Film speed test in winter

markbarendt · Jan 19, 2013

D F Cardwell did an article here on APUG way back when that had a big effect on how I thought about metering, developing, and curves. He pegged his curves to the mid-tone in the scene, the most important area to him, and most portraitists, and street shooters, and a few others, rather than to the toe which is more important to Zoners, West Coasters, and a great many landscapers.

That article laid the foundation that Dunn & Wakefield's Exposure Manual built upon later.

In the comments to that article you can see several participants asking for un-slid curves. These participants are, IMO, essentially asking for help to square DF's ideas with their reality.

(there was a url link here which no longer exists)

One of the participants in that discussion 2F/2F, in this thread (there was a url link here which no longer exists) , suggested adjusting the orientation of the incident meter head, rather than keeping the head pointed at the camera. At that point in time I was really having a tough time wrapping my head around that thought. It took a couple years for that to really settle in. Again it was Dunn & Wakefield's Exposure Manual built upon that later.

Once understood the utility of both of those concepts are really easy to use, very practical, and truly useful in making printing easier and more standard in relation to the original intent when shot.

Chuck_P · Jan 19, 2013

Stephen Benskin said:
If one camp claims exposure meters "read" 18% and another 12%, shouldn't a person have the intellectual curiosity to investigate?

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No, not if they do not wish to take themselves to that level just to improve their photographic skills, it's not a crime. Having one meter and using it intellegently and consistently is the key. I personally don't give a rats ass what my Pentax V spot meter is calilbrated for, my photography in know way is dependent upon knowing it. You get yourself up in arms waaaaaaayyyy too much any time the words "film test" is mentioned in a thread title.

How many of the people who do Zone System type testing ask themselves why their EIs are almost universally 1/2 to one stop slower than the ISO speed?

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Again, it is not a crime to not have a burning passion to know "why", knowing that it "could be" different and knowing "how" to determine it within the confines of their tools and working process has, for decades, worked so friggin well for many folks. Channeling one's passion into knowing "how" to make themselves better is no less an act of self-help than also laboring on the intricacies of the "why". So, any time a person wants to talk about film speed testing for "their" needs, it would be just grand if you would just once, provide some simple words of advice, rather than use it as a step ladder to a soap box. Not everybody needs to get neck deep with "battery" testing to make themselves and their photography better.

No malice in these words man, just an opinion. Perhaps take advantage of APUG and write a series of articles on, not only the "how" of things, but also on the nuance, the minutiae or all the little "whys" that can, so often, muddy the stream of consciousness thinking that goes into simply making an expressive image. Confine the spirit of the articles to what you do for yourself, not what you think we all need to be doing. I will read them and take interest in what you do.

Chuck

markbarendt · Jan 19, 2013

AndreasT said:
Yes Steven you are right. But...
Not everybody has the will or discipline to find the "why". Starting out one doesn't have a clue where to start so one has to rely on information coming from others. Some find it damn boring trying to find the why.
It takes time and money to find all this. I have little of both.
I do believe we may get blinded from all the information out there, while looking for that magic potion.
How often have I told people to read the Technical Pages published by manufacturers. Either they don't have the nerve or don't know they excist.
Yes to Bill with the filters, thank goodness I don't use filters that mush, lazy me. But when one has a sound idea how the film react I think not that much can go wrong. Besides when in doubt I just take two photos the second one with a half or full stop more and according to the first film change the processing of the second one as needed.
We still have multigrade to save us.

This is the perfect argument for following the manufacture's instructions and using an incident meter.

That is not a critisism. It is an acknowledgement of just how good Film and Incident meter makers are at their jobs.

Stephen Benskin · Jan 19, 2013

Chuck, as usual you've completely missed my point. I won't try to explain how because it wouldn't do any good.

My posts tend to be about what I think is missed in the discussions. If you are not interested in the topic you don't have to read them. I really don't need your opinion on what and how I should contribute.

