SOLVED: Zeiss Super Ikonta III blurry edges, pressure plate issue? [it's the bellows]

[henryvk]

Hello everyone,

I shot a little test roll of expired Ektachrome with my new to me Super Ikonta III.

Spacing and focus are bang on but along the left and right edges of the negative there is a very pronounced blur or steep fall-off? It looks to me like the film receeding off of the edge of the pressure plate.

Is this normal for the Ikonta or is there something going on with the pressure plate or film gate?

Happy for any input as I've never seen this effect before.

Cheers

Henry

 

[Dan Daniel]

Bellows intruding into image area?

Or something not set up right on the lens. Check if the rear group is screwed down completely.

Which lens, Novar or Tessar?

 

[Alan9940]

I had an issue similar to this with mine where one side of the image area was slightly blurry making it look like the camera was not focusing on what I thought it was. Turns out, the lens was not in perfect parallel alignment with the film plane. The best way to eliminate the lens is to open the back, lay a small piece of ground glass across the film rails, and focus the camera. Check to see if you're getting sharp focus across the film area. I would suggest doing this at several different focus distances.

Good luck. These pesky problems can be difficult to figure out.

 

[gone]

If you have a Novar lens, you just need to stop it down. If it's a Tessar and looks like this, then you may have a problem.

I'd like to see the negative though.

 

[markjwyatt]

Sometimes with folders (such as my Ihagee), the erecting of the lens can be unreliable. I've noticed if I do not do it just right, and I can have focus issues.

 

[Dan Daniel]

OP, do you have other images that show the problem? Between overexposure and jumps in distances I am not certain what I am seeing. Depth of field, lens sharpness drop-off, halation leading to softness... And the fuzzy black edges add their own element. Sort of a Rorschach test image to discuss focus issues

 

[Helge]

Can’t see how anyone can seriously suggest lens and standard alignment problems.
It’s two thin defined bands of out of focus and under exposure, at the very edges of the frame, exactly where the rollers and pressure plate engage.

I’ve had the same problem with a regular Ikonta I purchased cheaply recently. Super sharp on the rest of the frame except the aforementioned bands.
It is probably too little pressure from the pressure plate.

It is possible to disengage the pressure plate and try to carefully bend the springs to get more and more even pressure.

But I can say from experience don’t.
It’s a rabbit hole that will leave you feeling slightly dirty and never quite satisfied.

Instead take two strips of open cell foam, that you wedge under the pressure plate and you carefully cut down so get a level, higher tension plate.
You will need to do it again every other year or so, because of foam deterioration, but just write the thickness of the foam block springs in pencil on the inside of the door and it will be very quick to redo.

It’s a far better solution. It’s reversible and infinitely adjustable.

 

[guangong]

The Zeiss lens. erecting system design is rather fail proof unless physically damaged, unlike some other systems. Having said that, more info is needed. Dan Daniel gives a number of lines for investigation.

 

[henryvk]

Alright, homeboys. I guess I should have elaborated on the issue but in my defense, I was in a hurry because I have a small chubby boychild too look after.

Helge is correct, and even though we disagreed in another thread I extend my gratitude!

So, it’s not an alignment issue because I checked the film plane before shooting. Alignment issues always look like one half of the image is out of focus.

It’s not the lens elements either because I collimated the lens.

OP, do you have other images that show the problem? Between overexposure and jumps in distances I am not certain what I am seeing. Depth of field, lens sharpness drop-off, halation leading to softness... And the fuzzy black edges add their own element. Sort of a Rorschach test image to discuss focus issues

Yes, not super easy to parse. It’s expired xpro’d Ektachrome that I overexposed a bit. I was mainly looking for light leaks.

Here’s the negative, for posterity. Not the fuzzy underexposed edges:

 

[Helge]

Alright, homeboys. I guess I should have elaborated on the issue but in my defense, I was in a hurry because I have a small chubby boychild too look after.

Helge is correct, and even though we disagreed in another thread I extend my gratitude!

So, it’s not an alignment issue because I checked the film plane before shooting. Alignment issues always look like one half of the image is out of focus.

It’s not the lens elements either because I collimated the lens.



Yes, not super easy to parse. It’s expired xpro’d Ektachrome that I overexposed a bit. I was mainly looking for light leaks.

Here’s the negative, for posterity. Not the fuzzy underexposed edges:

Really‽ I’m not keeping track.
Forums exist mostly for amicable disagreement and ultimately fruitful discussion.

You might also want to have a look at the rollers to see if they are straight, and the pressure plate, if that is straight.
Anything can have happened in a moments hurry during the last seventy years.

