Central 'stripe' out of focus - Update

Craigus

Craigus

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Some of the shots on the last roll of film have something odd happening, the picture below shows it the most. You can see a stripe down the centre of the picture that is out of focus and whilst this picture isn't focused properly anyway, it is quite apparent if you look at the hill in the distance near the branches on the right, this area is sharper than the central part which is the same distance away. It also looks a bit soft on the left hand side.

What could cause this? The film not sitting quite flat? Dodgy lens? This is likely just be me being crap at manual focus but it seems odd.


R1-04467-0003 by Craigus89, on Flickr
 
Could be neg not flat in the scanner or lens decentred or just a poor lens.
 
Look at the neg with a loupe. If it's as OOF then it's the camera or lens. If interchangeable lens then try another to see if it has the same issue. If it's a fixed lens it's either the lens is way out of alignment or the film transport is iffy as the negative isn't sitting flat in the camera.

If the neg looks ok then it could be a scanning issue so try scanning it again. If it was scanned by a decent processor then it's probably not a scanning issue.
 
I'd go with film curl, although this would depend on the camera as some have better film paths than others. If you google with the terms "mamiya film curl" and if your Google gives you the same results as mine, you'll get a series of photos; the second and especially the fourth show a bent film.
 
It looks to me that the film was not laying flat in the film gate or the scanner.
Some cameras are famous for this including the excellent Rolleiflex.
In a Rolleiflex the film makes a sharp right angle bend in the position of the centre of the next shot. If the camera is not use for a while, and then more shots taken. the first of those pictures is always sharp corner to corner The next has a band of unsharp detail through the centre. This is also so for a number of other TLR's, except the Minolta Autocords which feed the film in the reverse direction.
 
Thanks for the replies, I'll have a good look at the negatives later and see what they look like. Taken on a Canon AE-1 Program by the way.
 
Craigus said:
Thanks for the replies, I'll have a good look at the negatives later and see what they look like. Taken on a Canon AE-1 Program by the way.
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Well if using a Canon lens you shouldn't have any problem with sharpness..just thinking if not a scanner problem, check if the mirror is operating quickly.
 
The mirror is definitely not right, it has the canon squeak which I have tried to fix myself unsuccessfully. I didn't think that would have this kind of affect though, how could that happen?
 
If the mirror moves out of the way too slowly and is still moving when the shutter opens you might/probably would get some sort of blur on the image. However, I don't know if the effect of that would be confined to two specific vertical areas of the frame? I'd be inclined to check the negs first before I did anything else, to see if the softness/blur is on the negative or not?
 
It's most likely the film not being flat at either scanning or taking, or a dodgy lens.

It's very unlikely to be anything to do with the mirror, as the blue would be horizontal on the image gde to the vertical movement of the mirror
 
Mr Badger said:
If the mirror moves out of the way too slowly and is still moving when the shutter opens you might/probably would get some sort of blur on the image. However, I don't know if the effect of that would be confined to two specific vertical areas of the frame? I'd be inclined to check the negs first before I did anything else, to see if the softness/blur is on the negative or not?
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The mirror plays no part in the creation of the image.
 
robhooley167 said:
It's very unlikely to be anything to do with the mirror, as the blue would be horizontal on the image gde to the vertical movement of the mirror
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That's what I was thinking to start with, but the Canon AE1 has a horizontal-travel, curtain type, focal plane shutter, so I was wondering if that would change the recorded effect in any way? Let's hope the blur is not on the negative and all this will be irrelevant then! :)
 
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Craigus said:
The mirror is definitely not right, it has the canon squeak which I have tried to fix myself unsuccessfully
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Well it wont go away and eventually the mirror will go up and down slowly and stop altogether...mind you it could be months\years into the future so no panic. I've done an Av1 and A-1 by taking the bottom plate off and using a long needle and using a small drop of sewing m\c oil..this guy uses a syringe and shows you where to lubricate from a stripped down AV1
View: https://www.youtube.com/watch?v=6XYX7AF2yto
 
Failing that, I believe if you choose the right repairer you can have it put right with a full service for about £55 (plus postage, and as long as no parts are broken, etc.). Given the price a fully working AE1 Programme seems to fetch these days it might be worth considering?
 
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Terrywoodenpic said:
The mirror plays no part in the creation of the image.
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Depends on the sequence of firing the shutter...if the shutter only fires when the mirror is fully up then you are right BUT if the shutter can fire with the mirror travelling slowly up this must have some effect...
Anyway when you have eliminated the impossible, whatever remains however improbable, must be the truth ;)
 
Have a look at the scanned image at pixel level - if the image was flat in the scanner then you should see film grain in the OOF areas, but if it was curled then the grain will be blurred there.
 
excalibur2 said:
Depends on the sequence of firing the shutter...if the shutter only fires when the mirror is fully up then you are right BUT if the shutter can fire with the mirror travelling slowly up this must have some effect...
Anyway when you have eliminated the impossible, whatever remains however improbable, must be the truth ;)
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In that case, it would shade the image like a shutter with one part correctly exposed and the rest tapering to under exposure. However it could not alter the focus.
 
