Stacking FIT files - but something weird is happening

[Delboy_Hog]

Hi all,

Attempting to stack and process a bunch of files in DSS, but the file that's churned out only seems to have data in the top left quarter......

Taken with a modified canon 600d with an Ha filter, but captured by an ASI-air as FIT files, rather than the usual RAW files I'm used to using straight from the DSLR (I haven't yet figured out how to save the images as RAW files to the DSLR at the same time as the ASI-air saves the files as FIT on its micro-SD card).  The tiny JPG file that the ASI-air produces of each photo suggests there's data registering across the sensor, so I'm hopeful I've just missed a step in the stacking process..............?

It's M33 in Ha, and on a slightly hazy night, so whatever's there is pretty faint!

Anyone seen this before, or know of a potential fix?  I'd be very grateful for any advice!

I didn't know if DSS had issues stacking FIT files so I even attempted to convert them to TIFF files first...still no luck...although I might have done it wrong!

Image below straight out of DSS....

 

Edited November 6, 2020 by Delboy_Hog
Think my first post was a bit confusing!

[Delboy_Hog]

Picture above wasn't hugely clear, so here's another - If there are any DSS experts out there, I'd be extremely grateful for any advice on what I might have done wrong here.  

Stacking FIT files - you can see the DSS output below (I've tinkered with the histogram so you can see the image properly - although I'm not sure what the X-shaped histogram is about??) - I've never seen this before.  It's always placed the data across the full screen, rather than cramming it all into just one quarter of it?  Any thoughts?

Edited November 6, 2020 by Delboy_Hog

[happy-kat]

Are you using the latest version, if so I think you have to create new calibration files, if you used any that you had previously taken prior to 4.2.5. Look for the word reduced.

https://github.com/deepskystacker/DSS/releases

It may have nothing to do with this and be something with the ASI-air

Edited November 6, 2020 by happy-kat

[JemC]

On 06/11/2020 at 12:20, Delboy_Hog said:

Picture above wasn't hugely clear, so here's another - If there are any DSS experts out there, I'd be extremely grateful for any advice on what I might have done wrong here.  

Stacking FIT files - you can see the DSS output below (I've tinkered with the histogram so you can see the image properly - although I'm not sure what the X-shaped histogram is about??) - I've never seen this before.  It's always placed the data across the full screen, rather than cramming it all into just one quarter of it?  Any thoughts?

Did you get this figured out ?? as i am having the same problem ?

[Eddie Jones]

Also getting image in top left corner.

First guess - tried disabling 2x2 drizzle - got the same result!

I can crop the image it in photoshop - just feel it would be nicer not to need to !

 

[Delboy_Hog]

I didn't figure it out I'm afraid @JemC, I found the "save files simultaneously to DSLR" option on the ASIair, so have gone back to using RAW files from the camera's memory card, rather than the FIT files from the ASIair, though would still like to know what's going on here!

Because I have to break up and pack away my kit after every night, the approach I have now means I can stick the intervalomter in the camera and start taking darks while I strip down the rest of the kit, rather than having to keep the ASIair plugged and powered.  Though having learned the hard way that you can't stack a combination of FIT lights and RAW calibration frames in DSS, I decided to go back to all RAW stacking.

Like you @Eddie Jones, I wondered if you could just crop and process the quarter that had data in.  That might still be the answer, I'm not sure, but since it didn't seem right, I was worried that some of the data might be missing / have been compressed in some way etc etc.

[JemC]

54 minutes ago, Delboy_Hog said:

Though having learned the hard way that you can't stack a combination of FIT lights and RAW calibration frames in DSS

Yep, I've just learned that to, pity it can't do it really, 

Strange thing is it's stopped doing it now, the only thing i did different was to reset all the custom settings that were in the DSLR ? Strange

[Eddie Jones]

Day off work, so had a play with DSS settings today. To test I've been stacking a single sub with no callibration images.
What has solved it for me is in the 'Raw Fits DDT settings'
Mine was set to 'Create Super - Pixels .........' changed it to 'Bilinear Interpolation' and all seems fine

 

[Delboy_Hog]

On 01/04/2021 at 13:34, Eddie Jones said:

Day off work, so had a play with DSS settings today. To test I've been stacking a single sub with no callibration images.
What has solved it for me is in the 'Raw Fits DDT settings'
Mine was set to 'Create Super - Pixels .........' changed it to 'Bilinear Interpolation' and all seems fine
 

Thanks Eddie, I'll have to have a look at that!