Zone VI modified Pentax Digital Spotmeter confusion

[Vaughn]

What print zone is it when there is a pure black with detail? Zone -I ?

It can happen with carbon prints...

 

[DREW WILEY]

Dye transfer was another medium where the depth of blacks went on and on and on; but white gradation suffered,
requiring highlight masks or bleaching, etc. And one needs to meter for sake of their specific print medium, provided the film they have chosen is up to the task as well.

 

[RalphLambrecht]

If an instrument has poor precision it also has poor accuracy. And instrument with good precision can still have poor accuracy. An instrument with high accuracy must have high precision as well. So when I pay for an instrument the accuracy is most important.

fully agreed

 

[DREW WILEY]

We're not talking about subatomic quantum mechanics here, but about practical film photography where working inside a third of a stop, or possibly even a sixth, is about as good as it gets. As for me, I sure as heck don't want a meter or any other kind of measurement instrument which is unreliable in terms of either precision or accuracy. You need consistent quality in both respects, or else it's a useless piece of junk. But what the hell do I know? - I only imported and sold top end tools for about fifty years, and even participated in engineering focus groups and on-site prototyping. And yes, quality and dependability was a constant topic, but never ever divided into the frivolous distinction between "precision" and "accuracy" encountered on this thread.

I also have a lot of precision film punch and registration equipment in my personal lab. Same principle. The tolerance for error is about a thousandth of an inch item to item. You can't compromise either precision or accuracy, or you're wasting your time and money. "Quality" - a plain English term - pretty much sums it up.

 

[Bill Burk]

Reminds me of a slogan at a printing company I worked for “zero tolerance” and it really meant “zero tolerance for not allowing the press 1/16 inch tolerance”

 

[guangong]

In the early years, the Zone VI business was run out of Lil's (can't remember her last name) house and, yes, it was always a mail order business. In later years, the business moved to a location in Brattleboro where they did produce their Zone VI 4x5 camera. Eventually, the entire business was sold to Calumet.

As I remember, the Zone VI 45 camera was a tweaked Wista.

 

[chuckroast]

We're not talking about subatomic quantum mechanics here, but about practical film photography where working inside a third of a stop, or possibly even a sixth, is about as good as it gets. As for me, I sure as heck don't want a meter or any other kind of measurement instrument which is unreliable in terms of either precision or accuracy. You need consistent quality in both respects, or else it's a useless piece of junk. But what the hell do I know? - I only imported and sold top end tools for about fifty years, and even participated in engineering focus groups and on-site prototyping. And yes, quality and dependability was a constant topic, but never ever divided into the frivolous distinction between "precision" and "accuracy" encountered on this thread.

I also have a lot of precision film punch and registration equipment in my personal lab. Same principle. The tolerance for error is about a thousandth of an inch item to item. You can't compromise either precision or accuracy, or you're wasting your time and money. "Quality" - a plain English term - pretty much sums it up.

There are places where absolute accuracy within the specified precision are important, but when we're dealing with human perception, those notions mean less than we might think. I spent a couple of years doing research on how people hear in noisy environments. After carefully constructing the experiments and doing tortured statistical reductions, we found that the things that were statistically significant to improve human hearing in noisy situations, were barely so. The human-to-human variably was so great that statistical significance barely poked out of the noise floor of the data.

I think this is analogously true for using a light meter. No matter how accurately calibrated the meter, each of us sees and places light differently, develops and agitates differently, prints/scans differently, and so forth. This is why the Zone notion of a "personal EI" is appealing. It tunes the process to you.

So, it seems to me that the important thing, pragmatically, for our purposes is better expressed in terms of repeatability across the range of light. I don't care if my meter is off 6 stops from the putative standards if it meets two important criteria:

1) It is consistently off 6 stops across the entirely range of light we want to measure

2) The 6 stops of error doesn't therefore cause the meter to cause nonlinear/wonky readings at the ends of it's metering range.

That's not theoretical either. I've resurrected a bunch of Luna Pros from the dead (I am a masochist in that regard). Even when they work really well, they show considerable nonlinearity at the top of the low light range vs. the bottom of the high light range. They also have anywhere between 1/3 and 1/2 stop variability from meter to meter.

That's why I use my Zone VI Pentax as the reference standard for all my other meters. It's not that it's "accurate", it's that it's consistent.

