Presbyopia And Focusing The View Camera

[Lloyd Chamber]

In using my 4 X 5, I find I have trouble accurately focusing. At age 36, I have slight prebyopia and I find I have to move my head away from the ground glass m ore than I'd like to be able to see it clearly. But when I do that, it's hard t o see the fine detail, and the darkcloth sags.

I assume some kind of reading glasses are in order, but which are best? I recal l hearing something about a jeweler's eyeglass and of course there are also plai n reading glasses. Do either of these improve the situation significantly?

[Dominique Labrosse]

I'm sure reading glasses might be in order for everyday stuff. But using a loupe on the ground glass of your 4x5 might be more practical. Hint: I found that my Nikon 50mm lens (off my 35mm kit) works great as a loupe.

Regards

[Jeff Buckels]

Lloyd: I'm a little older than you and have fairly substantial presbyopia. I wear good quality "reading glasses" all the time at work, but I find they don't work well with groundglass focusing. Reading glasses are optimized for, you know, a foot and a half or whatever. So, anyhow, I just wear a loupe around my neck and pop it in my right (strong) eye when I'm ready for fine focusing. I use my reading glasses up to that point. It's all a bit awkward, but as you suggest large format photography isn't "opimized" for people with eyesight problems. -jb

[Steve Baggett]

I had my optometrist write me a prescription for special reading glasses (for my presbyopia and astigmatism) for 6-inch viewing. He was a little incredulous until I carefully explained how they were to be used. He told me to make sure the optician accounted for some parallax adjustment, since at 6 inches your eyes are not pointed "in parallel". The glasses stay in my camera case and work well. They are "half-glasses" so I can put them down low on my nose to look over the top of them. You might give this a try.

[Sean Yates]

Presbyopia? Does this afflict other denominations? Or does it mainly afflict elected executive officers?

[Struan Gray]

I posted this in a loupe thread, but it bears repeating here. Those special prescription glasses are a stock item for surgeons who need a mild degree of magnification when working on something close. If you do a search on "surgical loupes" you'll get lots of hits.

[Steve Grimes.]

The solution to Presbyopia ("old eye vision") is reading glasses. So called "Plus Spectacles" are, in my opinion one of the greatest technical inventions of all time. They are so simple as to make explanation difficult. Plainly put, the more the plus the closer you can get to the thing you are seeing and be in focus. When looking at a ground glass you are looking at the glass itself, not the object in the picture. So the problem is exactly the same as in viewing fine print.

You can experiment with drug store spectacles available in up to plus 4 strengths. You can also add spectacles together (wear two at the same time). If nothing else, this can help you let your optician know what prescription you need for your use.

There is no "wrong prescription" in reading glasses. The only variable is the focusing distance from the object viewed. Reading glasses will not "hurt your eyes"

The special viewing devices used by surgeons are actually spectacle mounted telescopes which are different from reading glasses (plus spectacles) in that they magnify objects at a distance (in this case about three or four feet) rather than allow you to get close to the object viewed (and still be in focus) as with reading glasses or ordinary jewellers loupes.

SKG

[Henry Friedman]

Another possibility, alluded to in the initial question, is a clip-on jeweler's loupe. These can be attached to the wearer's eyeglass frame, and flipped down in front of one eye for magnification. This alternative gives the advantage of a longer viewing distance for general composition and a reduced viewing distance for critical focus. Two disadvantages of a jeweler's loupe are: 1. Lesser optical quality - they are typically not aspheric design. 2. As compared to a typical photographic loupe, there is no stand to block non-image light or provide optimal focal distance. One must move the head toward and away from the groundglass until image focus is found.

If you are so inclined, a jeweler's loupe should be relatively easily available from a quality optician, hobby or low-vision supply house. Look for a model with a sturdy mount, it will be bumped frequently by your darkcloth.

By the way, I am an optometrist, and disagree with the previous contributor's suggestion that the power of the reading glasses is unimportant. The wrong Rx may accelerate the development of focusing problems, and/or exacerbate underlying eye teaming problems. See your eye doctor for a prescription optimized for your needs and visual status.

[Sal Santamaura]

"Fortunate" that I am to be very myopic, there's one small compensation as presbyopia develops. I only need slide regular distance spectacles down my nose and look over them. Built-in 3.5X magnifiers!

[Struan Gray]

Steve, one pair of surgeon's loupes I have fits your description, but the other is more like a ordinary pair of glasses. The lenses combine a diopter for magnification and a shallow angle prism to let you look about six inches in front of the tip of your nose without crosseye strain. Unlike reading glasses they don't occupy your whole field of view, so you can look past them to see the whole composition.

They're the best thing I have ever used for looking at a ground glass. I recently inherited a large collection of mapmaker's loupes, jeweller's loupes, geologist's loupes and much else besdes, and of all of them the wacky specs are the nicest to use. My only worry is that they're a bit delicate for heavy field use.