blurred vision WHY?

[rich_yau]

okay. I'm chinese, but you can probably tell. Maybesomeone here knows why I have to wear my classes to see anything is the viewfinder. Okay my vision isnt that great (-2.25 about ), but usually i can see in class, i can see street signs, etc. The info displayed in the viewfinder appears very close to me, yet no matter how hard i squint, i can never read it. I'm guessing its some sort of optical depth illusion. Anyone know?

This is not a camera specific problem, as i have the same problem with film slrs.

[tim]

Have you tried changing the diopter adjustment? It's the little switch on the eyepiece.

[mocca]

Try adjust the built-in diropter. If that is still not enough, you can buy the Canon diopter +0.5, +1, +3, etc. If you are near-sighted, you will need + (+3 should give you pretty good adjustment range). With the optional diopter installed, you can use the diopter switch to adjust it to fit your eyes. This way, you can shoot without wearing glasses.

MM

[mr.photoguy]

I just tend to either use my glasses, when I wear them, or I will just wear my contacts.
Even with the Diopter set to the max, I still can't see crap.

[rich_yau]

I just tend to either use my glasses, when I wear them, or I will just wear my contacts.
Even with the Diopter set to the max, I still can't see crap.

yeah, my glases are small and quite far from my eyes, its very uncomfortable. Ive never had contacts. maybe I should have one contact lense just on my right eye. ;)

I am still wondering if there's a scientific explanation for this, because if i were looking at the field outside the viewfinder, i can see better.

[Bob_A]

I would think the issue is due to:

1. The viewfinder is not as bright as when you are viewing the scene without the camera.

2. There is some image quality loss due to the use of all the optics, mirror, pentaprism, etc with the viewfinder as compared to using the naked eye. The focus screen also has a matte finish.

3. With the naked eye you have a large depth of field, through the viewfinder the depth of field depends on the maximum aperature and focal length of the lens being used. So, quite a bit more of the scene you are looking at will be out of focus when you look through the viewfinder than when you view using the naked eye.


The Canon diopters are very inexpensive ($13.95 at B&H), and I would think that this would be your best choice since using your glasses in uncomfortable for you. Get one that is the closest to your prescription and then use the diopter adjustment on the camera to fine tune.

[Bob_A]

Try adjust the built-in diropter. If that is still not enough, you can buy the Canon diopter +0.5, +1, +3, etc. If you are near-sighted, you will need + (+3 should give you pretty good adjustment range). With the optional diopter installed, you can use the diopter switch to adjust it to fit your eyes. This way, you can shoot without wearing glasses.

MM

Wouldn't Rich need -2 (not +3)? I'm very near sighted and my prescription is -5.25. I checked and when I rotate the diopter adjustment on the viewfinder to the maximum negative position it is at the clearest with my glasses off.

I may be wrong (hopefully someone else will help here), but I think Rich's best choices would be a -2, or maybe a -3 if he thinks his vision is gradually getting worse.

[lostdoggy]

Astigmatism. I have it so I know. That is when even after being corrected with dioptics the lines of letters and numbers starts growing little fine hair. That is how it was explain to me. So not only am I near sighted but also have Astigmatism. Don't you hate furry letters & Numbers. I think the built in Dioptic goes from -3.0 to +2.0. There are addon dioptics but its a pain because when you look away from the viewfinder you'll need glasses again. I been considering Lasik.

[Hellashot]

It is likely because you are looking through glass/lens that is made for people with 20/20 vision. I have contacts in the range of -4.5 and even when wearing them I have to set my Drebel to -3 and I got a -4 for my new EOS-3.

[rich_yau]

i think my vision is worse than that. My glasses are kind of weak. Ive had the thing set to the lowest, then i thought it was backwards so i had it on the highest and its still blurry. I think the -3 to 2 is a bit liberal. The lowest setting +my glasses is about right, but i hate my glasses. I havent even gotten used to them yet. The only time i use them is in class. I get dizzy even when i walk with them.

[Andy_T]

Rick,

I have been wearing glasses practically all my life ... I am fine with them and always use them ... so also at shooting.

I assume part of your problem might be that you are not wearing your glasses constantly ... I would also get a headache if I only wore my glasses for reading (and it would maybe be pretty dangerous to walk across the street :rolleyes: )

So my suggestion would be to consider wearing your glasses permanently. The dizzy feel should go away 2-3 days after you start to wear them permanently, it's something you get used to.
Also, check if you need new glasses!!! If you have astigmatism, then you might be able to use weaker glasses if they are properly corrected.

That ... or getting contacts or LASIK.

Best regards,
Andy