stephen_benskin

Why not do a little test of our own. I'm interested in how Pryo works, but not enough to spend the money and time testing; however, I do have the tools for testing. These include a sensitometer, a densitometer, and a number of personally written plotting programs. If someone wants to do a test, we can work something out. I could expose the film. They could process it. I could then read and plot it, and then we could go from there. Come on gang, my uncle has a barn and there's some old cloths in the attic. Let's put on a show!

I know A&I. I know the guy who processes the film and they used a sensitometric approach in determining their processing. The guy who is running the department used to work under me many years ago at Photo Impact. A&I gets high marks in my book.

 

Kelly is just being nostalgic in my opinion. As many labs were crap then as there are now. Maybe there's something else to consider regarding your problem Jack. The default blame by photographers always goes to the lab. I've work in labs, and I can tell you, the blame usually rests with the photographer.

I just read the Howard Bond article and boy was I disappointed. Bond seems to be doing something for every issue lately. Maybe he is running out of steam. The article appears to be more of a pitch for unsharp masking than anything else. He did only one test, and the results weren't even compatible. There was so little information, they had to stretch out the apparent length by placing three large reproductions on two of the pages with text and dedicating an entire page to yet another reproduction of the same image.

 

I'm not surprised at his findings, just at the quality of the article.

I think the irony is in the absurdity that we call human nature. Who do we laugh at if not ourselves?

 

Here�s another observational question. Why isn�t there any indication that people freaked out back in 1960 when they changed the speed of films? Think about what would happen today if they did such a thing. Could it be that people were used to having various EIs anyway? It was still common place to have an EI for daylight and an EI for indoors.

<i>18% is from the printing world more or less</i>

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Then why do they sell 18% gray cards in photo stores?

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D., Isn't 1.5/2 = .74 and an antilog of .74 is 18%? That would make 12% 1.86/2 = .93. The antilog of .93 is 12%.

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<i>like I said the scales are not linear</i>

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Are we talking about Flechner's Law here?

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I'm reading a lot of hearsay about what "someone said", or "I've heard." Is this an indication that many concepts of middle gray are photographic myths?

So Carl, you are saying that middle gray is perceptual. Do you think you will get identical results with your test if the background is black, or white, or gray?

I haven't gotten around to testing the water bath method, but just to be the devil's advocate there is a passage to consider in L.P. Clerc's book <i><u>Photographic Theory and Practive vol. 4</i></u>, originally published in 1930 and completely revised in its 1970 reprinting.

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<i>The negative is transferred to a dish of water that is vigorously rocked to dilute uniformly the developer carried over. The negative continues to develop, by virtue of the developer contained in the emulsion, except in the highlights where the developer is almost instantaneously exhausted. However, it would seem that this method is not always as effective as it is sometimes made out to be. The sensitometric experiments of J. I. Crabtree and H. A. Miller (1939) have indicated that, in a case where the process has been claimed to be efficient, the transferring of the half-developed negative into an inert solution (water, glycerine, alkaline buffer) has given a result that could be <u><b>exactly equaled</u></b> by reducing the time of development by 25 per cent.</i>

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Food for thought.

Let's not forget the important part of the question - why?

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Jon says, <i>I always thought it had to do with being halfway between black and white</i>?.

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Black and white what? Perceptual? Print? Scene? Negative? Could there be a different and seperate middle gray for the perceptual, print, scene, and negative? Why not use the shadow as a reference point if shadow detail is key to print quality?

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Frank says, <i>It's just a fixed reference point that a commitee agreed upon</i>.

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Why did they agree upon that point? Is it an arbitrary point? Isn't knowing why something is as important or more important than just what it is?

I find it very ironic that many people find a lower EI to be

preferable to the ISO setting while the pre 1960 ASA setting had a

safety factor that produced film speeds that are 1/2 of today's

speeds. People then complained the film speeds were, in the words

from an article title, dangerously safe. So, in 1960, the standards

were changed, in effect doubling existing film speeds. Now people

think they are too high and open up 1/2 to 1 stop. I guess the members

on the standard's committee can't win for losing. Is it a wacky EI

world or what?

<i>(Moderator's note: I just spent at least two hours rereading and editing this thread in an attempt to salvage the useful portions from the petty bickering. If a particularly cogent and pertinent reply of yours was lost in the editing process, I apologize. However if I snipped off baiting, sniping or retorts to perceived slights committed by others... tough luck. Deal with it.<p>

 

Frankly, I'm shocked nearly speechless that some of you would react so furiously against a simple rhetorical device. And Stephens seems perfectly clear to me, despite the fact that I've gone 5 days with a severe bout with the flu and can't even remember what day it is. If you're not interested in such mental exercises as these threads provide then don't participate.<p>

 

Either discuss the topic in a reasonable manner or I'll delete your posts. Keep it up and you'll be temporarily suspended from the forum.</i>

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=====================<p>

<p>

I�m working on an article about middle gray, and I was hoping to get a

general consensus on a concept. The question of 12% and 18% aside (I

don�t want to get into that), where do you think the idea of middle

gray comes from. In other words, what makes middle gray middle gray?

Why use middle gray as a reference, metering point, or printing

target and not the shadow or highlight? I have my own theory so this

is just a survey, and would appreciate any thoughts.<p>

Niall, I think you just need to sit down and do some reading. You seem to be confused by the differences of exposure, film speed, and film contrast. Postings on these forums come at you from all directions. Reading a well organized book will give you a solid foundation.