Stephen Benskin · Jan 19, 2013

markbarendt said:
This is the perfect argument for following the manufacture's instructions and using an incident meter.

That is not a critisism. It is an acknowledgement of just how good Film and Incident meter makers are at their jobs.

I agree.

AndreasT

Starting out one doesn't have a clue where to start so one has to rely on information coming from others.

I try to referrence my statements and I have posted hard to find seminal papers. There are lots of knowledgeable people on this forum. Many of them are here because they love the medium and wish to give back. They are a great resource.

Chuck_P · Jan 19, 2013

Stephen Benskin said:
Chuck, as usual you've completely missed my point. I won't try to explain how because it wouldn't do any good.

My posts tend to be about what I think is missed in the discussions. If you are not interested in the topic you don't have to read them. I really don't need your opinion on what and how I should contribute.

With all the passion I can muster, please know that your point has not been missed! Trust me on that one Stephen. Have a good day and I look forward to reading your articles.

Bill Burk · Jan 19, 2013

I have two bulk loaders sitting on my desk awaiting speed tests before I use the film inside them... I expect APX-25 to be still good though expired '97 don't know about the 100

Bill Burk · Jan 19, 2013

We do pretty well until someone says "it doesn't matter to me"

When what should have been said is "for my purposes, the difference is so small as to be inconsequential" (to paraphrase Todd-Zakia)

For every argument that "it doesn't matter" I am pleased to find an exceptional case where "it does matter"... and the key here for all us is to remain open. Think for yourself.. Does it matter to you?

Stephen Benskin · Jan 19, 2013

Michael R 1974 said:
Going back to the earlier reference to "minimum exposure to maximum black", not that I ever used this method anyway, I found Richard Henry's experiments regarding that methodology quite interesting. It may or may not work better with current VC papers in comparison to the graded papers Henry used for the tests, but there are still variables to be considered, and they are pretty much never discussed.

Michael, thanks for jumping back in and for the Henry reference. Since Henry was evaluating the method as a way to determine a standard printing time and not as a way to confirm / determine film speed, he obviously didn't test the effectiveness for that purpose. He does have some interesting data on the the consistency of maximum black between paper grades. Notice how he mentions the effects of color temperature with both the response of the film and meter when describing the film testing part of the standard printing time test? He also graphs the effectiveness of the standard printing time method showing whether the the method is able to achieve its intended results. His scientific background is definitely apparent.

As you wrote earlier, Henry wrote this book as a reaction to the misinformation he saw in popular photographic literature. Similarly, Mike Johnston once told me that Phil Davis never read any of the articles written by other authors in PHOTO Techniques because he couldn't stand all the bad information.

jp498 · Jan 20, 2013

I think I'll never comment on a film speed testing thread again. The whole "my nerdy testing method is better than yours" is completely inconsequential compared to how much a camera's shutter might work differently in bitter winter conditions or if a CLA is overdue.

Stephen Benskin · Jan 20, 2013

There is a distinction between film speed and EI. Film speed involves precision testing to determine a numerical value that represents the sensitivity of the film. The other has more to do with how to personally apply the concept of film speed to exposure. Except for the ISO speed standard, all testing methods are concerned with finding an EI. Perhaps the whole point of my argument is that each has it's own purpose and not to confuse the two.

markbarendt · Jan 20, 2013

jp498 said:
I think I'll never comment on a film speed testing thread again. The whole "my nerdy testing method is better than yours" is completely inconsequential compared to how much a camera's shutter might work differently in bitter winter conditions or if a CLA is overdue.

You just provided a great piece of info to the discussion, your knowledge is important here. It is important to consider that stuff.

Example:

Part of the reason that I have basically "fallen back to" using manufacturer's recommendations as a baseline (box speed and normal dilutions, agitation, temperature, and times) is that I know they work and work really well. Similarly classic "point the dome at the camera" incident metering is so reliable that there is essentially no question about whether placement is workable or not.

