DIY diopters for prism finders (and WLFs?),-leave your glasses at home when shooting.

[emtor]

I'm getting old and far-sighted and focusing is a nightmare. I often forget to bring the right strength of glasses with me and they're always in the way when I do remember to bring them along. Being a Bronica owner, coming across diopters that suits my eyesight isn't easy.
So, here's a receipe on how to make your own custom diopters in 30 minutes for the price of a pair of cheap gas-station reading glasses.
This method should suit well for all kinds of cameras and their prism-finders and making diopters for waist level finders shouldn't be that hard either.
To find the correct strength of glasses, choose the strength of glasses that makes you see through the prism-finder sharply.

Below:
A pair of cheap reading glasses and calipers and a needle.
Measure the original diopter's opening with the calipers and place it on the glasses.
Scribe two paralell lines.

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Turn the calipers 90 degrees and repeat the process.

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Here's what you should end up with:

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Cut out the square using a fine-toothed modellers saw, file the sides if they're uneven and press it in place on top of the original diopter and that's it.
No more focusing trouble for us older guys and girls.

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Making diopters for WLF's is only a matter of finding glasses large enough to cover the original enlarging lens. A tiny drop of epoxy-glue will hold it in place.
Don't use super-glue. The vapours will make a frosted diopter. Not good . . .

 

[paul ron]

Great idea, I like it.

Just a side note, be sure to center your cuts around the center of the lens or you will not get the correct diopter magnification.

 

[emtor]

Great idea, I like it.

Just a side note, be sure to center your cuts around the center of the lens or you will not get the correct diopter magnification.

I did, but the thickness of the lens will still not have a uniform thickness.
That does not seem to ruin too much though.
The image in the finder seems very well in focus all over.

 

[emtor]

And here's a diopter for the magnifying-lens of the WLF:

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[paul ron]

So I made your diopters for both my RB and my ETRS prisms. Now I still can't see the shutter and F stop settings n still have to carry a pair of glasses. Any cures for those yet?

Thanks, nice project.

 

[Steve Smith]

So I made your diopters for both my RB and my ETRS prisms. Now I still can't see the shutter and F stop settings n still have to carry a pair of glasses. Any cures for those yet?

Laser surgery?!


Steve.

 

[resummerfield]

So I made your diopters for both my RB and my ETRS prisms. Now I still can't see the shutter and F stop settings n still have to carry a pair of glasses.......

I had the same problem when I tried to use a diopter lens on my SLR. In the end i just used my regular glasses and leave the normal diopter on the finder. Getting old is no fun!

 

[emtor]

So I made your diopters for both my RB and my ETRS prisms. Now I still can't see the shutter and F stop settings n still have to carry a pair of glasses. Any cures for those yet?

Thanks, nice project.

I noticed the same thing, the shutter speed indicator in my prism finder isn't in focus either. The cause of this must be that the indicator segments aren't in the plane of the camera ground glass but located nearer to the diopter.
I haven't tried yet, but it may help to not letting the lens go all the way up on the original diopter, leaving a narrow slit to view the segments through, or even using a piece of lens with a different strength in the segments part of the field of view.
I'll give it a shot as soon as time permits.
The segments are still readable in my finder despite being a bit out of focus, but this may be dependent on the lens strength used for the diy diopter.
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[paul ron]

A good way to see what strength diopter you need is to take the lens off the camera, look through the finder, facing a white background, n look for the grid lines to be in focus or any details on the GG or screen. Once you find the sharpest one, that is the strength you need. You only have to focus on hte screen not an image through the lens, this is where it is projected and adjusted to

I think I can get use to "being" old but not the "getting" old part of it. I use to be able to see the pecker of a fly at 1/4 mile, now I can't tell the sex of an elephant at 40 paces.

see my new cure?