Milton Wilcox R.I.P
Quote: Is that not what MANY of us would REALLY like for astronomy ?
AL MasterObserverC #24
Celestron 15x70 Apogee RA-88 Vixen 70mm refractor No name 80mm refractor
Quote:What about the old issue of the internal prism cut-offs reducing the effective aperture--as in the Apogee RA-88? I don't remember if anyone has told us whether the manufacturer did anything similar with the BT70s. Are the exit pupils perfectly round? Can you see a prism cut-off when you look back through the objectives?lwd
Jeff Morgan - Wile E. Coyote School of Telescope Making
Quote:Actually it wasn't related to objectives. It was either one of or both prisms that were too small to span the prism shelf, leaving a gap in the prism aperture and internal workings inside the binocular that interfered in the light path, blocking a portion of the light cone before it reached the prism.
17.5" f/5 Dob. IM-715 MCT. 120ED. Lunt 60mm Ha. Zeiss, Leica, Fujinon, Nikon, Pentax, Bushnell bins
Quote:For about the same amount of money, you could get the fuji 16x70 with much better build and optics or the miyauchi 22x60 with better optics-is 90 degree and interchangeable eps worth the lost in quality?
Quote:... prism aperture... may limit the maximum fov obtainable...edz
Quote:How many of us use a telescope without a diagonal? I'm sure some do, but most don't.
Quote:For my application, the 90 degree and interchangeable eps was important. I wanted a binocular that functioned like my telescopes. If all I looked at was in the area of the horizon, straight binoculars would be fine, but looking up with them is not too ergonomic. For celestial viewing, it is much more comfortable 'for me' to have a 90 degree eyepiece. The BTs allow me to use a telescope mount with my observing chair and not have to be a contortionist.
Quote:Anyone have experience using the "Sky Window" or other similar products?Tom