Suppose I’m trying to shoot a close up or a medium distance photo - does that determine which layer of my trifocals I look through in order to focus my camera? I never had this problem before, as I always looked through the distance part of the specs, as I remember. But I just got a bunch of picture back and some are really blurry and all I can think of is that I remember struggling to get some into focus, and maybe it was because I was looking through the wrong layer of the trifocals. Would that make a difference in the final focus? Suppose I’m trying to take a very close picture with a normal lens - not a macro lens. Wouldn’t I use my normal distance (top) layer anyway? Is this a question for an optometrist? A camera specialist? How do I figure this out?
More information is needed.
How is the adjustment to focus on your camera done?
E.g., on a digital camera with a screen, you look at the screen and adjust until it is in focus. Since the screen is closeup, you look thru the corresponding segment. On some cameras, you adjust until two parts line up. Which segment to look thru doesn’t matter aside from comfort and composition.
So it all depends.
On a telescope or binoculars, you can turn the focus knob to compensate for your eyesight. If somene with 20/20 eyesight focused a pair of binoculars for himself, then handed it to you, you’d have to re-focus it.
But a camera doesn’t work like that. On a SLR camera, there’s a focusing screen (basically a frosted glass) at the focal point. You aren’t looking through a camera, you’re looking at the screen. So the correct eyeglass section to use is whichever allows you to see the screen better. There are probably lines and other features on the screen; find out the best way to see those clearly. Digital cameras with electronic viewfinders are the same.
Sorry I didn’t make that clear. This is a SLR film camera with a through the lens viewer. No screen. I used to be able to just look through it and turn the focus ring until the image was clear, but with these new glasses, I’ve gotten a bunch of pictures back that were out of focus. I assume I was looking through the wrong layer in my glasses.
Even on an SLR where the image is presented in a frosted glass screen, there is a concave lens between the screen and the eyepiece that makes the eye perceive the screen as being a little further away than it actually is (usually comfortable reading distance, I think). Unless you are short sighted, it’s impossible to focus properly on an object held just an inch or two from the eye.
I assure you there is a focusing screen. Take off the lens and look at the top of the interior; you’ll see something that looks like a frosted glass or a fresnel lens. As Mangetout said, there is a lens (and prisms) between the focusing screen and the viewfinder (where you normally look into).
Using the wrong layer of your glasses does not shift the focus point. It just makes it difficult to see the screen clearly. That is, it looks fuzzy even when the camera is properly focused.
When you look into the viewfinder, is there a focusing aid or reference in the center? Maybe a focusing prism, or a square to indicate the center of the image? Can you see those clearly? If you can, your glasses aren’t the cause of your problem. If not, use whichever layer of the glasses that allow you to see them clearly.
Yes, yes, of course there’s a focusing screen in the viewer. I knew that. I should have said that. I thought you meant one of those big screens like the digital cameras have. So if I can get that little gizmo in focus that’s all I need to be concerned about? Regardless of the lens I’m using or the distance to the subject? Great. Yes, the camera I use has a little circle with a diagonal across it that is supposed to some how match when the subject is in focus. Either that or I should be able to see the subject in focus in that circle. So if I can do that, I should be ok, regardless of what lens I’m using or where the subject is? It’s done for me by the optics of this type of camera? I just have to find the place in my glasses that allows me to see that circle clearly? That’s what you’re saying?
Camera focusing systems are made to acomodate normal ranges of vision. If you wear glasses find the best area of the tri or bi focal, or no glasses at all. Whatever gives the best view of the focusing system is the way to go.
CC, does your camera have a diopter adjustment ? It changes the focus of the viewfinder. Finally, a feature made specifically for us with glasses. I’m guessing you adjust it by mounting your camera to a tripod, have someone with perfect vision focus your camera, then you step over and adjust the diopter so it looks focused to you. The link covers another method.
It’s a little knob, usually next to the viewfinder. On my Olympuses (Olympi?) it was visible; my current Minolta hides it beneath the viewfinder cap. If you can’t find it, please post the kind of camera for further assistance.
nope- it’s just an old Pentax P30t
The good news is that diopter adjusters are usually available. The bad news is the “name brand” ones are probably hard to find, but a good camera store will probably have universal adjusters that slip over the viewfinder eyepiece.
A word of warning. If your eyes are at the point they need trifocals, your days of manually focusing a camera may be numbered. I was at the “might benefit from bifocal” stage when someone looked at my negs and said “You’ve got astigmatism!” based on how my shots were all justhisclose from in focus.
That’s when I decided to stop wasting film and switched over to an autofocus SLR.