What's the point with ISO 125?

When I first started in darkroom photography, in 1967 when I was nine years old, I had some books to read about cameras and film. I do remember reading about XX, but until recently didn't know anything more about it, other than being ASA 250.

 

I still have the "Kodak Films in Rolls" book I got in about 1967. There is no XX, but it does have Royal-X Pan. I never saw a roll of RX120 until I got a roll from an eBay auction, along with some other films. I haven't tried it yet, though. Rolls of XX620 appear once in a while on eBay, but I don't have one.

On the F2, the intermediate collar position is "normal" while one is for time exposures and one locks the button. On the F, you use the collar to switch between advance and rewind-it functions a lot like the little lever on screwmount Leicas and the like.

 

I think that on this one, the shutter may actually have been capping rather than firing at any certain designated speed.

 

I don't know the specifics, but a lot of mechanical shutters are infinitely variable over certain ranges. On the older Rolleiflexes with Compur-Rapids, for example, the speeds between(I think) 1/30 and 1/250 are that way. 1/500 engages a "boost" spring so there's in-between on those. I'm pretty sure F and F2 shutters are infinitely variable also at least down to the flash sync speed.

I started out in photography shooting sports with a press camera and Tri-X. It was a very forgiving film that allowed me to deliver prints under almost any circumstances. Since there was money involved I really appreciated this film.

 

Now days, I use Ilford fp4. At least with my 4x5 lenses and my light meter, there is a noticeable difference between 125 and 100. Not a big deal but detectable. Since I no longer have a dark room, being able to really nail the exposure makes me less reliant on the processor who was not there when the photo was taken and not in my head seeing what I saw. So, for me it matters.

Since you can see the aperture, as long as it isn't waterhouse style, it seems fine to set the aperture in between. Without reading it in the manual, it seems less obvious on the shutter speed that in between values should work. The F2 has a detent for X sync at 1/80 that is in between 1/60 and 1/125. That is, with half the spacing as between other shutter speeds. This is unlike some Canon models with X outside the normal shutter speed range.

Now days, I use Ilford fp4. At least with my 4x5 lenses and my light meter, there is a noticeable difference between 125 and 100. Not a big deal but detectable. Since I no longer have a dark room, being able to really nail the exposure makes me less reliant on the processor who was not there when the photo was taken and not in my head seeing what I saw. So, for me it matters.

 

While not humongous, there are some marked differences between Plus-X and FP4--having nothing to do with rated speed. Compared to FP4, Plus-X is was a product "ageing in place." With the move from FP3 to 4, Ilford offered a finer grain, longer tonality, thinner base, and easier to build on contrast. Many, including myself, liked Plus-X for casual human studies and portraits. Its 'softness' lent a 'creamier' look to the finished print. FP4 eventually took the front seat though before Plus-X became photographic history.

 

There were also differences in whether one developed in D-76 or ID-11.

Plus-X was a wonderful film. I used to expose it at ASA 64 instead of ASA 125 and develop in Microdol-X 1:3, great stuff. Now I stick to T-MAX 100 for both 35mm and 2¼.

My favorite B&W film was Plus-X 125, I still shoot at ISO 125 with my digital camera....

I have about 50 rolls of Plus-X in the freezer, albeit all in 35mm and unfortunately all 24 exposure rolls.

 

The lot I have expired in 2012. I think there's some newer stuff out there, but not a lot newer(2012 sticks in my head as when they stopped making it, which would probably make the newest expiration 2014 or so).

 

I've been using a lot of FP4+ lately, although I took a lot more of an interest in it when I got into 4x5. If you want to "go yellow" in 4x5, there are three different emulsions available and one of the three is now only available in 4x5! I have some expired Tri-X Professional 220 in the freezer, although the half finished roll I have in one of my Bronica backs is the only roll I've started of it. I want to get a feel for it before I crack open the $100 box of 4x5.

