ASA/ISO in Large Format

[yeknom02]

Preface: I'm new to large format and trying to get through my first box of film, 50 sheets of T-Max 400, exp. 2003. I'm actually shooting a photo a day until it's exhausted, at which point I may continue the project and order another box, but I'm trying to decide what film to try shooting next.

I was having a discussion with an older pro photographer, and he was surprised that I was asking about lower-ASA film (namely Delta 100) in 4x5 sheets. He said that most Large Format shooters would ideally use 400-speed film since the format is so large and you can use faster shutter speeds at that film sensitivity.

While I was fairly sure it was bogus reasoning to apply to the whole LF community, it did get me thinking. I use a 400-speed film (HP5+) as a general-purpose film on smaller formats and switch to something like Delta 100 or Acros when I want something sharper or more fine-grained. But again, that's for smaller formats. Do you think that your philosophy about choosing a film (and it's ASA) to shoot changes once you've moved up to large format? Or do you still find yourself noticing differences in sharpness and resolution once you're dealing with a gigantic negative?

[Daniel Stone]

He's right.

When you have a larger negative, you(should) have the need to expand(enlarge) it less to get to a larger print(even an 8x10 print is only a 2X expansion, where as a 35mm negative needs 7.5-8X, IIRC to reach an 8x10 print size).

Having a "faster" film helps one to get more shutter speed, especially if stopping the lens down to achieve the desired/required DOF for the photograph.

Tmax 400(TMY, now TMY-2) is a wonderful film, IMO. It has virtually no curve contrast wise, and can be developed to the moon, and still retain detail in the highlights. IMO, a spectacle of engineering in film design!

"If it ain't broke, don't fix it" I like to say. If you like the results, why change?

-Dan

[DanK]

I've personally never used a film faster than 125 with large format, typically closer to 25...but I only occasionally use a lens with a mechanical shutter...so I'm usually looking for long exposures...

It's personal preference in my opinion, I relate speed to grain, and really enjoy grainy images - but with large format I prefer no hint of grain. If I do need grain I will choose a smaller format, and faster film - or lith print a larger neg.

But, as mentioned before - depending on the size of your enlargements - I doubt the difference between 100 and 400 will be noticeable at smaller enlargements (I personally don't see a significant difference between films rated at 25 and 100 or 125 in 4x5 printed to 8x10 - but may be quite evident mural size)

Cheers,
Dan

[Herb Cunningham]

You will find a lot of 35mm shooters use 400 speed film, especially Tmax 400. They claim 16x20 enlargements of great quality. I don't enlarge 35mm that much but you can get really great prints out of 400 speed film, and I expect 4x5 and larger would depend on exposure, negative density and what kind of development. Over developing Tri X and those kind of films results in larger grain. Don't have experience with T grain. When you are exhibiting, grain is seldom an issue with the judges.

[Brian Ellis]

My standard film with LF for many years was HP5+ for the reason stated above, i.e. it allowed faster shutter speeds which was useful when foliage was moving around or in any similar situation. I also used TMax100 out of necessity when using Readyloads. If there was any difference in the technical quality of the prints from either film at my maximum darkroom enlargement (16x20) I never noticed it. Of course I had done the necessary testing to determine my rated speed and my normal, plus, and minus development times for each film.

[ic-racer]

8x10 camera + dark scene + f64 + slow film can produce a negative showing no shadow detail due to reciprocity failure in the shadows.

[Jim Noel]

To say that MOST LF photographers use 400 speed films is incorrect. A significant number do s. However a significant number also use lith film in camera at a film speed of 3-6. Significant numbers also use films with speeds in between. I always start my students with 100-125 speed films because of their finer grain, ability to be expanded and usually good film curves. Personally I use about equal quantities of lith and FP4+, with only an occasional sheet of HP5+.

[Jim Noel]

8x10 camera + dark scene + f64 + slow film can produce a negative showing no shadow detail due to reciprocity failure in the shadows.

Carry a card with reciprocity departure information for the film you are using to eliminate this problem.

[Drew Wiley]

Everything is relative. To me, anything in 16X20 printed from 35mm looks like a ball of
fuzz. I sometimes shoot TMax 400 in 4X5 just for the speed, but really prefer 400 speed films in 8X10. With the smaller f-stops typically used in large format, combined with windy conditions, having a faster film often helps. The nice thing about larger film is that you can pay more attention to tonality as opposed to grain, since the magnification required for printing is less.

[jp]

I've got two film choices. For most purposes TMY2 is hard to beat and is what I use most of the time for high quality 4x5.

I also have Fomapan 100 (which may not be quite 100 depending on the developer used) for 8x10 when shooting wide open. The 8x10 lenses' shutters don't go that fast. I think my kodak portrait lens only goes to 1/50th and my 300/5.6 scheider only goes to 1/125. portrait lenses for sf work are usually best close to wide open. A ND filter could permit use of iso400 film outdoors wide open, but it's good to have option; in bright weather I might need the ND and the slower film.

Of course, I also have fomapan 100 for 4x5 and TMY2 for 8x10. I'm just going to stick to two films for now. The kodak is higher quality material and more capable, but the foma is significantly cheaper and has an older look. Not implying TMY2 has a newer look; it has a bunch of looks as it's very versatile.