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WO Binoviewers, revisited

Started by Charles Geiger, 02/11/2006 09:49PM
Posted 02/11/2006 09:49PM Opening Post
I received my WO binoviewers about 3 weeks ago and was able to first try them out last evening in my little C-5 under a gibbous moon and terrible seeing conditions. Firstly, the workmanship of the binoviewers appears first rate. The glass of the 20 mm supplied oculars seems very highly polished and all coatings seem flawless.
I started observing with a 26 mm Celestron Plossl and then changed to the binoviewers. Unfortunately, the wind came up and the seeing got worse. I played with the adjustment for interocular and find that my eyes are close to the 60 mark. Then I fooled with the individual diopter adjustments and found that my left eye is about a quarter of a turn off from my right eye. However, I had to play with the compression ring screw placement to get the images to merge. Again, the screws ended up similarly alligned. Funny thing is, it seemed to me the left eye AFOV appeared smaller than the right eye AFOV. Even though the images merged, the AFOV's didn't seem to merge. I adjusted the interocular distance all the way in each direction and just found it difficult to perceive fov matching. The moon did appear awesome as it seemed that I was truly hovering above it. Again, the fov seemed not distinct. And the left view seemed dimmer than the right view. Saturn gave the 3D effect as did the Orion nebula. Stars were definitely dimmer in the binoviewer although the field seemed darker and the contrast on the Orion nebula seemed better with the binoviewers. At one point, I could not get the images to merge whatever I did. So I took my eyes away and rested a minute and looked back in and got the images to merge easily...I suspect eye fatigue. If I crammed my eyes right up to the oculars I got the best merging of fov. I can't say the actual fov's appeared different in size at this point but they still didn't overlap perfectly. Again, the images did overlap. Maybe the best way to put it is the field stop did not seem distinct but more like two overlapping field stops.
At any rate, what do you think? I truly feel this binoviewer experience is awesome if one can get proper eye placement. I do have glaucoma and astigmatism so maybe that is affecting me. I did get good intra and extra focal diffraction patterns so I felt astigmatism wasn't too much of a problem. And since the image merged easily I feel the prisms are alligned well enough. Collimation in the C-5 is good. I need more practice but do I have a binoviewer problem or is it me?
One extra thing...the OCA supplied did work although it has a very small aperture...I could see no advantage using it and it further reduced light throughput it seemed. All the optics seem very good when comparing to a single ocular and also using a 2.5X Televue barlow but, again, seeing was very poor.
Posted 02/11/2006 10:49PM #1
Hi Charles,
The first thing that would need to be checked is switching the EPs left to right to see if one of the EPs might be different than the other. If they are not matched, it would not work as well.
I have not had any problem with the compression rings and alignment. I do not tighten them beyond being tight enough to stop the EP from rotating.
Also, the inter ocular distance will effect the view in each eye. Try messing with this some more.
Next, I do not put my eyes against the eye cups at all, but rather place my eyes away 15mm or so. This made the images merge better for me. The FOV showed the field stops on both EPs as equal.
There is some possibility that your pair of Binoviewers or EPs have a problem too. But I suspect that a bit more time with them might find a solution.
I have had no problems in matching EPs or aligning them in the holders. So, maybe I am just lucky?

[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue grin
Amateur Imager
Posted 02/11/2006 10:49PM #2
Hi Charles,
The first thing that would need to be checked is switching the EPs left to right to see if one of the EPs might be different than the other. If they are not matched, it would not work as well.
I have not had any problem with the compression rings and alignment. I do not tighten them beyond being tight enough to stop the EP from rotating.
Also, the inter ocular distance will effect the view in each eye. Try messing with this some more.
Next, I do not put my eyes against the eye cups at all, but rather place my eyes away 15mm or so. This made the images merge better for me. The FOV showed the field stops on both EPs as equal.
There is some possibility that your pair of Binoviewers or EPs have a problem too. But I suspect that a bit more time with them might find a solution.
I have had no problems in matching EPs or aligning them in the holders. So, maybe I am just lucky?

[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue grin
Amateur Imager