Mythbuster "You have to expose for the shadows and develop for the highlights"

ChuckP · Mar 5, 2008

Maybe Sam should try that on Bergger 200 instead on TMY.

Renato Tonelli · Mar 5, 2008

Christopher Walrath said:
My head hurts. Attempting second half now.

Mine is about to explode - I must log out.

ic-racer · Mar 5, 2008

Sam's Determination of EI

There are two issues addressed by Sam's technique. One is "determination of EI" and the other is "determination of development time." I'll address each separately.

An explanation of Sam's Determination of EI:

Short answer: He used the method for determining an exposure index for REVERSAL (slide) film.

Longer answer: He used the SHOULDER of the HD curve as a basis of his exposure, rather than the FOOT of the HD curve.

What difference does it make if you use the SHOULDER or the FOOT of the curve?

Short answer: Negatives based on the SHOULDER (of modern films) will be denser.

Long answer: There are a lot of permutations here and I will bring up a few. Exposure based on the foot of the curve (the common way) causes the shadows to fall on the foot of the HD curve, and the rest of the image falls on the middle (sometimes, straight-lined) portion of the curve.

An exposure of negative films based on the SHOULDER causes the HIGH values to fall on the curved shoulder and the low and middle values to fall on the sometimes straight middle part of the curve.

Something else to think about. Imagine a film with a short density scale, for example 8 stops. In this case the exposure index will be the same or similar, irrespective of if you use the shoulder or the foot. In real life, most films have many more than 8 stops range, so the exposure based on the shoulder is going to be much denser than the other.

For example, a long scale film like TMY used in the story, puts the exposure determination based on the SHOULDER way out at 5 to 6 stops more exposure than the EI based on the FOOT.

So, SAM overexposed his TMY by 6 stops. The thing is, he tested accurately. For example, he did not overexpose by 9 stops because he tested for the 'end of the shoulder' with the densitometer (0.1 log below maximum film density). So he showed us the 'Maximum exposure you can make on TMY and still get an acceptable print.'

This is in contrast to Bill who showed us the more conventional 'Minimum exposure you can make on TMY to still get an acceptable print.'

The two pictures from Todd and Zakia show a "Normal" exposure (based on the foot of the HD curve) whereas the other picture shows the best print from an over exposure of 6 stops.

T&Z describe a method of EI determination based on a series of pictures like these. That is, viewers rated pictures from negatives with varying exposure. The EI was based on the best print from the negative with LEAST exposure. These negatives with least exposure have been analyzed and ultimately this forms the basis for the popular use of 0.1 log in EI determination.

The bottom line here is that knowing about how to use 0.1 log above film base plus fog saves you from having to make a bunch of pictures and show them to a group of observers for exposure rating. The work was already been done. So the 0.1 log is a incredibly useful, shortcut. But, as Sam showed us, its not the only way!

If anything does not make sense, ASK don't FLAME. This is supposed to be amusing and entertaining and encourage 'thinking outside of the box.'

Next, the explanation of Sam's determination of development time. (Einstein, really??)

Snapshot · Mar 5, 2008

Didn't Mortensen’s 7-Derivative technique use the principle of expose for the highlights and develop for the shadows? Mortensen certainly made some nice photographs.

Ed Sukach · Mar 5, 2008

To me, the key word is "HAVE". Neither I. you, or anyone else HAS to do a damned thing; IF anyone chooses to wring out and spend a lot of time and energy "dealing" with the quest for a 'perfect' exposure (whatever that may be ...), all well and good. More power and luck to them.

For me, I'll contemplate the incredible beauty and majesty of this world, try to stay light and cool, so as not to miss anything (or at least not the important stuff), and make my not-so-perfect exposures (system: experience, mainly).

There is always the darkroom. dodge and burn, pre-flash ... multi-grade paper...

panastasia · Mar 5, 2008

Steve Smith said:
I quite like that attitude. If someone says to me "you can't do it like that...." my immediate reaction is "why? What would happen if I did?".

Steve.

Steve, I get the same from engineers that are still wet-behind-the-ears. I say to them: "Why can't I? What will happen? The same thing you said. Then they give some dumb answer so I'll think they know something. One in particular, with a masters degree, wouldn't know how to get out of a room if the door knob only turned one way. He's from Cornell University - I thought that was a good school. It makes me wonder.

