Out of focus wihen using manuial focus

[paul_heagen1]

<p><strong></strong>A lot of pictures I take using manual focus are, well, out of focus.<br>

I am being very careful, yet when I look at the pics later, they are clearly out of focus. The focal point is somewhere else, often behind my intended point. I have checked using auto focus and they come out fine. <br />I adjusted the eyepiece diopter and it seems right. Is there a chance there is something about my eyes that simply doesn't focus correctly? If I can't get this figured out, I will have to revert to auto focus all the time, which i would prefer not do to. <br />Thanks for any help.</p>

[hjoseph7]

<p>Are you switching the lens to manual focus or are you overriding auto focus ?</p>

[paul_heagen1]

<p>Switching to manual. </p>

 

[joe_fikes]

<p>Manual focus is pretty tough on a DSLR. The problem is - you can't see the screen well enough to make critical focus adjustments. The image in the viewfinder just isn't big enough. And there are no focusing aids. If your camera supports live view, then you can use that mode, magnified 5x and 10x to make very accurate focus adjustments. That being said, I've done tests which show that the autofocus on my cameras does as good a job as I can manually using live view's 10x magnification.</p>

<p>Joe</p>

[paul_heagen1]

<p>I understand and make sense. However, I am racking the lens back and forth and it is obvious I am reaching a point of focus. Plus, the shots show the focus is way off. I still wonder if there is something else going on, like a disagreement with the eyepiece diopter. </p>

<p>>></p>

 

[brad_trostad]

If you place the camera on a tripod with auto focus on and press the af button does the image generally appear in focus to your eyes

when looking thru the viewfinder or does it look slightly blurry. Does it do this with different lenses?

 

Another thought would be depth of field. Are you handholding a shallow depth of field setup (eg shooting 50mm at f1.4 or macro lens

wide open). If you are shooting shallow dof hand held with auto focus perhaps the camera is quick enough to get the shot in focus

but when doing this handheld there could be too much camera movement between your manual focus adjustment and pressing the

shutter button. Disregard if all your tests are with the camer on a tripod.

 

Your initial post sounds like textbook back focus but the af is working?

[scott_ferris]

The AFmodule is in the bottom of the camera, manual focus by eye through the viewfinder relies on exact placement of the

focusing screen in the top of the camera so the two systems are totally unconnected, it could be that your focusing screen needs shimming to get it to the correct

place. Most camera repair shops can do this though most people would only trust this kind of job to an authorized Canon

repair facility.

 

It is also worth noting that focusing screens actually have an effective aperture, modern DSLR screens are around f 2.8,

this makes it impossible to manually focus more accurately than that unless you can change screens, so people claiming

to get 100% accuracy manuually focusing super fast primes wide open with standard screens are talking bull.

[paul_heagen1]

Scott

 

You may be closest to the issue. As stated, the autofocus is fine. Only problem is manual. I actually took the same exact

shot with same f stop and shutter speed f2.8 x 5,000 shutter. The auto was perfect. The manual was way off. It is not

even a matter of misjudging. I racked the lens and know it was in focus. There was no point in the photo that was in focus

 

This is not a problem of camera shake or even severe depth of field since it happens whether I am near or far from the

subject. I shoot open a lot and never had the problem until this week. No, I did not drop the camera.

[andrewkurcan]

<p>Put up some examples that you've shot. Also, for your piece of mind, print a focusing guide for your lens, throw the camera on a tripod, and do a shot with and without AF. Post that too. Either something is out of adjustment on your camera, or some sort of user error is taking place - I've had a prime lenses slip manually as they age - once the mechanisms get looser it can be a real pain. </p>

[john_tran14]

<p>what you see on focusing screen is not the same as what you will get, but we still can focus accurately manually with a screen of F2.8 effective aperture. Just because the real capture photo has shallower dof doesn't mean we can not focus accurately</p>

[tony_buckwell]

