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Another rusty BF question...

Posted: Sat Jul 14, 2018 10:53 am
by Helen
Hi All,

I bought a BF10 to go with a SM40 front filter (which was originally bought to double-stack a PST) as a neat travel set up. But on testing found the view really poor. Investigation shows I have rust...

I need to go with a replacement filter and would welcome recommendations about which is best (I'm in UK)

But I was also wondering if there is a quick fix - at least for imaging - in the meantime? I have the usual mix of coloured, IR/UV, Ha, Continuum filters etc.

Alternatively, would a Lunt BF work safely with the SM40?



Re: Another rusty BF question...

Posted: Thu Jul 19, 2018 2:37 pm
by sonneyboy
Hi Helen,

I purchased my BF10 ITF filter replacement from Beloptik a few weeks ago, it shipped to UK inside 5 days.

It takes around 5 mins to install if you take your time not to scratch anything. You just unscrew one small lens ring holding the original rusted glass in place, the rusty glass drops out, carefully put the new filter where the rusty one was (get it the right way around as the two faces have different properties though Beloptik will tell you which way to install it), re-screw the ring back in to hold glass in place. Done.

You can get small lens wrenches to help undo the retaining screw but instead I used a thin flat piece of metal which fit across the flats in the lens screw. It wasn't particularly tight to undo.

I'm very happy with it though I have nothing to compare against other than the badly rusted original there are other brands/solutions out there.


Re: Another rusty BF question...

Posted: Sun Sep 23, 2018 2:48 pm
by ronatu
How about bf not itf? Any recommendations for replacement?