Problems with binoviewers

[GordonCopestake]

I've never really tried binoviewing properly before but have heard good things! So I recently purchased a pair of Binoviewers second hand. They are cheap(ish) synta versions and seem fairly common.

In day time tests I can't seem to get the image to merge though. The 2 images appear to be offset at about 45 degrees to each other. The binoviewers are the single thumb screw type to hold the eyepiece in place. I have tried to pull one of the eyepieces out slightly and pushed it to one side in an effort to aid collimation, this works well and I can get the image to merge in this configuration.

This leads me to think that there is something wrong with my binoviewers and they perhaps need collimating? I found using 32mm eyepieces much easier to merge but the problem is still there.

Does anyone know how I can go about collimating these cheap synta bins or indeed IF they are collimatable?

Hopefully these images will assist in identification

Rear view

Front view

Close up of eyepiece holder

Original eyepieces, 17mm 65degree

Additional 32mm eyepieces (meade s4000 super plossls)

[GazOC]

I've got a pair of those Gordon, I've never had to adjust them but sometimes the images won't merge if the inter pupilary distance is not set right for my eyes, I take you've tried that though?

Failing that maybe the prism may has moved. You can take a look by removing the black plastic wings, they come off (and go back on) pretty easily.

[GordonCopestake]

I've tried moving the IPD until i'm blue in the face hehe, not tried taking the "wings" off though. Do they just snap on and off? Screwdriver under the plastic sort of thing?

[GazOC]

Screwdriver under the plastic sort of thing?

Yep.

[GordonCopestake]

Thanks Gaz, i'll have a play and see what I can see

[mike bacanin]

Gordon, i've had 2 of these. sounds like a collimation issue with the bino.

the only time i could not merge was with 5mm or less eyepieces, and that is really something that can happen at the price level of these binos, but generally the views i had were very good using 10mm and up eyepieces.

regards

mike

[robindurant]

The one I have hinge in the middle like a pair of Bins to centre the two tubes to your eyes so that the image merges into one. I found them great for Planets and the Moon jumps out at you. Hope you get them right. I also found that the highest mag eps I could use were 2x 30mm but with a lens less barlow it gives you great magnification.

[GazOC]

Yep, they are great for planets and particulary the moon. How come you can't use higher mag eyepieces Robin, I use from 9mm to 30mm in my cheap pair? Is it Focus issues?

[philsail1]

Gordon,

Have you binoviewers been dropped or taken a knock of some kind? Are they brand new and under guarantee?

I don't anything about "binoviewers" but I have repaired the odd pair of old binoculars in the past - binoculars which were badly out of collimation due to one of the prisms having moved. (usually through being knocked or dropped).

If, and when you take yours apart, try and see if you can notice if one of the prisms have moved. In older binoculars the prisms were held in by screwed down strips of steel, with a drop of wax to seal them in position. I don't think the newer ones will be held by wax as well as screwed down sprung steel.

Look though each of the oculars in turn - sometimes you can see which one is off the horizontal view.

If you do adjust - only move one prism until you get it right with the other one.

Good luck!

Phil edwards.

P.S. apologies if you already know all the above!!

[GordonCopestake]

Blimy! I can't seem to get the plastic covers off. Theres not even enough space for a stanley knife blade to slip in. More effort needed perhaps but then that runs the risk of damage to the covers.

Thanks for the tips guys, keep em coming!

[GazOC]

I've just checked mine again Gordon and there does seem to be a little glue residue on the pastic, maybe I had to force them a little more then I remember. The two prisms are fixed on with screws so it should be pretty obvious if they are out of alignment.

[GordonCopestake]

Thanks Gaz, i'll have to get my elbow grease out!

[GordonCopestake]

Finally got around to messing with these. Discovered the best way to get the plastic off is with a sharp rap with the back of a butter knife (dont ask). Worked like a charm though.

Got the plastic off only to discover though that the prisms are cemented in Means that theres no adjustment and i'm stuck with a pair of bins out of collimation I can't adjust. I guess i'm stuck to using 32mm eyepieces which are just about usable. Hey ho, you live and learn

[Emil J]

Hi I would like to add my two cents worth, The glue, cement or wax can be removed, dont know how, but There is this guy online Cloudy Nights, Denis, who car srvice or upgrade binos for a fee, he removes the adhesive and replaces them with screws, dont ask me how so all is not lost.

Im having issues with my binos also which i just purchased, seeing doubles, I figure the prisms are out of syns, so Im going to do a bit of DIY to rectify myself, too much trouble to return them to China.

Emil J.

[Vondragonnoggin]

Denis has a few threads showing various BV’s taken apart and some steps he’s done. He also lists BV’s in the classifieds he’s already “Supercharged” (increasing clear aperture to accept eyepieces with wider field stops).

 

I have a William Optics BV and it was cheap used but works ok, but definitely has given me the incentive to save for a better BV that will take my pair of 24mm 68° eyepieces without vignetting. When you get a good BV, the planetary and Lunar views are really rewarding. Last clear night I had was the 8th of June and I spent two hours out on Jupiter alone. Had some really good seeing and took my 6” mak to 260x 

 

I spent the first hour straight on the moon. I see much more detail at less magnifications with two eyes.

Edited June 17, 2019 by Vondragonnoggin