The fact is, I was probably "doing it like that" before they were born.

Paul

ic-racer · Mar 5, 2008

Snapshot said:
Didn't Mortensens 7-Derivative technique use the principle of expose for the highlights and develop for the shadows? Mortensen certainly made some nice photographs.

Do you mean RAY Mortenson? I love his work! I know nothing of the man or his technique (other than what is in the pages of "Meadolands"). He has a tonal scale to die for, that is for shue.

ic-racer · Mar 5, 2008

Final notes on Exposure...

Is there any practical value to any of this, or is it just a mind numbing web of irrelevant information?:rolleyes:

I interpret two messages:

Message 1: Basing exposure on 0.1 is good, and mastering the techniques of densitometry and sensitometry can allow great control of the photographic process when you understand the principles involved. (including all Zone systems and beyond..)

Message 2: Grab that favorite manual camera sitting on the shelf, load it with TMY (thats T-Max 400), leave your meter at home, and 'reprogram' yourself for shooting at IE 100. Thats right 100. If you haven't memorized the little exposure chart, then bring it along, but remember to bring the EI100 chart!
From the story you should see now that you have SIX stops of exposure latitude! So by aiming your exposure near the MIDDLE of the HD curve you get a 3 stop buffer for guessing on each side! Its all based on the same proven densitometric and sensitometric principles that form the foundation for the various Zone systems!

If it's an auto exposure camera, or has a built in 'averaging' meter, fine, you can use it. Just set it to EI 100! You have 3 stops of 'fudge factor' on either side of the meter reeding. That should absorb many or all of errors from 'average' metering.

Happy shooting!

Film development next....(Einstein????:confused

David H. Bebbington · Mar 5, 2008

ic-racer said:
Is there any practical value to any of this, or is it just a mind numbing web of irrelevant information?

As far as I am concerned, in the (I hope imagined) example you quote, if a photo instructor introduces his class to a needlessly complicated system based on pseudo-scientific mumbo-jumbo, he ought at least to do in a way the students understand. If he can't do this, he shouldn't mention it at all. And if he can't explain things properly, and nonetheless tries, and totally confuses the students, he should be taken out and shot.

Second point: B+w negative film has some intrinsic exposure latitude which will compensate to a certain degree for incompetent technique. T-grain films lke T-max have far less latitude than conventional films, downrating T-Max 400 to EI 100 for normal subjects and development is not a good idea.

Third point: Speed numbers on film boxes and manufacturers' development recommendations are there for a reason - they work quite well (not perfectly) and provide excellent gudiance for those who don't know what they are doing and a good starting point for those that do. Downrating films by 2/3 stop and cutting the recommended development time by about 7% will work for normal exposure situations for almost everyone - why not take this as a basis, forget the [non-]scientific experiments and go out and take some pictures? Or take a break from the heady thrills of amateur densitometry by doing something really exciting, like collecting toothpicks?

Regards,

David

Ray Heath · Mar 5, 2008

an excellent response David, i could not agree more with all 3 points

Anscojohn · Mar 5, 2008

gainer said:
I'm confused about how that old adage got to be associated with the Zone system, which didn't come until later. I knew the rules of the ASA system,
*****
I'm with you, Gainer. When I started, my favorite 35mm was Tri-X and it was an ASA 200 film-----and it has always been an EI 200 film for me. Of course, I use D23, so I really did not have to worry about overdeveloping the high contrast scenes. I called rolls like that "staccato rolls"--some high contrast shots, some lower. D23 is a very forgiving developer for those of us who would rather shoot pictures than spend our alloted time on this orb testing, and testing, and testing.

John, Mount Vernon, Virginia USA

Chuck_P · Mar 5, 2008

ic-racer said:
From the story you should see now that you have SIX stops of exposure latitude!

Latitude in exposure is relative to the subject brightness range; it is not a fail-safe mechanism for all exposure situations. This presumably is the approach that Sam would take. But since Sam had his head up his a##, this fact escapes him.