 

[Alan9940]

Alignment issues always look like one half of the image is out of focus.

Really? Mine had a complex out-of-alignment issue that did not present itself as half the image out of focus. Have you checked focus with a piece of ground glass across the film rails? If the focused image is sharp across the entire ground glass, then it's definitely not an alignment issue.

 

[beemermark]

It's not a lens issue, it's not an alignment issue. I think the pressure plate is not holding the film flat. The film and winding mechanism has enough tension to almost hold the film flat, but not enough to prevent the film from curling on the edges.

 

[250swb]

I've seen this before and think it's a lens issue. As the camera is new to the OP it may have been serviced beforehand and maybe some dust blown out from between the front and rear elements. If the rear element, the most likely one to be taken out for cleaning, isn't screwed in again all the way this is exactly the effect it gives. Old screw threads can gum up and on a folder putting enough torque into tightening the rear element is always scary unless the threads have been cleaned or the entire shutter removed.

 

[Helge]

I've seen this before and think it's a lens issue. As the camera is new to the OP it may have been serviced beforehand and maybe some dust blown out from between the front and rear elements. If the rear element, the most likely one to be taken out for cleaning, isn't screwed in again all the way this is exactly the effect it gives. Old screw threads can gum up and on a folder putting enough torque into tightening the rear element is always scary unless the threads have been cleaned or the entire shutter removed.

How would the lens result in two narrow bands at the edge of the frame?

 

[henryvk]

Really? Mine had a complex out-of-alignment issue that did not present itself as half the image out of focus. Have you checked focus with a piece of ground glass across the film rails? If the focused image is sharp across the entire ground glass, then it's definitely not an alignment issue.

Yes, I have checked focus across the film place. I don’t use ground glass for this because I find it hard to tell what’s in focus even with a loupe. Instead I use the „indoor infinity method“ with an SLR and some hair across the film gate.

It's not a lens issue, it's not an alignment issue. I think the pressure plate is not holding the film flat. The film and winding mechanism has enough tension to almost hold the film flat, but not enough to prevent the film from curling on the edges.

This is my conclusion. I should have made it clear in my initial post that I have ruled out alignment etc etc leaving the pressure plate as the likely culprit.

I've seen this before and think it's a lens issue. As the camera is new to the OP it may have been serviced beforehand and maybe some dust blown out from between the front and rear elements. If the rear element, the most likely one to be taken out for cleaning, isn't screwed in again all the way this is exactly the effect it gives. Old screw threads can gum up and on a folder putting enough torque into tightening the rear element is always scary unless the threads have been cleaned or the entire shutter removed.

Negative. Like I said earlier, the lens was collimated by me, nothing scary about it.

 

[xya]

How would the lens result in two narrow bands at the edge of the frame?

I agree. This is something happening at the frame itself. Pressure plate might be a solution.

 

[250swb]

Yes, I have checked focus across the film place. I don’t use ground glass for this because I find it hard to tell what’s in focus even with a loupe. Instead I use the „indoor infinity method“ with an SLR and some hair across the film gate.

This is my conclusion. I should have made it clear in my initial post that I have ruled out alignment etc etc leaving the pressure plate as the likely culprit.

Negative. Like I said earlier, the lens was collimated by me, nothing scary about it.

So somehow you must have a curved pressure plate, one that holds the film flat in the middle and is bent out towards the edges. Easy to measure, but now tell us how that happens? Maybe the pressure plate spring isn't strong enough so any longitudinally curvature in the film's base layer is over-riding the pressure plate spring, but the middle area of the negative would then be OOF and the edges sharper.

 

[Helge]

So somehow you must have a curved pressure plate, one that holds the film flat in the middle and is bent out towards the edges. Easy to measure, but now tell us how that happens? Maybe the pressure plate spring isn't strong enough so any longitudinally curvature in the film's base layer is over-riding the pressure plate spring, but the middle area of the negative would then be OOF and the edges sharper.

Pressure plates in folders is a very complex topic.
Because of the simple film transport, they work quite differently than say in a Rolleiflex.

It’s quite maddening (not really) to keep hearing the same old advice of “adjust with ground glass on the film rails”, and “adjust the lens to infinity”.

Folders use the natural curvature of film as a counter spring to keep flat and not bulge, instead of trying to brute force squeeze and stretch it flat.

 

[darinwc]

i dont see any problems with film flatness, misalignment of the lens, pressure plate etc. in that image.
The image looks perfectly sharp except for the dark edges.