 

In any case, I agree that while FP4+ and PX are superficially similar, they do have a very different feel. I've always described PX as having almost a "creamy" look and I love the way it renders caucasian skin tones.

 

As much as I try, I've never warmed up to T-grain films. I recently bought a couple of 35mm rolls of TMY2 to give it another fair chance, but I just can't seem to make it look like good old faithful Tri-X and other "traditional" films. The owner of the used camera store where I spend a couple of hours a week loafing(plus generally handing over my fair share of money) gave me a sealed 25 sheet box of TMX that expired in the early 90s a few months back, and I'll crack it open one of these days. I want to play with the Ektapan and Graphic Arts film first :) .

 

BTW, if you want to complain about odd film speeds, Tri-X Professional is rated at ASA 320. Historically, a lot of of slide films have been ASA 64-notably Kodachrome 64, but there was also an Ektachrome 64T(I think I still have a roll or two of the consumer Elite Chrome 64Tt) and a comparable Fuji product. The legendary Pan-F was ASA 32.

Since you can see the aperture, as long as it isn't waterhouse style, it seems fine to set the aperture in between. Without reading it in the manual, it seems less obvious on the shutter speed that in between values should work. The F2 has a detent for X sync at 1/80 that is in between 1/60 and 1/125. That is, with half the spacing as between other shutter speeds. This is unlike some Canon models with X outside the normal shutter speed range.

 

Offhand, the only Canon body I can think of(and I've owned/currently own and use most of the FD bodies) with a separate flash sync setting is the New F-1. It syncs at 1/90, and there is a position for this on the dial that is separate from the main shutter speed settings. Of course, it will also sync correctly at 1/60 and lower. The F-1 actually undergoes a mechanical change when crossing these two shutter speed settings, as 1/90 and faster is mechanically timed and 1/60th and slower is electronic. With the battery removed, the New F-1 will actually function correctly at 1/90 and faster as well as B, although it will seem completely dead if a dead battery is installed. Earlier bodies(EF with its copal square shutter excepted) sync at 1/60, as do the A series bodies. I'm a bit fuzzy on the Ts, although I know the T90(the only one I really care about :) ) syncs at 1/250.

 

The F3 isn't much better than the New F-1 with regard to its flash sync setting, since there's no step between 1/60 and 1/125 and it also has a separate X position on the dial to fire at 1/90. The one that leaves me scratching my head on the F3 is that the "emergency" mechanical lever fires at 1/80 and not the flash sync speed of 1/90.

The camera that I used for much of my early years, until I bought an FM near the end of college years, is a Canon VI. (Which I still have.)

 

The Canon VI has an X position, where all other shutter speeds are M sync.

 

Also interesting, for both the Canon VI and Nikon F2, the shutter speed knob goes all the way around. That is, from B to X (for VI) or B to 2000 for the F2.

But with the meter on, both cameras shutter knobs don't go all the way around.

 

Also, the the Canon VI you can feel a little extra as the shutter speed goes between 30 and 60, as the mechanical timing changes.

 

I don't have an F1, (new or old) but I do have an FTb. I forget how its knobs work.

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?!

Back in the days of films when it was ASA instead of ISO the were films (I happen to use Kodak) that were at ASA 32 - Pan-X, ASA 125 - Plus-X, ASA 320 - Tri-X Professional (a lovely negative) and ASA 400, Tri-X. Each had its own grain structure and rendering. While Pan-X had the finest grain structure it tended to be a bit on the punchy side. Plus-X was also a bit contrasty. Tri-X Professional (I used it in 2 1/4 rolls) was a lovely film. Not too grainy and lovely for product and people images... Tri-X was my film of choice in 4 x 5.

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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.

The camera that I used for much of my early years, until I bought an FM near the end of college years, is a Canon VI. (Which I still have.)

 

The Canon VI has an X position, where all other shutter speeds are M sync.

 

Also interesting, for both the Canon VI and Nikon F2, the shutter speed knob goes all the way around. That is, from B to X (for VI) or B to 2000 for the F2.

