| Author |
Message |
    
Sam_am
Tinkerer
Username: Sam_am
Post Number: 1
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 16, 2013 - 03:54 pm: | 
|
Hi,
My Canon AE-1 Program has a problem. When I manually bring the image into perfect focus, steady myself, and take the shot - the resulting photo is out-of-focus. I got back a whole roll of pictures completely out-of-focus. Not knowing what was wrong, I took a second roll of shots with random settings, including intentional shots that appeared to me to be out of focus. The result: the ones I took that appeared to be out of focus developed in-focus. The ones that appeared to me to be in-focus, were out-of-focus.
If it helps, I can see some dark marks when I look through the viewfinder. I think the marks are on the screen above the mirror. The mirror and lens are clean, and the lens mount is tight.
Thanks in advance! |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 2
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 16, 2013 - 04:11 pm: |
|
One more thing:
I know it's not motion blur because a couple of the pictures where I focused on something far away, had focused on something close-up instead.
(sorry, couldn't edit original post) |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 507
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 16, 2013 - 05:44 pm: |
|
Does this happen with more than one lens?
Does the mirror look like it's in it's proper position when the film is wound?
Did you watch the action of the mirror to see if it is rising when you wind the film?
Did this just start, or was the camera like that when you got it?
Can you tell if the focus point is in the front or back of the subject?
What could be happening, is the mirror is out of alignment, and thus throwing off your focus. It depends on (at rest) whether it is hanging too low, or too high, which way the focus will be off. Looking at my A-1 (forerunner to the AE-1P) there is a stop to keep the mirror from hanging too low, and I figure it's similar on your model. So if you can push the mirror any distance against the stop, then it is hanging too high. I've luckily not had to take one of these apart, so I can't tell you how to adjust it if that is the problem.
PF |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 3
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 16, 2013 - 06:59 pm: |
|
I only have the one lens: "CANON LENS FD 50mm 1:1.8"
When I received it, it was working perfectly. Got some beautiful pictures out of it 5 years ago. But regrettably, it's been sitting in a drawer since then (air conditioned).
The focus point is in front of the subject. When I focus on a subject 6 feet in front of the camera, the number inscribed on the lens dial says it's focused 3 feet in front of me.
The mirror doesn't move when I wind the action, and it seems to be resting on top of a small pin (on one side) that acts as a backstop. It doesn't seem to have any give, or move downward at all when i lightly push on it.
Your theory seems to fit the problem better than anything I thought of. Maybe the mirror or focusing screen is off and I just can't see it...
 |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 165
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, March 16, 2013 - 07:23 pm: |
|
It's almost certainly the mirror. It's possible it could be the lens or the screen, but not likely. Some cameras have a convenient screw for adjusting the mirror angle, but I haven't worked on an AE-1P so I can't say about that one. |
Fiftyfifty
Tinkerer
Username: Fiftyfifty
Post Number: 66
Registered: 07-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 17, 2013 - 02:40 am: |
|
May I suggest that before you blame the camera mirror set up test the focussing screen, it is removable on the AE-1 Prog, remove the screen, clean it and then replace it so that it is seated correctly.
Doug |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 166
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 17, 2013 - 07:58 am: |
|
That's a good point: the screen is easily removable on the AE-1P, so that's easy to check.
What's unusual is that it was working fine at first, then it sat in a drawer, and now it won't focus properly. Could it have been dropped at some point? |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 4
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 17, 2013 - 10:54 am: |
|
I removed the focus screen, cleaned it, and re-seated it. It's pretty easy to take out and put back in.
I tested the focus, and nothing has changed. It still says it is focused 3 feet when I focus on something 6 feet away. |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 429
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 17, 2013 - 11:25 am: |
|
This camera doesn't have a diopter adjustment, does it? |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 5
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 17, 2013 - 12:41 pm: |
|
I don't see one anywhere. I looked online, and it appears the AE-1 Program doesn't have that feature (apart from interchangeable viewfinder lenses that go behind the eyecup). |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 508
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 17, 2013 - 07:26 pm: |
|
The only other thing we have not investigated in this scenario is the prism. That said, I don't think it could go out of adjustment. It should be fairly solidly set in place.
So we have to now turn our attention to the lens. It could be that the focus ring has been over rotated, and you would have to expose the set screws, and refocus the lens. Again, I've never done this with a Canon lens, so others may have help for you on the proceedure. I have done it on a couple of Yashica lenses, but they are somewhat simple in design, which makes them easier to work on.
