Thickness of 120 Colour Film

[Russell W. Barnes]

Apologies if this has been asked before...

I thought I'd have a go at this C-41 lark and so bought some rolls of Fuji Pro 400 negative film to run through my Mess-Baldix 6x6. The process seems to have worked (phew!) but I note that the frames are pushed right up against each other with the last two (11 and 12) overlapping slightly. My 'bonus' 13th frame that I enjoy is fine as I compensate for it by a slight wind-on past frame 12.

So... Is colour 120 film thicker than B&W 120 film? Is this likely to happen with other brands of colour 120 film, or is it just Fuji? I'd like to know so I can compensate at each wind-on, but I don't want to use another brand and compensate each frame, and so risk losing my 'bonus' 13th shot!

 

[Filter Factor]

Hi Russell,


If I recall, this camera has an automatic frame counter. Is there also a red window to count the frames? You could verify the operation of the mechanical frame counter by watching the numbers in the red window. My suspicion is that the mechanism needs adjustment or cleaning and is thus shortening your advance. The frame number spacing remains constant on the paper backing, in your case from 1 to 12. A 13th frame is possible if you "crowd" the spacing a little between each exposure.


Cheers,
Robert

 

[Russell W. Barnes]

Hi Robert,

Thanks for the reply. I thought I'd got to grips with the Mess-Baldix (same as Hapo 66-E) frame counter after a few false starts - I wrote a bit about it in the 'Classic Folders' threads. On B&W film I've never had a problem since then, and there's always been a sufficient gap in the frames. I understand that the Mess-Baldix frame countor factors in the thickness of the take-up spool as the film advances, and, sure enough, the film comes out fine.

I once tried using the red window and numbers but after so many frames, it wouldn't fire from the button and I'd to go in at the shutter lever directly after cocking it, so suspect the mechanism had got its knickers in a twist as I was not winding in accordance with the instructions!

I thought I may be getting the 13th frame because the film starts early: some cameras have the red window in an upper or lower position relative to the Baldix and looking at the backing paper, I'm getting a 'head-start' where the numbering is. But perhaps not, given what you said. I'm not ruling out a sticky ratcheting mechanism, but I suppose I'll only know this if I can compare my film with that of a film from another Baldix where the ratcheting mechanism is working perfectly.

 

[Dan Daniel]

On a Zeiss Super Ikonta IV, you can stop the overlap by adding a layer or two of tape on the takeup spool before loading film. It does frame spacing based on rotation of the spool, and thinner film bases cause less film travel per spool rotation. You'd need to measure film and paper total thicknesses to see why different films are giving different spacings in your particular case. Thinner total thickness equals tighter frame spacing.


I don't know the Mess-Baldix mechanism but maybe there are similarities.

 

[Russell W. Barnes]

Thanks for that, Dan.

I may have another go at just using the red window numbers as an index and see how I get on. Sounds like a nice dodge you mention with the tape though! I'm not entirely sure how the frame index works on the Baldix.


As alluded to, I'm maybe getting the thirteenth frame inadvertently - better to get twelve full frames than thirteen dodgy ones.

 

[Moto-Uno]

Fuji Pro 400 film is .0045" thick and Fuji Acros is also .0045" thick . This is for the 120 format film . Kodak film spools are .450" thick and Fuji spools are .462" . And it's always nice to get an extra shot ! 🙂 Peter

 

[Russell W. Barnes]

Thanks for that, Peter.

I've only used Ilford Delta, FP4+ and HP5+ thus far and when I got the camera, I did actually rewind the backing paper onto a spool and run it through again to see how the numbers aligned with the automatic frame counter. But, of course, it wouldn't work, as the thickness of the reel would be different with not having a film in it!

I once looked at a Mess-Baldix that had a wooden reel in it and it looked fatter than the plastic ones. I'll experiment...

 

[Dan Daniel]

There are two basic methods I've seen for frame spacing with 120 film. Rolleis, other TLRs like Autocords and YashicaMats, Voigtlander folders, and the Kodak Medalist have fine-toothed gears that ride along the edge of the film itself. This gear motion is then transferred to the metering mechanism. On these cameras the notches on the metering disk that stops the wind mechanism are equally spaced. Relatively precise linear measurement system unaffected by film thickness, paper backing, etc.

The other method I've seen in Zeiss folders uses the spool winder to drive the frame metering system. These systems are the ones with problems with film/paper thickness. The metering disk has its notched with uneven spacing to deal with the increasing amount of film moved as the diameter of the film on the spool increases. So with thinner film/paper, there is less travel of the film per spool motion and the frames get tighter and tighter as you move through a roll.

Look at the rollers on either side of the film gate. If there are fine teeth or a gearing look at one or both ends, this may be the metering system. If there is none, and no visible gear or wheel that would be able to register film movement, there's a good chance that the frame spacing system is driven by the spool, and so spool inner diameter and film/paper thickness will be important.