When I shoot a modern (well by film standards) body with Matrix metering seems that box speed is spot on with D76 or HC 110, Rodinal also seems to be at box speed, does change with other developers, I don't use Xtol which I assume would give box speed as well. Once I use a mechanical shutter with a aged light meter, TTL or handheld all bets are off. I have 2 Spots, difference is 2 stops,, I have 4 Miranda, EEs each is off, my MF and LF are held metered, Gossen, Weston and GE, all are different. Using my Minolta 9 or a Sony 77A DSLR can be used to calibrate the other meters but does not take into account the difference in shutters. Basic film testing is not a bad idea as your testing your camera as well, on the other hand for me the reason to own a camera is to take pictures not to test film. I know there are others who enjoy testing films and developers, what ever floats your boat.
Does changing film speed affect zone employment?
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This confused me as well, until I realized the meter reading of the shadows is overexposing by two stops to bring the values up to Zone V. So you are actually normalizing the exposure when you change two stops. Hope that makes sense.
OP
OP
Michael, let me ask, why 2/3 stop ?
ZS is pre 1960. In 1960 speed was modified by 1 stop on the box with no change in the manufacturing... IMO consumer photographers "interpreted" that change as a change in the safety factor, while many artists and Pros that were metering accurately exposed the pre than post 1960...
are those 2/3 stops related to that speed change ?
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IMO, BOX SPEED is the best if performing regular full speed developments...
But standard Speed Point distance vs BOX SPEED may vary from the 3.33 standard stops... Personal E.I. makes sense when using different films/developments, a bit to always have the Speed Point in the same place, this helps consistency, let me point some examples when E.I. makes sense:
> Manufacturers round the technically calibrated speed to a commercial grade, so BOX SPEED may vary a bit from ISO speed.
> Foma an others use an speed boosting developer and a higher than standard Contrast Index for the calibration.
> Aged film.
> We may use a developer that changes speed by 1/2 stop.
> A particular camera/meter system may deliver shifted readings
At the end we want consistence in our exposures, IMO best advice is using ISO speed (3.33 stops over Speed Point wich is 0.1D over B+F), but our film/processing combination may deliver a true ISO SPEED that is shifted compared to Box Speed. In that case it is more practical dialing a different E.I than remembering and shifting exposure to compensate the true Speed Change from what stamped on the box.
Still, the Box Speed it is a great reference, and IMO we usually require a correction that is under or around 1/2 stop.
Personally what I do is trying to use a "PSEUDO TRUE ISO SPEED", I spot meter and bracket shadows, to allow a E.I. targeting 3.33 underexposure for 0.1D+B+F density. It is PSEUDO becuase C.I. may not be the standard 0.62... but still I want to use an E.I. that places Speed Point at -3.33 stops, in that way I have a very solid reference. Still different films have a different toe... so extreme shadows will have a different nature.
Other reasons to use a personal E.I. is accounting inaccuracies in the metering/exposure, for example many LF shutters are not very accurate and we may not have a shutter tester... a E.I. correction may be used as a safety factor, as some 1/2 overexposure won't harm negative film images and we have a safety factor for the shadow detail. Slides are different, we have to nail their exposure !!!
Problem is not using BOX SPEED or personal E.I., problem is not understanding what we are doing both with BOX SPEED or personal E.I.
IMO we should take that red BOX SPEED like an insult, it's just a coarse emphasization, a bit coarse perhaps but not a war declaration. We are to be vaccinated soon, COVID will be over... we need to keep calm in the meantime
.IMO we should take that red BOX SPEED like an insult, it's just a coarse emphasization, a bit coarse perhaps but not a war declaration. We are to be vaccinated soon, COVID will be over... we need to keep calm in the meantime
Haha i was thinking more of "boomer" than boxspeed.
No need to speak to other members like that imo.
How do you know that michael_r is 57 year old or older?
ISO speed is determined by a specific testing method.
Zone speed is determined by a different specific testing method.
Personal EI under any exposure metering method is (or ought to be) determined by a specific testing method.
If you don't test your film and develop according to manufacturer times, you're probably ahead to shoot at box speed. If you do, use the speed your testing determined. If you're one of those people saying "but my shadow details suck when I shoot at box speed" you've done a type of testing that's given you a lower personal EI; use that value.
Until I can do sensitometry, I'm happy with the results I get at box speed. Good shadow detail, highlights I can print (haven't printed lately, but I have confidence my scanning doesn't deviate far from what my darkroom will produce once I get my enlarger back in operation), easy-peasy.
