[stephenmcleod]

Hey all,

I recently picked up a Spotmatic F, and I'm looking about for a diopter solution as I am pretty blind.

I've got the corrective lens adaptor coming, but I'm unsure what size the corrective lenses actually are. I know the originals are basically impossible to find, but my thinking is that I could either cut one out of reading glasses (not mad keen on this idea...) or else I could find a corrective lens for another camera and use that - but obviously it will be size dependent.

Does anyone happen to have the dimensions of the lens for the Spotmatic F/500?

Thank you!

---------- Post added 08-20-20 at 09:40 AM ----------

Ah, found it:

Diopter / correction lens size question - PentaxForums.com

19mm. I thought this was just for the 67, but seems to be the K series.

[stevebrot]

The genuine article to fit Pentax K-series bodies and earlier is hard to come by in the more moderate diopters, but a bit easier for larger correction. I use Nikon DK-20C correction eyepiece adapters on my Spotmatics and KX with good success. Note that if you would take a +1 with the Pentax adapter, the corresponding Nikon would be +0.0.


Steve

[stevebrot]

I've got the corrective lens adaptor coming, but I'm unsure what size the corrective lenses actually are.

Oops! I missed this part. I have the round Corrective Lens Adapter and yes, the glass is 19mm diameter.


Steve

[Praktica*ist]

Hello.
I'm using the Nikon rectangular eyepiece correction lens DK-20C on my Spotmatic F. It has the right overall size. Notice that at first, it was very hard to push into the viewfinder's guiding rails. But after a fine filing work on the grooves of its plastic housing, the correction lens will fit right in.

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Last edited by Praktica*ist; 08-20-2020 at 12:01 PM.

[kypfer]

For a circular lens, a local optician would probably cut an appropriate lens to size very easily.
With age, my short-sightedness has significantly reduced, so I can now utilise the built-in correction on my DSLR's, but back in the "old days", when I could read newsprint on the end of my nose, I had a couple of lenses cut to size to fit different cameras. They always seemed keen to help and pleased to have something slightly different to do

[stephenmcleod]

Following up here to err, square the circle, so to speak. Hopefully it will be useful for someone in the future.

1. I got a hold of a Pentax 'corrective lens adapter'. I was searching for Pentax diopters and not turning up much. These essentially allow you to use different screw-in corrective lenses, or lenses without a screw.
2. Olympus 19mm, Nikon F2 and F3 screw-ins do not fit.
3. Canon F1 screw-in lenses work perfectly.
4. You can get 19mm corrective lenses on eBay for fairly cheap which will fit inside the Pentax adaptor.

[stevebrot]

Following up here to err, square the circle, so to speak. Hopefully it will be useful for someone in the future.

1. I got a hold of a Pentax 'corrective lens adapter'. I was searching for Pentax diopters and not turning up much. These essentially allow you to use different screw-in corrective lenses, or lenses without a screw.
2. Olympus 19mm, Nikon F2 and F3 screw-ins do not fit.
3. Canon F1 screw-in lenses work perfectly.
4. You can get 19mm corrective lenses on eBay for fairly cheap which will fit inside the Pentax adaptor.

Thanks! This is super helpful. I have the Correction Lens Adapter for the M42 bodies, but no glass that works for me. I may try your suggestions.


Steve

[ZombieArmy]

I should try getting something like this for myself. It's kinda tiresome to smush my glasses into the back of the spotmatic to just get "most" of the frame

[stevebrot]

Canon F1 screw-in lenses work perfectly.

When you say "does not fit" or "work perfectly" do you mean as a direct screw-in to the Correction Lens Adapter or just the glass portion?


Steve

[stephenmcleod]

19mm glass lenses (without the black screw part) work with the pentax lens adapter. Screw in lenses (with the black metal screw rim joined on) from Olympus and Nikon F2/F3 do not fit/screw in to the adapter - but the Canon one I mentioned does.

Hope that helps!