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-   -   Super Ikonta folder focus anomalies (http://www.rangefinderforum.com/forums/showthread.php?t=168687)

Fjäll 06-04-2019 13:29

Super Ikonta folder focus anomalies
 
I recently bought a Zeiss Super Ikonta 532/16 with a very stiff focus ring. I disassembled the lens helicoid and cleaned it. I then shot another test roll and most images were out of focus so I redid the assembly and the next roll came out sharp at f/2.8.

I'm now noticing the focal plane isn't aligned vertically(?). I've never tried tilt & shift photography but the effect seems reminiscent to that of a tilted lens. In and out of focus areas aren't flat. Excuse my lack of terminology but here's some images:


The left side of the image should be all out of focus. f/8.0


Jacket zippers blurry but shoulders sharp. f/2.8



I'm suspecting the lens isn't completely perpendicular and slightly tilted. Is this a common problem in folders? It is somewhat noticeable.
It might not show very well in the image weather the lens is perpendicular or not but how much tilt does it take to become noticeable?

The lens doesn't give much at all when I try to push it, its all bolted in place, no screws or anything. I definetely don't want to push it too hard.

Is there a solution to this I might not be aware of?

Really enjoying this camera by the way!

Steve M. 06-04-2019 14:53

Well yeah, look at the angle of your lens in the last pic! Something is bent for sure. It's angled up while the camera body is pointing down. Not good. You're going to have to bend things until they're straight, which may be as simple as firmly pulling the lens down at the top to make it align w/ the film plane. A lot of people will dis this, but I've straightened the lens assy on lots of folders. A couple of small levels will be your friend for lining it back up.

rumbliegeos 06-04-2019 16:26

Have you tried to pull the lens assembly outward, away from the camera body, at the top of the assembly? Index finger on the top of the lens and thumb on its base. I had a Perkeo that required that last step for the lens to snap into its final aligned position.


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TenEleven 06-04-2019 18:50

The lens looks out of alignment to the body as others have suggested. You could try to gently pull it back into alignment.

However it is likely that there's also a couple of other things going on:

-Those early high-speed (2.8) tessars haven't the flattest field of focus. Even on a dead flat camera with good film flatness (Rolleiflex 2.8A) the focal plane curves towards the camera at the edges.

-The film flatness on those folders is not very good. Film usually bows towards the lens at the center. This was known to the engineers and designed to be the area of best focus. (Since it's also where the RF patch is.)

-Opening the folder *after* winding on worsens the above problem. (Air rushes in from behind and pushes the film and paper outward.) Always open the folder and then wind on, or just leave it folded open while you're shooting.

Sarcophilus Harrisii 06-04-2019 19:17

As others have said the lens is clearly tilted relative to the body. To correct this I'd set the camera up on a surface plate and using a depth gauge or dial gauge and holder true the parallelism this way. It's a methodology endorsed by various manufacturers of top quality equipment, Eg Rolleiwerke. If the lens is close to correct infinity focus at present that's a plus, because the process of correcting the alignment may still dictate re-calibration of the focus, afterwards.
Cheers
Brett

Fjäll 06-05-2019 03:06

Thanks for the great suggestions. I managed to position the lens upright after carefully pulling it for about 10 minutes.

Now the lens gets in the way of the shutter release mechanism and won't trigger the shutter. Oh well it can still be triggered by my finger.


Pherdinand 06-05-2019 04:44

Something else is wrong there as in correct parallel lens board case the shutter trigger shoul dnot be that far from the shutter lever of the camera body.
Are you sure that you've installed it back correctly? Could it be that the whole lens assy is shifted further from the camera body compared to where it was/where it should be?
Quick check: Focus on something with the RF closeby like at 1m, and check if it matches what the distance scale tells you. Then also check at infinity (a very distant object is good enough).
If you see a mismatch like e.g. at 1m rangefinder focused, the lens focus scale indicates visibly shorter than 1m (say 0.9), means the lens board is too far out.
If they match, then somehow your camera shutter lever got bent.

Steve M. 06-05-2019 05:25

Usually, the problem you're experiencing now is that the lens needs to be rotated so that the shutter release is in the best position. I'll bet that it's loose, or loose enough that you can gently but firmly twist it to the right until the shutter tab is on the bottom, then back to the left to get it lined up correctly. The lens is held on by one big thin locknut around the lens assy on the rear of the lens. Once you close the camera and open the back it will be clear as to how it is tightened and loosened. I have a pair of long nose pliers that I filed the ends to a point on for getting these lens screws on and off easily, but often you can push it around w/ a screwdriver held into the two grooves of the shutter ring.

