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Archive 2008 · I am an idiot and need to have my eyes checked

  
 
thrice
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p.1 #1 · p.1 #1 · I am an idiot and need to have my eyes checked


Ok, turns out I relied too much on focus confirmation and I need glasses... the following is what I originally posted:



I tried a focusing chart and with each of my alternative lenses the 5D mark II consistently front focuses on the chart. I change the "focus micro-adjust" to whatever value with no effect. Is this feature broken with manual focus lenses?

If the focus micro-adjust only affect auto-focus lenses then should I take the body in for a sensor distance adjustment?

anyone with a mark II out there can confirm that the focus micro-adjust does nothing with their manual lenses?



Edited on Dec 16, 2008 at 07:17 AM · View previous versions



Dec 16, 2008 at 06:41 AM
dcains
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p.1 #2 · p.1 #2 · I am an idiot and need to have my eyes checked


How could AF micro adjust possible work with MF lenses?


Dec 16, 2008 at 06:47 AM
thrice
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p.1 #3 · p.1 #3 · I am an idiot and need to have my eyes checked


I didn't know it was AF micro adjust as it is just called focus micro-adjustment in the menu. I would assume that it moved the AF sensor slightly, but obviously that is not the case then?

EDIT: to clarify I am referring to focus confirmation with alternate lenses. Manual focus works fine and lines up with focus confirmation but still gets me front focused pictures. I was hoping focus micro adjust could fix this but in retrospect it definitely seems like a misaligned sensor. I'll test my EF glass.

I guess I need to take it into a service centre *sigh*



Dec 16, 2008 at 06:53 AM
Ronan O Keeffe
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p.1 #4 · p.1 #4 · I am an idiot and need to have my eyes checked


The focus confirm has a slight tolerance either side of critical focus. So it can light up when an image is considered to be sufficiently in focus rather than perfectly in focus.

If you're using third party chipped adaptors that must also add another variable into the equation.

I've also seen threads reporting that ZE lenses show focus confirm when not perfectly in focus. So it's not just an adaptor problem.



Dec 16, 2008 at 07:00 AM
ovredal73
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p.1 #5 · p.1 #5 · I am an idiot and need to have my eyes checked


Thrice, do you already have the EG-S? I cannot focus worth @&% without the right screen.


Dec 16, 2008 at 07:03 AM
dcains
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p.1 #6 · p.1 #6 · I am an idiot and need to have my eyes checked


I'd bet $$$ it's not the body. As mentioned, it could be the adapter, but most likely it has to do with the focus screen. The stock screen doesn't accurately reflect DOF of large aperture lenses, and IIRC, it approximates f/2.8, which would show a much larger DOF than a lens set at f/1.4, 1.8, etc. You might try a split-prism screen instead. It's an easy swap on that body.


Dec 16, 2008 at 07:05 AM
thrice
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p.1 #7 · p.1 #7 · I am an idiot and need to have my eyes checked


I have an Ee-S (same as Eg-S) and Haoda split-prism screen and have seen the same results with both screens.

I believe all these issues must be adapter related... unfortunate really. But I will still test my EF lenses.

EDIT: 24/1.4 spot on every time... yep it's adapter(s).

Edited on Dec 16, 2008 at 07:12 AM · View previous versions



Dec 16, 2008 at 07:08 AM
s23chang
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p.1 #8 · p.1 #8 · I am an idiot and need to have my eyes checked


Have you compared "LiveView" focus vs viewfinder focus vs AF chip focus?


Dec 16, 2008 at 07:09 AM
thrice
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p.1 #9 · p.1 #9 · I am an idiot and need to have my eyes checked


I haven't yet, but that's a good idea, the whole live-view thing still hasn't caught on with me yet

EDIT: Live view is accurate... so it's my viewfinder!? or my eyes? ugh damn sorry to waste everyone's time with this thread



Dec 16, 2008 at 07:12 AM
Jonas B
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p.1 #10 · p.1 #10 · I am an idiot and need to have my eyes checked


The problem has nothing to do with the adapters. How could it? You also don't adjust the sensor.

Here: It's your viewfinder screens not exactly at the same optical distance from the lens mount as your sensor is.

Canon can fix this by add or remove shims at the viewfinder screen, or you can buy shims from them. Note: this was at least true with the 5D, I guess they have shims for the 5DMarkII as well.



Dec 16, 2008 at 07:20 AM
Kingfishphoto
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p.1 #11 · p.1 #11 · I am an idiot and need to have my eyes checked


I believe Jonas-has the correct answer. If the viewfinder screen doesnt allow true inf. focus, you wont be able to achieve proper manual focus. If its off a bit from Canon factory, it needs to be adjusted by a repair facility.
Cheers
Harry I believe they use a device called a collameter (spelling ?)