 

I find it very interesting how many people find a lower EI to be preferable to the ISO setting. The pre 1960 ASA setting had a safety factor that produced film speeds that are 1/2 of today's speeds, and people complained the film speeds were, in the words from an article title, dangerously safe. So, in 1960, the standards were changed in effect doubling existing film speeds. Now people think they are too high. I guess the members of on the standard's committee can't win for losing.

Now that you have some opinions you should call Fuji's tech center and ask if there are any reported defects. Have the film handy because they will want the emulsion number. They may ask you to send in a sample if there aren't any defect reports. They will tell you definitely what the problem is. If it is the film, they will compensate you, if it is the lab, you may wish to change labs.

Pablo's example still looks dark to me, but now with a little more contrast.

Francis, look at the shadows. They aren't that far down. I can see enough detail. That says to me that they aren't all that underexposed.

Kirk, below is an example of a tone reproduction curve with an unsharp mask from <i><u>Theory of the Photographic Process</i></u>. Keep in mind it doesn't have to look like this. You can just incorporate the additional density and ignore the local influences of the mask.<div></div>

There is no limit to the number of quadrants. You can breakdown the process to isolate each and every aspect. Now that some are becoming familiar with the four quadrant, it's time to put a scare into them. This is an example of a tone reproduction curve with somewhat limited elements. An interesting aspect of this one is that it also incorporates subjective aspects into the mix.<div></div>

Sometimes it's just fun to play the devil's advocate. Never assume the statements made here in just a few words illustrate the range of knowledge of the poster. I am a USC graduate with a BS in Cinema Production, so never assume. In the area of photography, I am considered by some to be very knowledgeable in tone reproduction and exposure theory. To many, the Zone System is too technical. To me, it is not only overly simplified, but inaccurate.

 

Digital has changed the photographic world faster and in ways no one expected. I personally shoot large format B&W. The quality of the digital image has a ways to go in that area, but people who do headshots, catalog work, photojournalism, and many, many other areas have all gone digital. Samy's Camera in Southern California lost 50% of their darkroom sales when LA Times went digital. Kodak used to have a catalog of specialty films geared toward the scientific community. Most of those films are gone.

 

EG&G was the last company to produce personal sensitometers (not densitometers) until their biggest client, the military, went digital. These very important testing tools are now only available used, and EG&G quadrupled the cost of calibration because they no longer want to deal with them.

 

Yes, film in some form will be around for sometime. Yes, Kodak has made decisions that are hurting themselves. But never conclude these posts reflect the full scope of anybody's knowledge.

When interpreting an image, you should also consider the lighting and tonal conditions of the original scene. Some see picture #6 as flat. I see it as "printed" dark. The scene is front lit and made up of mostly midtones. In other words, the original scene is not too exciting from a tonal stand point. This does not mean there is anything wrong with the processing. Attempting to suggest a change in processing based on this image would be ill-advised.

I don't want to get into a fight here, but I think it's ironic that while Antonio feels Lucas' statement is stupid, there's a little film shot by someone with the last name of Lucas. You may have heard of it, Star Wars 2 and 3. There's also a new fangled thing called digital projection. No film involved here, and no statements on the quality of film vs video.

Looks like chemical splatter to me.

The monster has escaped the lab and is terrorizing the villagers.

 

For the moment, I just want to make an uncharacteristically short post. Kirk, I do have Zone System references in the program. The guide lines represent one stop increments (except for the log 2.2 step). I just don't have a cute little gray scale reference.

 

I've also been thinking about a way of doing Pyro lately. Not sure if it will go any farther than that though.

Reason 1001 why Kodak is tanking. Not only have they lost vision and direction, but business sense too. The only thing that will save them is to rid themselves of their endless parade of generic CEOs and find another George Eastman.

Defining a Normal contrast negative doesn't come so much from the desired negative density range, but from what is considered average conditions. What is the average scene's luminance range? What is the average flare factor? A Normal negative is whatever the CI is that will reproduce these conditions satisfactorily under the desired printing conditions, be it platinum or point source, be it printing-out-papers, or gum bichromate, be it grade 1 or grade 4.

Not at all crazy. If you start from a scanned negative, then you have eliminated the camera image and film curve. So the program will just be about the effect a certain paper and paper exposure have on a negative.

 

From a devil's advocate point of view, will the differences (other than grades) be noticeable to the observer? Not only are we talking about just 256 steps, but will the slight differences in curve shape show? Plus, how many people use multiple paper types? Most people only use one type of paper so mostly we are just dealing with a question about contrast. If this is the case, why not just use Photoshop to get an idea of how you want it to look?

 

Back to Kirk's point about people not having the tools to properly utilize or understand sensitometry. There's no better way to learn and understand something then to do it. Hand's on experience turns theory into practice; however, I would like to reemphasize one of my points. Much control can had by simply understanding the concepts of tone reproduction apart from using sensitometry. Learn how film speed is determined and why those conditions were chosen. How does film speed interrelate with metering? What are the average conditions of use? etc., etc., etc.....

You might want to double check what they say on the RIT Articles website.

 

A Use for that Last Cup of Coffee: Film and Paper Development

 

Dr. Scott Williams and the Technical Photographic Chemistry 1995 Class

Imaging and Photographic Technology Department

School of Photographic Arts and Sciences

Rochester Institute of Technology

 

http://www.rit.edu/~andpph/text-coffee.html