But with the meter on, both cameras shutter knobs don't go all the way around.

 

Also, the the Canon VI you can feel a little extra as the shutter speed goes between 30 and 60, as the mechanical timing changes.

 

I don't have an F1, (new or old) but I do have an FTb. I forget how its knobs work.

 

The only Canon RF I have is a IVSb, which is very much like a Leica IIIc both in appearance and operation(although IMO the Canon has the better viewfinder since it combines the RF and viewfinder into one window, and also has a zoom function for precise RF focusing and for correct framing with a 135mm lens). In any case, it's quite "old" in how it functions in that it has two shutter speed dials and the main one(top one) "unwinds" as the shutter fires. When you advance the film you can see the dial spinning back to the set shutter speed. Truth be told, it reminds me a lot of my Speed Graphic, where you have to reset the tension on the shutter while firing(although thank goodness the Canon/Leica shutter caps-heaven help you if you've forgotten to put the dark slide back/removed the film holder when you rewind the Speed shutter). In any case, I think it's the same in that it has an X setting on the front dial.

 

The FTb, like all of the other Canon SLRs I've used, has a hard "stop" at each end of the shutter speed dial. Granted I did learn on Canons, but I prefer this to the Nikon fully rotating dial as I can set the shutter speed entirely by feel by referencing the stops. To be fair, if you put a Photomic finder on an F or F2, you do get the hard stops on the dial. The F3 and F4 are a bit of a different story still, as the shutter dial does infinitely rotate but it will lock when you hit the "A" position and you have to hit the center button to unlock it(from which point you can rotate it either direction). The New F-1 physically locks OUT the A position-you have to lift the dial and rotate it to get to it(or out of it)-again it's probably familiarity, but I prefer that approach since you won't inadvertently twist the dial there and then spend a second wondering why it won't turn.

The New F-1 physically locks OUT the A position-you have to lift the dial and rotate it to get to it(or out of it)-again

 

That hasn't bothered me as much as lenses that lock at minimum aperture, which might be all lenses in Nikon AF style

 

Using them on a camera like the FM, where you adjust the aperture as part of metering, and then having it lock when you don't expect it.

That hasn't bothered me as much as lenses that lock at minimum aperture, which might be all lenses in Nikon AF style

 

Using them on a camera like the FM, where you adjust the aperture as part of metering, and then having it lock when you don't expect it.

 

With the caveat that I don't have as much experience with Nikon lenses, the only lenses where I've seen any sort of lock is on AF lenses, and at least on the ones I have you have to manually engage it.

 

All of that said, I prefer how it was done on Canon FD lenses. The aperture ring has a lock position marked "A"(or sometimes just a circle on older lenses) that is used for shutter priority and program, along with certain aperture priority bodies. It physically signals the body, as moving the ring into this position pushes out a pin on the mount to signal that the ring is there. Engaging the "A" position requires physically pushing the lock button, as does getting it out of that position. If you're adjusting the aperture without looking at the ring, you won't accidentally put the ring there. Heck, on some bodies(the FTb comes to mind) it's not even physically possible to move the lens to the A position as there's no corresponding hole in the lens mount bayonet.

In the old days, meaning the 1970s in my case, 400 speed TriX was blazing fast, 100 speed anything was sorta standard, and 64 speed kodachrome was pretty much what there was in terms of color. There's hardly any difference between 100 iso and 125 iso but remember those are subjective, suggested standards, anyway. TMAX 3200 works far better for me at 1600, etc. The iso race was like the megapixel race but slower. So 125, or a quarter of a stop, seemed like "one giant leap for mankind."

Ilford FP4 is still one of my goto films for day to day stuff in decent light. I just rate it at 100 anyway.