Bob, knows that flat, low contrast subjects use very little of the exposure scale; therefore, there is some "latitude" in the available exposures for recording the necessary detail when contrast in the scene is at a minimum. And he exploits this latitude to his advantage, I'm sure. I would bet your keyboard too that Bob, being the Zonie that he is, knows that as the subject brightness range increases within the scene (say, he's in a forest scene with lots of sun and shade scattered about), more and more of the exosure scale is being used, and less and less of the latitude is available. This is a "red flag" situation to Bob, while Sam, who went along with Bob to the forest, is doing, well, whatever Sam does.

Bob exposes for the shadows, providing for enough exposure to reveal detail where he wants it in the deep shade and then uses development to control his important highlight value, which "fell" on Zone X crying outloud! "Shit! My latitude is gone", Bob says to himself. No worry for Bob though because he's going to develop at N-2, so that the Zone X brightness value develops only to a Zone VIII negative density value so detail will be revealed in the print at a Zone VIII tonal value.

Sam shoots for the middle and hopes for the best because he erroneously believes there are automatically six stops of film latitude to cover every conceivable exposure situation. Sam's clueless and he just doesn't know it. Sort of like the deer that is hit with a 30-06 high powered rifle and takes off running into the forest, he's dead, but he just doesn't know it yet.

Bob passes and Sam flunks. Bob gets invited to Fred's for dinner.

JMO
Chuck

fhovie · Mar 5, 2008

I read that "Moonrise over Hernandez" was an exposure based on pure guesswork and that Ansel struggled to get a good print. An intuitive understanding of film, developer and exposure is foundational - then - try some Kentucky Windage and go create an image and not an exposure.

Chuck_P · Mar 6, 2008

I'm sorry. I was just having some fun with Bob and Sam. Sorry for the windage.

Snapshot · Mar 6, 2008

ic-racer said:
Do you mean RAY Mortenson? I love his work! I know nothing of the man or his technique (other than what is in the pages of "Meadolands"). He has a tonal scale to die for, that is for shue.

No, I'm referring to William Mortenson. He was a contemporary of the F/64 group, who really didn't like him very much.

Paul Verizzo · Mar 6, 2008

Divided Development to the rescue!

nworth said:
The really important thing is that you have to give enough exposure to the darkest thing of interest in the scene to make it register on the film (expose for the shadows). Development affects the shadows more or less the same regardless of extent (OK - extreme underdevelopment will underdevelop them too, but the shadows are more or less unaffected by the degree of development). The highlights are affected by development, however, and overdevelopment caused them to block up badly on older films. That's where the "develop for the highlights" came from. The situation is not so bad with modern films, but sticking to the adage still makes your printing easier. The zone system uses development to control contrast, which is a related but quite different thing. Since you can't avoid the "expose for the shadows" part and the zone system uses adjustments in development, confusion was bound to happen.

Ho hum.

Paul Verizzo · Mar 6, 2008

Yup.

Snapshot said:
Didn't Mortensen’s 7-Derivative technique use the principle of expose for the highlights and develop for the shadows? Mortensen certainly made some nice photographs.

I was thinking the same thing as I slogged through this brain damaging thread. (However, I'm immune, brain already damaged.)

Bruce Thornton tells about his discovery of Mortensen's portrait method in Edge of Darkness. (If you don't own this book, do so. I just got mine a month ago and found it deeply spiritual, to say nothing of tech.) Thornton has a portrait of his wife in there done with Mortensen's one light system and expose for VIII (IIRC).

Snapshot · Mar 6, 2008

Paul Verizzo said:
I was thinking the same thing as I slogged through this brain damaging thread. (However, I'm immune, brain already damaged.)

I was experiencing a bit of "brain freeze" reading this thread as well. However, it certainly was an interesting exercise.

ic-racer · Mar 6, 2008

Sam's Development Testing

So what about the statement "Sam Developed for the Shadows?" That has to be false because we all know that physical properties of the film and developer dictate that development has more of an effect on the right hand side of the common HD curve (as is commonly plotted). Sam can't change these physical properties but what CAN change it the FRAME of REFERENCE used to interpret the data on the HD curve.

