ITF in Coronado BF10

[armichael]

Hello!
I purchased Coronado's BF10. Given that I already own B600 from Lunt I was quite surprised by the amount of light that pass through them. I compared first just watching at clouds through the bare diagonal and observed that the image was significantly (time more) brighter in BF10. I started to be cautious if there could be the ITF missing. Here comes my first question: Where the ITF is located inside BF10?

The very next - sunny - day I did a test wit 50mm achromat equipped with Lunt 50mm etalon. The view through B600 was of course great, like I'm used to. Then I replaced B600 with the Coronado BF10. the view was magnificent, bright and detailed but I enjoyed it just for a second or so. Nothing happened to my eye I only did not want to look through this too long while I'm not sure it's safe. Oh, I forgot to mention - I added 7nm Ha filter in front of the diagonal, just to enhance safety. so second question: does this seems like an ITF could be missing?

Before all this I read an article here about troubles with pre-owned PST viewtopic.php?p=384337&hilit=PST+ITF#p384337
Robertm in the initial question describes the sun as greenish-yellow and in his pictures the ITF is clearly missing. I compared my BF10 with PST box too. In mine there is ITF where it should be. When I unscrew upper part with 5mm blocking filter from PST box and look through it, the view at cloudy sky or even countryside is exactly as robertm describes -- greenish yellow. But then back in combination with the ITF it becomes properly red. And it's also properly red, with no greenish tint if I inspect the BF10 in question in the same way. This leads me to third question: With all this comparisons it seems that everything may be alright with the BF10, it just passes more light than Lunt's B600. Right or wrong?

So far I am not brave enough to expose my retina to sunlight through this filter until I gather enough information and eventually fix it with additional ITF (ordering one just now).

Kindly asking for your advise.
-michael-

[marktownley]

Hi Michael

Welcome to the forum. Post a picture of the bf10 from either end so we can see what filters are there and their condition.

Mark