220 film in a 120 roll holder?

[pete_biro]

Is it possible to use 220 in a 120 roll film holder such as the

horseman or arca 6x9, or horseman 6x12? I had heard it was possible

on a shen-hao 6x12 and wondered if it could be forced into use

(obviously without the counter function)

[photojim]

Unless you can adjust the position of the pressure plate on the holder to compensate for the lack of backing paper on 220, you will have a slight amount of focus error, so it probably isn't a great idea. Cameras and backs that can use both films have backs that adjust to compensate for the thickness of the paper.

[pvp]

There will <I>not</I> be a focusing error; the emulsion is positioned by the polished rails that it rides on, not by the pressure plate. It is possible, although not likely, that the film won't stay as flat, and you should check the pressure plate for smoothness; 220 film has no backing paper, so the film itself is in contact with the pressure plate. Any imperfections on the pressure plate might scratch the back of the 220 film, where it wouldn't be an issue with the paper backing of 120 film. Those are the reasons for differences in the backing plate pressure, NOT anything to do with plane of focus. Don't mean to offend anyone, but that's how it is.

[reinhold_schable]

Right on, Alan... it's amazing how that misconception about the

paper backing influencing the plane of focus never seems to go

away.

 

Now... to the question: yes, it is possible to use 220 in a

Horseman 120 roll film back. I've run hundreds of 220 rolls thru

my Horseman 6x12. You'll need to do some experimenting to

find the best starting mark, and create some sort of a stick-on

label at the advance lever to space the frames.

 

Sacrifice a roll of film.... You'll find that the starting mark should

be in the left bay, about 3/8 inch to the right of center. Put a sticky

label in there to indicate a starting point. Wind past frame #1,

which is now considered "leader. The actual film begins at frame

#2. After the 6th frame, you'll need some marlks on the label to

indicate where the advance lever must be stopped each time. By

marking on the sacrificial roll of film, you can make indexing

marks on the label. You'll find that the marks get progressivly

closer with each frame.

 

I created a computer graphic for an avery label for the top of the

holder, just under the advance lever which gives me very good

spacing. I also rigged up a little couner to slip into the little film

box holder to keep track of which frame I'm on, so I don't mess

up when advancing to the next frame.

[bob_salomon]

And then there is the question of what happens when you advance the film after the last

shot on 120 would have happened?

 

Many backs will simply try to wind the film out. How will you know where to stop winding

after what should have been the last shot on 120 if it doesn't wind the film out? The

counter will only count for 120 exposures. Not twice as many as 120.

[reinhold_schable]

I should add that I can get 14 full 6x12 frames, spaced about 3/8 inches apart

per roll of 220 film. But... my holder doesn't roll the film tight enough to

prevent some edge fogging on the last frame, so I tend to quit after frame

#13.

 

Also... I wish this BlinkkittyBlank response window was larger and had a spell

chekker. Grrrr.

[gary_frost1]

Well, there _IS_ a difference in the film plane/pressure plate spacing

for 120 and 220 film on both my Horseman 6X9 back and Fuji GW690.

(I have a bunch of old folders that couldn't care less about this)

There are 2 sets of rails: inner and outer. If you look/measure carefully, you will see the outer rails are raised up higher than the

inner rails. This depth is the thickness of the film + paper for 120

and the film alone for 220. The pressure plate rests on the outer

rails and creates a 'channel' for the film or film+paper to slide

through. On the Fuji, you flip the pressure plate over to change 120/220 and this spacing is adjusted accordingly. As I said, I have a

bunch of old folders that are not designed this way at all,(and also

suffer from film flatness problems). As others have said, it it likely

a minor issue but a high quality roll film back will adjust for the

film + paper thickness.

[pvp]

Gary F. is correct, in that better quality roll film holders will make an allowance for 120 vs. 220, and Bob S. is exactly on the mark with "after the last shot on 120." Bob's question is critical, because he's right: many 120 holders will simply assume "end of roll" when they hit the length of a 120 roll, so you may not be able to use 220 film there. I suspect that almost any 220 holder would function OK with 120 film even if not intended as such.

[ilkka]

I have a Shenhao 6x12 back and it will not work with anything except 120 film. It would ruin 220 without its backing paper.

[bob haight]

The thing to do is test drive a 220 through a Mamiya 7 or Bronica 645 RF at the 120 setting and vice versa and see the results. Both camera manufacturers advise to carefully check and see the correct setting is in place before shooting, so I suspect it does degrade the image in some way.

[paintdetective]

I use a Mamiya 645 with both 120 and 220 inserts.

The 220 insert pushes a lever on the counter, which allows it to run to the end of a 220 film. The 120 insert, meanwhile, does not engage with the lever, so when the counter gets to 15 exposures, the camera automatically runs the film through to the end, regardless of whether it is a 120 or 220.

The pressure plate is spring loaded, and as far as I can see, is seated in exactly the same position on both 120 and 220 inserts.

However, I'm not sure whether the thickness of the 120 backing paper about 100 microns) would affect focusing?

I will try to do some measurements, and will post the results if of any interest.