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Thanks for the inputs on this. I finally found out that it’s the non-letter characters in the file name created by ASTAP
E.G it sprays in commas and brackets etc.
Took these out and it worked.
I susected the files size too at first but it’s 200Mb limit.
I don’t know why it’s necessary for ASTAP to resize the files. The originals prior to stacking and calib were all 32Mb
Thanks
KevinThanks for the tips and leads on this problem. The files are indeed converted to (BITPIX=-32) by ASTAP and doubled
in size being 65Meg.
AAVSO people have advised me to check that FITS header details for my system correspond to registration info on VPhot
which it didn’t. I corrected this expecting success but sadly no.
I just want to upload my obs. Very frustrating.
If anyone can spare the time I’ll upload the FITS header.
The uncalibrated files from ASIair load fine
The stacked and calibrated file from ASTAP will not
KevinThanks Paul,
Does the actual file name suffix make any difference.
The raw files are .FIT and upload fine
The ASTAB calibrated files end in .FITS and will not load.
It’s a real shame because I have spent many hours and struggled to get any where calibrating with AIP4WIN, ASTROImJ and DeepSkyStacker.
ASTAP is very user friendly and seemed to work very smoothly until I hit this problem.
KevinThanks Tim,
I couldn’t find them on EBay but camera shops stock them.
Bought a kit and it worked very well.
KevinThanks Robin,
The 5e per ADU figure, is that something that can be adjusted?It looks from the graph that this is the definition of or correspondence with zero gain, which is what I have used so far.
To clarify, each pixel has to receive 5 electrons before it outputs/registers 1 ADU
Is that what the charts are saying?
Regards
KevinThanks Grant,
Yes I see the CALSTAT entry
I didn’t see much vignetting on the raw although flats show it all too clearly.
Have a look at the images I uploaded comparing raw and calibratedThanks Ian,
I don’t know what stretching is.
I have attached two images. The left is one of the original raw images 30s exp. Right is the calibrated output file of the stacked (only two lights) after application of darks, flats and flat darks in ASTAP.
The calibrated file looks rather washed out compared to the nice dark sky original which was a surprise.
KevinAttachments:
Your right Ian,
Thanks for your patience.I had been playing with various files and I felt sure that I had read one that stated that it did not conform.
Obviously not that one. That’s great. Have moved forward another small step.I think my worry was that maybe I had done something wrong.
I was expecting to have an output of master flats, master darks and master flat darks and then having to do something with them.
Subtraction I assumed.So the image it outputs, is that a calibrated image? Is it possible to tell?
What does the software do to the original uncalibrated lights?I have no feel for what’s going on under the bonnet.
ThanksKevin
Update
I threw caution to the wind and ignored the Defender warning for Astap.After I have had literally a play with the following with a view to just being able to just calibrate.
AstroimageJ
TychoTracker
DeepSkyStacker
AIP4Windows
AstapASTAP seems at first to be the most user friendly for someone of my limited experience of image processing and has
a dedicated routine for flat darks which seems to be missing from the others.
I loaded some lights, flats, darks and flat darks and ran the program which seemed to work(Furthest I have got so far).
It output a pretty nice “looking” (but huge image 62Meg)
I would have liked to upload it for inspection but it’s way to big, so I have attached the text file that appeared in the window.
I assume this is the FITS header. Only concern is the opening line which states:SIMPLE = T / file does conform to FITS standard
Which I know is a bit of a deal breaker as they have to conform. So that’s where I am. Any thoughts please?I’m sure that the others may prove much more powerful and useful when I am a bit more advanced.
The problem for me is that the more advanced and versatile the software the more parameters there are to play with.
Thanks to everyone for useful input for future plans. I will almost certainly ask some more questions.
KevinA few first impression comments about the suggestions. Working my way through them.
ASTAP intiates a Windows Defender warning.
Calibration Intro Tutorial for Tycho Tracker seems to suggest it’s for moving targets.
I have installed AstroImageJ, found the DP button but there is no option to process flat darks.
So I have found various tutorials but I’m getting the impression they are for CCDs which do use bias frames I believe.Trying not to be too negative but I think I need something with very basic tutorials that walks you through it.
Kevin
Thanks to everyone who has taken the time to advise on this post.
The main criteria for me is simplicity as I really only need calibration initially.
I have never done coding or written scripts.
I think I can do everything else I want with AAVSO packages.
Quite happy to spend some money on this but probably not as much as Maxim DL.
Clear Skies
KevinThanks Ian,
I think I have that.
Just to clarify
My flats taken with a light pad and T-shirt required exposures of 2.3 sec to get the histogram max
between 1/3 and 1/2 of max ADU count.
That means I need to take a set of darks at the same exposure (all other things as you say replicated, temp gain etc.)
Thanks
Kevin
PS I thought I posted this already but can’t find it.Thanks Ian,
Very useful starting point for me.
Some imagers have advised to cool to only zero, but I believe that there is some advantage in going cooler with CMOS cameras, but I’m not sure about this.
Regards
KevinThanks Paul,
How do you calibrate defocussed images? Presumably you have to take all the flat frames at that the same defocus?
