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Old March 29th, 2006, 09:42 AM   #1
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focusing for glasses wearers...

This may have been addressed before (I know I'm not the only person who wears glasses here) but I couldn't find anything in a search, so I'll risk what might seem like a common sense question--
When I focus using the viewfinder on my PD170, I have my glasses off. I wear progressives, just a bit farsighted. When I focus on my subject, how do I know what looks focused to me is actually in focus? Hope this isn't an idiotic question, it just seems that when I'm focusing I would be adjusting it to my slightly off vision, not 20/20...
Thanks for any help.
Vin
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Old March 29th, 2006, 09:54 AM   #2
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Actually, it isn't a stupid question. I'm starting to reach an age, and my eyes aren't always at 100%. Pretty soon, I'll have to deal with glasses myself, and have wondered how to compensate.
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Old March 29th, 2006, 10:03 AM   #3
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Quote:
Originally Posted by Vincent Croce
This may have been addressed before (I know I'm not the only person who wears glasses here) but I couldn't find anything in a search, so I'll risk what might seem like a common sense question--
When I focus using the viewfinder on my PD170, I have my glasses off. I wear progressives, just a bit farsighted. When I focus on my subject, how do I know what looks focused to me is actually in focus? Hope this isn't an idiotic question, it just seems that when I'm focusing I would be adjusting it to my slightly off vision, not 20/20...
Thanks for any help.
Vin
Vincent,

I don't have a PD170, but most cameras have a diopter to adjust the viewfinder to your vision. That may help you. Also, sharp focus is sharp focus, you can't make it sharp to your eye and not be in focus. That didn't come out to good!

If your vision is not sharp, you can just adjust it to were it looks best.

I think I stayed up too late.

Mike

PS: The diopter adjusts the screen to your eyes just like your glasses do. So if you can see well enough without them, you can just adjust the diopter to your eyes and not use your glasses. I wear mine, so I adjust the diopter to my vision with the glasses on. Either way, sharp is a physical function on the screen itself, and you can see it as sharp if it is not.

I need more coffee.
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Old March 29th, 2006, 10:10 AM   #4
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Yeah Mike, I use the diopter, but I still question the logic of what looks sharply in focus to my 'deflicted eyes' (Zappa) will look sharply in focus to perfect vision. If I focus it properly to my eyes and then have you look through the viewfinder, how can it look the same to you? I'd hate to think I'm stuck wearing my glasses and using the LCD for shooting properly...
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Old March 29th, 2006, 10:15 AM   #5
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Quote:
Originally Posted by Vincent Croce
Yeah Mike, I use the diopter, but I still question the logic of what looks sharply in focus to my 'deflicted eyes' (Zappa) will look sharply in focus to perfect vision. If I focus it properly to my eyes and then have you look through the viewfinder, how can it look the same to you? I'd hate to think I'm stuck wearing my glasses and using the LCD for shooting properly...
Been rubbing yellow snow in your eyes?
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Old March 29th, 2006, 10:18 AM   #6
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Can't get anything past you, Keith-

Brings a smile to my face just thinking about that album--
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Old March 29th, 2006, 10:21 AM   #7
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I think I might be getting it now...

Ahhh, so what you're saying, Mike, is that the diopter adjustment compensates for any vision problems and therefore the actual lens focus remains the same! Is that the crux of the biscuit? (The apostrophe)
Thanks!
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Old March 29th, 2006, 10:24 AM   #8
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It's my eyes that are going, not my... um... what's that thing called , were you remember stuff?

And to top things off, I got a bad infection in my left ear a couple years ago, and haven't been able to hear quite right out of it. Talk about throwing off your sense of stereo!
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Old March 29th, 2006, 10:26 AM   #9
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Quote:
Originally Posted by Vincent Croce
Yeah Mike, I use the diopter, but I still question the logic of what looks sharply in focus to my 'deflicted eyes' (Zappa) will look sharply in focus to perfect vision. If I focus it properly to my eyes and then have you look through the viewfinder, how can it look the same to you? I'd hate to think I'm stuck wearing my glasses and using the LCD for shooting properly...

I having on hell of a hard time thinking this morning and finding a way to explain this, but I'll try one more time.

If it is in focus to you as you view it in the viewfinder, then it will be in focus while it is recording. You can not make it look like it is sharp when it is not. It is like looking at a photograph. If it is a properly focused picture it will look sharp when your eyes are adjusted to correct your vision. If the picture is not in focus, no glasses in the world will make it look in focus to you.

Focus is the point where the light beam is just a single point on the surface it is projected on. At any point in front of or behind that focal plane you will no longer have a point, but a circle of ever increasing size. It called the "Circle Of Confussion." Any Circle Of Confussion smaller than one thousandth of an inch looks in focus to the human eye. These are called "The Circles Of Least Confussion," and that is how we preceive Depth Of Field. It is the area where the circles of confussion do not exceed 1/1000 of an inch.

Mike
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Old March 29th, 2006, 10:30 AM   #10
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Mike--Or, in simpler terms, the diopter serves the same purpose as my glasses...
Duh, now I know it was a dumb question. And I already had my coffee this morning.
Thanks for the great explanation.
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Old March 29th, 2006, 10:35 AM   #11
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Definetly not a dumb question, a very good one in fact! I experimented when I got my cameras and had to figure it out. I wear my glasses all of the time so all cameras are set to my eyesight. If someone else picks one up, they may have to adjust it to their eyes.

I am willing to bet that about 10% or more of the cameras out there do not have the diopter adjusted. The people don't even know they have on on the camera!

Good luck-----Mike
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Old March 29th, 2006, 10:56 AM   #12
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Hi all

I've been wearing glasses for all my photography career and yes it can be a pain...scratched lenses on my right eye etc...

Now on the FX1 I've taken to using the LCD and the expand focus 90% of the time. I just find this easier...

Not sure what I'll do when I can't see with these glasses as I too am getting to the age where close up is getting blurry...

cheers
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Old March 29th, 2006, 12:19 PM   #13
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If your cam has the ability to display color bars (always in focus), turn them on. Then, with your glasses off, use the diopter to acheive maximum focus through the viewfinder of the bars. Now, mark that setting and from now on, when ever shooting without your glasses, you can reset to a point you know will be in focus.
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Old March 30th, 2006, 09:27 AM   #14
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I put text display on the viewfinder screen,(time code, etc) adjust the viewfinder until that is in focus, then the viewfinder is set for my eyes. then I can go about focusing the image.

I know it's been said many times, many ways ;-) but I figured it was just another way to say it.
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Old March 30th, 2006, 02:21 PM   #15
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Thanks to all for the great replies!! This forum ROCKS!
Vin
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