsight.com/tutorials/24-bit-stf/

hopefully after all this gum-flappin' this is your problem, if not i apologize!

rob

[headdown]

Hello Rob and Geoff,

I apologize for the late reply.  I have been out of internet range lately.  I am very pleased to say that your solution was the right one, and the display problem is solved.  Thanks very much for your help!

Dean