Is there a wallet-friendly way to test for film speed and development time?

[Ian Grant]

Over the years I began using the Zone System and quickly found that the testing was simple and very effective. As manufacturers dropped products and I had to switch film it has allowed me to make consistent negatives which are easy to print. There is no tradition of lab/darkroom testing of film using step wedges and densitometers in the UK and most well know B&W photographers use or pay lip service to the Zone System.

Recently I looked seriously at BTZS to see if it had anything to offer for my photography, I concluded it didn't. That doesn't mean I dismissed BTZS, it does offer a more quasi scientific approach to the Zone System which is of great benefit if you intend to produce negatives for "Alternative Processes". The only rational comparison I've seen of the two systems has been by Sandy King in recent posts on this Forum

Despite being predominantly an LF user I've always done all my initial Zone System tests using 35mm film of the same emulsion. This allows me to do about 5 series of test exposures and process them for different developing times, doing quick test prints to determine the film speed, and development time. The method of testing is very similar to the View Camera article mentioned earlier, and allows me to save time and film, final tests are made with 5x4 film.

The major rationale for using either the Zone System (or BTZS) is to get consistent negative quality, and achieve the best possible prints from each film used. This has makes it easy to make coherent sets of prints from negatives made over the past 20+ years on films regardless of whether shot on APX100, Tmax100, EFKE PL25 or Fortepan 200, or different developers..

A person just needs to consider how agfa would give times for much higher contrast then other makers.

It's interesting in how the film speed and developing times determined using the Zone System vary from the manufacturers published times. In my own case using Agfa APX100 and Rodinal they were the same, but with Tmax100 I had to use it at 50 EI and drop the development time - however Kodak did have a small paragraph in their early Tmax data-sheets that for greater tonality use at 50 ISO and reduce the dev time, so that was in line with the tests again.

I think the currently published Agfa data has changed since I was using 5x4 APX100

I'm inclined to agree with

the proof is not in curves, or steps tablet souffle things, the proof is in the image and the message conveyed
Ray

to a certain extent, he's right and it is the images that are more important.

At the end of the day the old adage of expose for the shadows, develop for the highlights is only saying the same as the Zone System & BTSZ, and many great photographers just knew by instinct when to give extra exposure or development to control contrast.

Ian

 

[CBG]

I keep reading about people getting non-standard speed results with B+W film. Funny thing though, that with color film, a touchy film like 100 speed Velvia, almost no-one says they're getting 400 speed or 25 speed.

Why all this variability and testing? It's largely testing yourself, your preferences, process and equipment. Do the same manufacturers who seem able to produce incredibly consistent color emulsions turn into stumblebums when they make B+W? That doesn't ring true to me.

The precision needed to keep three (or more) contrasty color emulsions matched almost perfectly in exacting color transparency films like Velvia demonstrates the major manufacturers have phenomenally good process control. If the emulsions didn't match acceptably every time, those transparency films would be unusable.

I suspect people add confusion, and extra work, with non-standard preferences, materials and procedures, at least when they are talking about B+W.

I don't hear about the same range of variability when people refer to say - transparency film.

My experience doesn't support the contention of great variation in film speed. When in the studio I shoot almost exclusively transparency film, and have spot on results at the manufacturer's speed. Mostly I am shooting in the pretty controllable set up of reproductions of my paintings. What I get is based upon consistent and controllable variables. Errors are not too hard to diagnose.

I do not represent myself as some sort of perfect precise photographer. I'm not. I make as many errors as the next person and then some. But by iterating the process and eliminating the major sources of error, I've achieved pretty dependable results, enough now to know when the lab is off. I use two Gossen Luna Pro digital meters (and others) to be sure I am getting good readings. They read to tenth stops and match each other to within one tenth.

Once I had my process down, my results became very reliable. And they are at the manufacturer's speed.

Once I had myself "trained" I had just one single time I got a batch of film back from the lab that ran too light, where the least exposed brackets saved most of the shoot. I'm pretty sure the lab process was running "hot" that time since a reshoot came back from a second lab right on with the same exposure levels. The lab that ran hot was a lab that went out of the E6 business soon after and I suspect their E6 line was no being used enough for replenishment etc. to run properly.

