topic Re: T3i sharpness and diopter in EOS DSLR & Mirrorless Cameras

T3i sharpness and diopter

GWK — Fri, 10 Apr 2015 00:01:54 GMT

I have a T3i. When I set the diopter so that the autofocus ‘squares’ are sharp (-2 notches from center,on the wheel for me) my pictures are blurry. When I adjust the diopter to +5 “notches” on the wheel, the squares are blurry, but when I focus to the least blurry view I can get with that blurry diopter setting, my pictures are very sharp. Are my eyes or is the camera messed up? (I don’t wear corrective lenses). Thanks.

Re: T3i sharpness and diopter

cicopo — Thu, 09 Apr 2015 23:34:29 GMT

The diopter doesn't effect the photo. It's there to allow people like me to see properly without my drug store bought reading glasses, which in general I need to put back on to carefully examine the image on the LCD after taking the photo. Set the diopter so that what you see with the shutter button 1/2 depressed is at it's clearest (after the AF has finished focusing).

Re: T3i sharpness and diopter

GWK — Thu, 09 Apr 2015 23:53:23 GMT

Thanks for the reply, Cicopo...If I'm manually focussing, the diopter adjustment sure seems to have an effect on the photo, as I adjust the lens to match the sharpness that I see in the viewfinder. I'm often shooting wildlife in the woods, where autofocus is often impossible (tree branches, etc.).

Re: T3i sharpness and diopter

GWK — Fri, 10 Apr 2015 12:35:47 GMT

Think I may have resolved…while I don’t wear corrective lenses, I do have an uncorrected ‘ -1.50’ in my right eye. Gonna order a corrective -2.00 dioptric adjustment piece from Canon to see if that gives me better focus/diopter 'sync'.

Re: T3i sharpness and diopter

cicopo — Fri, 10 Apr 2015 13:31:22 GMT

When you've had a chance to try it let us know your thoughts.

Re: T3i sharpness and diopter

GWK — Fri, 10 Apr 2015 13:35:21 GMT

I'll let you know, cicopo, thanks.

Re: T3i sharpness and diopter

ebiggs1 — Fri, 10 Apr 2015 14:18:21 GMT

"If I'm manually focussing, the diopter adjustment sure seems to have an effect on the photo"

It does when you use manual focus. It does not when you use auto focus.

Modern DSLRs are generally not user friendly for manual focus. There are MF screens for some models that help.

Re: T3i sharpness and diopter

GWK — Fri, 10 Apr 2015 14:24:13 GMT

Thanks ebiggs1. As mentioned, shooting in the woods (owls, etc.,) often requires the selective focus of 'manual', in order to isolate a creature perched in branches, or in marsh grasses. I do believe I'm just outside the diopter adjustment for the normal eye T3i...I'll report on the '-2 dioptric adjustment' piece I ordered for my mildly nearsighted right eye 🙂 . Cheers.

Re: T3i sharpness and diopter

jrhoffman75 — Fri, 10 Apr 2015 16:15:36 GMT

I believe the T3i has an in camera diopter range of +1 to -3; that should accommodate your vision. The add on diopter is additive; with it on the camera would then be -1 to -5.

I agree with ebiggs1 that manually focusing on the viewfinder groundglass can be difficult depending on the subject. But, there is no physical linkage between the eyepiece and the lens. If the desired subject looks sharp in the viewfinder it will be sharp on the sensor (as long as you don't change anything.)

Something sounds wrong to me. Try testing in conditions where you can both manually and auto focus. If I switch to manual focus on lens and hold down shutter button the focus point lights and beeps when image is visually in focus (when I have the focus squares in focus with diopter). If I then turn diopter everything gets blurry; no amount of lens adjustment changes that. Which is what I would expect.

Is your left eye "normal". What happens if you try with that eye.

Some situations lend themselves to focus-recompose. Choose a single focus point that is close to your desired subject (to minimize required camera motion), place that on the subject, allow camera to auto focus, switch to manual focus and recompose. You could also manually focus and allow the foucus point to light and then recompose.

Re: T3i sharpness and diopter

GWK — Fri, 10 Apr 2015 17:45:52 GMT

jrhoffman75....thanks for that. I've been messing with it all morning (and ordered the -2 diopter). Anyway, following your advice, I think things just may be adjusting back my way 🙂 Thanks for your help. I'll have a diopter for my retirement, lol. Cheers.Thanks again.

Re: T3i sharpness and diopter

MikeSowsun — Sun, 12 Apr 2015 02:24:33 GMT

I find the best way to adjust the diopter control is to make the numbers in the LED display in the viewfinder look sharp. You can do this with the lens capon so there is nothing to distract you.

Re: T3i sharpness and diopter

GWK — Thu, 16 Apr 2015 18:55:00 GMT

Well, I rec'd my -2 diopter corrector. Before installing, I checked the 'stock' diopter wheel setting, and it was +4 and not +5 "notches/clicks" on the diopter adjustment, where I was getting sharp images while managing to select the best of blurry diopter squares/image in the view finder@ +4. I then installed the -2 diopter, and when I focussed, the 'squares'& image were sharp @ +4, and the focus 'light/beep' sounded when the shutter was 1/2 depressed (as in, things we in sync). Images are much improved. Thanks all, for your input. Perhaps I have a flakey eye, or approach, but I seem to have a better relationship with my camera, these past few days, lol. Whatever works.

Re: T3i sharpness and diopter

ebiggs1 — Fri, 17 Apr 2015 11:29:18 GMT

Re: T3i sharpness and diopter

SueZ1 — Tue, 18 Apr 2017 00:07:32 GMT

Hi, I have a Canon Eos t3i. I dropped it the other day and now the image in the viewfinder is blurry. I've tried adjusting the diopter wheel but that doesn't work. I understand there is something inside the camera that is probably no longer functioning properly but I don't know what it is and don't know how to fix it. In addition, Canon says it could cost as much as $200 to fix the issue. If that's the case should I just buy another camera body?

Thanks in advance for your help!

Re: T3i sharpness and diopter

Waddizzle — Tue, 18 Apr 2017 00:27:47 GMT

@SueZ1 wrote:
Hi, I have a Canon Eos t3i. I dropped it the other day and now the image in the viewfinder is blurry. I've tried adjusting the diopter wheel but that doesn't work. I understand there is something inside the camera that is probably no longer functioning properly but I don't know what it is and don't know how to fix it. In addition, Canon says it could cost as much as $200 to fix the issue. If that's the case should I just buy another camera body?

Thanks in advance for your help!

If Canon still has the parts to fix it, then I would let Canon fix it. Your camera will be returned in nearly "new" condition. Your other choice is to spend at least twice that amount on a used camera, while you still have a busted one.

Re: T3i sharpness and diopter

ebiggs1 — Tue, 18 Apr 2017 09:33:02 GMT

"Canon says it could cost as much as $200 to fix the issue."

I would send it in for evaluation. You might be surprised and it is less. I doubt it but who knows? It may be more than $200 if the lens is broken, too. But the lens needs to be checked also. IMHO, even $200 is too much to spend on repairing a T3i so I would replcae it with a newer model. A used T3i is probably $275 to $350 so that should be a guide. Haven't checked in a while, though.