10x eyepiece for 23.2mm tube that fits this 33mm smartphone holder?

[jason]

I bought this phone holder recently:
https://www.amazon.com/gp/product/B07KF57C5K

I like it reasonably well, but I find the 20x lens it comes with to be a little too zoomed in. It'd be nice to have one that matches the other eyepiece in my binocular head. This would be nice because I could look through the lens and get things positioned for the camera. Right now, the focus is different for the 10x eyepiece and the 20x one. So if it's in focus in the 10x eyepiece, it's out of focus in the camera.

What I'm wondering is if you can find 10x eyepieces that have a head wide enough to fit in this adapter. The eyepiece it comes with is 33mm at the top (the part that jams into the adapter tightly to keep it together). It's a bit bigger than my eyepiece that came with my Olympus KHC shown in comparison:


And the 20x has a smaller diameter lens than the 10x, but I assume that's just a 20x thing. I assume if I got a 10x that fit in there, it'd cut off some of the field. But maybe it'd fill the full frame of the camera lens more?

The one that came with it also has a groove that a removable rubber ring goes around. This helps keep it firmly in the adapter.

[david_b]

I'm thinking that with a 10x you would see a circular image within the rectangular phone display.
You'd then need to use the phone's zoom to fill the screen.
The supplied 20x eyepiece is doing that for you, optically instead of digitally.

[Chris Dee]

If you know someone with a 3D printer they might be willing to design/print an adapter for you.

[jason]

I'm thinking that with a 10x you would see a circular image within the rectangular phone display.
You'd then need to use the phone's zoom to fill the screen.
The supplied 20x eyepiece is doing that for you, optically instead of digitally.

Even with the supplied eyepiece, it's a circular image that has to be zoomed. Maybe it works better with other smartphones (mine is a motorola nexus 6), but I don't think so.

[david_b]

Then I'm not understanding, "I find the 20x lens it comes with to be a little too zoomed in..."

[jason]

Then I'm not understanding, "I find the 20x lens it comes with to be a little too zoomed in..."

It's a 20x, so it's twice as zoomed in as my 10x eyepiece that's on the other side of the binocular scope. So the focus point for one side is different than the other. And it's often much easier to find something to see on the 10x because you're going to be able to see a larger field. Plus, by going with a 20x eyepiece, I'm not getting any more actual resolution than with a 10x.

[david_b]

Wouldn't it be easier and cheaper to buy an adapter that clamps on to your existing 10x eyepiece?

[Scarodactyl]

I think that your olympus 10x there is compensating. One reason they might supply the adapter with a 20x eyepiece is to crop out the outside of the field of view where eyepiece corrections are more important to improve chromatic aberrations and field flatness. If you do use a generic non-compensating 10x eyepiece the results will likely be worse at the edges. If possible it would probably be better to get another identical Olympus eyepiece and use tape or something to make it a snug fit.

[jason]

The main reason I haven't pursued an adapter that would let me use regular eyepiece is that I also haven't seen any that do such a thing. It seems pretty non-standard.

Maybe I should order this one, which seems like it'd fit a variety of diameters of eyepiece. Of course, it may fit lot of eyepieces poorly rather than one eyepiece fairly well like the one I have.

Thanks for all the responses.

[Scarodactyl]

I have one with a screw-driven clamp for the eyepiece that works fine.