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02-11-2013, 11:57 AM   #1
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camera focus and spectacles

I wear glasses, my optician tells me my short sight and long sight have degraded, but I do not wear them when using my camera. When I focus on something, using one of my manual lenses I rely on the focus icon and beep to tell me focus is achieved. To my eyes focus is at a different position to that the camera a KX decides it is.
how reliable is the camera at focusing? does anyone else notice this.
I have no idea how the camera works out the focus point, does it use the same system for the auto lenses and catch in focus?
Any help on this much appreciated.
Thank you Steve

02-11-2013, 12:19 PM   #2
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It's using the AF system so it is as accurate as AF. You need to adjust your diopter so that what you see is what you get.
02-11-2013, 12:19 PM   #3
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I have similar problems, however, I remove my spec's for camera use and have the diopter set to suit my eyes without specs. I find this works quite well, but I do rely still on camera focus beep a bit as well.
I find a little sharpening is always necessary in PP.

I am about to have cataract surgery (next week) so hopefully, photography wise, things will improve "out of sight"
02-11-2013, 12:20 PM   #4
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It uses the same system, but only the center point. The k-x isn't the best camera in achieving focus. It has taken me a year to get used to my k-x, but with fast lenses, it can be a little bit of a crapshoot sometimes. This is because the k-x has large focusing points, much older focusing technology and algorithsm, and a very tiny viewfinder.

Pay attention to the focus icon (green hexagon), not the beep. The beep is not meant to say you are in focus, but to say "I'm near focus". The green hexagon stays solid once the camera thinks it is in focus.

02-11-2013, 02:56 PM   #5
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Is your diopter set correctly?
It's the slide on top of the viewfinder, you need to adjust till the information in the viewfinder is at his sharpest.
02-11-2013, 06:33 PM   #6
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As I have gotten older and my vision, even with glasses, has slightly degraded, I have wondered about the same thing you ask. I especially have difficulty using my longer MF lenses to focus and have started to depend on using the Catch-in-Focus feature. It seems to be more reliable than my eyes but is not 100% perfect all the time. I'm going to follow this thread with interest to see how others manage to overcome this limitation.
02-11-2013, 07:51 PM   #7
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Similar situation... I use catch-in-focus (CIF), but I've tested to see how it works for each lens. Some lens I get best results by going long and then coming back to focus. Some lens I start short and focus by going long.
02-11-2013, 08:14 PM   #8
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I have worn glasses for distance from before I took up photography 30 years ago. At first I tried using diopter correction for my viewfinder and shooting without glasses, while I could focus easily, I had a hell of a time seeing what was going on I the outside world without my glasses. I soon decided to shoot with glasses because overall it was easier to not keep taking my glasses on and off.

One thing that is interesting from the OP is thenimpression that the focus is different with his glasses and the camera focus. This is unusual. Manual focusing is done by focusing the image sharp on the screen, an error in eyepiece diopter would not do this, the image would always be blurry, so there could be an issue that the focusing screen might need to be shimmed, or the camera needs to have the AF set up with adjustment for the lens in use

02-12-2013, 09:03 AM   #9
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I've worn glasses full-time since 1960, and it would be a pain to remove them to use a camera. I choose cameras considering this as they differ in accommodating us 4-eyed shooters. I also use manual focus 99% of the time, as autofocus misses critical focus more than I do.
That's a reason I use Leica rangefinders for critical work, as I can focus them more accurately as my vision weakens. I seldom use an SLR with wider than 90mm, as an RF is more accurate below that (except for very close work).
02-13-2013, 12:41 PM   #10
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Original Poster
Thank you to everyone who replied I won't reply individually but try to answer all in one go
I have set my diopte all the way to one side, I think I would like it to go further than it get the image perfectly clear.
I do not know why but I prefer the view finder I find it even harder to tell when focus is achieved using the screen .Although most of my pictures look to me like they are in focus on my computer monitor
I will trust the focus beep, and the catch in focus.
I have never tried contact lenses so I think a trip to the optician is a good idea, to see how they works out. Thank you again Steve
02-13-2013, 01:34 PM   #11
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Someone else will have to chime in, but I believe there is an optional eyepiece that changes the range of the standard diopter.

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