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Solar Wedge and Celestron 102 Refractor

Posted: Wed Mar 25, 2020 6:03 am
by DeepSolar64
All,
I plan to buy a new solar wedge soon to use on my Celestron 102mm refractor. Do I need an ERF with it or will it work fine by itself? Obviously I hope it'll work stand alone as it will save on cost. But it's gotta be safe and not damage my eyes or the scope. I will also use it with my Astro-Tech 72EDII refractor as well. I plan to get the 2" size. I am looking at the Altair, Lunt and APM wedges. I know I will need a polarizing filter with it.

James

Re: Solar Wedge and Celestron 102 Refractor

Posted: Wed Mar 25, 2020 6:40 am
by marktownley
I don't think you'll go wrong with any of them, they're all good.

Re: Solar Wedge and Celestron 102 Refractor

Posted: Wed Mar 25, 2020 5:45 pm
by DeepSolar64
The Baader wedges are very nice too, but pricey.

Re: Solar Wedge and Celestron 102 Refractor

Posted: Wed Mar 25, 2020 8:37 pm
by MapleRidge
HI James...

The Lunt wedge is safe to use up to 150mm aperture and there is no need for any ERF since the optical design prevents much to the light from making it to the eyepiece. There is a built in ND3 filter in the Lunt unit and you can add a continuum or other filter if you like to enhance the contrast more. Lunt recommends adding additional polarizer for visual use (from their tech sheets).

I have a UV/IR Cut+Baader continuum mounted before the eyepiece in mine and it works very nicely.

From what I read the APM is very similar, with a twit lock on the eyepiece holder which is a nice bonus.

One thing to watch is that they do take up a lot of focus travel, and reaching focus may be a problem on some scope with limited focuser in -travel.

Brian

Re: Solar Wedge and Celestron 102 Refractor

Posted: Thu Mar 26, 2020 5:08 pm
by DeepSolar64
Brian,
I think the Altair wedge has the twist lock feature too. Not sure.

Could you use extension tubes like used to connect a DSLR to bring it to focus if you lacked focus travel? Put a T adaptor at each end. One to fit into the drawtube and the other to fit into the wedge?

James

Re: Solar Wedge and Celestron 102 Refractor

Posted: Thu Mar 26, 2020 10:25 pm
by MapleRidge
James...

If you need to move the wedge back to reach focus you could use any form of extension before the wedge or between the wedge body and camera/eyepiece. The body of the wedge seems to be physically larger than a typical diagonal so this is what makes in-travel more limiting.

My C102 had the tube shortened long before the solar wedge arrived, so I can't honestly say how much focus room there is with my Lunt wedge.

Brian

Re: Solar Wedge and Celestron 102 Refractor

Posted: Fri Mar 27, 2020 6:54 am
by DeepSolar64
Thank you Mark and Brian for your replies. Most informative they are.

James