So from our conventional 'frame of reference' (and Bill's also) we are standing on the X-axis and see the shoulder of the HD curve move up and down as development time changes.

If we employ Einstein's principle of relative motion, and place Sam on the shoulder of the HD curve, we can imagine Sam's frame of reference. From Sam's frame of reference he is stationary, and as he alters development time, he sees Bill and us, down by toe of the curve, moving up and down. So, as Sam decreases development time, he sees the toe of the curve getting higher and the X-axis coming up toward him.

So, when Sam checked his film development and lowered his development time, he moved the shoulder of the curve down just like everyone else. But from his frame of reference, it seemed as if the shoulder of the curve was stationary and the toe was coming up toward him and getting denser. So, in Sam's frame of reference in this 'black box' testing, it seemed as if the Zone I frame became more dense with decreased development. It seemed as if he actually was "Developing for the Shadows!" But if we put his Zone I frame under the densitometer, we would see that was not the case. He was just exposing his test print for less time, because his fogged film base was less dense from the decreased development. Thus, requiring a shorter exposure to reach maximum white. A picture graph of this is probably worth a thousand words. (I'll make one if interested)

So, if we go back to the original question regarding if the statement "You Have To Expose For the Shadows and Develop for the Highlights" I would have to agree with the poster that indicated that you do not "HAVE" to do anything.

To further explain, the physical properties of light and chemical reactions are fixed, but I think of the RULES of photography as guides or short-cuts so those with less experience or knowledge can have a path toward a good photographic print or a path toward control of the photographic process. The common RULES are probably a mixture of a) ideas handed down in 'apprentice' type settings, b) ideas from formal schooling or lessons, b) books and now c) the internet. (and J Brunner videos )

So, this leads to my conclusion that part of what constitutes "contemporary analog photography" should include devotion of a portion (even a very small portion) of energy toward passing on the art of photography to the next generation. If you think that the statement "Expose for the Shadows and Develop for the Highlights" will guide folks toward a good print, or toward good control of the process then use it, it's not a myth. If you can explain things better then do so. Either way, pass on what you know!

Anyway, the story was supposed to be funny. It was supposed to be challenging to follow, otherwise, who'd stay around to hear the explanation

ic-racer · Mar 6, 2008

Next week...

Don't miss next weeks "Mythbuster"

Myth or Fact: "Film can be developed in the Cuyahoga river" (Cleveland, OHIO, USA)

JBrunner · Mar 6, 2008

Paul Verizzo said:
Ho hum.

I'm a little baffled by this epic contribution.

ic-racer · Mar 6, 2008

JBrunner said:
I'm a little baffled by this epic contribution.

Come on, where is your sense of humor? I thought you'd see it as Sam making the 'zonies' look foolish by beating them at their own game

And be nice too, otherwise I might start contact printing again....

Chuck_P · Mar 6, 2008

David H. Bebbington said:
Second point: B+w negative film has some intrinsic exposure latitude which will compensate to a certain degree for incompetent technique. T-grain films lke T-max have far less latitude than conventional films, downrating T-Max 400 to EI 100 for normal subjects and development is not a good idea.

David,

I agree, not a good idea is right and just downright bad advice, IMO, to anyone reading who is new to b&w film exposure and development. I should have stated it so simply in my other post, but I had to give Sam a little ribbing, while praising Bob .

Stoo Batchelor · Mar 6, 2008

Bruce Thornton tells about his discovery of Mortensen's portrait method in Edge of Darkness. (If you don't own this book, do so. I just got mine a month ago and found it deeply spiritual, to say nothing of tech.)

Sorry for being pedantic, but before people rush out looking for a book by 'Bruce Thornton' I think you will find that his name was Barry.

Best

Stoo

DannL · Mar 6, 2008

It interesting how long the old adage has been around. Having taken different forms over the decades.

expose for the shadows and the high-lights will take care of themselves (< 1876)

expose for the shadows, not for the lights (< 1857)

expose for the shadows and develop for the high lights (< 1912)

http://books.google.com/books?as_brr=1&q="expose+for+the+shadows"&btnG=Search+Books

. . . going at least as far back as 1857 if not farther.

Mythbuster "You have to expose for the shadows and develop for the highlights"

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