And if it is possible to correct your vision with the camera lens, can the picture then be printed with the same clarity for the poor vision haver?
Disclaimer: I’m not an optician. I do, however, work in advertising and happen to have a number of clients in the lens manufacturing industry. Take what I’m about to say with a grain of salt.
Short answer is, not really.
Diagnosing vision issues is much more complicated than simply “is it in focus”. The shape of the cornea, how your eye physically reacts to light, distance from an object, and disease all have an impact on how you perceive the world around you. That’s why you have things like aberrations, glares, near sightedness, far sightedness, and a plurality of other vision problems. When someone is fitted for glasses or contact lenses, a number of parameters (read, dozens) are required get what is considered a proper “fit”.
There are some similarities between how a camera lens works and our eyes, but you also have to consider that you’re not just looking through the lens itself, you’re focusing on a screen that’s attached to the lens. So, if you can’t focus your eye sight at the distance the screen is at, it doesn’t matter what the camera is seeing, because it’ll look like garbage to you either way.
I think they might be referring to a camera with a direct, through lense, viewfinder. Like a pair of binoculars.
I thought the same maybe, but I assumed an actual camera because of context (using the camera’s manual focus and printing out the photo afterwards). @[email protected] ? Did I misunderstand?
You can adjust the dioptres of the viewfinder with a little scrollwheel next to it, to match your personal eyesight. Farsighted people will then be able to look through the viewfinder without wearing their glasses or contact lenses and see a sharp image. They will see the same sharp image as a person with perfect vision would see looking through it with the dioptre setting at 0. Then the photographer can use the manual focus to take a picture that looks sharp to them (with adjusted dioptre-setting) and it will also be a sharp photo ‘to the camera’.
I’ve wondered about this. Sometimes I use my phone to find my glasses, I can hold it close to my short-sighted eyes and see things clearly that are far away.
Binocu-spectacles would be pretty cool, we already have the technology to make a digital display with a voice-activated stepped zoom control…
DSLR’s have optical focus adjustment knob right next to viewfinder, at least on Canon DSLR’s. You have to calibrate it first, though.
I think not, if the camera uses a screen to display images it’s essentially the same as an image on our computer/phone, as a bunch of pixels a fixed distance away from our eyes. Change focus point of our eyes can’t unblur an image.
However if there’s a camera that when taking photos the person looks directly into the lens, it will be different. Here the lens funcions as glasses.
Manual focus cameras were in use way before the invention of pixels or electronic screens ;). The focusing screen was a plate of frosted glass that the lens image projected onto. It was all completely analog. The the length of the light path through the lens to the focusing screen had to exactly match that to the film, or else the images would be out of focus.
If the person can view the image through the glass directly probably. Not so much if it’s put onto a screen or printed. In simple terms the data is “flattened” and will just appear extra blurry rather than correcting anything.
For a full explanation you’d want to learn about how glasses work to correct vision in general. Maybe how camera lens focus or how light refraction works.
I would think so. If one is nearsighted and can resolve the display of a camera, then focusing the camera on a distant object should let the viewer see the distant object without any other vision correction.
Yes, at least in the era of serious manual focus cameras, you could get diopter correction eyepiece adapters. For example this:
https://www.nikonusa.com/en/nikon-products/product/eyepieces/dk-20c-2.0-correction-eyepiece.html
As I remember, the Nikon FA had something like that built in, rather than it being an accessory that you had to buy. But that was in the distant past so I’m not sure.