You can make this as complicated as you like, but I recommend not making it any more complicated than it needs to be.
Zone speed is determined by a different specific testing method.
Personal EI under any exposure metering method is (or ought to be) determined by a specific testing method.
If you don't test your film and develop according to manufacturer times, you're probably ahead to shoot at box speed. If you do, use the speed your testing determined. If you're one of those people saying "but my shadow details suck when I shoot at box speed" you've done a type of testing that's given you a lower personal EI; use that value.
Until I can do sensitometry, I'm happy with the results I get at box speed. Good shadow detail, highlights I can print (haven't printed lately, but I have confidence my scanning doesn't deviate far from what my darkroom will produce once I get my enlarger back in operation), easy-peasy.
You can make this as complicated as you like, but I recommend not making it any more complicated than it needs to be.
Michael, at the end we disagree only by 1/3 of stop... but ZS table specifies middle gray for Z-V, this is the key reference IMO:
Obviously that table became obsolete post 1960 because of the Box speed change in the norms, because the meter started aiming x20 the light in the speed point instead x10, so IMO formally for ZS metering we have to use a full 1 stop correction, not 2/3. Pre 1960 photograpers were instructed to meter Z-V at 0+/-, not +1/3 ....
So historically and formally (IMO) the correction is one stop, still using that 2/3 will underexpose (compared to 1959) by 1/3 stop, which is mostly irrelevant in practice.
If one uses a lower than box speed ISO and the Zone System, one gets a denser negative. Some like that.
Not at all... ZS is not a way to craft denser or thinner negatives, it's a way to craft the negative you want. Very often we develop N-1 or N-2 or N-4, obtaining low contrast negatives that can quite thin.
Adams described the Zone System as "[...] not an invention of mine; it is a codification of the principles ofsensitometry"
ZS is kid's tale, a simple way to explain sensitometry without using logarithms, a useful recipe like Sunny 16 was before meters became popular. ZS is not good or bad, it only tells how film and paper behave.
ZS at all tells the image you have to craft, it tells an accurate prediction about what you will obtain depending on how you expose/develop.
Still ZS was intended to explain the bahaviour of the film of its era with more pronounced toe/shoulder, ZS requires some adaptation with linear films, for example TMY has perfect detail at +4, but we'll to compress those extreme highlights to be printed on paper.
That is the boat I'm in Paul, the three cameras I use all have slower or faster shutter speeds compared to each other. I compensate exposure for each slightly, based on my past experience, which keeps me in the ball park roughly .
That safety factor was for consumer photography. Pros and Artists exposed the same in 1961 than in 1959, because Pros of that era were true masters that by 1959 knew perfectly how they had to expose optimally. In particular proficinent artists rated the same film at the same speed than they used pre 1960. LOL if an artist (that is a master of his tools) has to shot differently because consumers were genarally overexposing and industry found that solution is changing an stamp on the box.
That 1960 speed change required a change in the ZS 1940 table, but today ISO (ASA) is x2 the one of 1940, solution is using the Pre 1960 speed (the half), so you don't need to change the table.
IMO that change was for consumers, the real photographers are still laughing.
... So ... let's see ... First, the Zone System speed point is a fixed density above film-base+fog. It has nothing to do with pre- or post-1960 anything. It's its own thing and, as Michael points out, deviates from ISO speed (and earlier ASA speeds) due to the different methods of determining the speed point. It is a convenient simplification of film-speed testing that delivers good negatives. Don't try to correlate the ZS speed point with other, differently determined, speed points.
Second, Zone V falls where it falls after you've determined your speed point, established a working E.I. and found a development time for "N" that puts Zone VIII in the right place. It, by itself, is not a calibration point, and can, in practice, vary from 18% middle grey significantly, even with "N" development. Additionally, Zone System expansions or contractions are going to move Zone V around by a lot; a Zone or more with extremes. Anyone who has made Zone Rulers for their particular film/developer/paper combination knows this just from looking at the stripes on the paper.
Your chart is an idealized description of "N" in the Zone System, not an actual print of anything. Still, as far as a guide to what "N" development should be (according to this 10-Zone model) it is still perfectly valid and relevant, regardless of the change in "box speed" determination around 1960.
Very true. I'm one of those who likes denser negatives (but I'm a boomer... maybe gen Zers like thinner ones?). Still, IM-HO the ideal negative is the one with the least exposure to get the shadow densities and separation one desires.
