My rant on shooting box speed. Am I out to lunch?

chuckroast · Jun 19, 2025

Milpool said:
I've got some in the gallery here if you want (go easy on me - they aren't scans or anything, just iphone snapshots of the prints).

Media added by Milpool

www.photrio.com

Nice stuff therein. It's only fair that I reciprocate

These are scans of 8x10 silver prints from my workbooks - prints that are not exhibition quality but approximately "right". My goal is to someday go through hundreds of these images and pick a sort of "top dozen" for larger rendering and/or wall hangings.

These are relevent to the thread at hand because more than a few were "tests" of effective film speed, agitation techniques, and/or developer dilutions:

https://www.tundraware.com/Photography/Gallery/Silver/

pentaxuser · Jun 19, 2025

Don_ih said:
I'd say let people do what they want with their film, if they're getting their desired result. You shooting box speed is great if that's what you want.

Don't worry, though. You'll get lots of smart opinions in this thread.

Is there any other kind of opinion on thread like this

pentaxuser

chuckroast · Jun 19, 2025

bernard_L said:
The ISO value is defined by a published (paywalled) standard; end of story. Except when the distributor of a boutique film cheats for marketing reasons.

Then there are the discussions about fractional gradient, Delta-X etc… Unending story. All that for a fraction of an EV.

Then I’m in the woods. Light levels can be surprisingly low, like 1/30 f/2.8 @100ISO. But there is a tree trunk hit by the sun, reading 1/125 F/16. What to do? (I shoot FP4, thank you) The answer does not reside in the choice of an ISO value.
Assuming of course that the top level goal is to bring the picture home.

There is no one way of course, but assuming your meter is correct and is giving you the reading that would lead to middle gray/Zone V, this is how I would handle that situation:

I want to place the shadows on Zones III. In this case, 1/30 at f/8.
The tree trunk wants to be placed somewhere around the top of Zone VI. 1/125 @ f/16 is the same as 1/30 at f/32, so that placement would be at f/22 .
So we have a conundrum: If we place for the shadows, we blow out the highlights. If we place for the highlights, the shadows will go black.
I could use N-3 or even N-4 development and increase EI accordingly but I hate doing this with this sort of scene. It compresses the mid tones badly and the image loses its snap.
So what I would likely do it us extended, low agitation semistand development for a long time with a semi-compensating developer like D-23 or Pyrocat-HD. This would give the shadows time to fully develop and keep the highlights from over developing.
Another approach would be to use SLIMT, but since I never have tried it, I cannot recommend it one way or the other.

I have scan of a print from a somewhat similar situation here (ignore the fact that it needs more burning on the bottom right - it is a workbook print):

In the actual scene, the light was very flat from cloud cover after a snow storm, the area inside the shed was a uniform very dark gray, and what sun there was, was hammering down from the upper right. The true range of light was probably north 12 stops. To preserve the mid tone contrast and keep the snow in bounds, I used the technique described above. Like I said, the print needs some more work, but you can see the general idea.

I find woodland shots like you describe particularly challenging because it is not enough to manage the range of light. Too many of these end up with boring middle tone contrast with no real sizzle to the print. So doing things as I have described is my way of trying the make the mid tones "pop" and make the image more interesting. Here is another I took after a rainstorm in an absolutely flat dark gray day with a really boring range of light:

Both of these were metered at box speed but that was a minor detail compared to the larger manipulations they required.

Milpool · Jun 19, 2025

I would say film speed is one thing and metering / exposure decisions are another.

If you are going to use an exposure meter you have to decide on an exposure index. This is where most of the gobbledygook is, particularly where "personal EI" "tests" are involved.

I suppose one way to define overexposure in a strict sense would be an exposure which adds no contrast to areas of the negative corresponding to the lowest subject luminance areas of the scene. In other words, any additional exposure has no impact on tone reproduction. Of course ultimately in practice the lowest subject luminance is often truncated by the user to "lowest luminance of importance", so we can modify the definition to ...additional exposure has no impact on shadow tone reproduction. Anyhow either way the idea is that from a tone reproduction perspective additional exposure adds no value. In that case it is just additional density, which degrades image structure (increased granularity, decreased sharpness). In fact image structure was one of the reasons for the removal of the safety factor from B&W negative film speeds in 1960.

