Today’s Question: I know you wear glasses and I also wear glasses, but they are “progressive” lenses. As a result, I often seem to have trouble getting manual focus exactly right. What would your advice be? Should I get a standard pair of reading glasses or a prescription just for photography?
Tim’s Quick Answer: I would recommend using a pair of reading glasses when focusing manually, using live view on the camera’s LCD display to evaluate the focus. If you prefer to focus through the optical viewfinder, I recommend getting a pair of glasses with a single distant-vision prescription rather than using progressive lenses.
More Detail: My eyeglasses do have progressive lenses, so I have dealt with this challenge firsthand. It can be challenging to make sure you’re looking through the right area of the lens to ensure your vision is sharp for evaluating manual focus.
I find the use of live view on the camera’s LCD display tremendously helpful for accurate manual focus. Most cameras enable you to zoom in with this live view display, so you’re able to get an even closer look at the area of the scene you want to use for evaluating focus. Since you would therefore be viewing the LCD from a close distance, reading glasses work very well in terms of avoiding the challenge of progressive lenses.
If you prefer to adjust focus by looking through the optical viewfinder, you’ll likely need distance vision correction, since your eyes will be focusing at the same distance as the subject. In this case you would likely find it easiest to have eyeglasses with a single prescription to correct your distant vision.
It is also worth noting that you may be able to apply enough of a diopter correction to the viewfinder (if your camera includes a diopter adjustment) to compensate for your vision so you could use the viewfinder for manual focus without wearing your eyeglasses at all. When adjusting the diopter setting, you can evaluate the text and symbols projected by the camera in the viewfinder. When the text and symbols appear sharp, you’ve achieved the proper diopter adjustment.