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TV 2.5x powermate with BF10 on pronto?

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#1 Keith

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Posted 12 November 2012 - 06:40 AM

I have not yet tested this, because I do not have a sol-searcher yet, so my 60 has not yet been mounted to my pronto.

Before deciding on trying to sell my maxscope 60 OTA, I wanted to make sure I would be able to reach focus with a DSLR with my BF10. I am pretty sure threading a Cmax barlow lens attachement to a 1.25" T adapter/nosepiece would work OK, or the Cemax barlow itself, also along with a 1.25" t adapter. I do not have the cemax (and hesitated on my last chance to get the taiwan version of it), and I would prefer not to use 1.25" T adapter (cheezeballs), so I figured my 2.5x powermate with T-ring adapter might be the option. Technically it should be parfocal with an eyepiece, so that should help focus issues. But will it make the effective focal length (1200mm) too long for the BF10? I figure since the PMT is amplifying after the BF10, it might not be an issue (free lunch perhaps?).

I have a cheapie GSO shorty barlow, which is basically the cemax but with standard coatings, so I guess I could use that if I had to, but prefer to avoid the 1.25" nose/setcrew combo anyway.

Has anyone tried this? Also, is it safe to use a barlow or powermate before the BF? I know this would limit the BF10's field, but is there any risk to the coatings having the unfiltered IR going through the glass?

Any experience would be appreciated, thanks!

#2 Philip Levine

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Posted 12 November 2012 - 09:05 PM

Hi Keith,
I have a Pronto with 60mm Coronado SolarMax II H-alpha and BF 10.
I have not done any astrophotography, but can tell you I have used a TV 2.5x Powermate and 15mm plossl inserted into the BF10 diagonal. Not only was I able to reach focus, but the combo of TV 2.5x Powermate and 15mm plossl produced superb results, much more detail against a black "sky". This combo gave me the best solar views by far, than any single eyepiece or other combination of Powermate and any other eyepiece.
What I do not remember, however, is if I used my short TeleVue tube extender ($25 ?), before the BF10, in order to reach focus.
Phil

#3 Keith

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Posted 14 November 2012 - 05:45 AM

anybody tried it with the t ring adapter and a DSLR?






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