Best diopter for focusing glasses

[BetterSense]

I can still focus my eyes down to around 1 foot without needing correction. My normal prescription only corrects for astigmatism. But, for extended ground-glass viewing, I would like to order a version of my standard prescription with +2 or +3 power. The purpose is more comfort and possibly being able to get my face very close to the screen so I don't need a loupe.

How much power is too much for this kind of thing? is +3 or even +4 too much?

[Kevin Crisp]

Hard for anybody to answer anything so personal, and variable. Go to a drug store with reading glasses on display. Figure out how close you want to get, then try them on. I'm guessing a 2.5 would probably eliminate need for a loupe if your eyes are really that good.

If I could really focus down to 1' already I could probably get by without a loupe in many situations.

[BetterSense]

One of my cameras is a 6x7 view camera. So the naked eye is marginal, yet using a loupe is also tough.

[Greg]

I use a Galvin 2x3 view camera.
Eyes can focus a little closer than one foot
+3.25 works for me (but I much prefer a reflex back).

[Graham Patterson]

I have reading and computer prescriptions - the computer set focuses to just beyond arm's reach. But switching from normal to closeup sets is a pain in the field, and I don't like bifocal or blended vision. So I use a set of flip-up magnifiers on my standard prescription. Suits me. I keep one set with the LF gear, and another set at work for odd jobs.

Just work out how close you want to be to the ground glass, and ask your optician for a suitable prescription if you want a close set. Eyewear is not a place to skimp or make do if it can be avoided.

[Eric Woodbury]

You can try out different diopters at the local eyeglasses display at the drugstore. The problem with getting very close with eyeglasses is that small changes in your eye-to-groundglass distance will blur the image and you won't know whether 'you' or the camera is out of focus. A nice lupe fixes this since it is set at a fixed distance from the ground glass.

Good luck.

[LabRat]

Do go to the store display and try different reading glasses... But first, set-up your camera and note your common eye to GG viewing distance as a baseline so you will be looking for glasses that will optimize that distance for you...

For me, I need very minor C/U correction for my nearsighted condition, much less than the diopters that are sold in off-the-shelf glasses, but I wanted a more powerful pair for loupe use... I found a bunch of hard to find metal framed full eye (rather than bi-focal) glasses at a bargain store for $1.50, and started trying out +3.0, but I found that they gave me more eyestrain than +2.0 (at the same viewing distance distance) so I went with those... (The full eye glasses gave me more freedom to view the entire GG and at angles to see the corners better, but bi-focals would be able to allow "looking over" the glasses to see at normal distances better without taking them off...)

If in doubt, go to an optical store, and they will hand you a tray or box set of reading glasses and you can try all, and order whatever you prefer... (I ordered a custom pair of +0.25 mild for computer or print viewing distances (at arm's length...)

Steve K

[ic-racer]

You might want to look into 'progressive' corrective lenses. Just got my second prescription in that style last week. It might save you having to change glasses to focus.

[BetterSense]

I just played around with reading glasses at Walmart.

If I want to use the glasses as a loupe, and get really close, then +3 is better than +2. However, once I get that close, I'm too cross-eyed to be comfortable with two eyes. It's fine if you close one eye, though, which leaves the possibility of either a high-mag lens in only one side, or, using prism power the cancel out the cross-eyed effect, which would make the glasses truly worthless for anything more that that exact distance. I think I will get a pair with no correction on the left, but my standard correction in the right eye plus 3 diopters. It will be my wearable loupe.

I have nice everyday glasses, but I also buy cheap glasses from Zenni at $12 each fully coated, for yard work or if I want a different prescription. I have some tinted ones at +1 my normal for brazing.

[neil poulsen]

You can try out different diopters at the local eyeglasses display at the drugstore. The problem with getting very close with eyeglasses is that small changes in your eye-to-groundglass distance will blur the image and you won't know whether 'you' or the camera is out of focus. A nice lupe fixes this since it is set at a fixed distance from the ground glass.

Good luck.

I used to have prescription glasses for this purpose. I worked with my optician to get the correct magnification. But, those were misplaced. :o

So, off to the drugstore to do the above. With some of the drugstore glasses, it's possible to pop the lens out of one pair and back into another. The advantage is being able to correct for both eyes, each of which may require different magnifications. This costs me about $22 to correct both eyes.

I use these glasses at about 11 inches or so, only for composing. Then, I use a loupe for fine focus. Works great.