Mamiya 7 Dioptre question...

[Bobfrance]

Hi guys,

I wear glasses and I need an eyepiece dioptre for my Mamiya 7, however I'm not sure what level of correction to go for. I visited my optician, (who does dioptre checks for the local Leica dealer) and he said I needed a Dioptre that cancelled out the viewfinders built-in correction.

Unfortunately I haven't been able to find out what that correction is. I've asked at Robert White's and they said they didn't think it had any built in correction, but weren't sure. If they're correct then that means my optician is wrong.

I've been unable to find the relevant technical info on the web. So i'd be very grateful if anybody could enlighten me.

Also I'm in the U.K and would be interested to hear of any good suppliers. Robert White has said delivery would be six weeks. I'm sure I could get one quicker from Japan.

Thanks!

Bob.

 

[hlopsys]

Mamiya 7 certainly doesn't have any built-in correction. Diopters are coming in -1, -2, -3 and +1, +2, +3. I've bought my -1 from Adorama (delivery to Singapore - quick but costly via UPS) last year

Hope that helps

 

[Bobfrance]

Thanks!

Just to be clear, when I say 'built in correction' I don't mean a built in adjustable diopter like many cameras have, but that the viewfinder has a degreee of lensing in it's design. Leicas for instance naturally have something like -0.5 (so I'm told).

 

[john_s]

The viewfinder system of most cameras is designed so that a person with normal sight at infinity will see the image at a virtual distance of something like a metre or two. You don't have to "cancel it out." Theoretically, you need a diopter that will enable you to see an object at infinity (without the camera).

For example, my right eye needs -1.75 to see at infinity (for driving etc). I am short sighted. For Mamiya, since there is only -1 and -2, I have to try both. It turns out that -1 is better for me than -2 even though you might think that -2 is closer to -1.75. The -2 is quite a strain.

The choice between -1 and -2 for me has something to do with the Mamiya viewfinder as well as my eyes, but it's mostly about my eyes. If my eye prescription was +4 I'd need something like a +4 diopter.

 

[ChrisN]

Not specifically related to the Mamiya question, but there's a good article on eyepiece correction in Andrew Nemeth's Leica FAQ.

 

[Bobfrance]

Thanks for the feedback.

I fear i've stilk not been all that clear. I wear glasses when shooting (short sighted) so my vision is corrected for distance. It's focusing on the shutter speed numbers and rangefinder patch I have the issues with.

 

[nathan96]

If you are wearing you prescription classes when shooting the Mamiya 6 then you don't need a diopter.

The problem you may be struggling with is eye relief. You may wish to try shooting WITHOUT glasses but with the correct diopter in place

 

[john_s]

If you can see infinity well, and you're wearing your glasses when using your camera and you are, well, shall we say, not very young, you might need a +ve diopter to see the details in the viewfinder. A +1 would be worth trying. I might have one that I don't need (it came on a camera i bought). I'll have a look early next week if you're interested.

There is a scary page on wiki about optical prescriptions that shows the decline in accomodation as we age. When we are young, the wrong diopter is not much of a problem because of the flexibility of the eye to change focus. When old, it's a different story. When very young, we can adjust over about a 10 diopter range. Me, now, it's about a total range 0.5 diopter which is why the choice of diopter is critical.


As a matter of interest, what is your eyesight prescription?

 

[Bobfrance]

Thanks for the info and the kind offer John. I'm short sighted and perscpiption for my right eye is -3.00 (think it's a minus).
I ordered a +1 diopter from Robert White's today after being advised that the Mamiya viewfinder is -1. I'll try it and see how it goes.

I'm 41 BTW. 🙂

Bob.

 

[john_s]

.........I'm 41 BTW. 🙂

Bob.

Sorry, I thought you might be as old as me! Seriously though, it does become more difficult. My prescription for driving (=infinity) has barely changed since I was a teenager, but getting the right diopter has become more tricky. I have recently had to go from -2 to -1.5 for my Leica M6.

Let us know how the +1 goes.