ATIK 4000 CCD - Problematic Shots - Help needed

[cpartsenidis]

Hi people!

I've just returned from a night where me and my friend were taking pictures using his new ATIK 4000 Monochrome CCD camera.

After downloading the pictures and taking a couple more to be sure, we noticed that all pictures had square shapes in them, for no apparent reason. We also spoke with some of our friends who have been using CCD's for years, but no one is able to explain the cause, so I thought it would be a good idea to post the issue here and hope someone can provide some feedback.

All pictures were taken through a Skywatcher 100ED and we used ATIK Artemis to control and take the shots.

The first picture is M82a. I've taken a screenshot from photoshop at 200% normal size. Notice the small blocks that a visible in the picture:

The second picture is the same file, opened using windows photo viewer. Notice the square blocks around the object:

Any feedback or help is much appreciated!

Many thanks!

[steppenwolf]

Are you sure this is a mono CCD camera? - this looks very much like a pattern effect caused by re-sizing a colour image from a one shot colour CCD camera that has not yet been de-Bayered.

[cpartsenidis]

Steve,

Thanks so much for your response - much appreciated.

This is definately a monochrome camera.

To help a bit more, I'm uploading two pictures in full resolution.

Please let me know if you spot any possible reasons for the patterns they exhibit.

Thank you!

http://www.firewall.cx/pictures/chris/M82a.jpg

http://www.firewall.cx/pictures/chris/M15a.jpg

[steppenwolf]

Can you please attach a FITS file?

[cpartsenidis]

Steve, I'll see what I can do to get one from my friend and attach it. In the mean time, do you have any idea what the problem might be?

Many thanks!

[GlassWalker]

I just tried de-bayering the big versions above. It looks like colour to me, although I'm not sure of the correct mapping. And I see lots of dust spots on the M82 one!

[cpartsenidis]

Guys, from what I know, its a monochrome camera, but I can't be 100% certain.

The FITS file is now available here:

http://www.firewall.cx/pictures/chris/M82.fit

Hope this helps - thanks for everyone's input and efforts.

Chris.

[steppenwolf]

I can't open the FITS file but, sorry, I am sure this is a colour CCD and we are looking at the Bayer Matrix

[cpartsenidis]

Steve,

You should be able to download the FITS file. I've just tried it and it works.

In addition, I've requested the product/model number to double-check it.

I'm going to also zip the FITS file and upload it again, just in case it got corrupted.

I'll post the new link in 5 minutes.

Thank you.

[cpartsenidis]

Thumbs up to Steve - I just confirmed the model number and its ATIK-4000C, which means its the colour version!

My friend took these shots using the luminance settings, so its not a camera problem after all.

Steve, thank you so much for your input and thanks to everyone else for taking the time to respond!

Much appreciated!

[steppenwolf]

By analysis of the raw text data in the FITS header, I can confirm that this is an Artemis ART4021 which means that it is from an ATIK 4000 but no fits data is available for the actual chip spec. I can't, however get a full import into even Artemis CCD software but the partial load I get confirms that this image has a Bayer Matrix.

[steppenwolf]

OOps, doubled with you, Chris but at least we now know for certain where the squares come from!

If you now convert the image to colour using your ATIK software, you should get a colour result.

[cpartsenidis]

Steve,

No problems, I highly appreciate you taking the time to walk me through. The camera is my friend's so now he knows its a colour CCD while he was under the impression it was a monochrome CCD.

I myself have just started working on Astrophotography and am now using my newly purchased EOS500D as a starting point.

If anyone could point me toward a site offering good tutorials on photographing with the DSLR, it would be great!

p.s I really like your site Steve!

[steppenwolf]

My pleasure, Chris - I love a happy ending!

[ollypenrice]

I have both OSC and mono 4000s. The 'luminance' (or alternative) settings are just for screen display. They don't affect data capture so your data is fine. However, read up on OSC processing. It is not the same as mono processing. I like AstroArt for my colour processing. Firstly I dark and flat calibrate my individual subs without debayering to release the colour. Then I stack and debayer these calibrated subs in a second pass in AA5. The hot pixel filter is, for some reason, far more important on the OSC than the mono, but the one in AA5 works fine.

Olly