 

[RalphLambrecht]

We're not talking about subatomic quantum mechanics here, but about practical film photography where working inside a third of a stop, or possibly even a sixth, is about as good as it gets. As for me, I sure as heck don't want a meter or any other kind of measurement instrument which is unreliable in terms of either precision or accuracy. You need consistent quality in both respects, or else it's a useless piece of junk. But what the hell do I know? - I only imported and sold top end tools for about fifty years, and even participated in engineering focus groups and on-site prototyping. And yes, quality and dependability was a constant topic, but never ever divided into the frivolous distinction between "precision" and "accuracy" encountered on this thread.

I also have a lot of precision film punch and registration equipment in my personal lab. Same principle. The tolerance for error is about a thousandth of an inch item to item. You can't compromise either precision or accuracy, or you're wasting your time and money. "Quality" - a plain English term - pretty much sums it up.

As a quality engineer, I encountered only a few people who could explain what 'quality' actually means.

 

[chuckroast]

As a quality engineer, I encountered only a few people who could explain what 'quality' actually means.

Robert Pirsig had a POV on that

Having worked with many QA processes over the years, "quality" in practice ends up mostly being seen as "conformance to specifications" not some sort of absolute standard of goodness.

 

[DREW WILEY]

As someone who engineers often entrusted with prototypes to functionally test, as well as test market to end users, "quality" meant everything. But yeah, everyone had jokes about ivory tower engineers who couldn't comprehend the necessity to communicate or design on a practical wavelength. A particular huge Japanese corporation would send me up to a dozen engineers at a time, but they had a ranking. The experienced ones did the talking and hoarded the translators, while the apprentice types stood on the perimeter listening. And since we had our own substantial repair facility, those folks were often involved too. It's was just as important for the engineers to learn blue collar thought and lingo as it was for us to appreciate what they could or could not do for us.

All manufacturing "quality" is a kind of compromise between the target market, cost and feasible of production and recouping R&D expense, distribution and service connotations, etc. But under that umbrella, there can be a considerable divergence between budget gear and professional expectations. The meters made by Pentax, Minolta, and certain other brands were distinctly of the superior category, or they wouldn't have remained classic for so long a time, or still be highly usable.

As per Chuck's philosophy that as long as meters are repeatable, it doesn't matter whether they're calibrated to a hard industry standard or not, well, that notion might be acceptable for someone isolated on a desert island, sitting cross-legged and meditating over how many Zones there are to the universe; but there are in fact far more dominant aspects of commercial photography and filmmaking which demand conformity to a common denominator standard. And it also makes an enormous amount of sense when buying a new or replacement meter.

That fact doesn't stop one from offsetting a reading in a personal EI sense at all - all you have to do is tweak the ASA dial to your own expectations. That takes about one second, and you can just leave it there if you wish.

 

[chuckroast]

As someone who engineers often entrusted with prototypes to functionally test, as well as test market to end users, "quality" meant everything. But yeah, everyone had jokes about ivory tower engineers who couldn't comprehend the necessity to communicate or design on a practical wavelength. A particular huge Japanese corporation would send me up to a dozen engineers at a time, but they had a ranking. The experienced ones did the talking and hoarded the translators, while the apprentice types stood on the perimeter listening. And since we had our own substantial repair facility, those folks were often involved too. It's was just as important for the engineers to learn blue collar thought and lingo as it was for us to appreciate what they could or could not do for us.

All manufacturing "quality" is a kind of compromise between the target market, cost and feasible of production and recouping R&D expense, distribution and service connotations, etc. But under that umbrella, there can be a considerable divergence between budget gear and professional expectations. The meters made by Pentax, Minolta, and certain other brands were distinctly of the superior category, or they wouldn't have remained classic for so long a time, or still be highly usable.

As per Chuck's philosophy that as long as meters are repeatable, it doesn't matter whether they're calibrated to a hard industry standard or not, well, that notion might be acceptable for someone isolated on a desert island, sitting cross-legged and meditating over how many Zones there are to the universe; but there are in fact far more dominant aspects of commercial photography and filmmaking which demand conformity to a common denominator standard. And it also makes an enormous amount of sense when buying a new or replacement meter.
work with us.
That fact doesn't stop one from offsetting a reading in a personal EI sense at all - all you have to do is tweak the ASA dial to your own expectations. That takes about one second, and you can just leave it there if you wish.

Well sure, if I am expected to produce outcomes relevant to third parties, absolute calibration matters a lot. Things like color temp measurement in movie making leap to mind.

But that's not the context here. We are, all of us, largely on your metaphorical island working in our own interest. I don't care a whit what you call Zone V and I suspect you feel the same about me. In this context, all that matters is consistency and linearty (logarithmically speaking, of course). If my LunaPros are off a full stop, it just doesn't matter b/c I adjust according to how I work. You are unaffected by this absence of meeting the calibration standard.

