Thoughts on a Power Newt (F/2.8)

[Meru (Michael)]

Folks,

I would like to hear your opinion on these fast F/2.8 newts. In particular is the Boren-Simon brand, here is what I am referring to:

https://www.teleskop-express.de/shop...strograph.html

This company seems to be a sister company of ASA Austria, famous for their fast systems. It's effectively a 10" f/4 CF scope with a 4-element ASA ED reducer/corrector. Having spent most of my imaging life at F/7.5 or slower, this appeals to me very much. We don't get many clear nights here in Melbourne and 5min subs on my mono? Yes please I can have the 10" shipped here with GST for $3500, or a 8" shipped with GST for $2800. Beauty is that the ASA reducer makes the scope 720mm, and with my MPCC it will be 1000mm. So it's kind of a ''2-in-1'' scope so to speak.

I always thought my dream scope would be a nice, expensive large APO. I have a thing for refractors, probably because I really really dislike collimating. At F/2.8 the critical focus range would be about as thin as my receding hairline I also do not mean to (And please do not) start a refrac vs newt argument!

So what do you think?

[jase (Jason)]

Yes, the 10" model would be a photon killer. I'd say you need to get out of the burbs to take full advantage of the system's speed.

http://www.powernewts.com

Great images in the gallery section.

[Tandum (Robin)]

I'm sure I've read they are a GSO scope with a different focuser and a 2" asa corrector/reducer. MrB bought one of those 2" reducers/correctors from ASA so maybe ask him how it works in a normal newt. I got a 3" ASA corrector here in a GSO newt, the image circle on the 2" corrector/reducer was too small for my camera. The 3" does the job but not cheap. The corrector cost more than the scope

[Lee]

Originally Posted by Tandum

I'm sure I've read they are a GSO scope with a different focuser and a 2" asa corrector/reducer. MrB bought one of those 2" reducers/correctors from ASA so maybe ask him how it works in a normal newt. I got a 3" ASA corrector here in a GSO newt, the image circle on the 2" corrector/reducer was too small for my camera. The 3" does the job but not cheap. The corrector cost more than the scope

From the pics on their website, that's exactly what it looks like... comparing to my GSO f/4 newt revealed no differences I could see.... right down to the 'average' focuser....

[naskies (Dave)]

Originally Posted by Tandum

I got a 3" ASA corrector here in a GSO newt, the image circle on the 2" corrector/reducer was too small for my camera. The 3" does the job but not cheap. The corrector cost more than the scope

Robin, how do you find the ASA corrector? Is it easy / practical to use with your newt?

[Meru (Michael)]

Yup it certainly would be a photon killer! Most of the images on their site were taken from a desert in Israel I think, extremely dark skies. From the suburbs it wouldn't be used to the full potential, but atleast for narrowband it should be ok.

I didnt know there were GSO scopes!? If it's just the corrector then I might find out from MrB the details of his corrector. Yes I've heard they are quite expensive, I'd probably need to upgrade my focuser thats for sure.

[gregbradley]

I think the key thing to know is how well does it hold collimation? At F2.8 collimation is going to be critical.

The other thing with these types of scopes is that they are really sensitive to flexure and weight.

So if you used a light weight camera/filter wheel with it that would be the smart strategy.

Try to put a FLI Proline on it and you'll end up throwing it in the lake!

Greg.

[Satchmo]

I think its an F4 with a tele-comressor coma corrector at 0.7X .

I'm not sure how that translates in the collimation sensitivity stakes.

[Tandum (Robin)]

Originally Posted by naskies

Robin, how do you find the ASA corrector? Is it easy / practical to use with your newt?

Dave, On the 3" GSO focuser, once you unscrew and remove the 2" adapter, the ASA fits the focuser tube exactly. I drilled and tapped for 3 - 4mm grub screws around the drawtube. I bought 3 - $6 4mm grub screws with nylon tips from small parts and bearings but it took so long to get all the adapters together I lost those $6 screws and just used normal ones to get it going. Rotating is a pain. Apart from feathertouch and baader, I don't know of any other 3" focusers for 12" newts and I can't afford either of them anyway