Leaving image structure considerations aside, overexposure latitude depends on the luminance range of the scene, the characteristic curve of the film, and to varying degrees the processing/developer. For an average scene, most general purpose B&W films have quite a lot of latitude before highlight detail is compromised.

runswithsizzers said:
I find this whole discussion to be very confusing because without defining imprecise language, I don't know what prople are trying to say.

It seems like some people are defining "overexposure" as metering at an EI below box speed, and "underexposure" is defined as metering at above box speed. These definitions depend on the assumption that metering at box speed gives the "correct exposure," which may or may not be true. And it ignores the fact that the box ISO speed was determined using a specific set of developing parameters. If you use a different developer, processing time, or agitation scheme, then the "correct exposure" is no longer correct.

In my mind, the definitions of under and overexposure should be determined by the final results. Practically speaking, I would define an underexposed negative as one which lacks adequate shadow detail, and a correctly exposed negative as one which has adequate shadow detail. Intoducing the word "adequate" means the definition is subjective -- as it should be. They are your negatives so they should be correctly exposed for your purposes.

The definition of overexposed negatives is a little more difficult. Unlike slide film where overexposure is easily defined as lack of highlight detail, I think it is possible to have negatives which are overexposed, but which still have some highlight detail. Overexposed negatives will be "too dense," but without a densitometer how do we define "too dense"? I think darkroom printers and the people who scan their negatives may heve different definitions of overexposure?

So @Autonerd, to answer your original question, yes, I think you are a little bit out in left field because your rant does not mention shadow detail, which I think should a part of any discussion about metering.

I am delighted that others have already addressed your use of the words, "right" and "wrong" (mostly "wrong"), so I don't have to. Those words are much harder to define than under and over exposure, and tend to convey a moral judgement, so should probably be avoided.

albireo · Jun 19, 2025

pentaxuser said:
Is there any other kind of opinion on thread like this

pentaxuser

Well there are the usual suspects, providing meta opinions

Vaughn · Jun 19, 2025

My only rant about all this is why do people say under or over exposed if it is done on purpose -- and one gets the results one expected?

Bill Burk · Jun 19, 2025

Slixtiesix said:
Many years ago I read Barry Thornton's essay on the "No-Zone System". He explained at length that you usually need to overexpose BW negative film, because the vast majority of films do not reach the box speed, as advertised by the manufacturer, and therefore would turn out underexposed if used at box speed. According to Thornton, a slight overexposure (which technically is the correct exposure), will lead to better tonality and finer grain.

You can find his article archived at The Online Photographer.

I just read and enjoyed it.

Barry Thornton is mistaken about film speed.

But I still worship him.

He’s using Zone System. We have long threads that explain why Zone System leads to 2/3 stop downrating.

It’s not 2/3 stop additional exposure to get additional detail in the shadows. The Zone System intends to give the exact correct exposure.

But it’s the index which shifts.

I’m going to have to get that Nikon FA, because that’s where you would see the difference.

If you do Zone System tests and carefully evaluate a scene with Zone System placement of shadows, having set your spotmeter at 2/3 stop less than box speed, you should get the exact same negative from a Nikon FA set to box speed, shot in automatic taking advantage of the evaluative metering.

F4U · Jun 19, 2025

As this discussion continues, if I may, I'd like to mention 3 American companies whose products were above all, in quality, ruggedness, and calibration. Hewlett Packard, Tektronix, and Eastman Kodak. The first 2 were the gold standard in laboratory equipment. Los Alamos used their gear. There was none better. . Similarly , Kodak on the photographic side held their products to like standards. I dare guess that the Kodak test labs had HP and Tek gear in their departments. Let's consider Kodachrome and Ektachrome. I believe I recall Kodak held their manufacturing standards to within 1/3 of a stop of the speed printed on the box. From batch to batch. The boxes had already been printed. I never saw a roll of Kodak film where one run of film had custom speed for THAT RUN. Extachrome 64 was always 64, within 1/3 of a stop. And color reversal film is very unforgiving of error. Given that, it was incumbent on the end used to keep his equipment calibrated and development procedure to high standard. I'm sure black and white film was made to the same high standard as Ektachrome/Kodachrome. If I keep my eye on that ball, then shadow and highlight detail will be as good as film can be, and logically, the problem solves itself.

chuckroast · Jun 19, 2025

Vaughn said:
My only rant about all this is why do people say under or over exposed if it is done on purpose -- and one gets the results one expected?

