What's the point with ISO 125?

Ehm... maybe I haven't understood the whole ISO metric

system (100, 200, 1600, 6400, and so on...) very well,

but... what's the deal with 125 films?!

 

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I mean, there's an obvious difference between, say,

100 and 400 (grains, speed, and more), but what big a

difference could there be between 100 and 125? It's not

so much faster that you can clearly see a difference

in the grains or so. So... what's the point? Am I missing something?

I've tried using Kodak's 125 film, with not so positive

results compared to Tmax 100 or Fuji's Neopan SS, so...

does anyone know the "secret" behind 125 films?

 

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Thanks.

You're referring to Plus-X, right? Plus-X and Tri-X (ASA 125 & 400) are very different to T-Max 100 and T-Max 400 (100 & 400, hardly suprprising).

 

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In a similar vein, Ilford have FP4+, HP5+, Delta 100 and Delta 400.

 

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The newer emulsions have a very different grain structure, among other differences. Some photographers prefer the new, some the old. So the point of Plus-X is not to provide and "extra" speed between 100 and 400, but is available as Kodak's "old" emulsion at (about) ASA 100.

 

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Strictly speaking, it's called "ISO" rather than "ASA". The American Standards Organisation no longer exists. The International Standards Organisation does.

The point is simply showing a bigger number! In the old days

manufacturers thought they could gain a competitive advantage

with "faster" films. Like General Motors, big companies make

changes in attitude slowly, if at all. This is especially puzzling because

the published ISO's (EI's) are never accurate! They are usually

off by as much as one stop. True film speed is determined by

measuring the point on the curve where density is 0.1 above

film base + fog. By this method, the published ISO's are

irrelevent. You should measure your own personal film speed,

but if you don't have access to a transmission densitomiter,

a safe bet is just to divide the published ISO by 2. See Ansel

Adams' book "The Negative" or Fred Picker's VHS "Photograhic

Technique" (avalilable from Calumet) on the proceedure for

film speed and development time tests.

The secret is simple. It is a film designed years ago and that is the speed Kodak came up with. Many photogs still use PlusX and love it. A number of pro labs output your digital B&W to PlusX for negs.

If you work with it you can get excellent results, just as with every modern film on the market. If you have something you like better, for whatever reason, use that. The 125 speed films serve us by giving one more alternative to work with.

Strictly speaking, it's called "ISO" rather than "ASA".

 

Actually, ASA is the proper designation for 100 speed film.

The ISO rating would be ISO 100/21.

ISO was decided to be a combination of ASA and DIN.

125 vs 100 doesn't significantly change the exposure, as negative films have a lot of latitude.

Since my Plus-X stock continues to age(although I'm probably not running out soon), I tend to shoot it at ASA 100 :)

 

I've been using a lot of FP4+ lately(I don't have any medium format or sheet PX), and if it bothers you that much you probably won't notice any difference if you run it at EI 100. Heck, I shoot it at EI 200 all the time and aside from extending my development time a bit I don't see much difference.

 

The speed is what it is. The same could be asked of FX32, K64, E64T, or any other partial-stop films.

I was one of those people who didn't like the TMax films early on but I don't like anything new for a while at least. I grew up shooting mostly Tri X and pushing it up to 1600 in Acufine quite often. Plus X had its uses as well when I knew I might be needing bigger prints since I wasn't using medium format back then. TMax grew on me though and I can use it without really debating what I want to accomplish. Ilford was there too and easily available but for some reason I didn't use it very often. If I had to just pick one now it would still be Tri X.

 

Rick H.

Not so long after I started in photography, I figured out that for Kodak, X was 64 for color, and 125 for black and white.

 

Note that there is XX, double X, at 250, and Tri-X rounds to 400.

 

For color slides, we had Kodachrome-X and Ektachrome-X, both ASA 64.

 

Many of these trace back to before ASA setup the system, and so one just measured the films as they were.

 

It was in the C41 and E6 days that Kodak mostly went to the 100, 200, 400, series.

 

Early in E6 was Ektachrome 64, but not so much later that was replaced with 100.

 

But yes, early light meters would be lucky to be within one stop, so why set speeds

at 1/3 stop intervals? The ASA standard rounds to the nearest 1/3.

 

Some might say it would have been too mean to round to whole stops, where

a film that was just slightly below another would round to a whole stop difference.

 

List of discontinued photographic films - Wikipedia

 

Panatomic-X traces back to 1933, just two years after Verichrome (not yet Pan).

