These irritating spikes

[ollypenrice]

That is major improvement, the spikes are almost faded into the colour of the frame , I guess you just cant beat an Apo

There are other ways to avoid spikes, though. In fact any system at all can avoid them if you replace the spider with an optical window. Apos of any size are bound to be fairly slow and big ones are prohibitively expensive as well. Or there's the ingenious self correcting Riccardi Honders Astrograph. I don't mind spikes on long FL images too badly though I much prefer not to have them at all. It's not so much the spikes as the squarish smaller stars that upset me.

Olly

[Mark72]

Thanks Olly,

It's amazing job. I'll try it out.

Mark

[dugpatrick]

If you have photoshop then you could try 'content aware fill'.

I would agree that rotating the camera would work, with sigma kappa stacking, if you can get enough different angles. I've never tried due to the effort, and I think post processing might work too.

A generic example: http://www.photoshopessentials.com/photo-editing/content-aware-fill-cs5/

Doug

[Sp@ce_d]

If you have photoshop then you could try 'content aware fill'.

I would agree that rotating the camera would work, with sigma kappa stacking, if you can get enough different angles. I've never tried due to the effort, and I think post processing might work too.

A generic example: http://www.photoshop...aware-fill-cs5/

Doug

Interesting.. bit like cloning?

[russellhq]

Would rotating the scope/camera affect your flats?

I wonder if it would be possible to design an object that could be placed in front of the scope and would interfere with the diffraction from the vanes and cancel it out?

[ollypenrice]

Would rotating the scope/camera affect your flats?

If you rotate them together, no.

Olly

[IanL]

Would rotating the scope/camera affect your flats?

If you want to maintain the same framing for all of the lights, then you'd need to rotate the scope (say) 45 degrees and then rotate the camera back to its original orientation by -45 degrees. That will certainly affect the vignetting, and so you would need a set of flats after each rotation.

If you only want to stack the centre of the frame and crop a fairly big chunk around the edges, then you could just rotate the scope and OTA together and use one set of flats. You might have issues if your focuser droops under gravity, but then you'd probably have issues with coma and changes in vignetting as the scope tracks anyway in that case!

[Mark72]

Thanks for your help guys,

I tried to remove them

http://www.astrobin.com/31129/B/

This thread shows how to deal with them in the first place

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5597414/page/0/view/collapsed/sb/5/o/all/fpart/1

Mark