Just to revive this thread, I've had a couple more rolls developed and the same issue is showing itself again. @ancient_mariner said above about grain in the oof areas showing it not to be a scanner error, this is the case, the grain is consistent so we can rule out scanning error.

It doesn't show on every photo either, some shots are spot on throughout. I don't think how much I stop the lens down effects it although my first thought was that was the case.

It is very much a 'stripe' that is out of focus and just feels like it is the film not laying flat. Is there anything I can do to remedy this?

(Canon AE-1 program)
 
I don't know the Canon AE-1 - never even seen one as far as I recall - so this may not be appropriate. Check that the film pressure plate is flat and functioning; if it is film-not-flat then the effect should be worse with wide angles and less with long focal lengths. Is this the case?
 
I'm afraid I only have the one lens with it so have been unable to test any others. I may pick up another if I can find a cheap FD mount lens just to test. I have another roll in it at the moment so I'll check the pressure plate when I next load.
 
Have you had the camera serviced yet to cure the mirror squeak? If not, then if nothing has changed then you can't really expect a different result, can you? Rather than spend money on another lens on the off-chance it might be a lens issue, why not get the camera checked and serviced (if not uneconomical to do so) and working properly first, then at least you'll know that's not causing it.

Even if it's not the camera, at least you'll have had the squeak fixed and know the camera will probably be right for quite a few years to come. Try contacting Miles Whitehead or for a quote http://www.mwcamerarepairs.co.uk/. I'm sure if you sent the camera with the lens fitted he could give that a quick check and give you an honest professional opinion on the cause of the fault you're experiencing whilst fixing the squeak on the camera. Hope this suggestion is useful. :)
 
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There used to be an old trick involving cameras and greaseproof paper :)

When you haven't got a film in. open the camera back and fix a piece of greaseproof paper over the film gate where the film should be, and open the shutter (T if you have it, B with a locking release otherwise) and examine the image on the paper to see if the focus issue is there. Use a magnifying lens to examine the small image. A subject in one plane and easy to check for focus would work best - say a brick wall or patterned wallpaper.
 
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Sorry should have said, I have diy'd the mirror squeak and it works without 'coughing' now. I thought we determined it wouldn't be the mirror causing this in any case, I find it impossible to think it would cause an effect like this of this orientation when the mirror moves up out of the way.
 
Craigus said:
Sorry should have said, I have diy'd the mirror squeak and it works without 'coughing' now. I thought we determined it wouldn't be the mirror causing this in any case, I find it impossible to think it would cause an effect like this of this orientation when the mirror moves up out of the way.
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It was scraping the barrel for an answer other than a faulty lens, I've had lenses lenses giving similar results and throw them away.....h'mm well the cheap ones, but just can't throw away my Canon 19mm :(
 
Just by way of an update to this as it may be useful if anyone ever comes across something similar, I realised I had another roll in this camera so finished the roll off. About half of the images have this out of focus area and half are fine. I'm starting to think it could be the lens now depending on focus distance, though the below shot of the cat may disprove that. Not good photos by any means but by way of illustration... (the cat image is an odd one, his face is out of focus thought he carpet all around isn't)

000107130007 by Craigus89, on Flickr

000107130009 by Craigus89, on Flickr

I'm going to pick up an FD lens cheap from somewhere and see if that solves it before sending it off for a service with Mr Whitehead if that fails.

Any more thoughts welcome. (y)
 
Seems most likely that the film isn't being held completely flat, and that's putting a portion of the image OOF.
 
The pressure plate was my first assumption but couldn't understand why some shots showed no sign of this and some are really bad. I would have thought if there was enough of an issue for the pressure plate to cause this then it would be almost impossible for the film to sit flat at any point.
 
Craigus said:
The pressure plate was my first assumption but couldn't understand why some shots showed no sign of this and some are really bad. I would have thought if there was enough of an issue for the pressure plate to cause this then it would be almost impossible for the film to sit flat at any point.
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Maybe the variation of effect relates to your aperture, subject distance and consequent depth of field, so if parts of the film were a bit closer sometimes it would matter a lot and sometimes not?
 
Craigus said:
The pressure plate was my first assumption but couldn't understand why some shots showed no sign of this and some are really bad. I would have thought if there was enough of an issue for the pressure plate to cause this then it would be almost impossible for the film to sit flat at any point.
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Small apertures? If you're shooting wide open the depth of focus might be so shallow that the few mm the pressure plate is out is causing issues.