Fjäll 06-05-2019 05:32

Quote:

Originally Posted by Pherdinand (Post 2891914)
Something else is wrong there as in correct parallel lens board case the shutter trigger shoul dnot be that far from the shutter lever of the camera body.
Are you sure that you've installed it back correctly? Could it be that the whole lens assy is shifted further from the camera body compared to where it was/where it should be?
Quick check: Focus on something with the RF closeby like at 1m, and check if it matches what the distance scale tells you. Then also check at infinity (a very distant object is good enough).
If you see a mismatch like e.g. at 1m rangefinder focused, the lens focus scale indicates visibly shorter than 1m (say 0.9), means the lens board is too far out.
If they match, then somehow your camera shutter lever got bent.


The shutter trigger was working fine prior to bending the lens mechanism slightly forward. Now it hits the (what I suspect to be) double exposure prevention lever. It's usually blocking the shutter trigger if you haven't yet advanced the film. Now it blocks the shutter regardless because of the bending.

The focusing mechanism is a simple contraption and I didn't have to get very far to access it. It was nothing more than removing the front ring and unscrew the front element. It was actually installed incorrectly before I started to tamper with it. I assembled it back the same way I took it apart. That's why it wasn't correct when I assembled it again. But I yet was unaware of this problem.

Now the focus is correct, the rangefinder too. It's sharp at its closest focusing distance wide open and sharp at infinity aswell. The problem now is the vertical focal plane which isn't perpendicular. Something I didn't notice before but I can't see how my disassembly could've caused it in any way.

I will shoot another roll to see if the lens now perpendicular will render properly at least.

Fjäll 06-05-2019 05:49

Quote:

Originally Posted by Steve M. (Post 2891924)
Usually, the problem you're experiencing now is that the lens needs to be rotated so that the shutter release is in the best position. I'll bet that it's loose, or loose enough that you can gently but firmly twist it to the right until the shutter tab is on the bottom, then back to the left to get it lined up correctly. The lens is held on by one big thin locknut around the lens assy on the rear of the lens. Once you close the camera and open the back it will be clear as to how it is tightened and loosened. I have a pair of long nose pliers that I filed the ends to a point on for getting these lens screws on and off easily, but often you can push it around w/ a screwdriver held into the two grooves of the shutter ring.

I'm not sure what mean exactly. Everything on the lens mechanism is aligned to the corresponding numbers of the shutter speed, aperture and focus distance. Rotating anything on the lens except for the settings seems like it would mess up any alignments.

So if I was to loosen the ring in the back you're talking about I could rotate the only the shutter part (in the front) so that it doesn't intervene with the prevention lever?


johnnyrod 06-12-2019 09:47

Yes but normally there is some sort of index pin to make sure the shutter goes back on in the right orientation, not just for this sort of issue but also so that the rotating wedges will align with the RF window. Can you post a frontal shot of the camera please? The shutter is indeed sitting at an angle, it should be parallel with the body! Does it unfold easily, almost on its own, or is it stiff? It may have been dropped.

Sarcophilus Harrisii 06-12-2019 23:25

Quote:

Originally Posted by Fjäll (Post 2891894)
Thanks for the great suggestions. I managed to position the lens upright after carefully pulling it for about 10 minutes.

Now the lens gets in the way of the shutter release mechanism and won't trigger the shutter. Oh well it can still be triggered by my finger.



Quote:

Originally Posted by Fjäll (Post 2891926)
The shutter trigger was working fine prior to bending the lens mechanism slightly forward. Now it hits the (what I suspect to be) double exposure prevention lever. It's usually blocking the shutter trigger if you haven't yet advanced the film. Now it blocks the shutter regardless because of the bending.

The focusing mechanism is a simple contraption and I didn't have to get very far to access it. It was nothing more than removing the front ring and unscrew the front element. It was actually installed incorrectly before I started to tamper with it. I assembled it back the same way I took it apart. That's why it wasn't correct when I assembled it again. But I yet was unaware of this problem.

Now the focus is correct, the rangefinder too. It's sharp at its closest focusing distance wide open and sharp at infinity aswell. The problem now is the vertical focal plane which isn't perpendicular. Something I didn't notice before but I can't see how my disassembly could've caused it in any way.

I will shoot another roll to see if the lens now perpendicular will render properly at least.

My previous post explained how to check the parallelism of the lens to film plane properly. It's a more accurate method of adjusting the lens standard than The Force—which is why I suggested it. Why don't you give it a try?


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