Do you have knowledge of another lens you could borrow to test out the focus? That would be a big help in determining the cause of the problem.
PF |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 167
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Sunday, March 17, 2013 - 08:43 pm: |
|
As a quick test, you could put some Scotch tape across the film rails with the back open and check the focus. That will tell you if the lens is at fault. |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 6
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 18, 2013 - 08:33 am: |
|
Sadly, I don't have access to another lens. There are no camera shops anywhere near where I live. I'd have to get something off ebay.
The focus ring and everything else on the lens is really tight, operates smoothly, and has no marks from wear or damage. That's what makes this so puzzling, as this was my Dad's camera - so I know it's been barely used since he bought it new.
I did the scotch tape test following these directions:
https://kyp.hauslendale.com/classics/collimator.html
When I have it focused to infinity, the tape is crystal clear. Not only can I see the X in-focus, but I can see the grain in the tape. When I move it from infinity towards 1, it goes out of focus. |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 7
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 18, 2013 - 05:20 pm: |
|
I didn't do the test quite right - just realized it now. I didn't have another camera, I just looked through the front of the lens. |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 168
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, March 18, 2013 - 06:04 pm: |
|
You don't have to have another camera -- simply focus to infinity, and look through the back of the camera at a distant object (a faraway telephone pole, the moon, etc.). The object should be in sharp focus on the tape. |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 8
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 09:06 am: |
|
Ok, had to wait for daylight to do it right ;)
I focused to infinity, aimed it at a faraway house, faraway trees, faraway telephone pole. Looking through the back of the camera at the tape, the objects were in sharp focus. I unfocused the lens to be sure, and it's definitely in-focus when set to infinity. |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 430
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 09:58 am: |
|
I'm intrigued. If you have eliminated the lens, than it has to be the mirror, screen, prism or viewfinder.
Is the film pressure plate on the door in the right position? |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 169
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 10:56 am: |
|
Does the mirror have a screw for adjusting its angle at rest? |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 9
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 01:18 pm: |
|
The film pressure plate looks straight.
Not sure if the mirror has a screw for adjusting the angle.
Here's some pictures.
http://imgur.com/a/Ko84C
Should I try that screw visible in pictures 2 and 4?
(Also, the mirror isn't scratched, that's the focus screen. I was careless a few posts ago when I tried to remove it.) |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 431
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 01:30 pm: |
|
That "screw" in picture 3 ( with the hex) is the rest for the mirror. It looks like it is eccentric. If you rotate that, it should adjust the position of the mirror. |
Sam_am
Tinkerer
Username: Sam_am
Post Number: 10
Registered: 03-2013
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 06:58 pm: |
|
That seems to be working.
I've been adjusting it to lower the mirror.
Start: I focus 4ft away, the lens says it is focused 2.75ft away.
End: I focus 4ft away, the lens says it is focused 3.5ft away.
But the mirror won't go any lower, and the hex screw was tight. Which leads me to believe this is only a workaround, and isn't solving the real problem (whatever it is). I could always attempt to sand down the hex screw to force the mirror to sit lower... but that seems pretty out-there. |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 432
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 07:05 pm: |
|
Remember, when you are measuring the distance to your target that you should be measuring to the film plane, not to the front of the lens.
If the hex is eccentric, can you try adjusting it the other way, so it will eventually go lower without tightening? |
Waynemel
Tinkerer
Username: Waynemel
Post Number: 433
Registered: 08-2009
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 07:13 pm: |
|
Once you get things close with the mirror, I think you should set the lens to infinity and look at a distant object. Adjust the mirror until the object is in focus (leaving the lens at infinity). That should get the focus correct throughout the entire range. |
Br1078lum
Tinkerer
Username: Br1078lum
Post Number: 509
Registered: 11-2010
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 07:22 pm: |
|
No need to do any modifications, there should be plenty of throw in the stop to get to the point it needs to be. And like Wayne says, measure from the film plane. It's that mark on top of the camera of a circle with a line through it. That will give you your true focus distance to the subject.
PF |
Donnie_strickland
Tinkerer
Username: Donnie_strickland
Post Number: 170
Registered: 09-2006
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, March 19, 2013 - 08:04 pm: |
|
Yes, definitely use infinity to correct the focus. That way you don't have to worry about measurement errors. |