The old Super XX was a different film from the currently produced Eastman 5222 (aka Eastman Double-X). 5222 is actually motion picture film with a bit less contrast than Plus-X or Tri-X. Super XX in roll film sizes was replaced by Tri-X, which offered one stop more speed and eventually finer grain. Sheet film continued until the early 90's even though it sold for more than most other sheet film emulsions. It's tonal range was prized by many and its uniform spectral response made it a good choice for preparing color separations for newspapers. I still have about 35 to 40 sheets of it in 4x5.

Many if not most mechanical cameras have a 125 shutter speed making it easy to do sunny 16 exposures. When using my Nikon FM2n I find ILFORD FP4+ convenient.

I think the ASA 125 film speed number was chosen because 125 corresponds to a real shutter speed (125/1000, etc.) and allowed old pros to easily apply the "Sunny 16" rule. I see James said the same thing! Old timer?

You all do realise that the original question was asked nearly 20 years ago, right? No idea why this thread was brought back to life, but if the dates are correct, this thread really did start in sept. 1997....

 

(... shooting FP4 at ISO100 myself....)

Wouter, there's a fair amount of that going on. Since the redesign, I've grown to like and participate in the No Words threads. Lately, I've noticed a lot of threads from a decade or more ago being resurrected. Most of the people who participated in those old threads are long gone. I wonder if there is some search function or other default mechanism that is causing old threads to be more easily accessed or found in PN2.0. In any case, sometimes it's more fun reading the old threads than the new ones, because of the more wider array of participation from years ago. But sometimes, it's a bit moot.

I have to confess that a few of these older threads I posted to as if they were new. I think it's because I see the name of last poster on the right and click on that, sometimes not bothering to read the information that shows the name and date of the member who was the original poster. Not due to new design, just due to me being too lazy to look at the starting point.

It's not an accusation to anyone, and indeed the new design doesn't help as it sorts by last contribution, where the old one sorted by date created. It's true the old(er) threads can be fun to (re)visit, it's just that this thread struck me since I relatively frequent visit this forum and saw this thread ending back on top over and over ... :-)

It's not an accusation to anyone, and indeed the new design doesn't help as it sorts by last contribution, where the old one sorted by date created. It's true the old(er) threads can be fun to (re)visit, it's just that this thread struck me since I relatively frequent visit this forum and saw this thread ending back on top over and over ... :)

 

In relation to sorting, I noticed that if I submit an old photo (that I uploaded to PN some time back) for critic, it is not displayed towards the top in the critic requests page. I suspect the system is sorting the photos not by the date of the critic request, but the date of uploading the photo and hence pushed back to the end of the stack. I think sorting be the date of critic request should be the right behavior. Wouldn't you agree?

As you know, photographic film is made by dispersing salts of silver in gelatin. The gelatin is the transparent and flexible glue that together with light sensitive chemicals is called the emulsion. There are three light sensitive salts of silver in common use. Silver bromine naturally has the highest ISO followed by sliver chloride. Silver iodine is the less sensitive of the three. Photo film recipes call for these three halogen (Swedish for “salt maker”), in various proportions. If they are chemically pure (laboratory oddly), they are incentive to light. Impurities are needed. These disturb the electrical balance of the crystal and it is the imbalance that makes all this stuff work. During film fabrication, impurities like gold or cadmium or sulfur are added. This is called “doping”. Also, the crystals are grown in the gelatin broth to a specific size. Trade secrets abound as s to the actual procedure used.

 

 

Larger silver salt crystals are more likely to be hit by a photon and therefore receive sufficient light energy during the exposure to become developable. Sensitivity to light is augmented by modifying the shape of the crystal. Modern films are often comprised of crystals shaped like stepping stores. The flat tabular shape, when orientated so the flat surface faces the lens, ups the likelihood of being hit by photons. The tabular shape offers has less mass thus the developed crystal displays a smaller grain structure.

 

 

As the industry improved film performance, tiny refinements made big difference as to the marketability of films. An increase in film speeds by as little as 1/3 of an f-stop translates to more sales. Thus an ISO 125 film, 1/3 f-stop faster than ISO 100 film, is likely the winner.