Exactly. I would suggest that - except in the case of an accidental misexposure - what it is being described here is "the correct exposure" for the scene.

Similarly, I don't buy the push/pull nomenclature. These are used casually as if changing development discipline magically changes the sensitivity of the film in some huge way. Mostly what is happening is some slight change of EI in service of changing the slope of the CI straightline area. The Push Patrol seem especially unclear that what they are (mostly) doing is underexposing the shadows, increasing the highlight contrast to the point of harshness, and often really cranking up the visible grain. That isn't to say this can't be an effective aesthetic only that your ASA 400 film didn't suddenly become ASA 3200.

But what do I know ...

Alan Edward Klein · Jun 19, 2025

Steven Lee said:
Everyone, despite what they're saying, is shooting box speed. They simply have no choice because the speed of film is not under their control.
People just meter differently, and permantently dialing some kind of fixed of exposure compensation for every shot is a dumb way to meter.

What's a better way?

chuckroast · Jun 19, 2025

F4U said:
As this discussion continues, if I may, I'd like to mention 3 American companies whose products were above all, in quality, ruggedness, and calibration. Hewlett Packard, Tektronix, and Eastman Kodak. The first 2 were the gold standard in laboratory equipment. Los Alamos used their gear. There was none better. . Similarly , Kodak on the photographic side held their products to like standards. I dare guess that the Kodak test labs had HP and Tek gear in their departments. Let's consider Kodachrome and Ektachrome. I believe I recall Kodak held their manufacturing standards to within 1/3 of a stop of the speed printed on the box. From batch to batch. The boxes had already been printed. I never saw a roll of Kodak film where one run of film had custom speed for THAT RUN. Extachrome 64 was always 64, within 1/3 of a stop. And color reversal film is very unforgiving of error. Given that, it was incumbent on the end used to keep his equipment calibrated and development procedure to high standard. I'm sure black and white film was made to the same high standard as Ektachrome/Kodachrome. If I keep my eye on that ball, then shadow and highlight detail will be as good as film can be, and logically, the problem solves itself.

If you've never seen it, try to get a copy of "Making KODAK Film" by Shanebrook. I haven't seen him around for quite a while so I do not know if it is still for sale. It's a fascinating and technically detailed look into how the The Great Yellow Father made film.

I too am a great admirer and owner of HP and Tek analog test equipment. I have a nice bit of it in my own shop

But, I think it bears repeating: Determining the effective EI for yourself isn't about variability in the film's sensitivity to light. As you point out, the film manufacturers have very tight production tolerances. It's about taking into account the variability of your light measurement equipment, your shutters, your thermometer, your timer, your development discipline and - most importantly - how the scene you are capturing is illuminated.

Bill Burk · Jun 19, 2025

Vaughn said:
My only rant about all this is why do people say under or over exposed if it is done on purpose -- and one gets the results one expected?

Theres a photographer I follow, Tanya Boros, whose work is often improperly exposed and developed.

I hope more than anything that she never gives increased exposure, because that would ruin the look.

chuckroast · Jun 19, 2025

Alan Edward Klein said:
What's a better way?

Yes. Tailor the exposure to the scene, the intended development method, and the intended output medium and rendering.

Film never changes its speed. How I ask it to capture light changes all the time, and changing EI is a convenience to simplify doing this.

chuckroast · Jun 19, 2025

Bill Burk said:
Theres a photographer I follow, Tanya Boros, whose work is often improperly exposed and developed.

I hope more than anything that she never gives increased exposure, because that would ruin the look.