Dec 16, 2008 at 07:28 AM
thrice
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p.1 #12 · p.1 #12 · I am an idiot and need to have my eyes checked


Live view only allows shooting at 1/focal length even in Tv mode *sigh* go canon.

I would say yes I need shims. I'll contact my service centre and ask for some shims.

Jonas, it's a bit of a moot point as it obviously isn't the problem here but can't you adjust the distance of the sensor with the two little bolts in the mirror box?

http://photography-on-the.net/forum/showthread.php?t=345457

EDIT: so, by the looks of things I need to add washers between my screen and the viewfinder? As it's front focusing.

Found out my pentax-EOS adapter has scratched my camera locking fin for the pentax lens (part of the big_is adapter) scratched through the black paint in my mirror box. Will need to get some paint to fix that up.



Dec 16, 2008 at 07:37 AM
Conner999
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p.1 #13 · p.1 #13 · I am an idiot and need to have my eyes checked


Jonas is correct. AF adjust has NOTHING to do with manual focus. Nada. Zippo.

Accurate MF relies on the distance from the rear mount of the lens to the sensor being EXACTLY the same (did I say EXACTLY?) as the distance from the rear mount to the focus screen.

If they are off even a minisucle amount what looks in focus via the VF you won't be - the plane of focus will be just in front of or just 'behind' the plane of the sensor.

For manual focus lens users, the 5D (and by logical extension the 5DII) is infamous due to loose manufacturing tolerances for needing to have it's focus screen re-calibrated IF the factory installed focus screen is replaced with ANY (as in ANY) other focus screen -- INCLUDING any focus screens sold by Canon.

Because of manufacturing tolerances, the degree of re-calibration required, like the mirror clearance issue, will vary on a body-by-body basis. You'll also need to test/re-shim/test/re-shim/test EVERY time you change screens.

Shims (obtained from Canon Parts) can be changed (thicker/thinner), removed or you can use thin strips of scotch tape or metallic duct tape on the edges of the new screen in lieu of adding shims. You can also send the camera and new screen (Canon only of course) to Canon for calibration as well - but you'll do a better job yourself.

Because of tighter manufacturing tolerances, 1 Series bodies don't have the same issue. You can change focus screens 5x a day in any one them with no issues.

Edited on Dec 16, 2008 at 08:57 AM · View previous versions



Dec 16, 2008 at 08:42 AM
thrice
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p.1 #14 · p.1 #14 · I am an idiot and need to have my eyes checked


Never had that issue with my 5D, guess I was lucky.

Ever since I got the mark II (popped in Ee-s before even using it) I've thought the viewfinder looked a little blurry, even with diopter adjustment.

I hope I don't have to wait too long to get my washers, otherwise I may just tape the screen but I never trust tape not to leave any residue.

Is the washer installation process difficult? do you simply "sit" them ontop or underneath the screen while it's sitting in the little cradle?

EDIT: I had another look and it seems there are two washers between the focusing screen and the viewfinder pentaprism... I managed to detach them at the front but at the back they're still attached. If the viewfinder is back focusing (it says appears in focus but the lens is front focused) should I remove these shims? it's terribly hard to describe.



Not my pic btw, it looks like he's removing the AF points but lets pretend it's my focusing screen for now. I have two shims up in the area circled, so they're BETWEEN the screen and the pentaprism.

When I take a picture the plane of focus is closer to me than it appears in the viewfinder. Should I remove these shims?



Dec 16, 2008 at 08:50 AM
Conner999
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p.1 #15 · p.1 #15 · I am an idiot and need to have my eyes checked


Changing shims is no biggie - just be careful (are very thin) and use some plastic tweezers - or metal ons with the tips covered in tape just in case you slip (lots of easily-scratched plastic/glass in the area). Have a note pad to keep track of what thickness came out vs. what needs/went in. Test via tripod and cable release (removes variables) using any number of focus test charts off the web - or a ruler.

With tape the idea is to ad one thin strip on each side of the screen, install, test, add another strip if needed, etc. Metallic duct tape is apparently 0.001" thick - and even one strip can make a big difference.

It varies by body. My 5D (now long gone) took every lens I tossed on it - but focus screens were another matter. Drove me freaking nuts until I did more research and figured out what the problem was.



Dec 16, 2008 at 09:05 AM
Conner999
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p.1 #16 · p.1 #16 · I am an idiot and need to have my eyes checked


Hard to tell from pics - but those look like retention clips. Also looks like a 20D/30, etc - no distinct SI plate and focus screen

The shims are lose - not attached to anything. Going off memory now, but they are very thin U-shaped (IIRC) strips metal that are simply placed between the SI plate (plate with the #$%Y etched focus marks that are illuminated by an LED) and prism.

