eyepiece not in focus

-halli-

-halli-

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Hi, my eyepiece doesn't seem to get in focus even when I adjust the dioptre dial. The photographs come out focussed with both of my lenses, but the view through the eyepiece is rarely focussed properly. If I manually focus I can make the view through the eyepiece pin sharp, but the photo comes out really blurred.

Now, I do have poor eyesight. I have "infantile cataracts" (born with them) and have an astigmatism too. My glasses help, but I do sometimes suffer from double images (ghosting) when looking at high contrast things (text on white paper)

However, it confuses me that I can manually focus and get the image pin sharp in the eyepiece with or without my glasses.

Is there a setting or calibration that can be done on the Canon 400D? Or am I destined to guessing if it is in focus, judging by the little red dots of focusness?
 
Edit ..

Must read op properly in future....


MD
 
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..MD.. said:
I may be wrong But..!!!! I always thought that the view through the eye piece made no odds to the Image itself ??? ....



It should make no difference what you see through the eyepiece to the image you take...

MD
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:agree:
 
I think what -halli- means is that he's having trouble telling when an image is in focus because the diopter adjustment isn't providing sufficient correction for his eyesight so he is dependent on the focus indicator alone.
 
Have you tried the other way...? mount the camera on a tripod, AF on something similar to what you might typically be shooting and then adjust the dioptre dial until it comes into focus. Should at least give you a good starting point.

If that doesn't get you close I think you can have a stronger dioptre fitted???
 
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I just view with my glasses on and given your probelms that's probably favourite. Adjust the eyepiece correction to show the meter and settings info at the bottom most clearly. Then the image will be in best focus too.

If that's still not very good, take your camera to an optician and ask for a custom eyepiece correction lens, and ask them to fit it into a viewfinder lens holder available from Canon.

You might need to brace yourself for the cost.
 
So it looks like it is my eyes then :( I can get the meter settings and the focus rectangles in focus with the dioptre wheel, just the image looks OOF.

Can someone try this please? With the dioptre making the screen OOF, can anyone else confirm that they can make the image in focus using manual focus please? I just find it odd to say the least!

HoppyUK said:
If that's still not very good, take your camera to an optician and ask for a custom eyepiece correction lens, and ask them to fit it into a viewfinder lens holder available from Canon.
Click to expand...

Sounds good. I didn't know that could be done. Sounds a bit like the prescription windscreens that Billy Connolly made a joke about!

HoppyUK said:
You might need to brace yourself for the cost.
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Oh. :(

What about these magnifier lens things I've seen on eBay? They claim to magnify the centre part of the image. Has anyone any experience of these?

I'll get SWMBO to have a look through the viewfinder and see what she thinks.
 
mick m said:
This thread, posted a while back may help,
http://www.talkphotography.co.uk/forums/showthread.php?t=223322

Mick.
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Cheers, at least there might be something "off the shelf" that could help me.

It was with macro that I first noticed the problem. The image was sharp as a tack in the viewfinder and the image was focussed further back when I viewed the image on the computer later.

Now I'm noticing it more and more with general photo taking, especially when in lower light conditions.
 
Hmm, looking into the "Canon Dioptric Adjustment Lenses" it seems that they add + or - to the outer edges of the current dioptre settings. Not really what I need.

I CAN get the metre settings and focus indicators in focus using the dioptre settings, but the image is OOF. No amount of fiddling with the dioptre has resulted in a focussed image when the AF has locked and the lens switched to MF. Only manually focussing creates a focussed image in the viewfinder, but as stated earlier, this results in a photo that is OOF.

I think I need to continue to experiment in good light conditions.

Next question. Could it be that the mirror is off, or the focussing screen perhaps?

Would a different focussing screen help? Perhaps one of the ones with a circle in the middle (not sure what they are called)
 
I've put a wanted ad on for one of the eyepiece magnifiers to see if I can buy or borrow one here

Worth a try before I risk eBay.
 
