can you buy a flatner only for william optics gt81 ?

[red dwalf]

afternoon all, 

i have currently got a william optics gt81 with a 0.8 x flatner / reducer which works ok, but would rather only have just a flatner, does anyone know if you can buy a flatner only for the william optics gt 81 please.

[rl]

This might be worth a punt. The manufacturers claim they're good for many types of apo.

http://www.teleskop-express.de/shop/product_info.php/info/p1010_TS-Optics-Universal-APO-Flattener-TSFLAT2-for-refractors.html

Expensive new; they change hands for about £100 secondhand on ABS. I've got one (and a GT81) but have yet to try them together. This flattener needs a much bigger spacing than usual which allows for other accessories in the optical chain(and looks like it is a bit more tolerant of errors).  I intend to use a vixen flip mirror to get the spacing right which would give the added convenience of seeing the target for framing..

I don't know of anything more specific. There are loads of flatteners only available from Altair and Skywatcher but I don't know how good they are on the GT81. Might be a case of getting one on ABS and selling it on if it's not a good match.

RL

[brantuk]

Don't know what problem you're trying to resolve Rob - but you're welcome to borrow my TRF 2008 if that would help.

(its x0.8 for 400mm-600mm fl)

[red dwalf]

what  i`m after achieving Kim is a lower resolution / pixel rate than i`m getting at the moment, the only other way to get this would be a longer focal length or bigger aperture scope, ideally i`d like to get a resolution / pixel of around 1.5

[ronin]

The answer has to be Yes.

WO made a flatener for it that wasn't a reducer, was £135 when the scope came out. Reason I am sure is that I have one for my GT81. Got it from FLO.

Presume the problem is actually getting hold of one now.

AST do this one:

https://www.astromarket.org/astrofotografie-5/fieldflattener---reducer-5/flattener-non-reducing-5/non-focal-reducing-field-flattener-5

 

[brantuk]

Ahh I see Rob - ok so my trf is not going to help there - no probs

[red dwalf]

thankyou Ronin, and Kim,

i don`t suppose you would be interested in selling yours Ronin ?

[DaveS]

Would one of these work on your 'scope?

https://www.firstlightoptics.com/reducersflatteners/hotech-sca-field-flattener.html

[red dwalf]

that one would be very useful Dave, i think i`d better get onto FLO and see what`s what