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View Full Version here: : Field Flatteners and the ED127


pmrid
05-12-2009, 11:15 AM
Does anyone have any recommendations for a field flattener suitable for the ED127? Would a MPCC do the job? And if it would, would the usual 55mm rule still apply?

Peter

AlexN
05-12-2009, 11:27 AM
I dont know about the ED127 Peter, but the MPCC works fine with my refractor.. I use the 55mm spacing that Baader recommend, It seems fairly critical though. I had an old adpater that was for my QHY8 to MPCC, which was 1.8mm too long for the Orion StarShoot Pro camera. I got 'Good' but not perfect results using that spacer, I then had a new one turned up that was the exact measurement required and the results were perfect.. Luckily, this spacing is the same as the spacing for another flattener I have for the refractor, so I can use the MPCC to shoot at 480mm F/6 or the TV 0.8x reducer to shoot at 384mm F/4.8...

Other flatteners that you could try..
The TS2 flattener - I think these are available from Optcorp, Not certain though... if you google TS2 field flattener you should find it.

The Astrotech 2" field flattener

Both those options are a pure flattener, no focal length reduction at all. If you want to flatten the field and reduce the focal length a bit, you could try:

WO 0.8x V3 or V2
Borg DG-L 0.85x

Cheers.

pmrid
05-12-2009, 11:31 AM
I've got a couple of MPCCs and spacers to suit so I'll have a play with those and see how the results stack up first and go from there. Thanks for the recommendations.
Peter

Octane
05-12-2009, 12:47 PM
Keep us posted, Peter. I'd be interested in your findings.

Regards,
Humayun

gbeal
06-12-2009, 11:17 AM
I'll second the MPCC, worked for me on the 80mm Alex now has.
Gary

Mighty_oz
06-12-2009, 11:56 AM
Hey u guys mind if i ask a Q here as u are talking flatteners etc ?
Think the MPCC would work with my 120mm f5 skywatcher refractor ? Or would i be better off with another ? I'm thinking that a reducer/flattener might be to much for the narrowband imaging i'm going to attemp with it with baader 7nm filters ? Or would that be ok.

multiweb
06-12-2009, 11:59 AM
I use my MPCC with a 130mm Newtonian which is F/5 and it works great if this helps. Although not a refactor it should be a similar focal length so my guess is yes it would work. I've also used the Baader 2" 7nm Ha filter with this set-up.

AlexN
06-12-2009, 12:31 PM
A reducer flattener should be fine with the 120mm F/5 achro, the MPCC should work too.. Also, for narrowband work, because the stellar profiles are greatly reduced and a slightly curved field will not be noticed...