If you can see the viewfinder readout clearly, then the viewfinder image is also in focus, Whether or not the image itself is clear depends on whether the lens is also correctly focused on whatever you're pointing the camera at.

Are you wearing your specs when you do this? It's possible that when you swivel your eye to look at the image itself, above the readout, you are looking through different part of your spectacle lenses which gives a different degree of correction for your eyesight (eg varifocal effect spectacle lenses, or something else particular to your vision).

Try repositioning your glasses and eye in relation to the viewfinder. You need to be square on and as close as possible. You need to be able to see all four corners at the same time.
 
HoppyUK said:
If you can see the viewfinder readout clearly, then the viewfinder image is also in focus, Whether or not the image itself is clear depends on whether the lens is also correctly focused on whatever you're pointing the camera at.

Are you wearing your specs when you do this? It's possible that when you swivel your eye to look at the image itself, above the readout, you are looking through different part of your spectacle lenses which gives a different degree of correction for your eyesight (eg varifocal effect spectacle lenses, or something else particular to your vision).

Try repositioning your glasses and eye in relation to the viewfinder. You need to be square on and as close as possible. You need to be able to see all four corners at the same time.
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I have tried it with and without my glasses. They are just plain lenses, nothing special like varifocal or prism lenses.

I'll give it a go tomorrow :thumbs:
 
you mention earlier that it is particularly noticable when in low light conditions and that you sometimes get ghosting in your vision too. All these things will not help when viewing things through a viewfinder, which is small and troiblesome for 'weary eyes' and whilst dioptre corrections can help, you might never get it perfect without some serious expenditure. IN the overall scheme things this isn't a problem when auto-focusing I guess, as the camera will get it rght for you anyway. Manual focus is another matter though....however, as hoppy says, if the readout in the vf looks in focus, you could use that as a guide and see how the resulting images look on the computer screen afterwards?
 
Yv said:
you mention earlier that it is particularly noticable when in low light conditions and that you sometimes get ghosting in your vision too. All these things will not help when viewing things through a viewfinder, which is small and troiblesome for 'weary eyes' and whilst dioptre corrections can help, you might never get it perfect without some serious expenditure. IN the overall scheme things this isn't a problem when auto-focusing I guess, as the camera will get it rght for you anyway. Manual focus is another matter though....however, as hoppy says, if the readout in the vf looks in focus, you could use that as a guide and see how the resulting images look on the computer screen afterwards?
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I agree, and to be honest this is how I've been doing it (relying on the AF red dots and looking at the images on the screen afterwards)

Perhaps I should consider getting the cataract operation my consultant suggested. Just seems like overkill at 38 yrs old! Plus would mean I'd only have single focus eyes to a certain degree (I can choose close up or distance replacement lenses for my eyeballs and will require specs to correct the opposite)
 
If it's any consolation Halli, it doesn't really matter if you can't see if the image is spot on focused or not. Not with an AF camera, the AF system ensures that it is. DSLRs are not designed for manual focusing - their viewfinders tend to be quite small and dark (for reasons of size, weight and cost) and most focusing rings are not precise enough for really fine control.

So long as you can see that the relevant focus point is over the part of the subject you want sharp, then it by and large it will be.
 
I wear glasses and have a 400d too - and I set the dioptre wheel the way you tried, by getting the LED display in the viewfinder as sharp as possible. With that in focus I find that what looks in focus in the viewfinder is in focus in the final image.

