Medium Format negatives

Wmcgowin · Apr 10, 2006

I am fairly new to medium format, coming from 35 mm.

It seems to me that my 645 negatives don't have as much contrast, and that I am using filters on my enlarger (and my camera) more than I did with my 35 mm if I want contrast.

I am using the same film as before (Delta 100) and developing them the same way (in D-76).

Is this to be expected? Is this a stupid question?

kaiyen · Apr 10, 2006

Do you mean mostly highlight density? Some folks add a bit of time when developing 120. I usually add 15% or so. It seems to bring my negatives to about the same spot.

allan

FrankB · Apr 10, 2006

I just took a quick look at the Massive Dev Chart. It lists the same times for Delta 100 in D76 ( and virtually all other developers) under 35mm and 120. However for the Paterson Aculux 2 and Acufine developers it increases its times from 8 minutes (35mm) to 11 minutes (120).

I'm afraid I'm not experienced enough to draw any conclusions from that other than, "Hmmm....!"

Thoughts anyone?

kaiyen · Apr 10, 2006

Well, the MDC is populated from people's personal experiences, right?

So perhaps one person who uses a condenser with 35mm gave the one time, and another person with a diffusion enlarger gave the 120 time? Plus throw in a bit extra for that 15% I use and..voila.

allan

Photo Engineer · Apr 10, 2006

There is no technical reason why development time should change between formats of any size.

I've used the same times for 35mm and 120/220 and processed them in the same tank and gotten comparable results.

But, I always say, do what works for you. After all, you are the judge.

PE

fschifano · Apr 10, 2006

kaiyen said:
Well, the MDC is populated from people's personal experiences, right?

Yes, some of it is. Some of the data comes straight from the manufacturers tech sheets. The MDC can sometimes be a crap shoot, but on the whole it is pretty good.

Edwardv · Apr 10, 2006

Run a film test with the following ISOs (exposures in 1/3s): 125, 100, 80, 64, 50. Include a gray card, some black and white material and some plants with different colors. Base your exposure on the gray card if using the camera meter or hand spot meter. If using an incident meter get close to the gray card. Do not use a filter. Give 2 or 3 minutes more when developing. If you are using a diffusion light source include two more minutes. Hopefully will find a frame that will put you between grades 2 and 3. If not, then increase development time by 2-3 more minutes.

Good luck.

winger · Apr 10, 2006

Well, you are using a different camera. Are you metering the same way? Internal meter or external? If you're exposing the film differently but processing it the same, the end result will be different.

jim appleyard · Apr 10, 2006

Some folks say that the emulsions are different when comparing 35mm and larger sizes, even of the same film name. Some folks say that the sprocket holes help agitation of 35mm. I don't know, but in practice, dev times between formats are often not the same. I often add 1 minute to my 120 rolls over 35mm times.

FrankB · Apr 11, 2006

winger said:
Well, you are using a different camera. Are you metering the same way? Internal meter or external? If you're exposing the film differently but processing it the same, the end result will be different.

Nice point, Bethe. I for one had completely overlooked the blindingly obvious fact that this was a different camera! D'oh! :rolleyes:

As well as metering methods (which, if different, surely must be a very major factor), this also brings into play the fact that the lenses used will have different characteristics and may just not produce as contrasty negs.

I know that when I shoot Velvia 50 with my Nikon and with my Mamiya TLR, both sets of transparencies are processed at the same lab but it's very easy to pick which is which on colour and contrast alone (obviously leaving out size and shape!). I would suggest that the same could be said for B&W.

Personally, I process B&W in Aculux 2 and follow the MDC, adding a few minutes on to the process. It works for me.

Best of luck,

Frank

roy · Apr 11, 2006

I do not see why film size should make any difference. Surely you would test for exposure and development with any new film because switching from one format to another will generally involve a different camera.

Ben Taylor · Apr 11, 2006

winger said:
Well, you are using a different camera. Are you metering the same way? Internal meter or external? If you're exposing the film differently but processing it the same, the end result will be different.

Yup, I'd agree with that. I spent quite some time doing film tests with my 35mm outfit, when when I moved to medium format found myself constantly having to print on a harder grade.

So I repeated the film tests with my medium format kit - metering with my handheld meter as I would when out and about. I found my 'standard' exposure and processing times for my medium format kit and can now print as I would have expected to.

winger · Apr 11, 2006

I actually get more contrast with my MF. Possibly due to the better lenses and newer age of the camera. My 35mm ranges from an old (no meter) Pentax with prime lenses to a PZ1p with zooms. Each has handicaps that can lead to less contrast if I don't pay attention.

Tom Hoskinson · Apr 11, 2006

120 Roll film and 35mm - if they are the same film type/manufacturer, I develop them together in the same tank, for the same time at the same temperature, with the same agitation procedure.

I usually include a sensitometric test on each roll. The subsequent densitometry that I perform gives me the basis for saying that I see no format related differences between the fillms I am currently using.

titrisol · Apr 11, 2006

I think this is more an exposure/camera related issue.
Try overexposing by 1/3 or 2/3 stop and develop as usual.

Gay Larson · Apr 11, 2006

When i moved to medium format from 35 mm I didn't realize I couldn't expect the camera to do the same things in the same way my 35 mm did. Now my exposures are better because I am shooting for the mf camera. I also have a cold light head so I overexpose a bit to compensate. It took a while since I learn everything usually by making big mistakes.

George Collier · Apr 11, 2006

Also the lens could have different contrast properties. Maybe not as likely as the old days, but could be. Like someone said, develop for your condition and tastes.
You are also enlarging them to a different ratio, which theoretically shouldn't make a difference. If you are using a condensor enlarger, and if memory serves, the Callie effect will be more pronounced with more enlargement, which would make more contrast with the greater enlargement of the 35mm format. There is a lot of controversy about this, but some folks will tell you that.

Medium Format negatives

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