View Full Version here: : 8 inch f10 cass for DSO astro
06-03-2012, 06:32 PM
As per title. Will a 8 inch F10 cassegranian telescope be fine for DSO astrophotography work, or will the field be too narrow?
07-03-2012, 06:40 PM
Jase , you can get an F10 to F6.3 tele-compressor lens which will give a C8 a more appropriate F ratio for astro-photography.
07-03-2012, 07:58 PM
You will need a focal reducer or if it is a celestron a hyperstar for most DSO's and you get a wider view and faster acquisition times as well.
07-03-2012, 08:24 PM
C8 plus hyperstar images
It depends on:
- the actual DSO - won't work for Eta C, but great for M83
- Mount - you'll need at least an EQ6 probably
- Guiding - Need decent scope without flexure (or OAG)
- on your patience and expectations :)
07-03-2012, 09:55 PM
no probs guys. thanks again for your knowledge. i might stick with the refractor.
this one seams like too much trouble... especially for a beginner
08-03-2012, 09:37 AM
Well not quite right....at F10 you'll need longer exposures and or more subs. I've done the keyhole at F10 just fine. FOV is quite small though so you don't get a sense of the whole nebulae.
F10 in general just needs good tracking and longer subs.
Of course a SCT like a C8 is a damn fine instrument as it can do F10/6.3 and F1.8 with hyperstar. Of course it's not easy to just change to Hyperstar but it can be done and make'th it a versatile instrument.
Well, of course if you really like the full eta experience you could mosaic a stack of frames, but no-one is silly enough to do that are they (http://www.iceinspace.com.au/forum/showthread.php?t=72657)? :P
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