Problems Extracting Real Data

[admin]

I found out from CloudyNights that stretching was automatically applied to my image by DSS (which is terrible programming practice).

I have an unstretched version here: http://www.astrobin.com/58959/

Is there anything useful there?

Now that looks a lot better! We'd need the TIFF/FITS output from DSS to do any processing on it though.
Did you get to the bottom of why your flat frames don't seem to work properly? (they left remnants / gradients / stripes) Or do you reckon this is solved now as well?

[ICallHimGamblor]

Here is a link to the TIF version: https://drive.google.com/#folders/0By0h ... XAxUXdTLTQ

I have no idea if my flats are still off. My original flats were wrong just because I had no idea what I was doing when I took them. I hope these are better, but if they still suck, let me know.

[admin]

Here is a link to the TIF version: https://drive.google.com/#folders/0By0h ... XAxUXdTLTQ

I have no idea if my flats are still off. My original flats were wrong just because I had no idea what I was doing when I took them. I hope these are better, but if they still suck, let me know.

I'm getting "Unable to access folder with ID: 0AKVkjv6mi4-4Uk9PVA. Check access permissions on the folder."

[ICallHimGamblor]

I think I did that wrong: please try https://docs.google.com/file/d/0By0hG91 ... sp=sharing

[admin]

I think I did that wrong: please try https://docs.google.com/file/d/0By0hG91 ... sp=sharing

Indeed, that took care of the stretching, but you stil have those horizontal stripes and bad blotches/gradients in there.
You need to get to the bottom of that - it looks like bias and/or flat frames are incorrectly applied or just completely mismatch your data.

StephansQuintetNoAdjustments.jpg (811.98 KiB) Viewed 7332 times

[ICallHimGamblor]

Thanks a bunch for giving it a shot. Hopefully it is something obvious with my flats or something where I can salvage my time and images.

Thanks again.

[admin]

There's one last thing I'd like to try though. Can you put a (TIFF/FITS) stack up for download of just the light frames (e.g. an uncalibrated stack)?
I'm hoping we can process that one and still get some signal from that, while we get to the bottom of the calibration issues...

[ICallHimGamblor]

Here is a link to a light-only stack: https://docs.google.com/file/d/0By0hG91 ... sp=sharing

Also, there was a theory on CloudyNights that my bias frames were messed up, so I retook them and re-stacked. I am not sure it helped, but here it is: https://docs.google.com/file/d/0By0hG91 ... sp=sharing

[gminder]

I have only a few months experience with AP but I have found that DSS is garbage. I use Nebulosity exclusively and I am very happy with it. I would really recommend that you download a trial and give it a go. The trial version of Nebulosity overlays a big black "X" on images, but it doesn't affect your ability to evaluate results.

I follow the workflow at http://www.morrell.ws/index.php?option= ... &Itemid=42

Using Nebulosity I have produced a library of master darks and a master flat. The master flat was produced using my master bias. I get consistently good pre-processing results. I'd be happy to help talk you through pre-processing your quartet data in Nebulosity.

Hopefully Star Tools will one day include pre-processing. Until then I'd be lost without Nebulosity.

Gary

[ICallHimGamblor]

I will definitely think about that. I have a trial of nebulosity at home and will go through the workflow to see if I get better results.

I am also starting to think about the settings/options in DSS... there are a million of them and maybe a few got toggled incorrectly at some point. I am going to reset to defaults and investigate online what the most effective settings are.