I've been in engineering for nearly 5 decades and I'd argue that engineering as a discipline has not done a great job of designing for variability and larger tolerances. The plastic panels in 1980s American cars leap to mind where even premium products like Corvettes squeaked because the engineers made them fit so tight to the "standard", there was no room for movement.

 

[Alan9940]

As I remember, the Zone VI 45 camera was a tweaked Wista.

Actually, the very first one (I have it) was a tweaked Tachihara. Some time later, they moved to Wista's. Then came the progression of their own wooden field camera starting with Ron Wisner, then in-house built cameras, to their final resting place with Calumet when they bought the Zone VI business. No idea who made the "Zone VI" cameras sold by Calumet.

 

[DREW WILEY]

Ah, Chuck, if I were still young, I would have loved to pursue what they now call a "material science" degree. I was just talking to one of them yesterday, just about to transition from a University related apprentice position to a high paid Tech company role. He's only got his Masters so far, but it's enough to have gotten him a long ways already. I remember the long chats with the America's Cup teams and all the specialized carbon fiber samples they showed me, including Kevlar reinforced. (I supplied them all the fabrication equipment, not the carbon fiber material itself).
There is just so much going on right now. I never evolved past my early Phillips 8X10 with its innovative epoxy impregnated wood and fiberglass ply. It had held up wonderfully.

Speaking of dimensional standards, since I have a lot of plastic fabrication gear in my own shop, a neighbor asked if I could make him deluxe replacement windows for his own classic car. I had to explain that even polycarbonate would have too much dimensional expansion and contraction stress to fill the role. Heck, it's problem enough even with big picture frames.

 

[Chan Tran]

As a quality engineer, I encountered only a few people who could explain what 'quality' actually means.

For me quality means how close you get to your intended product. If you want to make it round how close you come to round?

 

[chuckroast]

Ah, Chuck, if I were still young, I would have loved to pursue what they now call a "material science" degree. I was just talking to one of them yesterday, just about to transition from a University related apprentice position to a high paid Tech company role. He's only got his Masters so far, but it's enough to have gotten him a long ways already. I remember the long chats with the America's Cup teams and all the specialized carbon fiber samples they showed me, including Kevlar reinforced. (I supplied them all the fabrication equipment, not the carbon fiber material itself).
There is just so much going on right now. I never evolved past my early Phillips 8X10 with its innovative epoxy impregnated wood and fiberglass ply. It had held up wonderfully.

Speaking of dimensional standards, since I have a lot of plastic fabrication gear in my own shop, a neighbor asked if I could make him deluxe replacement windows for his own classic car. I had to explain that even polycarbonate would have too much dimensional expansion and contraction stress to fill the role. Heck, it's problem enough even with big picture frames.

<Old Engineers Reminiscing>

The first part of my career was, by turns, RF, Radar, broadcast technology, and analog audio and medical equipment engineering - along the way, I also learned lessons about materials, fabrication, and manufacturing tolerances and how to work with a union-run shop floor (which is way harder than doing differential equations). Who knew that you could model mechanical inertance as electrical inductance and thereby analyze mechanical systems using circuit analysis tools? My boss did

But if I could go back? I'd probably go work in computational biology. There is immense potential for genetically engineering medicals talked for specific individuals that could really transform how we deliver pharma globally.

</Old Engineers Reminiscing>

 

[chuckroast]

For me quality means how close you get to your intended product. If you want to make it round how close you come to round?

Yabut the problem is getting the specifier to tell you 'How round is round?'. As noted above, engineering is a tradeoff between time to market, features, cost, durability, and so on. "Quality" is therefore a byproduct of meeting both the direct functional requirements and the nonfunctional expectations.

For example, Rolls Royce cars are engineered to have a service life that exceeds that of the original buyer (well, they were, anyway). But that puts them at a cost point that outside the reach of almost anyone but the very wealthy. The nonfunctional expectation of service life exceed that of keeping the price down.

Veering back on topic here, imagine you are in the market for a new light meter. Which would be more appealing: A meter that is calibrated to 4 digits of precision to an international standard but costs $3000 or meter with up to 1 stop manufacturing variability against that same standard but which provides highly consistent results - it's always off by the same amount - and costs $50?

Accuracy (how correct something is) and precision (to what granularity is it correct) are important, but they do not exist in a vaccum. They have to be balanced against the aforementioned nonfunctional expectations.

