Diopter Problem?

[beaconlightboy]

I recently recieved my camera back from canon service (needed a viewfinder cleaning). I decided to test the camera to be sure it was as i left it. Sure enough it doesnt seem to focus right. at least that is how it appears. I took a picture of text on autofocus, then on manual. In the viewfinder the manual looks super crisp while the autofocus looks like its front focused. When i load the images onto the computer the autofocus looks crisper and my autofocus looks the like its focused wrong.

I tried messing with my diopter settings (i think thats what its called, on the viewfinder) none of the settings produce a clear image sharp image.

any thoughts? can diopters be get mis aligned?

i haven't done any shots on people yet, mainly because without focus appearing correct, i cant function. it's to annoying.

[PacAce]

The diopter control determines how focused an image and the legends on the viewfinder appears to the eye when looking into the viewfinder. It has nothing to do with how sharply an image appears when you take a picture of it. That is determined by the AF system. If manually focusing your lens gives you sharper images than your AF images, then you should return the camera to Canon to have them recalibrate the AF system. They'll probably want you to send them the lens. too, in case it's the lens and not the camera that's giving you problems.

[jsfpa]

The diopter control determines how focused an image and the legends on the viewfinder appears to the eye when looking into the viewfinder. It has nothing to do with how sharply an image appears when you take a picture of it. That is determined by the AF system. If manually focusing your lens gives you sharper images than your AF images, then you should return the camera to Canon to have them recalibrate the AF system. They'll probably want you to send them the lens. too, in case it's the lens and not the camera that's giving you problems.


I think what he is saying that the auto focus is working but through the viewfinder is out of focus (to the eye). Sounds like it's a problem in the viewfinder to me.

[bgmoore]

Check to make sure your focus screen is seated all the way. I had the same problem and discovered that the focus screen hadn't clicked all the way. in. It looked like it was seated but wasn't. Autofocus shots looked out of focus throught the view finder but in focus on the the computer. Manually focused shots looked good on the view finder and out of focus on the computer.

[PacAce]

I think what he is saying that the auto focus is working but through the viewfinder is out of focus (to the eye). Sounds like it's a problem in the viewfinder to me.
His post is a little ambiquous because he does contract himself in one of his sentences.

I took a picture of text on autofocus, then on manual. In the viewfinder the manual looks super crisp while the autofocus looks like its front focused. When i load the images onto the computer the autofocus looks crisper and my autofocus looks the like its focused wrong.

[beaconlightboy]

jsfpa is understanding me correctly. i know what the diopter does.. ;)

bgmoore could you elaborate on this for me at all. the last time i touched that thing, it fell out and all those little brackets with it and i scratched the pieces trying to put them back in.. geesh can they be any more sensitive or what! Which screen is the focusing one? the first one, or the second one with the engravings on it.

[bgmoore]

I just looked at the instructions for changing a 20D focus screen. It's a bit different from the 1 series. Too many pieces for my taste. If you look at the focus screen in the camera, you should be able to see a little tab that you pull on to remove the focus screen and a felt strip along one edge of the screen. My problem and this was with a 1D2 was that the tab had not clicked back into place. So the focus screen was misaligned. You should be able to check that by getting something small and fairly soft, maybe a toothpick and pushing on that edge to make sure the screen has clicked back into place.

Since you just got the camera back from repair and they worked on the focus screen, I'd send it back and tell them you have every indication of a misaligned focus screen and that they did it.

Make sure you have your diopter adjusted correctly. I think the manual suggests using one of the illuminated focus points to adjust this, not some image in the viewfinder. Illuminate a focus point, turn the diopter knob until the focus point is in focus and you are done.

You can see the tab I'm talking about in this pdf. https://mywebspace.wisc.edu/xythoswfs/webui/_xy-3103323_1
Scroll down to page 4.

[Choderboy]

Check to make sure your focus screen is seated all the way. I had the same problem and discovered that the focus screen hadn't clicked all the way. in. It looked like it was seated but wasn't. Autofocus shots looked out of focus throught the view finder but in focus on the the computer. Manually focused shots looked good on the view finder and out of focus on the computer.

Sounds like the correct diagnosis :eek:

I managed to install a focus screen backwards in a 20D. Resulted in the symptoms you described.

[beaconlightboy]

thanks.. i'll give this a shot. need to get my 30d back up and running. i'm spoiled by its screen size. the 20d seems so.. antiquated..lol.

[beaconlightboy]

Aha, the little metal tab was not totally pushed in. Do you guys think it will come loose again? it deosnt really click in or anything.

[ron chappel]

The diagnosis sounds spot on -a loose or upside down screen will do exactly as you describe. I once inadvertantly reversed my brothers screen leading him to photograph a whole project out of focus (he allways manual focuses and this was a film camera)
You don't ever forget a mistake like that :(:(:(


The metal tab does click in -it's just very light so you may not feel .
I noticed the last time i worked on my 300D screen that all the parts don't fit in too well:( .I wish they'd make it all abit more secure

[Neilyb]

Just a question but why do DSLR's have a diopter? My SLR didn't....and it can be confusing when it gets knocked and your view is out of focus.

[Ravenscroft]

thanks.. i'll give this a shot. need to get my 30d back up and running. i'm spoiled by its screen size. the 20d seems so.. antiquated..lol. Correct me if I'm wrong - but I thought the 30D had the same viewfinder as the 20D?

:confused:

[ron chappel]

Just a question but why do DSLR's have a diopter? My SLR didn't....and it can be confusing when it gets knocked and your view is out of focus.

All of the upper range cameras have them,and have done for quite a few years.
I think the reason DSLR's have them (even the cheapest ones) is because it doesn't cost much to add (relative the the huge cost of DSLR's) yet is very usefull to some

[05Xrunner]

Correct me if I'm wrong - but I thought the 30D had the same viewfinder as the 20D?

:confused:
think he was talking aobut the 2.5" LCD screen on the back not the viewfinder.

[Ravenscroft]

think he was talking aobut the 2.5" LCD screen on the back not the viewfinder.
Oops - my fault. For some reason I understood him to mean focusing screen... :oops:

<I need more coffee>