To all,
My Black Night Binoviewers with Harry's new diopter adjustments have been back for a while and I finally got some decent skies for viewing last night after work.
With the temperature dropping fast I wimped out and just took my Celestron 102 wide field outside. This small refractor is mounted on a Bogen head and has a heavy duty tripod. Its a great grab and go when I just want to have a quick look outside. This is a cheap scope. I got it for $179 brand new. The focuser is very rough but does do the basic job.
I also purchased a 1.3 OCA when I got the Diopter upgrade. I have been using that with the C102. That OCA is a little too long to use in back of a 2" diagonal. I have however found that it works great when placed before the diagonal in a Petzval type arrangement. Since the 1.3x OCA has 2" nose and a 1 1/4 outlet, I have been using 1 1/4 diagonals and prisms before the Black night binoviewer.
The diopter adjustments worked perfectly. When I first saw them I thought they might be a little too coarse. They are capable of moving the eyepiece approximately 7 millimeters. This is accomplished in 3/4 of a turn or a 270 degree rotation.
I am very nearsighted and I like to view without using my glasses having the dual diopter adjustments allows me to fine tune each eye. The result is pretty spectacular. The moon looked great with views through my 24mm,19mm, and 15mm plossls. I even turned the scope up and got a nice view of Jupiter with the 15mm plossls. I admit I did not stay there for long. It was literally a pain in the neck.
My method of using the diopters is that I first set both the right and left diopter adjustments around a 1/4 turn (90 degrees) off of bottom. I then use the scopes coarse focus to bring the view into normal focus. For there I adjust the left eye and then the right eye diopters. Its like having a helical focuser for each eye. I really enjoy fine tuning each eye with each eyepiece for the absolute best focus. When I am done I know that I have the sharpest and clearest view possible with that equipment for that set of conditions at that time. With normal rack and pinion focusers I am never quite sure I have it completely perfect. There is always a tendency to go back and tweak the focus again.
The manufacture (Harry) says that once you have the diopters set you should lock them down and simply change eyepieces.
One of the things that I really love about my Celestron C9.25 is the Williams Optics Crayford focuser that I have on it. I have often thought about getting a Crayford focuser for my refractors. Then problem is the additional length in the focus path is a real pain to deal with. With these diopter adjustments on my Black Night I can get that same level of performance for each eye.
Don
My Black Night Binoviewers with Harry's new diopter adjustments have been back for a while and I finally got some decent skies for viewing last night after work.
With the temperature dropping fast I wimped out and just took my Celestron 102 wide field outside. This small refractor is mounted on a Bogen head and has a heavy duty tripod. Its a great grab and go when I just want to have a quick look outside. This is a cheap scope. I got it for $179 brand new. The focuser is very rough but does do the basic job.
I also purchased a 1.3 OCA when I got the Diopter upgrade. I have been using that with the C102. That OCA is a little too long to use in back of a 2" diagonal. I have however found that it works great when placed before the diagonal in a Petzval type arrangement. Since the 1.3x OCA has 2" nose and a 1 1/4 outlet, I have been using 1 1/4 diagonals and prisms before the Black night binoviewer.
The diopter adjustments worked perfectly. When I first saw them I thought they might be a little too coarse. They are capable of moving the eyepiece approximately 7 millimeters. This is accomplished in 3/4 of a turn or a 270 degree rotation.
I am very nearsighted and I like to view without using my glasses having the dual diopter adjustments allows me to fine tune each eye. The result is pretty spectacular. The moon looked great with views through my 24mm,19mm, and 15mm plossls. I even turned the scope up and got a nice view of Jupiter with the 15mm plossls. I admit I did not stay there for long. It was literally a pain in the neck.
My method of using the diopters is that I first set both the right and left diopter adjustments around a 1/4 turn (90 degrees) off of bottom. I then use the scopes coarse focus to bring the view into normal focus. For there I adjust the left eye and then the right eye diopters. Its like having a helical focuser for each eye. I really enjoy fine tuning each eye with each eyepiece for the absolute best focus. When I am done I know that I have the sharpest and clearest view possible with that equipment for that set of conditions at that time. With normal rack and pinion focusers I am never quite sure I have it completely perfect. There is always a tendency to go back and tweak the focus again.
The manufacture (Harry) says that once you have the diopters set you should lock them down and simply change eyepieces.
One of the things that I really love about my Celestron C9.25 is the Williams Optics Crayford focuser that I have on it. I have often thought about getting a Crayford focuser for my refractors. Then problem is the additional length in the focus path is a real pain to deal with. With these diopter adjustments on my Black Night I can get that same level of performance for each eye.
Don
