is it the grain or the negative size that matters?

hi there everyone. i have a question regarding films. i'm into

street photography, and have always used 35mm, which is so easy. now

i'm trying out medium format, and am having a hard time of it. i need

to use faster film, i'm finding. i used to use plus-x with 35mm, but

now i use tri-x 320 with my mamiya. that is sometimes still too slow,

so i'm thinking of pushing it to 800 to get motion control and depth

of field. so now i'm wonder, with the faster film and pushing, would

i be better off using my 35mm with a 125 film? which would produce

greater detail and enlarging possibilities, i guess is what i'm

asking. i appreciate any and all answers. btw, i'm using mamiya 645

pro. thanks!

A 645 frame is roughly 2.5 times as big as a 35mm frame.

 

If you enlarge 35mm by 15x, you end up with a print size of 36 x 54 cm, (14.2 x 21.2 in) and you will see grain in the print. In my experience, this is about as far as I want to push any film.

 

The same 15x enlargement of 645 results in a print of roughly 61.9 x 82.5 cm (24.4 x 32.5 in). Roughly, because I don't remember off the top of my head the exact dimensions of the 645 frame.

 

So you gain some print size at the same enlargement, which means you'll have about the same graininess and sharpness if you shoot the same film in both formats. Clearly, if you go up in film speed for the larger format, you loose some of the print size if you want to maintain the same graininess and sharpness characteristics.

 

I'm thinking that for what you are doing, the gain isn't enough to offset the pain of moving up in format. But you are the one doing the work. You should do what works best for you.

Rule of thumb: for the same size print, MF needs an aperture two stops smaller than 35mm for the same depth of field. Hence, where you would use a 100 speed film for 35mm, you need 400 for MF. Where you would use a 400 speed film for 35mm, you need 1600 in MF. I'm assuming handheld street photography, no tripods, of course.

 

Does using 100 speed film in 35mm equal the 'quality' of 400 speed film in MF? Too many variables: print size, type of film, developer, your own taste, camera and lenses, etc, to say definitively. Short answer: no, but in practice it may be close enough, especially if you can live with somewhat smaller prints.

 

Try Tri-X Pan (not Tri-X Pro 320) in Diafine, ei 1280 with your Mamaiya 645, for awhile and see if it is what you need.

That is the trade off.

 

Use tri x 400 and undiluted D76. It will look better than Plus x in any diluted developer. Don`t worry about supposed lack of sharpness.

 

I hated tri x until I found D76 undiluted. I use 5 min at 68, agitation 5/30 for a condenser enlarger.

 

You can also use divded developer for contrast control.

What are you shooting that you need this much DOF? I use a RZ67 for street photography and I use a lot of Ilford Pan F+ which is 50 iso. If it's really bright out (as it is a lot of the time in LA) I even rate it at iso 25. Sure this brings my lens about two or three stops in from wide open but I like to get close and fill my frame with only one or two people. I easily get 16X20 prints. Even a medium speed film like fp4 or efke R100 can do well at 16X20. I would imagine you are shooting with a wide angle lens and then looking for the picture within the picture by cropping. You will loose quality this way. I suggest using a standard focal length lens, shoot at the box speed or pull a stop and underdevelop if it's very bright out and get close to your subjects.

Regards,

Marc

Regina, for the sake of establishing the outer limit of the grain/enlargement/detail issue, I suggest trying a few rolls of Ilford Delta 3200 processed in Xtol. This is a great film and quite flexible. You don't have to shoot it at 3200 and depending on how large you want to print, it produces a pleasing grain structure and crisp detail. Needless to say, you won't have any trouble with depth of field in normal situations. Regardless of what film you settle on, I think it is a good policy to avoid any attempt at softening or disguising the grain structure. If that is a big issue, then a fine grain film is called for. I suggested the 3200 for the nice balance between the grain structure and it's influence on edge definition. And that much speed is always fun. Well, maybe not at the beach at noon inAugust....

Why are you using Tri-x 320 instead of Tri-X 400? There was just another tread comparing the films. I'd think that the 400 would be better for your use. Also in addition to grain be sure to compare the tonality of your 35 vs 645 prints. You may like the look of the medium format. And grain can sometimes result in a sharper looking picture.

I've been using TXP320 (in a Mamiya C330) pushed to 800 and developing with Press Maxx and I have been happy with the results. As has been mentioned 120 film has an area 4 times larger than 35mm. More area=more information.

hi again, everyone. thanks so much for all of your answers. i guess using 645 is a tradeoff. i just thought i'd go out there and get great big shots, but i guess it doesn't work that was. marc, l.a. is sunny! why are new yorkers so grumpy? lack of sunlight. no, all joking aside, i seem to always have to go to the lowest two stops when i use less than 400 speed film. i shot a llama a few weeks ago with ilford fp4 and the llama's eyes were in focus but his nose wasn't! also, i figured this is probably why so many of my pictures are out of focus. i never had this problem with my 35mm. oh, and i only use a normal lens and am a full-frame shooter. my first teacher discouraged us from cropping at all.

 

chuck, i missed the discussion of 320 vs. 400. i will see if i can find it in the archives. i didn't figure there would be much of a difference. i guess i'm wrong. i use 320 coz it's available in 220 format which for a street photographer comes in handy. but if 320 is a markedly inferior film, i guess i shouldn't shoot with it.

 

i guess the long and short of it is that it's easier to get good shots from a 35mm and you have to use higher speed film with a medium format and because of this the reprints you get are not so much bigger as one would think. maybe the medium format should be used mostly for studio work? i'm disappointed with that, but so be it. i really appreciate all of your input and thanks again : )

Regina, if you want "great big shots" consider a 6x9 folder. It's got twice the image size of the 6x4.5, or close to 6 times the area of 35 mm, but the same aspect ratio as 35 mm (56x86 actual negative, usually). The cameras fold small enough to fit in a coat pocket, and with 8 shots on a roll of 120, you can change emulsions often enough to always have the right film for the light. And you can get a good 6x9 folder with coupled rangefinder for under a couple hundred dollars, which saves a lot of money for film...<div></div>

To answer your question directly - from my experience, you will get better results from medium format and a faster (more grainy film) than from a slow film in small format - the increase in grain is not as big as the increase in film area. I'm comparing say a Neopan Acros 100 to Neopan 400 here. I base my comparison on scans of 35mm film.

The Tri-X 320 is really designed for studio conditions with controlled lighting

I`ve tried MF for street photography several times, but I always went back to 35mm: it was too hard to get the depth of field I wanted. For example, if f/8 was good for an 8X10 print from 35, I'd need f/16 for MF. But it didn`t stop there: the reason I used MF was to make larger prints, 16X20, rather than 8X10. To go from 8X10 to 16X20 and maintain the same depth of field, you need to close down an additional two stops, so that f/16 became f/32. Even if a very fast film is available, a 16X20 print from MF at f/32 is not very sharp.

 

I know it is not necessary to close down those additional two stops if the 16X20 print is viewed at a comfortable distance, say, four or five feet away. But by the same token, it`s then not really necessary to use MF instead of 35 when viewers cannot get close.

 

Of course, if you're looking for very shallow depth of field, MF is great. You can use slow films and high shutter speeds, make big prints viewers can scratch their noses on. In fact, this is an excellent reason (or excuse) to use MF: you can do something very different from your usual 35mm style. But enormous depth of field is one of the strengths of 35mm photography and you have to compromise when you use a larger format.