Those two choices with a reasonable bit of practice to learn and to become even marginally skilled in the mechanics of these tasks ensures "pretty darn good" results that will fall well within a range of where a high quality print can be made from the resulting negative.

Which brings me to your point.

By good results I mean that I can say with confidence that, given my baseline, the resulting films will show faithfully my artistic choices and how well my tools are working. If there is a problem I know where to look, it is either my choices, my inattention, or my tools.

A solid tested baseline gives each of us the ability to trouble shoot easily and share that info with others.

It is important, if anyone is going to use my info as a baseline, to know how it works.

The reason box speed and classic incident metering works just fine for most people, including me, is that it pegs what is typically most important in a shot, like Grand ma and the new baby. The latitude inherent in negative films normally takes care of the edges nicely with room to spare. This systemically works so well that IMO the grand majority of all photographers could do this and never be disappointed with their negatives.

There are ways to tweak this though for the people who want that little bit extra to reach the next level of shadow detail in print or whatever is most important.

One of the reasons shooting at 1/2 box speed is basically irrelevant to me personally is my metering methods. When shadow detail is really important in the shot I simply orient the head of the incident meter to measure, for example, open shade, rather than pointing the meter head at the camera which might make it cross lit. A person using classic "point at the camera orientation" would need to use 1/2 or maybe even 1/4 box speed to get the same reading/exposure placement I get.

The inverse applies also. Where others may shoot at double or quadruple box speed in low light, I may simply orient the meter's head to peg exposure from the light source. Our exposure placement may actually end up the same but the logic used to get there is very different.

Without knowing the mechanics of the system I employ knowing my EI is irrelevant.

Not knowing how your shutter behaves in the cold provides the same problem.

kbrede · Jan 20, 2013

The reason I started down this speed testing path, is I wasn't getting the results I wanted on paper. And that was by shooting at box speed and developing according to the manufacture's directions. I really didn't want to test, but by testing, I'd hoped to arrive at a standardized set of actions, from exposure to print. By standardizing my workflow, my hope was that I could find out where I was going wrong. It could be that shooting at box speed isn't my issue. It could be my metering technique, my developing time, my enlarger, my camera's shutter, etc.

Like many people starting out, I'm clueless. I'm not in a position to critically evaluate testing methods, which there doesn't seem to be a shortage of. Some methods use a densitometer, some don't. There's the test for zone I or zone III debate. People recommend changing the shutter only, changing the aperture only, changing ISO only, during the test. Shoot a gray card, shoot a wall, shoot a real scene, shoot a set of props, etc. Test at one stop, 1/2 stop or 1/3rd stop gradations. And so on.......

One of the positive consequences of all this variety, is that it's forced me to continue studying and I'm starting to slowly understand some of this stuff.

In the end, I think we all come up with our own methodology for testing, conscious or not. Repetition, practice, testing, whatever you want to call it, it leads to the same end, our personal understanding.

Everyone who has contributed to this thread has helped me. I'm not just saying that. I've discovered I already have a consistent workflow based on factory recommendations, with the exception of printing. A speed test isn't probably where I need to start. I think the most valuable thing for me at this time would be to find my "maximum black" print time, so I have a baseline in which to evaluate, how my negatives print. I just came to that realization today.

Now having said that, I shot my first rolls of speed test shots yesterday, so I'm going forward with testing anyway. I'm sure I'll learn something along the way.

I'll close with a couple reads I found interesting:

On this website http://www.barrythornton.com/ go to "technique guide" and choose "The NoZone System." This seems like a good way for ongoing evaluation and tweaking. If someone sees any glaring holes in this article, please let me know.

And this article, http://www.davidkachel.com/historical/calibrat.htm made me aware of variables I hadn't even considered effecting results.

Thanks everyone for your help!

markbarendt · Jan 20, 2013

Kenton,

Glad your getting something out of this.

Refining the print process is quite a process. There are some tools that can really help.

https://www.google.com/search?q=kodak+projection+print+scale these can be found here on occasion or on eBay.