Edit: Ninja'd by a good 7 minutes...
 
steveo_mcg said:
Small apertures? If you're shooting wide open the depth of focus might be so shallow that the few mm the pressure plate is out is causing issues.
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Depth of field or depth of focus? Depth of field is how far the subject can move and still be in focus, and depth of focus how much the film plane can be shifted and still give a sharp image. As depth of field increases, depth of focus decreases (and vice versa, of course). That's why having the rear standard truly aligned matters more with wide angle lenses on LF, and why Mike Walker makes a fixed back camera for wide angle use. The same phenomenon is exhibited in macro photography - you have to move the lens out a heck of a lot when you're close up to focus, and move the camera very little - hence focus slides.

IFF depth of focus is the problem, them the worst images should be those of distant objects, and there should be an improvement with subjects nearer. Unless I'm confused because it's late at night.
 
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is the film being loaded correctly? just wandered if leaving some slack could cause this, as there is always that little picture in film cameras instructions showing the correct/flat film loading. Mind you its not I problem ive ever seen
 
StephenM said:
Depth of field or depth of focus? Depth of field is how far the subject can move and still be in focus, and depth of focus how much the film plane can be shifted and still give a sharp image. As depth of field increases, depth of focus decreases (and vice versa, of course). That's why having the rear standard truly aligned matters more with wide angle lenses on LF, and why Mike Walker makes a fixed back camera for wide angle use. The same phenomenon is exhibited in macro photography - you have to move the lens out a heck of a lot when you're close up to focus, and move the camera very little - hence focus slides.

IFF depth of focus is the problem, them the worst images should be those of distant objects, and there should be an improvement with subjects nearer. Unless I'm confused because it's late at night.
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No I think you're right, getting my terminology mixed up.
 
steveo_mcg said:
No I think you're right, getting my terminology mixed up.
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OTOH I think you were right and I was wrong, it's depth of focus that should affect it... though I'm not sure @StephenM's analysis is the right way round...
 
Surely, if this is a film plane fault then the film would have to be going either concave or convex in just one part of it to give the results seen? Thinking logically, unless the film plate has a visible dimple in it (which would be apparent) then the film won't be moving away from the subject but towards it. So how could that physically be happening? The only thing I can think of that would cause this would be if the film were getting pinched against the film transport rails at a certain point , resulting in more pressure being exerted on one side of the film than the other, causing it to try to drag sideways and puckering up the film surface as it tries to do this.

To rule that out, with a gloved hand (to keep fingerprint grease off the back plate) then perhaps check the sprung film plate moves equally easily in all directions. If it's stiffer or unrelenting in any one particular direction (uneven pressure on one of the 4 corners could be a prime suspect to cause pinching) then this could be your problem? If it seems to move freely in all directions and there's no signs of uneven wearing or scuffing on the film plate surface or on the film rails on the camera (and there are no tell-tail scratches on the film above and below the image where the film rails would sit), then I'd suspect a lens issue.

If you try the above test then also try this when putting a small amount of pressure in the centre of the pressure plate, as the plate will be under slight load when the film door is closed, so try to replicate that as a stage of the test and see if it moves freely in all directions then too.

If all seems well with the pressure plate and film rails then is there anyone in the F&C section who lives nearby who has a known working Canon FD lens that you could meet up with to try the lens on a test film? I'd be happy to help out but as I live in Cheshire I don't think your travel time and costs would be worthwhile (probably about half the cost of a replacement AE1 and 50mm f1:1.8 lens!). Best of luck tracing the fault and I hope this suggestion is useful. (y)
 
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Thanks for the more detailed response Mr Badger. I've just ordered a cheap 28mm lens from WY Cameras and will run a roll through with that lens. I'll take some pictures of the pressure plate and post them up here. It does seem to be 'higher' on one side than the other on inspection.
 
I'd imagine it's more a case of it not moving freely and evenly in all directions (particularly each of the 4 corners) that might cause uneven pinching of the film, rather than it sitting just a bit higher on the left or right hand side? I can't check how the pressure plate sits on my Canon A1 for you as there's a film in there at the moment!
 
Some pics of the camera. First one shows it not being quite parallel.

Photo 10-02-2018, 12 02 43 by Craigus89, on Flickr

Photo 10-02-2018, 12 02 18 by Craigus89, on Flickr

Photo 10-02-2018, 12 02 53 by Craigus89, on Flickr

These are possibly not as helpful but when the shutter is open there are no obvious 'gaps' where the pressure plate isn't sitting flat against the film rails if I've explained that correctly.

Photo 10-02-2018, 12 04 12 by Craigus89, on Flickr

Photo 10-02-2018, 12 04 21 by Craigus89, on Flickr
 
Seems like a wear line on the bottom left hand corner of the plate (unless it's a trick of the light)? Perhaps see if that corner moves as freely and easily as the others?
 
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