Adding prescription Lenses to Binoculars (1 Viewer)

[kabsetz]

I believe there are markings on the lenses visible to an optician that show the optical axis of the lens if you know how to look for it. At least my Zeiss lenses do. If you have a friendly optician who makes your glasses, ask them to show you.

As far a which glasses, the thinnest lenses would be best, and not progressives. Glad it has worked out for you.

 

[mekidear]

In the end I set the bins to my IPD, put my specs on and looked through again, removed specs and bins together and marked the eyecup position onto the lens.

It came out pretty much dead in the middle of the lens.

I have these lenses installed now and tried to take a few more photos this time. Will post up details when I have tested that they work OK

 

[mekidear]

I have taken a different approach with this pair of binoculars DD LUX HR 8x25. I had a spare set of eyecup units when I did the Opticron Travellers so was confident the eyecups could be removed and taken apart. I do not have spares for these binoculars and do not know if the eyecups can be removed in the same way as the Opticrons or at all. I am not keen on trying to remove them without knowing for sure for fear of ruining a new pair of binoculars.

Luckily the eye rubbers can be pealed back (they did come off completely eventually) to allow clear access inside. The eye cup tube beneath the rubbers had no internal lip so it is possible to load the extra lens and mountings from the front without taking anything apart.





I machined a couple of lens housings from Delrin (fantastic stuff for jobs like this) and a little tool to help modify the spectacle lenses.
The lens is stuck to the tool with double sided tape, stuck in a drill and spun against a suitable abrasive - I have a belt grinder which is perfect for the job 3HP is enough.



The holder tool is the diameter of the finished lens so it was just a matter of grinding until I hit the plastic.

 

[mekidear]

The lenses are secured into their housings with slivers of double sided tape and the lens whole assembly is dropped into the eyecup. Rotate to get the sharpest image and fix in place - I used a smear of white mastic, I would have just used Blue Tack but my daughter has nicked it all to fix posters on her bedroom wall


Pop the rubbers on and thats it - job done.

As most do not have access to a lathe, you do not need to machine lens housings like I have done. Suitable size O rings either side of the extra lens would do the job. You might find it a bit trickier to rotate and set the lenses to the correct orientation (I presume if you are attempting this you must have astigmatism) The plastic lens housings do make this easier.

 

[mekidear]

I tested these binoculars in the field earlier today and they work perfectly. I know its not rocket science

I hope this helps someone else have a go at this - if you are long sighted with astigmatism and don't wear your specs out and about, this really is a good idea!!

 

[Maljunulo]

Although I have no need for it, I think it’s terrific, and I think that you have done a real service for those who have to cope with spectacles and binoculars.

 

[Hermann]

As far a which glasses, the thinnest lenses would be best, and not progressives.

That's actually good advice for anyone wearing glasses as well.

Hermann