Bino C6 or not? Bino experts help!
Posted 06 April 2013 - 07:23 AM
appreciate those comments. Actually, i sat back and thought things over. As it happens i have located a Baader 60 degree binoviewer. I'm waiting to send the payment for it. This bino will sort all the issues already discussed. I have decided i will cope with the 60 degree viewing angle. My friend used one one of these. The optics are very high quality indeed, but their small aperture input make them good mainly for planetary and lunar, which is just what i observe. Just hunting a pair of suitable eyepieces now. I will report on how it all performs when i have eyepieces and do a 1st light.
Posted 06 April 2013 - 03:59 PM
Posted 05 June 2013 - 06:50 AM
Hi Mark, Edggie,
I still have the original c6 1.25 v/back. I am very uneasy that it will hold the weight of even a typical WO or similar bino well. It is difficult to get at the two locking screws with enough pressure to really get a purchase on the diagonal well. I could certainly obtain something like a WO 1.25 diagonal though.
A much better grip would ben if i used my existing 2" v/back into which i insert a 2 to 1.25" self centring adapter, eg by revelation or orion. this would grip the 1.25" diagonal nosepiece well, but the combined length of the 2" v/b and self centre adapter would be around 60mm.
most WO etc are about 110mm light path. i think this would still bring a total light path over 200mm with a 1.25" diagonal. i am still concerned if i am operating at an undesirable f-ratio using the WO 1.6x. that then brings in issues about eyepieces to use. a friend has a pair of meade 5000 14mm plossls. i used these in the past and they were superb. will they offer a sensible mag in this potential setup? i do not know, as i do not know the operating focal length.
btw, i am actually looking at the original celestron 1.25 v/back, and to me it still looks to be around 50mm long to where a 1.25 diagonal would insert.
so, say 50mm v/b + 75mm for 1.25 diagonal + 110 for bino less 30 for 1.6x = 205mm. am i right? but still do not like the idea of all the weight on 2 little thumbscrews on that v/back!
You might find nylon screws (home depot) tighten better as they can squeeze against the barrel of the ocular or binoviewer.
Posted 05 June 2013 - 07:31 AM
Posted 05 June 2013 - 10:10 AM
I am still loosing a bit of aperture in the EdgeHD 8 even with this short configuration (about 7.6") but when I went to the Baader 15mm SCT to T2 adapter, I only got 7.7", and it was difficult to keep the diagonal from rotating because the Baader SCT/T2 adapter is simply not strong enough to hold the bino against rotation. It couples the way the old SCT diagonals do, with a lock ring, and if you get it tight enough to keep the diagonal from breaking free, it is hard to loosen it.
So, now I use the short Televue Short adapter and this works quite well. Neither the C5 or the EdgeHD 8" is working at full aperture, but I don't really use these for planets so much (though I use the C5 for the sun and moon) so it is a compromise that I don't like, but the utility makes it a better compromise than the Baader SCT/T2 15mm adapter.