Varifocal Lenses and camera use

[benjiboy]

It's time folks for me to have my eyes tested again and order some new glasses , at the moment I use bifocal lenses, but am tempted to order varifocal lenses this time, I am concerned about how suitable varifocals will be for use with my reflex cameras, has anyone any experience of this that they can share ?

 

[Roger Hicks]

It's time folks for me to have my eyes tested again and order some new glasses , at the moment I use bifocal lenses, but am tempted to order varifocal lenses this time, I am concerned about how suitable varifocals will be for use with my reflex cameras, has anyone any experience of this that they can share ?

My wife Frances Schultz (who wears varifocals) says she has no trouble focusing rangefinders, but can't focus eye-level 35mm SLRs with them. She say she seems to recall others saying the same.

On the other hand, she just puts dioptre eyepieces on her SLRs and focuses without glasses.

Cheers,

R.

 

[benjiboy]

Thanks Roger, if thats the case I think I'll probably stick to bifocals, because I use 35mm SLRs, and Mamiya TLRs and I'm concerned that if I'm on the "wrong bit " of varifocals my pictures will be out of focus, and as you will know with reflex cameras the eye becomes part of the optical system I'm not able to use eyesight correction lenses on my 35mm SLRs because I have astigmatism, and what looks in focus in the landscape format as soon as you change to the portrait format no longer looks in focus.

 

[Dan Fromm]

Bentley, I went from trifocals to varifocals and ran screaming back to trifocals. I don't know whether the lab made a mistake or what, but my varifocals' variable magnification drove me to distraction. They made objects that I knew were circular look oval. I gave the varifocals a month, then wrote them off as a bad mistake to which I'd never adjust.

Cheers,

Dan

 

[benjiboy]

That's what I 'm Afraid of

Bentley, I went from trifocals to varifocals and ran screaming back to trifocals. I don't know whether the lab made a mistake or what, but my varifocals' variable magnification drove me to distraction. They made objects that I knew were circular look oval. I gave the varifocals a month, then wrote them off as a bad mistake to which I'd never adjust.

Cheers,

Dan

Thanks Dan that's what I'm afraid of, I think that at least with bifocals you know where you are, so to speak.

 

[Woolliscroft]

I am a bifocal wearer. I tried varifocals a while ago but gave up on them. They just seemed to produce one sweet spot in each area where the world was in focus and differing degrees of blur everywhere else. Most of the time now I use the dioptra control in the viewfinder (even my old Leica IIIa has one) and keep my glasses on my head until I have finished taking pictures. I am long sighted, so I can still get a fairly good distant view without the glasses so I can usually see what I am going to photograph. My method might not work for short sighted people.

David.

 

[Mick Fagan]

Bentley, I have had quite a lot of problems with eyesight in the last four or five years.

I have gone the usual route of needing reading glasses, then requiring something better, so I went to multifocal.

In this case I tried Bi-focal at first, they were quite good. I then required a third set of adjustments and stayed with multifocal and had tri-focal, once again, not to bad.

Meantime I developed an eye disease which made it virtually impossible to get sharp focus, even using a magnifying glass.

I was at my wits end and was close to having to stop riding motorcycles, couldn't see a book well enough to read, television and/or cinema was out of focus.

I visited specialists with the only outcome being to line their pockets and have them tell me they were mystified. Finally I found a youngish woman eye specialist who made a correct diagnosis, that was the good news, the bad news is, there really isn't a cure.

She did though, have some interesting information for managing my symptoms, since re-inforced by my German, sister-in-laws husband, who is an eye surgeon and specialist in Munich. I visited him over last Christmas and he examined my eyes, confirmed the diagnosis and agreed fully with the proposition from my specialist in Melbourne.

Get big glasses, not those silly little rectangular current fashionista things.

Well, with some trepidation I ordered variofocal lenses for my biggish frame, which has housed my Bi-focal and Tri-focal lenses.

One of my particular problems is the requirement for me to see forward whilst I'm riding a motorcycle. When riding a bike, you usually lean forward a bit and this causes you to look through the very top of your glasses. I got the idea of large frames about 10 years ago when I remembered the fella on Pot Black playing snooker with upside down glasses, cannot remember his name, but I remember his glasses.

Well, they work a treat. Yes, they do have some problems with very narrow areas of focus, but when you do have focus, it's in focus better than multifocal. The reason is because you can change the angle of your head slightly and in doing so, you get pin sharp focus. I don't really get pin sharp focus anymore, never will again, but the effect is as good as you will ever get.

As my eyesights ability to focus clearly, changes on a sometimes weekly basis, I require variable focus lenses which can be manipulated, or re-focused, by changing the position of my head so that my eyes look though a different strength of magnification. Think about it and you will understand.