Yeah, let's remember that Edward Weston was notorious for producing underexposed negs and Andam's "Moonrise" negative was so underexposed he later chemically intensified part of it as I recall.

Milpool · Jun 19, 2025

chuckroast said:
If you've never seen it, try to get a copy of "Making KODAK Film" by Shanebrook. I haven't seen him around for quite a while so I do not know if it is still for sale. It's a fascinating and technically detailed look into how the The Great Yellow Father made film.

I too am a great admirer and owner of HP and Tek analog test equipment. I have a nice bit of it in my own shop

But, I think it bears repeating: Determining the effective EI for yourself isn't about variability in the film's sensitivity to light. As you point out, the film manufacturers have very tight production tolerances. It's about taking into account the variability of your light measurement equipment, your shutters, your thermometer, your timer, your development discipline and - most importantly - how the scene you are capturing is illuminated.

+1 to Bob Shanebrook's book. Amazing.

baachitraka · Jun 19, 2025

Incident meter the shadows (facing the camera) and shoot at the box speed.

khh · Jun 19, 2025

As a relative newcomer, my approach is to initially meter at box speed, develop using the manufacturer's recommended times, and evaluate the result. For Kodak, Fuji and Ilford products, I never really got further as the results were, best as I could tell, good. For Foma's products that did not quite get me the results I was hoping for, but adjusting EI and development has gotten me there for some stocks (100 and 200, I don't get along with 400 yet). That is the approach I would recommend to a beginner, if asked. That's really just advice to get people usable results as quickly as possible, though. I'll deviate from that approach if and as I want, and so should you.

bernard_L · Jun 19, 2025

chuckroast said:
There is no one way of course, but assuming your meter is correct and is giving you the reading that would lead to middle gray/Zone V, this is how I would handle that situation:

I want to place the shadows on Zones III. In this case, 1/30 at f/8.

The tree trunk wants to be placed somewhere around the top of Zone VI. 1/125 @ f/16 is the same as 1/30 at f/32, so that placement would be at f/22 .

So we have a conundrum: If we place for the shadows, we blow out the highlights. If we place for the highlights, the shadows will go black.

I could use N-3 or even N-4 development and increase EI accordingly but I hate doing this with this sort of scene. It compresses the mid tones badly and the image loses its snap.

So what I would likely do it us extended, low agitation semistand development for a long time with a semi-compensating developer like D-23 or Pyrocat-HD. This would give the shadows time to fully develop and keep the highlights from over developing.

Another approach would be to use SLIMT, but since I never have tried it, I cannot recommend it one way or the other.

I have scan of a print from a somewhat similar situation here (ignore the fact that it needs more burning on the bottom right - it is a workbook print):

View attachment 401129

In the actual scene, the light was very flat from cloud cover after a snow storm, the area inside the shed was a uniform very dark gray, and what sun there was, was hammering down from the upper right. The true range of light was probably north 12 stops. To preserve the mid tone contrast and keep the snow in bounds, I used the technique described above. Like I said, the print needs some more work, but you can see the general idea.

I find woodland shots like you describe particularly challenging because it is not enough to manage the range of light. Too many of these end up with boring middle tone contrast with no real sizzle to the print. So doing things as I have described is my way of trying the make the mid tones "pop" and make the image more interesting. Here is another I took after a rainstorm in an absolutely flat dark gray day with a really boring range of light:

View attachment 401128

Both of these were metered at box speed but that was a minor detail compared to the larger manipulations they required.

When I wrote "what to do?" it was just a way of stating that some real-life situations pose problems of a different magnitude than, e.g. the 2/3 stops between ISO and Zone System.
Your overview of your technical approch to large-SBR subject was nevertheless an interesting and worthwhile read. I like both prints.
In 120 or 135 formats one must have a homogeneous set of captures to apply a special development. What worked for me when doing a series on a dark hall of turbines and alternatifs with glimpses of the sunny outside through windows was: D-23 1+1.

Steven Lee · Jun 19, 2025

Alan Edward Klein said:
What's a better way?

