Focussing Issues with a Canon 5d Mark II

[skywalker_shiva]

Hi,

I recently purchased a new canon 5d Mark II

The AF of the camera works just fine
but the camera FRONT FOCUSSES when I try to manual focus.
I've tried it on many lenses - 35mm 1.4,  50mm 1.4,  85mm 1.8

No, I don't wear glasses and my eyes are just fine
when I use my Hasselblad 503 with a DB.

I've tried diopter settings but to no avail.

Canon insists the camera is perfect.

Anyone got any idea what's going on

The AF works just fine though.

[Johnny_Johnson]

Sounds like there too many shims under the focusing screen.  My 5D came from the factory with a back focus issue (when manually focusing) so I sent it back to Canon New Jersey for service.  It came back working fine.

Later,
Johnny

[phmg]

Hi Shiva ,
                 suffering from similar problems , with a 1dsmk3 . One thought that has crossed my mind but a google search has brought up no results
is that the mirror viewfinder alignment is out of calibration with the sensor. As I'm not quite getting the same results as I see in the viewfinder. I also
bought the ec-s precision screen and I'm still suffering.Although what throws me is I'm sure the af works off the mirror, if you use af adjustment that
could explain the disparity as you are compensating for a possible incorrectly seated mirror. I have +5 on my main used lense. I hope someone else
can shed some light on this.

[skywalker_shiva]

The camera is back from the service centre.

It still front focuses by a bit.

Any suggestions what I could advise the technician to do now
so that he gets it perfect this time around ?

[Ken Bennett]

Are you using the high-precision focusing screen? I find this makes a big difference in accurate focusing with my 1D2 bodies.

[skywalker_shiva]

No Bennett ... Its a stock camera bought 2 weeks back.

[Ken Bennett]

No Bennett ... Its a stock camera bought 2 weeks back.

The standard focusing screen is optimized for brightness, not manual focusing accuracy. Canon (and the other manufacturers) assume you'll be using the autofocus. In my casual experiments, I found that the stock focusing screen shows you the view at around f/4 -- that is, apparent depth of field in the viewfinder assumes you are at f/4, which means that objects will look like they are in focus on the screen, when they are not in focus on the sensor.

The high precision focusing screen is designed for manual focus with fast lenses. It does a much better job of showing the actual focus point wide open with a fast lens. Not only does this help with focusing precision, but it helps to more accurately preview the DOF of your lens when you press the DOF preview button. The downside of this screen is that it's very dark with slower lenses. Even with my f/2.8 zooms, the view is noticeably darker. It's usable enough that I just leave the screens in all the time.

[jake21]

Other than darkness are there any other negatives of the Ef-s screen (which I presume is the one you are using). I.e, does it interfere with metering or auto-focus ? (I do not actually own a 5d ii; still debating between a-850 and 5d mk2 - waiting to see what new products become available (I have a trip this summer where I would prefer to use ff; so I'll probably purchase a camera mid june; unless I bail and stick with apsc another year))

The standard focusing screen is optimized for brightness, not manual focusing accuracy. Canon (and the other manufacturers) assume you'll be using the autofocus. In my casual experiments, I found that the stock focusing screen shows you the view at around f/4 -- that is, apparent depth of field in the viewfinder assumes you are at f/4, which means that objects will look like they are in focus on the screen, when they are not in focus on the sensor.

The high precision focusing screen is designed for manual focus with fast lenses. It does a much better job of showing the actual focus point wide open with a fast lens. Not only does this help with focusing precision, but it helps to more accurately preview the DOF of your lens when you press the DOF preview button. The downside of this screen is that it's very dark with slower lenses. Even with my f/2.8 zooms, the view is noticeably darker. It's usable enough that I just leave the screens in all the time.

[Anthony R]

Other than darkness are there any other negatives of the Ef-s screen (which I presume is the one you are using). I.e, does it interfere with metering or auto-focus ? (I do not actually own a 5d ii; still debating between a-850 and 5d mk2 - waiting to see what new products become available (I have a trip this summer where I would prefer to use ff; so I'll probably purchase a camera mid june; unless I bail and stick with apsc another year))

I have the screen, no, no issues. I don't even notice that the vf is darker. It greatly improves manual focusing.

[Ken Bennett]

Other than darkness are there any other negatives of the Ef-s screen (which I presume is the one you are using). I.e, does it interfere with metering or auto-focus ? (I do not actually own a 5d ii; still debating between a-850 and 5d mk2 - waiting to see what new products become available (I have a trip this summer where I would prefer to use ff; so I'll probably purchase a camera mid june; unless I bail and stick with apsc another year))

You may need to tell the camera which focusing screen you are using. Check the menus or the custom functions. There are metering issues with using screens other than the stock screen. This is trivial, though.

Using fast primes, the EF-S screen looks just like the stock screen. Using f/2.8 zooms, on my cameras it is noticeably darker, but still usable. Same with my 300/4. Not sure what it would look like with anything slower.