Although in my experience the 400d viewfinder is too small to allow accurate manual focus. :(
 
Right, I've just done some rough tests to see if I can work out the difference between the AF (which is correct) and my manual focussing (which looks correct in the viewfinder but OOF in the pic)

Using my 50mm lens at f1.8 on a tripod with cable release

at 1000mm from subject to the mark on the body that denotes the sensor position

AF was in focus when the focus dial on the lens was lined up to roughly 1.20m
510mmAF.jpg


My focus in viewfinder was when the focus dial on the lens was lined up to roughly 0.81m
510mmMF.jpg


A difference of 39mm

--------
at 740mm from subject using the same lens

AF was 0.8m
740mmAF.jpg


MF was 0.68m
740mmMF.jpg


a difference of 12mm

----
at 510m from subject using the same lens

AF was at 0.54m
1000mmAF.jpg


MF was at 0.47m
1000mmMF.jpg


a difference of 7mm

Any ideas? As I say, the image in the viewfinder is pin sharp when I focus manually, but blurred in the viewfinder when AF is confirmed. I can get the viewfinder close using the dioptre control (it is around the middle) and I can blur the viewfinder on both sides of the dioptre meaning I'm not at the end of the dioptre's range thus requiring a corrector lens.

I'm stumped.

(also posted in this thread)
 
I would say its your eyesight, when did you last have new glasses? your prescription might have changed, ie your eyesight may have deteriorated, I know I am experiencing that myself at present.
 
I agree re eyesight.

If when you look through the view finder and it is in focus the image is out and vice versa then the ONLY possible explanations are

a - the dioptra setting is set wrong.

b - your eyesight is wrong

c - the lens in the view finder is damaged

If you get someone else to manually focus it and take a shot and auto focus and see if it is in focus then that will tell you if it is (a or c) or b.
 
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iancandler said:
I would say its your eyesight, when did you last have new glasses? your prescription might have changed, ie your eyesight may have deteriorated, I know I am experiencing that myself at present.
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I had them tested recently and the prescription hadn't changed much.

I can get the image in focus through the viewfinder though. The LED display is in perfect focus, just the image is out. very confusing :thinking:

I've been digging around 'tinterwebz and it seems that the focus screen might be shimmed incorrectly.

I think I'll take it out and try without a shim, and perhaps try a slither of scotch tape on the shim if it needs to be thicker.

I might order one of the split view focussing screens off eBay too. Worth a try too.
 
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cowasaki said:
a - the dioptra setting is set wrong.
Click to expand...

I can dial the dioptre either side of the correctly focussed LED display., so I don't think it is that.

cowasaki said:
b - your eyesight is wrong
Click to expand...

My eyesight is cr@p! But I can see the LED display in focus and can adjust the focus to be pin sharp in the viewfinder.

cowasaki said:
c - the lens in the view finder is damaged
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I reckon it is this. Perhaps not damaged, but just needs a tweak.

Does anyone know the canon parts website/phone number to see if the shims are available off the shelf?
 
Ok, did another experiment.

I took a photo through the eyepiece with my point and shoot.

Turned dioptre to bang on centre

with my manual focussing (but resulting photo will be OOF)
SV209560.jpg


With AF confirm (resulting photo will be in focus)
SV209561.jpg


I'm not sure if this proves anything though?
 
I've bought a 45 degree split screen off the bay so I'll see how that performs when it arrives some time in the next month.
 
Sometimes the dioptre adjustment isn't enough.
When that's the case, you need a custom-made eyepiece correction lens in place of the standard viewfinder lens.
Contact Canon for details.

I know Nikon supply 'blank' lenses to be ground to the correct specs (pun intended) by your optometrist.
 
I installed the ebay split screen and I am amazed at the difference!

Sharp focus in the viewfinder, 45 degree prism works a treat and I can now use my manual focus lenses with ease!

I installed the viewfinder without the factory shim and it seems to have made all the difference. I never did try to shim up the old one, don't think I'll bother now!

Viewfinder is a little darker, and one half of the prism goes black if I try to focus with a lens stopped down past f5.6, but that is fine, I'll focus and then stop down if required.

I'm looking forward to testing it in anger tomorrow :D
 
Focussed on the "N" in the eyepiece for this shot (No. 1 & 2 macro rings attached to my Prakticar 50mm 1.8 manual focus lens.

IMG_3714.jpg
 
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