Years ago, I did studio product shooting. Almost all B+W, back then, very basic work, Tri-X, D-23, Polycontrast RC, Dektol. I paid attention todoing consistent processing and got dependable results at the box speed and manufacturer's time and temperature.

What's the difference with B+W? I'm guessing that the same film that person A says needs an extra stop will, if given standard exposure and processing, almost always prove to have the rated box speed. Personal preferences and assorted variables assert themselves given the flexibility of B+W with people doing their own processing.

Other than the chance of overwhelming beginners with technical overkill, I have no fundamental bone to pick with involved testing and personal EIs, but I would assert that most of the contention that a film is "running slow" or "running fast" represents an individual photographer's unique preferences, equipment and process. The major film companies are just too good at what they do, and they have too many customers who depend upon them, to let film out into the world way off published specs.

C

 

[Ian Grant]

The simple answer to your post is if you read most manufacturers data for B&W films they often recommend cutting the film speed if you want to make more tonal prints. Unlike colour there are also far greater variables at the printing stage, and more possibilities for control, remember both Fuji and Kodak produce a variety of colour films with different contrast and colour saturation characteristics.

Studio conditions are controlled lighting, very different to working with natural light in the landscape, or urban environments, or under artificial lighting conditions. So B&W film speed/developing time tweaking is merely a way of getting the optimal performance out of a film.

None of the film companies releases film outside of published specs, shooting Tmax100 (original) at 50EI is one recommendation by Kodak themselves.

Ian

 

[Nick Zentena]

There is no standard developer for B&W like there is for color. I guess D-76 is pretty close.

Fuji used to have info on their website for rating Velvia at different speeds depending on the goal.

 

[Ian Grant]

ISO and DIN testing used different standard developers for the testing of B&W films. One of the reasons that Agfa's dev times were more reliable was the DIN method of testing was more practical than the lab based ASA standard.

Fuji used to have info on their website for rating Velvia at different speeds depending on the goal.

That's very true Nick, and many photographers would tweak the ISO setting of transparency films under-exposing for reproduction rather than projection. Often clip testing and pushing or pulling in the E6 first developer for optimal results.

Ian

 

[snallan]

The precision needed to keep three (or more) contrasty color emulsions matched almost perfectly in exacting color transparency films like Velvia demonstrates the major manufacturers have phenomenally good process control. If the emulsions didn't match acceptably every time, those transparency films would be unusable.

This is exactly why colour films are subject to very standardised processing. Each of the emulsions have different characteristics when exposed to the developers, so the standardised concentration/temperature/time combination for developing a colour film is designed to give the optimum result for each of the emulsion layers. Whilst it is possible to extend, or reduce the first development times (say, to brighten, or darken transparencies), the variation in development of the individual emulsions can very quickly result in colour casts.

I suspect people add confusion, and extra work, with non-standard preferences, materials and procedures, at least when they are talking about B+W.

What's the difference with B+W? I'm guessing that the same film that person A says needs an extra stop will, if given standard exposure and processing, almost always prove to have the rated box speed. Personal preferences and assorted variables assert themselves given the flexibility of B+W with people doing their own processing.

The flexibility of B&W processing allows the photographer (or artist, if you like) to express themselves more fully. Using one film stock, a photographer may choose to develop some photographs for the best tonality possible, or if they require a particularly harsh feel, they may choose the developer, and processing technique to produce strong, in your face grain.

There can be confusion in the sheer choice available, which is why most photographers would recommend a beginner starts with one film, and one developer, until they become comfortable with the processes. If you then learn to test, there is a little extra work when you take up a new film, or developer, but this is usually a one off occurrence for each film/developer combination, and having tested, means that you can concentrate on the photography knowing how your materials are going to behave, each and every time.

Personally, I find I am more productive in the darkroom, because there is less variability in my negatives. The craft is under control, so I can concentrate on the art.

 

[smieglitz]

...For example, if zone VIII and N development gave a density of 1.3, N+1 would give that density at the zone VII exposure on the other roll and the slope of the curve would have to increase to do so. Contraction goes the other direction and the N zone VIII density of 1.20 would show up at the zone IX exposure value with the curve slope decreasing to achieve that...