<p>Paul (and others), I have precisely the same fault with a 10D body. The body was acquired second-hand so I'm unaware of its history. Focus is slightly out whenever I try to manually focus. The problem occurs with every lens I use and is unrelated to the aperture selected. If I focus manually and shift to AF the lens refocuses. I've read of the 10D requiring auto focussing adjustments when first released. Mine auto-focuses perfectly. Consequently I'm inclined to assume my 10D was sent away to be adjusted and maybe all the shims that enable the relative position of the screen to be adjusted in relationship to the position of the sensor, weren't replaced correctly. As this body was acquired purely as a "back up" and otherwise functions perfectly I don't worry - just never attempt to manually focus with it. My guess is that your body has the same problem as mine, Paul, and the relative position of the screen in relation to the sensor has shifted or been incorrectly adjusted at some point.<br>

Tony B</p>

[paul_heagen1]

<p>Here is the test shot I did using autofocus</p><div></div>

[paul_heagen1]

<p>Here is the manual focus. Virtually nothing in the frame is in focus. </p><div></div>

[philip_wilson]

<p>Some of the earlier APS-C cameras had a problem with the glue bonding the mirror onto it's frame. Is it possible that the mirror was re-attached at some point and not done exactly. This would put MF off but may not impact the AF sub-mirror. Just looking at how far off your MF seems to be it looks like there is a significant difference in the optical path to the viewfinder and the one to the sensor.</p>

[Spearhead]

<p>I tend to agree with the idea that there is something wrong, although that doesn't explain why nothing in the image is in focus, unless the camera is focused on something closer than the tailgate. You really should do a test similar to the ruler test used for back/front focusing and then post.</p>

<p>One thing I disagree with is this:</p>

 

<blockquote>

<p>Manual focus is pretty tough on a DSLR. The problem is - you can't see the screen well enough to make critical focus adjustments.</p>

</blockquote>

<p> <br>

People say this a lot, but it hasn't been my experience. My eyesight isn't great, but the other night I was using an accessory on my flash that blocked the autofocus beam. It was too dark to use AF without the beam, but amazingly, all my photos were in focus, and I was shooting at f4. It may be harder than it used to be, but it's not that difficult.</p>

[ed_avis2]

<p>You didn't say what camera body you are using. If the focusing screen is in slightly the wrong place it would cause the focus in the viewfinder image to be different from what eventually reaches the sensor. If your camera has a replaceable focusing screen, get a replacement and fit it (or just use the special tool to uninstall and refit your existing screen). If not, as others mention, you may be able to bodge the screen's position if it is out of place for some reason.</p>

[thomas_dannhauser]

<p>Seems amazing (to me anyway) that there could be such a huge discrepancy between autofocus and manual focus results. I mean, they are not even close! I can't answer whether an unaligned focussing screen could cause such a large difference, but before jumping to this, how about some more information?<br>

Tell us about your own vision.... corrective lenses or not? bifocals? etc. Are you wearing these when you adjust the eyepiece diopter? Are you looking through the distance part of your prescription when you manually focus?<br>

And just because I'm slow, please clarify for me.... When the camera autofocuses (correctly), does the image in the viewfinder look sharp? Are you adjusting the eyepiece diopter to make a correctly focussed image look sharp? If not, how are you adjusting the eyepiece diopter? Are you looking at a near-by object through the camera, or one at infinity? </p>

[brad_trostad]

<blockquote>Seems amazing (to me anyway) that there could be such a huge discrepancy between autofocus and manual focus results. I mean, they are not even close! </blockquote>

<p>Sort of kidding but ..... I could, put a piece of black tape over the eyepiece. Autofocus would work great (provided it was pointed in the right direction) but manual focus would probably worse than the examples shown.</p>

<p>I'm pretty sure the OP does not have a vision problem. He can easily test this with another camera someplace else (like at a camera store). He can even bring his suspect one along with to the store and have someone else confirm the problem. Or easier yet, have someone else with good vision try the same thing the OP is doing.</p>

<p>Sounds like the optical path from eyepiece to the mirror is screwed up somehow.</p>

[philip_wilson]

If you have a lens with a distance scale on it I would compare what the distance scale says compared to what is actually

in focus. Measure the distance, set this on the lens and shoot then focus manually and look at what the distance scale

says. Examine the images as it is hard to tell where you are focused from the a I've shot

[philip_wilson]

Sorry the auto correct garbled the last sentence. It should read

 

From the images you posted it is hard to tell where you are focused in the last shot