120 film...dev. longer than 35mm?

[Peter_S]

Hi!
On my way to a transition from 35mm to 120mm I saw that for some developers (e.g. FX-39) it is recommended to develop a bit (20%) longer (see alternate dev. times on Massive Dev. Chart). Ilford, on the other hand, does not seems to recommend that (as far as I have seen).

I cannot find a reasoning for developing 120 format film longer than 135...emulsions are the same. 20% is quite a bit, particularly with FX-39, which is great but can yield quite different results depending on dev. times and dilutions. Also, regular 135 times for FX-39 are quite short to start with. 8 min vs 9.5 min seems significant.

Can anyone explain why proposed dev time increase is? And, more importantly, what is your real-world experience?

 

[shortstop]

Hi! On my way to a transition from 35mm to 120mm I saw that for some developers (e.g. FX-39) it is recommended to develop a bit (20%) longer (see alternate dev. times on Massive Dev. Chart). Ilford, on the other hand, does not seems to recommend that (as far as I have seen). I cannot find a reasoning for developing 120 format film longer than 135...emulsions are the same. 20% is quite a bit, particularly with FX-39, which is great but can yield quite different results depending on dev. times and dilutions. Also, regular 135 times for FX-39 are quite short to start with. 8 min vs 9.5 min seems significant. Can anyone explain why proposed dev time increase is? And, more importantly, what is your real-world experience?

I don't know if it's true (should be confirmed by film data sheet), but the printer of a laboratory often said me that the advantage of 120 vs 135 is not only the aera but also the greater quantity of silver in the emulsion, leading to a better greys representation). This could explain the difference in development time. I also wonder if this is why in massive dev chart sometimes is indicated a development time for 135 for example and is lacking for 4x5 or 120. It's not certainly due to different agitation scheme, since we can develop now 4x5 sheet in tank. Anyone has technical data?
Enjoy

 

[Roger Hicks]

(1) The emulsions are usually but not invariably the same.

(2) Increased development means bigger grain and less sharpness. ALL development is a compromise. This means that sometimes you may wish to change the compromise.

(3) Rollfilm is more often printed with diffusion enlargers, which require slightly more contrast (longer development)

(4) I normally give roll film more exposure than 35mm, again because I prefer a different compromise (I'll put up with bigger grain and less sharpness in return for better tonality). As I use only diffusion enlargers, I develop both roll film and 35mm for the same time.

(5) As I had not previously heard the argument about "more silver" in some decades of studying the subject quite carefully, I think it's probably nonsense. The half-tone effect (different visual greys depending on grain size in the print) seems a lot likelier to me.

(6) It is possible to get altogether too excited about B+W pos/neg photography, looking for more precision than exists. Many who are convinced of the genius of their theories are in fact saved by the flexibility of the process.

Cheers,

R.

 

[JohnTF]

Roger, am probably a recovering victim of No. 6 -

Does the film base color come in to play here?

I recall many concluded we simply printed through that slight density in 35mm, but you know how I hate causes without corresponding effects, especially the ones I came to "believe" in?

I tried to give up over thinking much of this, but it keeps coming to mind.

In reality, I decided if I could find a process that gave me the results technically which I was looking for - I would let the details sort themselves.

Regards, John

 

[Steve M.]

My real world experience is that I develop 35mm and 120 for exactly the same periods of time, w/ the same temps and the same agitation schemes. While it may appear that there is more film area to be developed w/ 120 vs 35mm, the longer length of a 24 exp or 36 exp roll evens it out I suppose. Remember, for 120 film development you will be putting more developer into the tank to cover it. It is not going to matter, in my experiences. If you look at Kodak's development info for D76 there is no mention of 35mm vs 120, it just gives times and temps for various films. I also develop 2 rolls of 35mm for the same time as one roll. Everything looks great. I use D76 full strength, so it MAY make a difference at 1:1, but it's doubtful. Film grain is a product of film type, developer choice, exposure, agitation scheme, temperature etc. A lot of things play into it. Just shoot Tri-X and develop in D76 full strength, find an agitation and time scheme that works for you, and never have to worry about it ever again. Smooooth, even in 35mm, assuming everything else that I mentioned is in order. Very forgiving combination. I even shoot Tri-X at 100 if I want a slow speed film. Tonality is a little compressed vs 200 or 400 ISOs, but it looks very nice.

You may find the following handy information if you do shoot Tri-X.

 

[Bingley]

I also develop 120 and 35mm film for the same times. However, after noticing some streaking (bromide drag?) on my 120 negs, I've increased the agitation slightly, to three inversions every other minute for 120, instead of three inversions every three minutes which is my usual practice with 35mm (when using HC110). That took care of he problem.

 

[Fotohuis]

Indeed the chance of bromide drag on 120 roll films especially in a higher dilution is bigger so instead for 35 mm each 30s 2x agitation you can do for 120 roll film every 15s 1x agitation. A lot of emulsions are exactly the same in 35mm and roll film format. Only the layer can be different in thickness, 35mm 125um-135um and roll film often 100um where 35mm is often Tri-Acetate while roll film often Polyester is used.

 

[KenR]

Could it be a legacy of the old days when there were all those roll film box cameras around with crappy lenses? They had much lower contrast than good 35mm lenses and so would have required more development to get to the same contrast.