Developing this series of images further I used an RCOS 12.5 inch with an AP .75 telescompressor to make it F6.75.
This is 4 images x 60 seconds, modified Nikon D70 @ISO1600, unguided Tak NJP mount (what a beauty!).
Interesting to note the similar image scale to the Tak FS152 at F12.8 (using Q-extender 1.6X) but chromatic aberration is apparent in the FS152 shot - see a few posts below the last image posted under Omega Centauri- where the foreground bright stars have a blue halo. I thought that was from the camera but the RCOS with its mirror system and no lenses (except for the AP telecompressor) shows none.
The RCOS is a superb instrument with refractor-like (almost) sharp stars and fantastic light collecting ability. The electric secondary focuser really is a wonder. It seems their incredible reputation for a superb imaging instrument is well founded.
My backyard last night.
I may try this again at a dark site at perhaps F9.
Greg.
This is 4 images x 60 seconds, modified Nikon D70 @ISO1600, unguided Tak NJP mount (what a beauty!).
Interesting to note the similar image scale to the Tak FS152 at F12.8 (using Q-extender 1.6X) but chromatic aberration is apparent in the FS152 shot - see a few posts below the last image posted under Omega Centauri- where the foreground bright stars have a blue halo. I thought that was from the camera but the RCOS with its mirror system and no lenses (except for the AP telecompressor) shows none.
The RCOS is a superb instrument with refractor-like (almost) sharp stars and fantastic light collecting ability. The electric secondary focuser really is a wonder. It seems their incredible reputation for a superb imaging instrument is well founded.
My backyard last night.
I may try this again at a dark site at perhaps F9.
Greg.
Attached Image:
