Mosaics with a QHY8.

[Tandum]

I'm looking at trying to shoot and stitch a mosaic out of the qhy8 however after trying to combine different data sets I see that the overscan area from the sensor can cause all sorts of grief.

Has anyone else tried qhy8 mosaics? I figure the easy way is to set the downloaded image co-ords in maxim to exclude the overscan area. Does that sound like a plan?

[TheDecepticon]

Are you using the mosaic feature in MaxIm? I have never had too much trouble when using this, and the Blend feature seems to work well. You may also need to part process your images and equalize your backgrounds first. I have seen that cause problems.

[Tandum]

I haven't tried anything yet but after seeing what happens with the overscan area when I stack different data sets I'm wondering if a mosaic will be the same.

[jase]

The overscan area shouldn't cause you too much grief providing the panel overlap is sufficient. Mosaics are an activity you can't simply power up the scope and collect data. They take thoughtful planning in the way you are to execute the data acquisition. Start off with a high overlap between the panels. As you become more efficient and work within the bounds of your equipment (such as telescope pointing), you can reduce the overlap to increase the image real-estate (reduce overlaps). Nothing blending in with photoshop cant resolve.

[Astrod00d]

Hi,

I've tried a couple of mosaics using my QHY8.

Generally I'll stack subs using Deep Sky Stacker, then crop each frame to get rid of any alignment or overscan from the edges. After that, I mosaic the frames in Photoshop using bright stars as reference points. Then, stretch-fold-spindle-mutilate the image in PS to get pleasing visual results. :D
As I try to gather more frames over a longer period, I begin to run into gradient issues. Still trying to gather consistent data for a 6-frame mosaic of the Seagull Nebula complex.

Please follow this link to a mosaic I posted a while back, it's a 2-frame mosaic of the Rosette nebula.
http://www.iceinspace.com.au/forum/showthread.php?t=38367

Cheers,

Rob

[Tandum]

That looks pretty seamless Rob however I have sold the qhy8 so we'll see what problems the next camera presents :)