The problem with box speed for many is that it doesn't deliver the shadow detail expected, for whatever reason. In this case, the simplest solution is to simply rate your film slower than box speed by whatever amount you need to get the shadows you want with your particular meter, metering technique, lens, shutter, film developer, etc., etc. It's a whole lot simpler to do that than to go about calibrating all the other variables. Really, finding a personal E.I. is largely just compensating for the discrepancies and inaccuracies in one's equipment, materials and methods.
If you get shadows that you like at box speed, then fine. FWIW, my preferred E.I.s for the films I use ends up being 1/3 to 2/3 stop slower than box speed, i.e., pretty close to the Zone System speed-point method and not far from box speed.
I do all the ZS film-speed testing à la White, Zakia, Lorenz myself. However, if I were to give someone a down-and-dirty quick-start guide to exposure and development using the Zone System I'd just say, "rate your film 2/3 stop slower than box speed, find a development time that gives you highlights that print well at a medium contrast setting and keep good field notes. Tweak your process as you go based on them."
This, however ignores the main usefulness of the Zone System, which is as a tool for visualizing the final print before exposing the negative. That's a subject for a different thread.
Best,
Doremus
Doremus, look, the ZS photographers routinely rate film at 1/2 (*) of its today's fim speed, isn't it ?
... so pre 1960 they rated film at its Box Speed, isn't ?
______________
Of course you can refine you personal E.I. for ZS from developer, etc... if you loss 1/4 stop from Rodinal or HC-110 you will adjust that... you can say 2/3 if using Xtol (*), 1 stop if using D-76, or 1+1/3 if using Rodinal...
But Nominally the ZS table was shifted for a full zone in 1960, as the table was not modified but box speed was. There is absolutely no doubt that shift was exactly 1 Stop. If you were using ASA (ISO) box speed for ZS in 1959 then in 1961 you would have been using half the box speed, suposed your workflow was sound by 1959...
* (Well, Michael says 2/3 stop, instead 1 stop)
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There is nothing wrong with being a Boomer. I am one too. We cannot help it, we were born that way.
Is that a kind of quantum mechanics thing?
But seriously, your question prompted me to remember that I am super rusty with my zone exposure/development process. I read Ansel's books - The Negative and The Print when I first got started with serious photography. I've been an active and inactive practitioner for long enough to have this rust polished off multiple times. The rust has returned with a vengeance. Time to polish. Your question prompted this in me. Thank you.
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You may get good results with box speed. But when talking about Zone System, the way that you test film in the classic literature aims to put Zone I four stops down from Zone V.
By definition this one fact puts Zone System speed at 2/3 stop below ISO because standard speed point is 3 1/3 stop down (easiest to remember as 10x) from the meter gray. Since box speed is kind of determined at N+1 and Zone System speed is determined at a lower contrast (N) the lesser development is responsible for another smaller shift that I haven’t exactly accounted but I believe it is approximately 1/3 stop.
So when you hear “just use half box speed or 2/3 less than box speed” those are the keys that explain the commentary
OP
OP
The more I read and research, and the longer y’all discuss this, I’m learning that my metering is probably more the culprit of bland negatives than anything else. Depending on what I’m shoooting I’ll always meter and put it in the 18% category leaving me with no contrast, unless it happens by luck.
I’m taking the new 645 out for a couple rolls of Tmax and TriX today so I’m going to try and meter for the shadows. It’s relatively overcast so I think I’m going to have a “short scale” due to the low contrast light, so if I understand correctly I’ll have to do n+1 development to expand the contrast some.
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You can round up to a whole stop because standard development is like N+1 so the manufacturers gave their rated speed based on development you might consider a slight push.
It might all feel like deception until you go back to when Hurter and Driffield started verifying speed claims like Rapid and Ultra Rapid.
Now you have come back to my main points about ISO. If one has exposure problems with box speed
- Calibrate your light meters
- CLA your cameras
- Learn how to use the light meters correctly
- Aim the reflectance meters not to include the sky
MattKing
Moderator
Point your meter at your subject.
If you want it to average out as Zone V mid-gray - use the recommended setting.
If you want it to average out as Zone IV - one zone darker than mid-gray - use one stop less than the recommended setting.
If you want it to average out as Zone VI - one zone lighter than mid-gray - use one stop more than the recommended setting.
etc., etc.
Some subjects are hard to evaluate what they should average out at. Try walking closer, and metering a smaller area. That is what spot meters do.
Alternatively, use an incident meter and, in most cases, use its recommendation.
Contrast is another question. That turns on the quality of the illumination and the nature of the subject. Adjust development to take that into account.
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