I just caught a typo in this earlier post of mine but it is too late to edit it. (Perhaps the mods could do it and then cut this?) The density values used as examples above should not be different. Zone VIII should be 1.20 or 1.30, but not both. Sorry for any confusion.

Joe

 

[jd callow]

I just caught a typo in this earlier post of mine but it is too late to edit it. (Perhaps the mods could do it and then cut this?) The density values used as examples above should not be different. Zone VIII should be 1.20 or 1.30, but not both. Sorry for any confusion.

Joe

sorted

 

[jeroldharter]

This is just my take and you have a ot of advice here, but:

You asked for an inexpensive, and I assume simple, way to get started with film testing. I assume you are using 4x5 sheet film.

Buy a film test from The View Camera Store. It costs about $45. They send you 5 sheets of the film of your choice pre-exposed to a step wedge. You develop each sheet in the developer of your choice for the times they recommend. Then you send the processed film back so they can use a densitometer and measure the negative. They run the numbers through WinPlotter and send you a complete set of graphs and tables that will tell you everything you need to know about your process.

If you get into BTZS, the software for Palm is really great. I use it on my phone. I plug in the light meter measurements for different zones in the scene, include filter factors, bellows extension, etc. and it calculates the proper exposure including reciprocity effects. Then it save all of the information to a memo file including the proper development time which will be different for each exposure. Also, I can snap a quick digital photo of the scene on my cell phone and even record a voice memo if I want.

 

[Removed Account]

I've got a transmission densitometer and will be getting a step tablet for calibration with my next paper and chem order. Thanks for all the tips everyone, when I get that up and running I'll let you guys know how it went!

- Justin

 

[Rolleijoe]

No roll-film back for the 4x5, unfortunately. I want to be as exact as I need to be in order to consistently print well on a single grade of a single paper.


THE BEST WAY OF DOING THAT IS CONTROLLING THE LIGHT. WHILE LIVING ON MAUI, I WAS ABLE TO ALWAYS PRINT ON AGFA BROVIRA & PORTRIGA #3 BECAUSE IT'S ALWAYS SUNNY AND 75˚.

YOU NEED TO LEARN YOUR LIGHT

I'd like to be able to consistently give myself the best chance to make the best print that I can, rather than wasting paper trying to correct for deficiencies in the negative before turning to the creative printing.

THAT'S WHAT USING PAPER STRIPS vs FULL SHEETS FOR TEST PRINTS ARE FOR.

I'd like to know that when I get a bad negative it was because of poor planning, a silly mistake, or mechanical failure.

THIS COMES WITH EXPERIENCE AND KNOWING YOUR EQUIPMENT

If by "Can you tell a good neg by looking at it?" you mean that I can tell underexposed from underdeveloped and overexposed from overdeveloped along with making sure that everything I'd wanted to be there was there, then yes. I'd have a hard time telling you is contrast was too low, just right, or too high, except for extreme examples. Sometimes (like when working out bellows extension factors) I just confuse myself...

- Justin

IF YOU'RE HAVING A HARD TIME TELLING AN OVEREXPOSED OR OPPOSITE NEG BY LOOKING, DON'T KNOW WHAT TO TELL YOU THERE. IT SHOULD KNOCK YOU IN THE FACE BY 1st GLANCE.

IT'S SOUNDING LIKE YOU'RE WANTING "INSTANT EXPERIENCE", AND THERE IS NO SUCH THING. ONLY COMES FROM YEARS OF PRACTICING YOUR CRAFT.

 

[fhovie]

I sacrificed the dark slides from a couple of really ratty film holders I had to make a set of masks, allowing me to make eight separate exposures on one sheet of film. Each has a ¾" hole drilled in it, offset to one side of the holder. Using each in turn, and swapping them around in the holder allows the eight individual exposures.

I use one sheet for determining EI, including a zone VIII exposure, to see how close my standard development time using the selected developer is to the required time (if it is way out I will use another sheet for EI/zone VIII). Then a couple of sheets for -2/+2 development times, and interpolate for my -1/+1 times.

If I am evaluating the negs by eye, I shoot a textured surface, if I am using a densitometer, I shoot a plain surface.

That is a really good idea - I had thought I might just pull the slide out little by little buy I know there would be some light flare to influence my results -