More experimenting with the Astrophysics barlow and my TEC140. I think I get a flatter field and better star shape with the barlow at 1.8X rather than 2X. Unfortunately seeing wasn't particularly good over the two nights I imaged this, but I think it looks dramatic. Comments always appreciated. Thanks for looking!
TEC140 + Astrophysics Barlow at 1.8X = .63 arcsec resolution = 1746 mm or f12.6
ONAG Guider + St-i
12 mm Astronomiks Ha filter 126 min (9 min sub frames)
Processed in CCDStack and Photoshop CS-5
75% full frame:
http://www.pbase.com/prejto/image/152670115 removed
50% full frame:
http://www.pbase.com/prejto/image/152670116
Center Crop:
http://www.pbase.com/prejto/image/152670117 removed
Reprocessed 75% http://www.pbase.com/prejto/image/152773146
Reprocessed 50%: http://www.pbase.com/prejto/image/152773039
Reprocessed Center Crop: http://www.pbase.com/prejto/image/152773147
Hoping these are better!!
Peter