I wish they would not have discontinued Panatomic X and would love it if they would bring it back. ISO 32 in B&W film. Great stuff.

 

Rick H.

My favorite film, Verichrome Pan, was also 125.

I wish they would not have discontinued Panatomic X and would love it if they would bring it back. ISO 32 in B&W film. Great stuff.

 

Rick H.

I personally long for Plus-X, and what I have will hopefully last me a while(I just wish I could find sheets). FP4+ is a decent enough substitute, but it's still not Plus-X. That reminds me that I should put up a WTB on the LFP forum...

 

In any case, my only experience with FX32 was some frozen expired stock that I picked up in a big lot on Ebay a while back. I shot one roll and loved it, but after some deliberation I elected to sell the rest of my stock. I knew I probably wouldn't find any more at a reasonable price, and the money I got from it bought some other good film.

 

Have you tried Pan F? I don't have a lot of experience with it, but it is a nice fine-grained film.

 

I had high hopes when I bought a bunch of Efke 25 a while back, but I found a fussy film with relatively large grain and with more curl from fresh stock than I get from 20 year old Kodak.

I wish they would not have discontinued Panatomic X and would love it if they would bring it back. ISO 32 in B&W film. Great stuff.

 

Rick H.

 

Me too. I cut my photographic teeth on Pan-X souped in Microdol @ 1:1, and later 1:4 in a stand development. That film simply loved solvent developers.

 

Ilford's Pan F is indeed a nice film. I have only shot it in 120, but coupled with Rodinal in a stand development dilution will blow your socks off. Superb results too in any Pyro formulation--as well as a smoother contrast effect similar to FP4 when done in ID-11. I wish they made it in 4x5 sheets.

 

I was hoping for more from the now defunct Efke. Still have about 6 boxes in the freezer, all ageing out at 9 years now. One day I might attempt to get some in a film holder if I ever set the darkroom up again. This is another film that behaves better with dilutions and longer development times--and cooler ones to slow things down a bit!

Soon after I started in photography, I learned about Diafine from my grandfather.

 

I had fun with Tri-X at 1600 for 7th and 8th grade yearbook photography, for available light in classrooms,

but also I bought 100 foot rolls of Panatomic-X, though at ASA 40, from Freestyle.

I used to use that at Diafine box speed of 250, though that might have been stretching it a little too much.

 

I now have some old 100 foot rolls of usual Panatomic-X, but haven't gotten to using them yet.

 

They come around often enough on eBay.

Speaking of 100 ft rolls, from my perspective Kodak has seemingly priced those out of consideration for me.

 

I have a couple of Tri-X in the freezer and a roll of TMAX-100 that's been in a loader for probably too long, but aside from the fact that the boxed rolls take up less space I don't see a lot of point in them. When you factor in the film lost both at the beginning and end of a roll, you can actually end up paying more than buying loose rolls.

 

If I ever pick up one of the Kodak 100 frame or 250 frame backs(a local shop has an F-1 with the 250 that the owner likes to show off when I'm in) I might be tempted to break them out. Even at that, though, I have no idea how I'd process it....short ends of movie stock and a lab willing to process 250 frame rolls seem a lot more viable to me these days for those backs.

IN THE BEGINNING

film speed was merely a guide based on the manufacturer's best estimate for what would produce the optimum results from a particular emulsion and chemistry.

 

Much time was spent by amateurs in trying to find ways to either sharper pictures or faster speeds.

Later some chemistry/film companies used such non-optimum solutions in order to sell more film/developer/whatever.

 

Originally, "ASA" 125 was an empirically derived solution for Plus-X and other films. It was not at that time just an arbitrary number.

Many years ago, my father borrowed a Nikon F, which we had for a short trip.

 

I do remember reading about the 250 shot back.

 

The F in interesting, instead of the back opening like more cameras, it actually comes off.

You could then put on a different back, such as one with a motor drive attached,

or the 250 shot back.

 

I believe that there are tanks and reels for that, but I never saw one.

Panatomic and Plus X were finer grain and with good light produced quite different results than Tri x. All you needed was good light and the proper subject.

 

I never used the 250 back, but did load long 50+ exposure cassettes for the Nikons. I would simply keep track and shoot a couple of duplicate frames at around 36 exposures. I would load reels in the dark and cut when the first reel was full. the remainder would be loaded on the next reel. I had a few 20s as well as 36 Honeywells. If I recall correctly, 36 exposures = about 5 feet, so say roughly 7 reels to a 250 exposure roll. Could be done probably without loosing much -- got away with it a few times, mostly with the ELW with the winder.