P.S. It would be interesting to do the analysis, but I wonder if it would make economic sense to buy a new Rolls with a 30 year payoff right when you go into the workforce, and never drive anything else again.

 

[BrianShaw]

Yabut the problem is getting the specifier to tell you 'How round is round?'. As noted above, engineering is a tradeoff between time to market, features, cost, durability, and so on. "Quality" is therefore a byproduct of meeting both the direct functional requirements and the nonfunctional expectations.

Engineering is almost always, if not always, based in trade-offs. That is a fact. In modern engineering, especially of expensive or high-reliability systems, quality is definitiely not a by-product. Quality engineering has been a full-fledged engineering discipline for several decades. Engineering does not rely on dictionary definition or user interpretations of words like quality, reliability, maintainability, and the opther -ilities like is being promulgated by some in this thread. Those terms have real processes and measures of success. Users might use those words to describe their subjective assessment or desires that but the relationship between user opinion/experience and engineering in those domains are distinct.

But none of this really addresses the core point of hte thread. Just another rabitt-hole we've all been pulled into...

 

[chuckroast]

Actually, the very first one (I have it) was a tweaked Tachihara. Some time later, they moved to Wista's. Then came the progression of their own wooden field camera starting with Ron Wisner, then in-house built cameras, to their final resting place with Calumet when they bought the Zone VI business. No idea who made the "Zone VI" cameras sold by Calumet.

Richard Ritter was the guy who assembled/fixed cameras in house (not sure where the wooden parts were milled or by whom, it may have all been done in house). Richard is very much still around and working, and occasionally appears on the large format forum. I don't know this for a fact, but I suspect that Richard probably had a hand in the cameras even after Calumet bought them.

I once had a chance to chat with Fred Picker shortly around the time he retired. Unlike his very opinionated and marketing-driven publications, he was gracious to a fault, vastly curious about what papers I was using and how I found them, and generally just a really nice guy.

Despite the rocks hurled in his direction periodically, I've never regretted any of the Zone VI purchases I made ... well maybe one - in retrospect, the viewing filters were silly. A lot of people dismiss Fred and Zone VI as just a marketing hustle, but I think that's pretty unfair. The products were uniformly very well made - I still have a 100% functional Zone VI compensating development timer and a VC cold light head I cannot live without. The fact that he dressed all this up with a lot of marketing claims just means he was running a business, not that he was being disingenuous. Some of his stuff - like the Zone VI graded papers - have never had an equal since.

P.S. I liked the compensating development timer so much ... I built my own using modern tooling:

https://gitbucket.tundraware.com/tundra/devtimer

 

[BrianShaw]

People like Picker tend to have a certain genius that rubs some folks the wrong way. But they tend to be dedicated, albeit opinionated, and rarely wrong or deceptive. Even the viewindg filter, which I have 2 and hold the same opinion of hie relative uselessness, met a legitimate need in the day.

Does anyone else remember Drew Kaplan; Similar kind of guy?

The Fall 1984 DAK Catalog : Free Download, Borrow, and Streaming : Internet Archive

Digitized by Cabel Sasser.

archive.org

 

[chuckroast]

People like Picker tend to have a certain genius that rubs some folks the wrong way. But they tend to be dedicated, albeit opinionated, and rarely wrong or deceptive. Even the viewindg filter, which I have 2 and hold the same opinion of hie relative uselessness, met a legitimate need in the day.

Does anyone else remember Drew Kaplan; Similar kind of guy?

The Fall 1984 DAK Catalog : Free Download, Borrow, and Streaming : Internet Archive

Digitized by Cabel Sasser.

archive.org

Oh man ... "blasts" and "activators" - thanks for that trip down memory lane

 

[Chan Tran]

Engineering is almost always, if not always, based in trade-offs. That is a fact. In modern engineering, especially of expensive or high-reliability systems, quality is definitiely not a by-product. Quality engineering has been a full-fledged engineering discipline for several decades. Engineering does not rely on dictionary definition or user interpretations of words like quality, reliability, maintainability, and the opther -ilities like is being promulgated by some in this thread. Those terms have real processes and measures of success. Users might use those words to describe their subjective assessment or desires that but the relationship between user opinion/experience and engineering in those domains are distinct.

But none of this really addresses the core point of hte thread. Just another rabitt-hole we've all been pulled into...

Sorry Brian, I was the first to talk about accuracy. But let me explain, to me unless a meter is more accurate than the other it's not worth more than the other. The way it displays the information is irrelevant to me whether the dial or with digital display they are the same as I don't care. I see that the Pentax costing about twice as much as a Minolta with the same degree accuracy is not worth while to me.