Similarly https://www.google.com/search?q=beseler+pm2l or similar meters can many times be found for little cost and make printing much easier, once you learn to use it.

kbrede · Jan 20, 2013

markbarendt said:
You just provided a great piece of info to the discussion, your knowledge is important here. It is important to consider that stuff.

Example:

Part of the reason that I have basically "fallen back to" using manufacturer's recommendations as a baseline (box speed and normal dilutions, agitation, temperature, and times) is that I know they work and work really well. Similarly classic "point the dome at the camera" incident metering is so reliable that there is essentially no question about whether placement is workable or not.

I'm curious about this Mark. I've been using T-Max films and following factory recommendations and using an incident meter. I'm not good at evaluating negatives but printing with a #2 filter results in a super contrasty print. I don't think I've ever had an easy to print negative using T-Max, unless it looked very underexposed. So at least with T-Max, what you're recommending isn't working for me. Tri-X OTOH, I've not had as much problems with. Have you shot T-Max without any adjusting from factory recommendations?

One of the reasons shooting at 1/2 box speed is basically irrelevant to me personally is my metering methods. When shadow detail is really important in the shot I simply orient the head of the incident meter to measure, for example, open shade, rather than pointing the meter head at the camera which might make it cross lit. A person using classic "point at the camera orientation" would need to use 1/2 or maybe even 1/4 box speed to get the same reading/exposure placement I get.

I'm interested in learning more about incident metering. My interest lies in close up photography, verging on macro at times. Often the shadows on the subject are so small there's no way I can use a spot meter effectively, but the light conditions can very a lot. The basic point at the camera, from the subject I get. But I'm not seeing a lot about incident meter technique. Can you recommend any books on the subject? Have you written any articles on the subject?

Thanks,

markbarendt · Jan 20, 2013

Michael just gave a nice summary of what can be happening. Part of the magic of using the directions is that it is normally well within the range of VC paper to adapt.

As to exposure the best book for me was by far, Dunn and Wakefield, Exposure Manual. It is out of print but typically available used. 3rd edition is what I have and is fine, printed as incident meters were becoming modern, 4th edition would be a bit more up to date in that sense but the concepts taught aren't different, either will be good.

markbarendt · Jan 20, 2013

Also Keaton that you find TX easier to use isn't a surprise to me. In the 100 speed range I find the same with FP4 when stacked up against TMax or Delta.

There is no shame in using films you find easy to work with.

AndreasT · Jan 20, 2013

I prefer Tmax or Delta films, unless I use box speed. Haha!

AndreasT · Jan 20, 2013

Seriously though, I like the Tmax etc. but I find they have no leeway when underexposing.

markbarendt · Jan 20, 2013

AndreasT said:
Seriously though, I like the Tmax etc. but I find they have no leeway when underexposing.

Seriously though,

Which TMax?

And which etc.?

And you meter how?

And you develop how?

And shoot it at EI 100, 400, ... ?

kbrede · Jan 20, 2013

Michael R 1974 said:
Do you have enough shadow detail for your preferences? If so, and there is too much contrast, it could be overdevelopment. Note this does not mean Kodak's recommended development times are wrong. Perhaps your subjects are high in contrast. Even if this is not the case, there are several variables involved in the amount of development that occurs given a fixed development time. How accurate and stable is the temperature? What is the agitation procedure like? How much agitation? It should not be difficult to get good results with TMax films.

Micheal, I am happy with the shadow detail, the information is there, as well as the highlights, usually. I suspect I'm dealing with overdevelopment. Some of the scenes I've shot have been very contrasty but many have not been. Even if I shoot in shade, when I go to print that negative, the blacks build up fast, but the highlights are blown and that's with a #2 filter. With T-Max 100 and 400, I spend a lot of time with the #00 filter, trying to burn in the highlights. My last set of negs were a a nightmare. Even with a strait #00 filter, the darks would build up in seconds, before the highlights, and that was stopped down to f/22 and f/32 on the enlarger.