I have sitting nearby a box of Verichrome (not pan) V116. It is develop by May 1955, and has no speed.

 

So, yes, when ASA came out with their system then existing films were measured and given a speed.

 

And some years later, ASA changed they way it was done, and all the films changed.

 

But many old cameras only have two shutter speeds (I and T) and two or three aperture settings.

The manual tells you which to use when, likely assuming a specific film.

 

Earlier than Verichrome that was NC (non-curling), and before that I don't know that it had a name.

 

For some that I know, you use I (instantaneous) outdoors with the larger aperture, and T (time)

indoors with the smaller aperture. As well as I know, you guess and give something like a

half or one second exposure. (Sort of how fast you can press the release twice.)

 

Before enlargements, grain size should not have been so important, but as you make a

film more sensitive, the more likely it will fog due to thermal or chemical reasons.

I suspect that they chose the speed, by adjusting the process of mixing the silver nitrate

with the gelatin and KBr, stirring and mixing just right, to give optimal results.

 

As film technology improved, the speed at which a film could be useful increased,

though I suspect that they didn't expect people to be using some rolls 40 years later.

I have developed rolls of VP 50 years old or more.

 

Before Tri-X (TX) there was double X (XX), at 250. I suspect that the speed

differences were not big enough, so they kept Plus-X and Tri-X.

(It seems that XX stayed around as a movie film, but not a still film.)

 

Another interesting question, why both Verichrome Pan and Plus-X at 125?

 

Interesting, though, 32, 64, 125, match closer to the usual shutter speed series

than the more modern 100, 200, 400 series.

Super XX was at one time Kodak's fastest film--and a sure favorite of news photographers in the 4x5 format. It had a long, straight HD 'curve', and buildable density to die for. The Kodak 5222 is a nice film too--but not exactly the same film as the old Super XX. I think that XX was the last of the Kodak thick emulsion films.

 

I have several boxes of the now extinct Bergger 200 in the freezer, 4x5. While it is indeed a thick emulsion film, it is not similar to Super XX except at the center of the HD curve--regardless of what Gordon Hutchinson says about it... :cool:

Edited April 18, 2017 by PapaTango

The 5222 is worth a try if you can get it at good price. When short ends were easy to get it was really cheap. Back in the early 2000's I often bought it for 5 cents a foot. Today some vendors have it in bulk for a lot less than Tri-X or TMAX, but a bit more than most of the Ilford stock.

The long exposure back I'm talking about is for the Canon F-1, not the Nikon F. As I understood, the bulk backs were for use at the Olympics. Canon was really trying to capture the market in the late 70s and into the 80s, and made a lot of special configuration cameras. There was another F-1(I think a New F-1, but could be wrong) with a pellicle mirror that could manage 14fps. The 250 back at least can only be used with a motor not be manually advanced. I think the 100 frame back is the same.

 

If I'm not mistaken, Kodak kept Super XX around for a really long time in sheet film-I could be wrong, but I don't think they axed the sheet film until the early '90s.

 

I've been tempted to try some of the movie stocks-I hear great things about them and short ends are certainly economical.

 

Going back to the Nikon F-it's "quirky" enough that I often find myself getting confused by it, although I don't use mine all that much. When I bought mine(with the original external CdS Photomic), I bought from a camera shop for not a whole lot more than the value of the lens because the shutter timings were seemingly totally shot. When I got it home, I noticed that the collar around the shutter button was halfway between the two marks. Once I flipped it fully over to "A", the times were as good as you could ask for a 50+ year old camera. Still, though, every time I use it the back really throws me off and I find myself looking for a place to set it down :) . At least it's not as bad as MF dark slides-I seem to never find a place to put those unless I have a shirt pocket.

Edited April 19, 2017 by ben_hutcherson

Ben

Hold the camera with your left hand.

Then put one end of the back between 2 of your left hand fingers.

It is easier to do than to describe.

Once you get the hang of it, it is pretty easy to hold the back.

Gary,

 

Thanks-I'll give that try the next time I'm out.

 

At least I don't have to trim the leader like I do with my Canon IVSb(and any other bottom-loading rangefinder).

 

Reminds me, I believe that there are some Nikon SLRs that allow for shutter speeds between the marked values.

That might be the F2, and not the F. But yes, you might get unusual times in between.