The better way is the annoying way: to learn the behavior of the light meter, photographic materials, and meter each scene according to what's in it and the final image look one has in mind.

chuckroast · Jun 19, 2025

bernard_L said:
In 120 or 135 formats one must have a homogeneous set of captures to apply a special development.

I don't quite understand what you are saying here, could you explain?

Craig · Jun 19, 2025

chuckroast said:
I don't quite understand what you are saying here, could you explain?

Basically, you have to have all the exposures on a roll needing the same development, unlike sheet film. You can't have the start of the roll needing N+1 and the end of the roll needing N-2 for example.

Paul Howell · Jun 19, 2025

khh said:
As a relative newcomer, my approach is to initially meter at box speed, develop using the manufacturer's recommended times, and evaluate the result. For Kodak, Fuji and Ilford products, I never really got further as the results were, best as I could tell, good. For Foma's products that did not quite get me the results I was hoping for, but adjusting EI and development has gotten me there for some stocks (100 and 200, I don't get along with 400 yet). That is the approach I would recommend to a beginner, if asked. That's really just advice to get people usable results as quickly as possible, though. I'll deviate from that approach if and as I want, and so should you.

With my more modern Minolta and Nikon with matrix metering and Tmax 400 and 100 with a wide variety of developers I shoot box and get good shadow details and, in most case, printable highlights, With my older lens, Miranda, Minolta, Konica, and MF and LF lens, Kowa, Mamiya I shoot all over the map. This is not an issue with the speed of the film, it is due to errors caused by aging shutters and meters. I shoot a lot of Foma and at best their box speed is optimistic at best. I find that I can shoot Foma 400 at 320 and develop in D76, F76+ MCM 100 while Foma 100 at 64, while Foma 200 I can shoot at 200. With Kenmare and Ultrafine Extreme, mostly close to box speed.

From what I have read, without more details it is hard to say if someone is shooting at box speed due to inaccurate shutters and meters or are have they tested with a densitometer and after controlling for mechanical issues are rerating his/her film ISO.

Autonerd · Jun 19, 2025

Ivo Stunga said:
So - a deviation from "box speed" is beneficial after all?!

In this case, the photogs at the magazine where I worked said "For Velvia, set your meter at 40," and I, being an impressionable youth, just blindly followed. Sadly, the couple of rolls on which I tried this seem to be lost to time... I mostly shot Fujichrome 100 (at 100).

JerseyDoug · Jun 19, 2025

bernard_L said:
...... Then I’m in the woods. Light levels can be surprisingly low, like 1/30 f/2.8 @100ISO. But there is a tree trunk hit by the sun, reading 1/125 F/16. What to do? (I shoot FP4, thank you) The answer does not reside in the choice of an ISO value.
Assuming of course that the top level goal is to bring the picture home.

I have never been able to get a result I like with that range of brightness without a lot of heavy burning and dodging, both back in my darkroom days and now that I scan and edit with Affinity Photo. My usual approach when I encounter a subject like that is to take a quick shot with my iPhone which gives me both a rough cut of the subject and the GPS location and then come back when the sky is overcast to take a proper shot with a film camera.

Autonerd · Jun 19, 2025

albireo said:
For starters, something you really don't quite grasp and that you've been told multiple times on Reddit, is that some people might want to get to their final image by tweaking chemical or optical variables, and not by tinkering with the Photoshop sliders and dodge burn buttons. I'd accept that and move on, to do what you like to do best.

I don't have any issues with that -- I just think it's important to understand the medium and how it was meant to be used, back to that know-the-rules-before-breaking-them. I don't think people who are new to film generally understand the role of the negative. Better understanding leads to better decisions. You want to increase contrast through UE/push -- OK, go for it, but best to understand there are other ways to do this, and make an informed choice. (I also get irked at "Kentmere 400 is too flat!!!")

These gross deviations from manufacturers recommendations applied blindly, as if they were the key to unlocking some magical properties of those film somehow concealed by the manufacturer, don't make a lot of sense to me at least.

Yes! Very well said.

My rant on shooting box speed. Am I out to lunch?

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