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Baader 1.7x GPC ex-Maxbright for Mark IV?

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#1 R Botero

R Botero

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Posted 09 April 2013 - 08:26 AM

Hello All

I was using a nice pair of Baader Maxbright binoviewers + 1.7x GPC with my AP152 f/7.5 refractor until I came across a nicely priced Mark IV pair. I now have the Mark IV but kept the 1.7x GPC. The Mark IV come with a 2.6x GPC and the 90d prism.

My question is, can I use the 1.7x GPC I kept with the new “old” Mark IVs? I read somewhere that the orientation of the lenses is different in the GPCs that Baader puts together for the Mark Vs versus the Maxbrights...? Although this does not make much sense coming from a company like Baader...

I know the 2.6x is mounted in the opposite direction to the 1.25x or 1.7x but I wonder if my ex-Maxbright 1.7x GPC has to be mounted in some other way now that I am going to be using it with the Mark IVs.

Thanks

Roberto

#2 R Botero

R Botero

    Apollo

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Posted 12 April 2013 - 10:03 AM

Well, I answered my question last night. The ex-Maxbright 1.7x GPC with its current lens orientation - and keeping the concave part facing the sky - works well with the Mark IV. I have been told by another source that this is unfortunately not the case with the Mark V (but that's not my problem... :grin:)
I was surprised to see that in my old AP152 f/7.5 ("only" 4.5 inches of in-focus) with the following configuration:

Mark IV + 1.7x GPC + Baader T2 90d Prism + Baader Clicklock + AP 4.3" to 2.7" adapter

I still had at least 2" of free focuser travel. I may try the above without the GPC although I read that is best to keep one in the light path to reduce aberrations induced by the prism and the binos. I may get a 1.25x GPC.

My Mark IV came with a 2.6x GPC. I will keep that for high(er) magnification and possibly if the Baader Herchel Solar Wedge requires it.






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