View Full Version : Focus Vs Eyesight
Hi Guys.
Can anyone tell me what impact, if any, that poor eyesight has upon taking photos that are in focus?
What I mean is can a person that wears glasses take a photo without using his glasses and still be able to capture the image in "perfect" focus, or will it be blurred due to the photographers poor eyesight?
So, when taking photos if you wear glasses for driving, should I ensure that I take the image whilst wearing my glasses? The reason being that I walk around not using glasses but I always wear them whilst driving and I am unsure about what effect wearing, or not wearing my glasses, will have on the focus of the images.
I hope this makes sense? :)
Not sure which camera you have?...most have an adjustment (diopter) to compensate(?) for our poor vision.
I have to wear glasses for reading/driving but take them off to take my happy snaps.
- - - Updated - - -
Perhaps I should expand slightly...I take them (glasses) off and rely on the cameras AF. The diopter make the image look focused through the viewfinder.
Cheers - :beer_mug:
arthurking83
13-09-2018, 8:30am
...
Can anyone tell me what impact, if any, that poor eyesight has upon taking photos that are in focus?
What I mean is can a person that wears glasses take a photo without using his glasses and still be able to capture the image in "perfect" focus, or will it be blurred due to the photographers poor eyesight?
.....
Hard to answer as it depends on a few things.
Basically the answer is yes, but what camera do you have?
If you wear glasses, what diopter power are they?
If you have a reasonably high end(not fully high end, just not a P&S type) camera, it will have a diopter adjustment for the viewfinder.(assuming that you are asking about viewfinder, not liveview, P&S type camera usage)
If you can't adjust the diopter to suit your eye without glasses, then some camera makers have additional diopter accessories to match closely to what your eyes need. This accessory fits externally on the eyepiece of the VF and you then fine tune with the diopter adjuster again on the camera.
What camera do you use, or ask about?
An old Nikon 200D with Sigma 24mm Ultra Wide Macro f/2.8
I will read up and learn what a Diopter is. Thanks.
ameerat42
13-09-2018, 8:42am
^^ Snooks. I remember you have a Nikon D200 (from your Intro thread).
Go to this page here (https://www.dpreview.com/reviews/nikond200/2) and scroll down to the Label "Viewfinder". You can see that it has
a "diopter" (US spelling) adjustment feature.
Of course it's usefulness to you depends on just what your vision is like but if it's just a bit
of short- or long-sightedness within the range mentioned there, then you can adjust it to give
you a sharp image in the viewfinder without having to use your glasses. Of course, when
look away from the viewfinder you'll need your glasses for usual stuff.
Alternatively, if you have/get/use a camera with a Live View screen on the back, you can do
whatever you usually do to use that for sharp focus of your images. I cannot see from the specs
that the Nikon D200 has any "live view" capability. (It was less popular/more expensive in cameras
of the time).
Oh, and...
If you click this image (http://www.dpreview.com/files/p/articles/0489651410/Images/inhand01.jpeg) you can see the dioptre (our spelling) adjustment wheel near the top RH corner
of the viewfinder window.
I was thinking if my eyesight is "out of focus" but looks in focus to me, then I can't possibly take a photo that is in focus for people that have the correct eyesight.
So looking through the viewfinder, I go into focus but for people with the correct eyesight it "would" or "should" be out of focus. Or that is what is seems like to me.
My eyesight is not that bad, I can almost read the eye chart without glasses but I do use them for driving. My eyes are garbage when it comes to reading and anything close :(
ameerat42
13-09-2018, 8:43am
PS: As I was writing this you confirmed your camera model :th3:
PS: As I was writing this you confirmed your camera model :th3:
I have it in my signature but for some reason my signature is not showing?? Settings seem correct.
ameerat42
13-09-2018, 8:53am
I was thinking if my eyesight is "out of focus" but looks in focus to me, then I can't possibly take a photo that is in focus for people that have the correct eyesight.
So looking through the viewfinder, I go into focus but for people with the correct eyesight it "would" or "should" be out of focus. Or that is what is seems like to me.
My eyesight is not that bad, I can almost read the eye chart without glasses but I do use them for driving. My eyes are garbage when it comes to reading and anything close :(
A capital NO to the first bit, Snooks. The image in the viewfinder is formed on a screen.
It is either in focus, or not. Relative eyesight focusing ability will not affect that, but only
whether you can see it - in focus or not.
And so, your second line can never happen! - You can forget it.
From what you describe of your eyesight, it sounds like some degree of short-sightedness, and if
it's not out of the range of your camera's dioptre adjustment, you should be able to see a clear
image in the viewfinder.
In that regard, look for any text information in the viewfinder, like f-stop, shutter speed, etc.
That is your best guide for what is "sharp and in focus". Turn the wheel back or forth until that
becomes sharp.
Thanks :) Will look straight into that (lol).
arthurking83
13-09-2018, 9:42am
On the back of the D200(ie. as you use the camera) up at the viewfinder, you will see a small rotating wheel on the RH side of the viewfinder eye cup. It has a + and - sign in the direction of rotation.
This is your diopter adjuster.
You just turn it with your thumb.
Obviously I can't tell you which way to turn it as I don't have your eyesight, but turn it you should do.
Before you do tho;
1/. if you lens is on the camera, then place the lens cap on it.
2/. If no lens, then place the body cap on the body.
ie. make sure the light through to the VF is dark!
3/. camera on, some battery power may be needed for a few minutes.
4/. Half press the shutter to activate the light meter, which also activates the viewfinder info system.
That is, all the numbers, indicators and other buttons and bobs in the VF need to be lit up.
Can you see them clearly?
These are your reference points for adjusting the diopter, NOT the image through the lens into the VF. This is why we blank the lens or camera body. No unwanted distractions, and maximum contrast between vf info lighting and the background.
If the data/info stuff through the VF is clear to see without your glasses on, then you need nothing.
As you adjust(turn the small dial at the viewfinder) the image will become more blurry or clearer. If it's becoming more clear in one direction but it never becomes fully clear, then you can purchase a diopter accessory to suit your eyes. I think(from memory) there are abotu 3 different diopter accessories with varying power values. if not three I know of at least 2.
Note that D200 and D300 use the same vf accessories, so if you can't locate any for the D200(now a very old device, long since discontinued) then the more recent D300/D300s accessories may still be available.
BUT whatever you do, do not reply on a focused image through the lens as confirmation of focusing the VF. The matte screen is too inaccurate to allow for this.
hope that helps.
I meant to update earlier and forgot. I found that adjustment and the info provided helped me resolve the issue and yes, it is now so much better.
Thank you one and all :nod:
Powered by vBulletin® Version 4.2.3 Copyright © 2024 vBulletin Solutions, Inc. All rights reserved.