More egg shaped stars -Orion EON 80-QHY8

[Bob Jones]

Attached is the first image taken with my Orion EON 80 and QHY8. The coma was easily fixed by cropping the image which was probably necessary anyway.

In order to preserve the full view I'm hoping a Field flattener will correct the coma.Besides the Baader MPCC there are at least three field flatteners that might be suitable.

Televue TRF-2008
http://www.televue.com/engine/page.asp?ID=169 (http://www.televue.com/engine/page.asp?ID=169)

WilliamsOptics flattener-2
http://www.williamoptics.com/accessories/reducer_features.php (http://www.williamoptics.com/accessories/reducer_features.php)

WilliamsOptics flattener-4
http://www.williamoptics.com/accessories/flattener4_features.php (http://www.williamoptics.com/accessories/flattener4_features.php)

It seems that the distance between the CCD and the reducer flange is critical.
Please, can anyone recommend which will work best. (if at all)

Bob Jones
:help:

[toryglen-boy]

Hi Bob

Its a good pic!

TBH my ED80 has some coma, as do others of the same ilk, the Skywatcher ED80 i have briefly used had it to, and this looks to me to be cut of the same cloth.

I use a Baader MPCC attached to the T-ring with my DSLR, it has a nose piece to, so i can plug it straigh into the 2" focuser. That seems to work a treat.


;)

[Hagar]

Hi Bob, your image seems to be exhibiting field curvature. I had good sucess with a WO PFlat2 but I had to experiment quite a bit to get it positioned correctly. The distance from CCD to flattener is critical. You also must be aware that this is also a 0.8 reducer so will open up your field of view and make your targets a bit smaller. By the way the PFlat2 was designed for use with an APS size chip which is what is in the QHY8 and DSLR's.

Nice image appart from this.

[Bob Jones]

Doug

After talking to Theo I have decided on the Baader MPCC kit. http://www.myastroshop.com.au/products/details.asp?id=MAS-221B


Bob
:hi:

[Glenhuon]

Just bought an MPCC and gave it a first try a couple of nights ago. Very pleased with the result. Stars are round right to the corners. It does'nt move focus very much, about 10mm more outward travel on the focusser is needed. I previously used an 18mm spacer on the camera adapter to get focus, but don't need it using the MPCC. Rig is a Canon 300D on a 150 F5 Newt.
Skies look clear here so going to give it a better work out tonight.

Bill

[TheDecepticon]

The Baader seems to be getting a fair bit of use in more than the reflectors it was supposed to be designed for! Be careful buying it here, it is way over priced. Check out Andrews and also check out OPT in America, they ship here regularly and are user friendly. Mine landed here for AU$249, albeit, without the adapter kit, as it is not needed for DSLR.
Good choice!:thumbsup:

[Gama]

You can get them here for $285.00, which is great value.
http://www.myastroshop.com.au/products/details.asp?id=MAS-221