135 vs 120 development

[ymc226]

Should there be any difference in development (time, agitation schedule) of the above film formats for identical B&W films exposed similarly in terms of scene contrast and EI?

Any difference if the stand development technique is used?

 

[Blacknoise]

I can't speak for stand dev, but I've always used the same film both in 120 and 35mm (although this choice has changed over the years, Delta 400, HP5+, FP4+ and back to HP5 again). I've always used the exact same dev times, chemicals and agitation with no problems.

Hope this helps

Rob

 

[Konical]

Good Morning, ymc226,

Generally speaking, any differences should be very minimal or non-existent. Test if in doubt.

Konical

 

[Ronald Moravec]

Not in my experience. You may see a difference if the tanks are different or the 35 mm are Leica negs and the 120 is some 1950 Yashica TLR. Enlarger optics have to be the same and you may think the problem is different film development requirement.Again if a 50 apo lens is used for one and you found a 80 mm xxx at a flea market or some three element Omegeron that is filty inside, you may think the problem is film development.

 

[df cardwell]

Should there be any difference in development (time, agitation schedule) of the above film formats for identical B&W films exposed similarly in terms of scene contrast and EI?

Any difference if the stand development technique is used?

Yes. With 120, limit your agitation rest cycles to 3 to 5 minutes or you may well run into graduated, uneven densities in your negatives.

Steel reels are more efficient. Plastic tanks must be agitated vigorously with minimal agitation. In any case, load the reel into a tank already full of developer. If this is impossible (like if you use a changing bag to load the tank) use a diluted developer that gives you a development time between 12 and 16 minutes, and be sure to agitate your film for 10 to 15 seconds at a time.

 

[Jeff Kubach]

Like the foremention posts, the differences should be nonexistent. I use both sizes.

Jeff

 

[Laurent]

I'm not using stand development, but for 'normal' processing, I even mix formats when it's convenient (I shoot HP5 in 35 and 120, with the same EI)

 

[AgX]

Plastic tanks must be agitated vigorously with minimal agitation.

I am puzzled.

 

[edtbjon]

... Plastic tanks must be agitated vigorously with minimal agitation. ...

Ditto. (i.e. puzzled also.)

Anyhow, about the OP's question, most films are "the same" except for some Kodak films which actually are different emulsions on different backings. (Tri-X comes to mind. A film which comes in at least 2 incarnations, which are quite different and in a nice logical world would have had alltogheter different names.)

//Björn

 

[Larry.Manuel]

df carwell wrote: >Yes. With 120, limit your agitation rest cycles to 3 to 5 minutes or you may well run into graduated, uneven densities in your negatives.

Agreed. My stand development with Rodinal resulted in my 120 film being radically more developed on the top than the bottom. About 2 stops difference. This was with a single plastic spool [and developer only minimally covering the spool]. If I had put an empty spool under the full one, and had the equivalent level of developer above the spooled film I suspect that I may have succeeded.

My hypothesis: The path length for the developer molecules to diffuse is so much longer for 120 film that I wonder if true stand development will work consistently. I have settled on agitation [one inversion, or two back-and-forth twiddles] once each three minutes with Rodinal 1+100, and that works perfectly for my tastes.

 

[George Collier]

I had a lot of the problem Larry mentions with 120 film and after a year of many techniques, almost gave up on stand (or semi/modified stand). I always had surge effects on the top of the reel, but never in a consistent pattern - this with a SS Hewes reel and Kinderman tank. I finally solved the problem (with Rodinal 1:100 dilution) by a verrrry vigorous agitation for one full minute at the beginning (no presoak). The inversions are as aggressive as I can make them (if it was 35mm, I would fear for sprocket hole patterns), with a twist. At every 4 minutes, I do 4 - 8 of these inversions (4 - 8 depending on contrast desired, and film being used). It's almost like I'm trying to dump the solution out through the lid. I know it sounds weird, but it works for me with 120 film. So far I've only used a singe reel tank with one reel. I use 420cc of solution, just enough to cover the reel, so I get plenty of movement for developer. I also place a small spacer between the top of the reel and the lid, to keep the reel from sliding around, although this may not be necessary.
I wouldn't even try this with 35mm.

 

[juan]

I am puzzled.

Meaning that the time of agitation is minimal, but when agitating, agitate vigorously. Don't just jiggle the tank, invert the tank. If using a plastic tank, twist the reel vigorously.

Some folks (me included at one point) thought minimal agitation meant barely moving the developer. This is wrong - when the developer moves, it should really move.
juan