The shims ARE NOT attached to anything and are simply sandwiched in place by the SI plate and retention clips. They will fall fwd once the SI plate is removed and can simply be lifted out.

This site will give you a better idea

http://www.ascent-design.com/photo/Clean5D/

OH - BIG tip here. Use a magnetic screwdriver or tape a small strong magnet to the blade of the small Philips screwdriver used to remove the two top plate screws. This will avoid the screws falling into the mirror box.

Also be gentle and take your time. Small Philips screws tend to be very soft and if the screwdriver 'cams out' of the screw head because it wasn't held straight in, was too big or too small, or was allowed to 'ride out' of the socket (because not enough down-forced was used) it can mar it enough to make future removal/install a PITA.

Make sure you use a right-sized screwdriver and it is held straight into the screws with stays in the screw head when you gently screw them out. When re-installing just snug them down gently.

If skittish practice on an old radio/walkman, etc that you have around - the screws will be similar



Dec 16, 2008 at 09:14 AM
thrice
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p.1 #17 · p.1 #17 · I am an idiot and need to have my eyes checked


EDIT god I wish I read that post before I started....... I guess I got them out without removing the screws... go me.

EDIT 2: oh crap I looked at that link what I removed wasn't the shims I guess... Well I'll take it to the canon service centre and see if they can fix it... sigh.

EDIT 3: ahh yes they are the shims, they sit under the superimposed indicator screen in the mirror box, between the indicator screen and the focusing screen.

Well that was extremely difficult, the shims are held in with some kind of voodoo. I got them out but they got bent I tried with my haoda screen and it appeared I'd gone too far... I started sweating.... Then I put in my Ee-s screen and it's not perfect either... off to service centre.

I feel very unlucky and I'm going to sleep before I go ruin some other part of my $4000 camera.

I'll post pictures of the shims tomorrow, but that upper area is slightly different in the 5D-II compared to the 5D, I tried gently shifting/pulling/twisting in every direction before my patience gave out and I just forcefully removed them. Their completely rectangular with all sorts of pointy bits, not "U" shaped unfortunately.



Dec 16, 2008 at 09:35 AM
Cableaddict
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p.1 #18 · p.1 #18 · I am an idiot and need to have my eyes checked


Adding to the puzzle-

Supposedly there are also adjustment screws for changing the mirror position, and this is also a critical part of the puzzle. I can't recall what exactly this affects, though. Someone here must surely know.

Evidiently this CAN be adjusted by the user, but it requires small hands, and lots of patience. Probably best left to a Canon tech, if it's deemed necessary.



Dec 16, 2008 at 11:30 AM
brainiac
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p.1 #19 · p.1 #19 · I am an idiot and need to have my eyes checked


Cableaddict wrote:
Supposedly there are also adjustment screws for changing the mirror position, and this is also a critical part of the puzzle. I can't recall what exactly this affects, though. Someone here must surely know.


I wouldn't do that if I were you. The mirror position needs to be at exactly 45 degrees, otherwise I think it might be possible for the top of you viewfinder to front focus and the bottom of the viewfinder to backfocus. That's probably why Canon uses shims in the factory: it's easier to set the mirror at 45 degrees, and then shim the focussing screen up or down as required. That way it's just about distance, and not about angles. I know from experience that in-house engineers are very reluctant to adjust mirrors themselves. Shim it. The good news is that the whole process is easier with Liveview.



Dec 16, 2008 at 12:34 PM
shirozina
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p.1 #20 · p.1 #20 · I am an idiot and need to have my eyes checked


brainiac wrote:
I wouldn't do that if I were you. The mirror position needs to be at exactly 45 degrees, otherwise I think it might be possible for the top of you viewfinder to front focus and the bottom of the viewfinder to backfocus. That's probably why Canon uses shims in the factory: it's easier to set the mirror at 45 degrees, and then shim the focussing screen up or down as required. That way it's just about distance, and not about angles. I know from experience that in-house engineers are very reluctant to adjust mirrors themselves. Shim it. The good news
...Show more That depends on the mirror being exactly 45 to start with and many of these focus errors could be atributed to the mirror shifting out of position due to the constant impact of the mirror on the rests or simply being made that way. My 5D was checked and adjusted to 'within manufacturing tollerances' by a well known Canon certified Camera repair outfit in london but it still back focused. I applied some tape to the mirror rests on both the main and secondary and it's been fine ever since. I never use AF and the focusing is bang on.



Dec 16, 2008 at 01:12 PM
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