Flat Frames Will Not Process - Need Help!

[jimwaters]

I am getting the following error running "BatchPreprocess" and need help figuring out whats wrong.  I have checked each Flat and there are images in each of the CR2 files.  The histogram is 1/3 to 1/2 on the camera scale.  I went back and deleted the PI directories, restarted PI and tried again.  Same problem.  I can run the script without the Flats and everything is OK.

I am using a Canon 5DMkIV.

EDIT - The 5DMkIV has SD and CF memory cards.  The only difference is that I used a SD card to take Lights, Darks and BIAS.

Whats going on?

----------------------------

===== ImageCalibration: 15 succeeded, 0 failed, 0 skipped =====
49.015 s

************************************************************
* End calibration of flat frames
************************************************************

************************************************************
* Begin integration of flat frames
************************************************************

ImageIntegration: Global context

Opening files:

E:/Milky Way Wide Field/calibrated/flat/FLat_M5A0871_c.xisf
Loading image: w=6880 h=4544 n=1 Gray Float32
5 image properties
Computing image statistics: —
*** Error: E:/Milky Way Wide Field/calibrated/flat/FLat_M5A0871_c.xisf: Zero or insignificant signal detected (empty image?)
<* failed *>

************************************************************
* End integration of flat frames
************************************************************

[jimwaters]

Log file attached.

[pfile]

1/3 to 1/2 on the back of the camera is likely to be too dim for good flats. i don't think this is necessarily your problem... but i always shot flats at +2EV just to get the signal up.

probably the darks don't match the flats. maybe try running BPP on just the flats and the bias frames to see if you get a good calibration of the flats. also make sure that you have checked "CFA images" in BPP.

rob

[jimwaters]

Thanks for the reply.  I will run BPP.  I follow the same procedure with my Ha mod 6D and haven't had a problem.

After I posted I checked the 'Calibrated Flats' images.  The images are empty even after using STF.  They are ~ 122,000 KBytes in size. 

I noticed that the 5D4 was set to 'Dual Pixel Raw' which I have never used before for astro stuff.  Could this cause a problem?

[pfile]

hm. maybe? i only have a 5d3 so i don't know what dual pixel raw is. is it some kind of binning?

i didn't really process what you had written in your first post. i think more than likely the 5d4 is too new for DCRAW to support it... what happens if you just open one of the CR2 files onto the desktop... does it look like it's been decoded right?

rob

[jimwaters]

Its only the Flats that I have problems with.  I can process images with PI with Lights, Darks and BIAS.  Here's the image I am trying to reprocess with Flats - just learning PI...  The above were taken with Dual Pixel Raw turned off.  I did a bunch of Flats with it turned on by accident.

https://www.flickr.com/photos/153877775@N06/35848819974/in/album-72157686030274734/

Dual Pixel Raw info.  As far as I know the 6D2 and 5D4 support this.

https://www.canon.co.uk/cameras/eos-5d-mark-iv/dual-pixel-raw/

[jimwaters]

I just did a hand-full of quick Flats by holding the 5D4 in front of a gray computer screen.  BatchPreprocessing ran to completion without an error.  It looks like you can't use 'Dual Pixel Raw' CR2 files in PI. 

I don't consider this a bug but the BatchPreprocessing Diagnostic Script should check for stuff like this.  I will follow up in the Bug Reports section tomorrow.  Thanks all...