Quote:
Originally Posted by Ed D
Alex, I don't have a binoviewer but I have researched it as an option to my RFT. I can't find an article I recently read, but I do remember the article explained that in a binoviewer the light is being split, as opposed to two similar sized optical tubes in a bino, so the image is not as bright. The author wrote that in small scopes the splitting of the available light to each eye dims the image compared to the same small scope being used with one eyepiece of same magnification. Also, with binoviewers the point at which the image comes to focus changes, and a barlow is needed to bring the image to focus, usually around 1.5x and normally included with the binoviewers. The conclusion was that binoviewers are great for large scopes with their increased light gathering to observe at higher magnifications, not so ideal for wide-field use in small RFTs.
Found this one on CN: 'Do BVs Match Binoculars for Wide Angle Views?' http://www.cloudynights.com/ubbthrea.../o/all/fpart/1
I hope this helps.
Ed D |
Although the binoviewers split the light, the advantage of the light going to both eyes, and the processing then done by our brain, should not be underestimated.
I loved the difference that binoviewers made so much that I upgraded from my original WO ones to a better set. I use them mostly on the 4" F5 refractor and find them plenty bright enough.
As for the focus issue, I do what I have done with nearly every refractor I own, shorten the tube and get a longer focuser fitted, that way I get the in-travel required for things like binos and get plenty of room on the back for all the photographic gear when not going visual. That way I can get away without using the barlow.
( I still don't know why scopes are always just that bit too long, I wish the tubes were shorter by default)
I find I hate using a single eyepiece these days, I much prefer bino-viewing or using the mallincam and looking on the screen in realtime.
I'd love a true bino scope, but I imagine that is difficult and expensive though if I could find a way to do it with a pair of C8s I'd grab another one...
That sketch is wonderful Alex, it inspired me to dig out the binoculars and take a look at the same target, and your image really captures very much the feel of what I saw.