My film development is very consistent. These are the steps:

1. Develop, continuous agitation first 30 seconds, 3 inversions in 5 seconds, every 30 seconds thereafter. Always at published times.
2. Stop bath, continuous agitation, 30 seconds.
3. Fixer, 8 minutes, same agitation scheme as step 1.
4. Fill tank with water, agitate continuously for 30 seconds, repeat.
5. Perma wash for 2 minutes, same agitation scheme as step 1.
7. Final water wash. Fill and dump tank 10 times, taking 1 minute to fill tank.
8. Photo-flo and hang.

I fill two pans with 20c water and place all chemicals used in the bath. All chemicals are brought to 20c, just before I start. Water rinses are also temperature controlled to 20c.

I've got a glass calibration thermometer that I use to make sure my dial thermometer is accurate.

Chemicals in the darkroom start at 20c and may drift to 21c.

My light meter is a Sekonic L-508, calibrated by Quality Light Metric. I almost always use incident metering, pointed away from the subject, to the camera.

Stephen Benskin · Jan 21, 2013

Kenton, what type of enlarger do you use, condenser or diffusion?

kbrede · Jan 21, 2013

Stephen Benskin said:
Kenton, what type of enlarger do you use, condenser or diffusion?

Its a Beseler 23c with a condenser head. It seems to work fine with 35mm and Tri-X negatives but when I switched to 120 all hell broke loose. But I've never tried printing anything other than T-Max in 120. The top bellows is adjusted to 6x7 and its using a different lens obviously. Those are the only change from 35mm.

AndreasT · Jan 21, 2013

markbarendt said:
Seriously though,

Which TMax?

And which etc.?

And you meter how?

And you develop how?

And shoot it at EI 100, 400, ... ?

Etc. means Delta and Acros. Tmax 400. Out of photographing experience and looking at my ciurves, I find that these flat grain films rise very suddenly, nothing happens then when they rise they go very straight. If you underexpose there is no detail in the shadows. My point of view. With more conventional film (especially good old Efke) the toe is gentle in its rising and with an accidentally underexposure you would still be able to salvage a bit more detail.

Stephen Benskin · Jan 21, 2013

kbrede said:
Its a Beseler 23c with a condenser head. It seems to work fine with 35mm and Tri-X negatives but when I switched to 120 all hell broke loose. But I've never tried printing anything other than T-Max in 120. The top bellows is adjusted to 6x7 and its using a different lens obviously. Those are the only change from 35mm.

For a negative to print the same on the same grade of paper when comparing a condenser and diffusion enlargers, the negatives need to have different density ranges. Because of the light is more parallel with a condenser, a greater portion bounce off the film grain effectively increasing the contrast of the negative. This is called the Callier Coefficient. If the manufacturer has only one set of development instructions, they are usually for diffusion enlargers. So, if you are following the instructions and using a condenser enlarger, you are over processing. I don't believe this is the complete answer as to your situation, but it probably plays a factor.

This is a chart from Photographic Materials and Processes that compares the required negative density ranges for different paper grades printed in both a condenser and diffusion enlarger.

There is something you wrote that is somewhat puzzling, " Even with a strait #00 filter, the darks would build up in seconds, before the highlights, and that was stopped down to f/22 and f/32 on the enlarger." Is there something about the f/Stop that you believe is significant? I think there's something in this sentence that might help solve your problem.

Have you tried making a print without any filters? What about making a printed using graded paper? Maybe your processing is off with the 120 film. A simple test sensitometric test will tell you what you're getting. BTZS explains how to do it well enough to achieve something meaningful. You can also read one of your negative. If the density range should match the paper LER and you're still getting overly contrasty prints, then it can't be the processing.

The problem here is that what you are experiencing, too contrasty with 00 filters, seems to extreme if you are correctly doing everything you say and based on your positive experience with 35mm. I think we are missing a few pieces of the puzzle.

Film speed test in winter

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