Having largish lenses, instead of small lenses, means the manufacturer can make a better and more graduated change. Positioning of the lens in your frame is also important. As is the quality and thinness of the optical material.

Another consideration is the coating(s) you may or may not wish to have.

My Sister in-laws husband, advised me not to have lenses with the chromatic stuff, that auto darkens when in bright sunlight. The coating affects the ability and clearness of the optical material. He showed me some samples in his surgery which made me agree that the auto darkening feature is very handy, but for the absolute clarity requirement I need, not a good idea.

I have a clear set of glasses, as well as a set coated in a neutral grey. This grey coating does not add any colour cast and allows me to see colours reasonably well. Green sunglasses, actually do human eyesight a disservice in the colour department, it appears.

Now to the question you asked. I run Nikon F3 cameras with the High Eyepoint (HP) viewfinder, had them for just over 20 years and they are the best things for optical glass wearers. I can focus using these variofocal glasses quite well.

I can see through the viewfinder and focus my Nikon FE2 as well with these glasses

These type of glasses are not that good for reading a book. They are fine for reading a newspaper on a train or wherever, reading timetables and seeing the numbers on a mobile phone. But they are a pain in the rear for reading or using a computer. For that I have reading glasses which are far better.

Mick.

 

[Philippe-Georges]

What is the difference between the bifocal, trifocal, multi-focal and the varifocal spectacles.
As I was afraid of having viewfinder problems, I took two differed spectacles, one for reading and one for 'normal' use . But this is not very convenient so I am considering one combined set, but what to choose?
Thanks,
Philippe

 

[benjiboy]

I am a bifocal wearer. I tried varifocals a while ago but gave up on them. They just seemed to produce one sweet spot in each area where the world was in focus and differing degrees of blur everywhere else. Most of the time now I use the dioptra control in the viewfinder (even my old Leica IIIa has one) and keep my glasses on my head until I have finished taking pictures. I am long sighted, so I can still get a fairly good distant view without the glasses so I can usually see what I am going to photograph. My method might not work for short sighted people.

David.

Thanks David, I got my eyes tested last week, it had been three years since my last one and did need a new prescription (or a sharp tap on the side of the head: ) and had the existing bifocal lenses replaced with new ones, so I can use my cameras with them (Canon A1s ,FTbs and Mamiya C TLRs ) I have astigmatism, so correction lenses are no good to me unless they rotate.

 

[David H. Bebbington]

What is the difference between the bifocal, trifocal, multi-focal and the varifocal spectacles.
As I was afraid of having viewfinder problems, I took two differed spectacles, one for reading and one for 'normal' use . But this is not very convenient so I am considering one combined set, but what to choose?
Thanks,
Philippe

Bifocal, trifocal, multi-focal and varifocal are all the same insofar as one part of the lenses (the top) is good for distance and another part (the bottom) is good for reading. The only difference is how many steps the lenses take to get from one to the other (bifocal = 2 steps, trifocal = 3 steps, varifocal = stepless). To use a camera viewfinder, you need to look through the distance part of your spectacle lens - if the lens is trifocal or varifocal (stepless), the distance part will be that much smaller. If your eyes just need a diopter correction (i.e. you can see clearly without glasses but not at all distances), you have the option of fitting diopter correction lenses to your camera (instead of your face). If, like me and other posters here, you have astigmatism (inability to focus vertical and horizontal lines at the same time), you do not really have this option, sicne you need to wear your glasses all the time. LIke Mick Fagan and others, I have a pair of stepless varifocals for general use (including driving) and a pair of reading glasses - in fact I have 2 pairs, one to give a focus at about 1 meter for computer work, another for 50 cm for reading. When I used a view camera a lot, I had an extra pair of varifocals with a hinged supplementary lens that gave a focus at about 10 cm - this was guite useful!

 

[DWThomas]

I'm near-sighted, have astigmatism and have been wearing the varifocal type for maybe a dozen years or so, never had bifocals. I can do most things with them OK, including camera focusing, but they did take quite a while (months!) to get totally used to in the beginning. They do suck for reading music on a stand out in front (very narrow field of focus), for which I finally got a single distance pair which are also pretty good at the computer (though I usually don't bother). I suspect some of the reactions heard here could depend a lot on the specific prescriptions. Varifocals can indeed produce some odd curvature of linear patterns away from the center, but somehow the brain seems to learn to adjust that (scary huh!) Lately for real close-in fine work I've been putting on a pair of cheap +1.5 reading glasses right over the regular specs -- works quite well. I suppose in another ten years, I'll need the +3 jobbies.

Putting glasses on upside down is an attractive idea for working on plumbing, wiring or whatever over the head -- boy can that be frustrating!

DaveT