 

[Alan9940]

Richard Ritter was the guy who assembled/fixed cameras in house (not sure where the wooden parts were milled or by whom, it may have all been done in house). Richard is very much still around and working, and occasionally appears on the large format forum. I don't know this for a fact, but I suspect that Richard probably had a hand in the cameras even after Calumet bought them.

I once had a chance to chat with Fred Picker shortly around the time he retired. Unlike his very opinionated and marketing-driven publications, he was gracious to a fault, vastly curious about what papers I was using and how I found them, and generally just a really nice guy.

Despite the rocks hurled in his direction periodically, I've never regretted any of the Zone VI purchases I made ... well maybe one - in retrospect, the viewing filters were silly. A lot of people dismiss Fred and Zone VI as just a marketing hustle, but I think that's pretty unfair. The products were uniformly very well made - I still have a 100% functional Zone VI compensating development timer and a VC cold light head I cannot live without. The fact that he dressed all this up with a lot of marketing claims just means he was running a business, not that he was being disingenuous. Some of his stuff - like the Zone VI graded papers - have never had an equal since.

P.S. I liked the compensating development timer so much ... I built my own using modern tooling:

https://gitbucket.tundraware.com/tundra/devtimer

I became aware of Fred and Zone VI around the mid- to late 70's; attended his workshop in 1979. When I lived in MD, my wife and I visited VT several times for vacations and we always stopped in to visit with Fred. I would show him my new work and we took him to dinner a couple of times. Like you, I always found him to be very gracious and I always enjoyed his pithy demeanor. I actually toyed with the idea of being his photographic assistant when he floated that idea one day. Don't know if he ever actually had an assistant, but it just wasn't the right timing for me.

I have many Zone VI products that I use to this day and the only issue I've ever had was with my Compensating Development Timer. I noticed one day that it was running slow, based on a temp of 68 degrees. At that temp, the timer should run dead-on to real time. So, here's one for the books... I contacted Paul Horowitz and he fixed / recalibrated it for free! This is a timer I've had for 40+ years and Paul upheld Fred's "guaranteed for life" warranty! For fact, he said he also made a slight modification to something he didn't care for in the original design. I don't personally know of anywhere one can get that level of service!

 

[BrianShaw]

Sorry Brian, I was the first to talk about accuracy. But let me explain, to me unless a meter is more accurate than the other it's not worth more than the other. The way it displays the information is irrelevant to me whether the dial or with digital display they are the same as I don't care. I see that the Pentax costing about twice as much as a Minolta with the same degree accuracy is not worth while to me.

Apology not necessary. There is no problem, in my opinion, about talking about accuracy of light meters. Nor is there a problem, in my mind, with using a different meter that provides the same or similar levels of accuracy. It's the mistaken belieff that only one meter is accurate and the mistaken notion that using English words means the same in engineering. Being open-minded and thrifty are good attributes.

I learned photographic exposure using a Pentax digital spotmeter when they were within their first couple of years of existance. I'd still use one but found that other meters do the job just as well and a lot easier for my purposes. The spotmeter I bought about 10 years ago is seldom used, very accurate, and, for my purposes, much easier to use than a Pentax. That's me...

 

[chuckroast]

I became aware of Fred and Zone VI around the mid- to late 70's; attended his workshop in 1979. When I lived in MD, my wife and I visited VT several times for vacations and we always stopped in to visit with Fred. I would show him my new work and we took him to dinner a couple of times. Like you, I always found him to be very gracious and I always enjoyed his pithy demeanor. I actually toyed with the idea of being his photographic assistant when he floated that idea one day. Don't know if he ever actually had an assistant, but it just wasn't the right timing for me.

I have many Zone VI products that I use to this day and the only issue I've ever had was with my Compensating Development Timer. I noticed one day that it was running slow, based on a temp of 68 degrees. At that temp, the timer should run dead-on to real time. So, here's one for the books... I contacted Paul Horowitz and he fixed / recalibrated it for free! This is a timer I've had for 40+ years and Paul upheld Fred's "guaranteed for life" warranty! For fact, he said he also made a slight modification to something he didn't care for in the original design. I don't personally know of anywhere one can get that level of service!

Is Paul actively still working on stuff like this, I wonder, or was this some time ago?

 

[Alan9940]

Is Paul actively still working on stuff like this, I wonder, or was this some time ago?

It was a few months ago.