StarAlign is changing image statistics

[cbradshaw]

Star Align is changing my image statistics during registration.  I've tried several times but my 60 second exposures look quantized.  Nebulosity registers the images fine and 300 second exposures are fine.  It appears an artifact of the counts not being very high.  I tried to manually select the output format, but with the same results.

All help welcome,

Thanks,
Charlie

[Juan Conejero]

Star Align is changing my image statistics during registration.

Indeed. This is a normal consequence of pixel interpolation. If you want your statistics preserved (but at other costs), use nearest neighbor.

I've tried several times but my 60 second exposures look quantized.

Try enabling 24-bit STF LUT tables (IMAGE > Screen Transfer Functions > Use 24-bit STF LUTs). See this forum post, where 24-bit STF LUTs are described.

Nebulosity registers the images fine

Fine!

[cbradshaw]

Thanks Juan!

My confusion was the 300 second exposure interpolation statistics were not changed, only the 60 second exposures.  I would have expected both to be changed if it was the interpolation algorithm.

Thanks for the 24 bit STF LUT information.  I will give it a try.

The fine for Nebulosity is that the registered images are not strongly quantized.

Regards,

Charlie