PixInsight- Dark Border on Two Sides (Whats going on?)

[CRWPhoto]

Hi all.  I've been digging into manual integration and realized that I have a strange border that is on two sides of my frame.  When I open a file (Light, Flat, Bias, Dark, ) it displays this very strange artifact.  See attached:

These are Canon CR2, from Canon 750D.  I'm using PI v 1.8.

Any ideas what is going on here?

[Juan Conejero]

What's going on? Easy: Open RAW Format Preferences and disable the No image crop option. This option is always disabled by default, so you have enabled it manually at some point. See this release information post for more information.

[CRWPhoto]

Hmmm.  I don't see that setting.   

Also, with Dark Frames it is not quite the same as a full black border.  It's darker, but not black.

See attached for RAW settings and a Dark Frame.

The explanation you linked to makes sense to me.  I assume that image integration / calibration processes and scripts like BPP ignore this "unused" region.   So if I do noting, I don't really have to worry about it.... it will just look funny when I view the files.??

[CRWPhoto]

Juan,

I couldnt find the setting you recommended, so I checked to see if my version of PI was up to date.  It was not.  After performing an update, all is well. 

It looks like the new version handles the rendition of RAW files better for my camera as well.  Perhaps DCRAW update, or something else....  (Canon 750D)

Files used to be strange and red.

Thanks for your help!

[vicent_peris]

Hi,

By using the "No image crop" option you're reading the overscan areas of the sensor. If you find that the bias level changes in your camera (maybe being time or temperature dependent, or even random), the best way to calibrate your images is by reading that overscan areas and adjusting the bias level. You can find the overscan parameters both in ImageCalibration and BatchPreprocessing. Because the overscan is not just black but it has the current bias level of that image, it's displayed as grey (a bit darker than the rest of the image) in the dark frame.

Regarding the red images. Maybe something changed in the last version of DCRAW but, in any case, correcting that red is simply a matter of adjusting the white point.


Best regards,
Vicent.

[CRWPhoto]

Thanks for the additional information Vincent.  My images did not seem to suffer from the "red", but I just found it odd that Bias and Dark frames were not actually black before viewing with an STF.  They were clearly red prior to any stretch.  None of my other cameras' RAW files presented like this, it was only the 750D.  They should have been black when first opened...

Either way, it seemed to not be a problem when calibrating and with the new version of PI, all looks the way it should.