Dan Daniel had it right from the start. This is the bellows intruding into the image.
You can see it easy enough by opening the camera back, setting the camera on bulb, and looking through it.

The Super Ikonta iii is one of the smallest 6x6 folders with a rangefinder, and the bellows is just a bit too narrow.
I have one and love it.

These cameras are called 6x6 but never use the full 6x6 area of the film due to the rails.
Usually 56x56mm is about right but for the Super Ikonta iii you want to crop it down a bit more. 54x54mm should be about right.
Or even 56x54 if you like it a little more rectangular. Just keep that in mind when you are framing, leave a little buffer on the sides.

 

[bernard_L]

Folders use the natural curvature of film as a counter spring to keep flat and not bulge, instead of trying to brute force squeeze and stretch it flat.

+1
On my Super Ikonta A (645) there are inner rails (width of film) and outer rails (beyond width of film), raised slightly, definitely more than thickness of film+paper. .
The pressure plate spans the width of the outer rails. Meaning it cannot press the film to the plane defined by the inner rails. I believe the (raised) plate defines the film plane, the film being pushed backwards at both ends of the gate by the rollers, and held at the back by the plate.

So if one adjusts focus with a ground glass sitting on the inner rails, it will be wrong. I used a piece of film+paper with a hole in the backing paper, backlit by the "red window" and applied Oleson's "infinity indoors" method. This simulates closely "natural" operation. Alternatively, one could use a film (no paper) and a transparent backplate substitute (glass, plastic) with the size and position of the actual pressure plate.

Having stated that caveat, my take on the test image submitted by henryvk is : I fail to see unsharp image zones at the left/right, I do see blurred edges, that look like bellows vignetting, as stated by darinwc.

 

[bernard_L]

Advice for folders. Follow this sequence:

• Open camera
• Advance film
• Take picture

Do not advance film after taking picture, then close camera.

 

[Helge]

i dont see any problems with film flatness, misalignment of the lens, pressure plate etc. in that image.
The image looks perfectly sharp except for the dark edges.

Dan Daniel had it right from the start. This is the bellows intruding into the image.
You can see it easy enough by opening the camera back, setting the camera on bulb, and looking through it.

The Super Ikonta iii is one of the smallest 6x6 folders with a rangefinder, and the bellows is just a bit too narrow.
I have one and love it.

These cameras are called 6x6 but never use the full 6x6 area of the film due to the rails.
Usually 56x56mm is about right but for the Super Ikonta iii you want to crop it down a bit more. 54x54mm should be about right.
Or even 56x54 if you like it a little more rectangular. Just keep that in mind when you are framing, leave a little buffer on the sides.

That is the other possible explanation. The lines seems too well defined and straight for that to be the case.

I always give my bellows a very light brush with bees wax oil to protect and moisturize them. That might also help keep the bellows straight and not bow inwards due to drying leather over the fabric substrate.

One of the pluses for folders over box and other rigid cameras is that the bellows actually works as very effective light baffling, raising overall contrast.

 

[takilmaboxer]

So if one adjusts focus with a ground glass sitting on the inner rails, it will be wrong.
That hasn't been my experience.
I used a piece of film+paper with a hole in the backing paper, backlit by the "red window" and applied Oleson's "infinity indoors" method.
That is an excellent idea! I'm going to try it out. You could also use an outdoor scene that is very brightly lit...not a problem in New Mexico.
For the record, I also have witnessed the bellows shading the film edges. Stopping down can mitigate the problem.

 

[markjwyatt]

Advice for folders. Follow this sequence:

• Open camera
• Advance film
• Take picture

Do not advance film after taking picture, then close camera.

An alternate approach is

• Open camera
• Advance film
• Take picture
• Advance film

But the key with either methodology is STAY CONSISTENT. I find my self saying, "did I advance the film or not"? Not a good place to be.

 

[bernard_L]

My recommendation for the sequence is not an arbitrary choice for the sake of consistency alone.

• advance film just before picture taking to benefit from the film's natural curvature keeping it flat against the pressure plate (see post #18 by Helge)
• advance film after opening camera to avoid having the film sucked forward by the opening motion of the bellows

An alternate approach is

• Open camera
• Advance film
• Take picture
• Advance film

But the key with either methodology is STAY CONSISTENT. I find my self saying, "did I advance the film or not"? Not a good place to be.

what do you do after the second film advance? close the camera? and what is the sequence for the next picture?

Agree with the consistency part. Once habit has become second nature, you won't ask yourself "did I advance the film or not".