Zone System doubts

[jorge_gasteazoro4]

Stephen, although I find your statements accurate I have to disagree with you. Adams was not a scientist and his attempt to explain the zone system were geared towards photographers. Your statements about flare both in camera and meter are correct for your personal system, and are not a "universal" constant. In addition your examination does not take into account enlarger flare.

One can argue that we can make this thing as hard and involved as possible and I am always amazed at how some people make something so simple as the zone system such a complicated endeavor. I have to agree with Dan, go out, take pictures adjust the EI to get good shadows and development to get good highlights. This is basically what Adams reccommends.

If people are interested in reading an excellent treaty on this exposure and reproduction subject I would reccommend the book by Richard J Henry. Although the book is outdated the methodology and explanations are the best I have seen. But then the book is boring as heck to read.

[stephen_benskin]

Jorge,

 

I agree, Richard J Henry's book is good. There's also Jack Dunn's Exposure Manual among many others (most are also out of print). Of course we can make things simple and give only the minimal information needed to produce good photographs, but I've always been the type who wants to know why. I've just been attempting to tie the Zone System into Tone Reproduction Theory. Like I've said, the Zone System is simple sensitometry. Whenever things are simplified, information is lost.

 

I've found, however, the more I know about photography, the easier it is and the more I can control it. It's up to the individual photographer to decide how much they wish to know about their craft. The end result is ultimately all that matters.

 

"Your statements about flare both in camera and meter are correct for your personal system, and are not a "universal" constant. In addition your examination does not take into account enlarger flare."

 

Actually flare exists in all camera systems and it is a part of the determination of film speed. It's not a constant because it varies depending on the SLR, tonal distribution of the scene, and the camera optics. The one stop flare factor is derived from the average of extensive tests from scenes of statically average luminance ranges. The camera image quadrant of the tone reproduction curve illustrates the camera image with and without flare.

 

The LER or ISOR of paper does take into account the conditions of use which include enlarger flare. I believe I did mention enlarger flare in an earlier post, but my apologies if it wasn't clear. The paper curve in the tone reproduction curve is derived from an enlarged step tablet. It's possible to extend the tone reproduction curve to further breakdown each aspect, for instance, a quadrant only for the paper curve without flare and a quadrant for an enlarger flare curve. I left out a lot of information on the materials and proceedures used to help with clarity. Perhaps that was a mistake.

[jorge_gasteazoro4]

Yes Stphen, but look at how much trouble you have gone to illustrate a point that I am sure nobody will ever follow. I also went through my phase of film testing, and undoubtely it is a good learning experience, but overall this is not photography and given the uncertain nature of the material used, trying to get this exposures to the nth degree in zone placement is an exercise in futility. The differences in flare from lens to lens, spot meter, camera bellow, etc would necesitate you do a similar chart like you presented for all lenses, film, and meter or camera you use. To me that is over information and frankly a waste of time. After I did all my testing for every film under the sun, I came back to the same film and developer I original used. No matter how much testing you do, there is no substitute to experience and familiarity with the film as well as skill in printing. This zone this, or zone that and placing exactly at zone....I beleive is wishfull thinking.

It is not a matter of wanting to know how things work, it is a matter of knowing when the required knowledge is overkill, I dont need to know how the combustion engine works to know how to drive.

[brad_blair]

I think that its important to understand the concepts of the Zone System without getting caught up in the minutae.

 

I showed my teenage daughter yesterday in the darkroom and she caught on in about 2 minutes......if you print this a little darker, then you lose all detail in this portion.....tell me what you want this to look like and we'll see where the other stuff falls..

 

In typical teen fashion..("well, duh!") she could see it easily where those of us who have been doing this for years seem to miss it.

 

Brad

[stephen_benskin]

Jorge,

 

"I dont need to know how the combustion engine works to know how to drive."

 

Maybe not, but a car mechanic needs to know how a combustion engine works, and a person wanting to make photography more than just a past time should know something about thier chosen pursuit. I only shoot one film type. As an artist, I like to use what I'm comfortable with, but if I have to use a different film, nine step wedges processed at different times and I'm ready to shot the new film (pushes and pulls included) without a problem. I see that as an advantage. It's just up to the individual to decide how much they want to know. One person's minutia is anothers necessary information.

 

I've worked at high end custom photo labs and have been responsible for processing B&W film for many leading commercial photographers. Because of this, I found it necessary to own my own sensitometer as well as a densitometer. These are the tools I need to do my job. At one time, with all the different film types and formats, there was around 35 different black and white films on the market. So my need to know had to be greater than the average guy.

 

If you read my postings closely, you will see that I am saying all the variables make it virtually impossible to predict with precision the resulting negative DR in any given situation. So, any contrast testing will only offer a general idea of density placement. Adding to this is that the negative DR isn't a perfect method in defining the paper LER. One of my favorite sayings is, the more you know about photography, the more the phrase "close enough" is appropriate. This is what makes so many different systems work and why my grandmother, who takes pictures only at Christmas and birthdays, can produce acceptable photographs.

 

"there is no substitute to experience and familiarity with the film as well as skill in printing."

 

Absolutely, and adding knowledge to that just makes it even better. They doesn't have to be exclusive. I've worked hard at shooting and printing too. I've attached an image as an example.<div></div>

[jorge_gasteazoro4]

Nice shot Stephen.

 

Ok I think you are talking from a person who had to do all this testing as a matter of daily routine to do his job as opposed to those who only wish to get the necessary information on film.

To give you an example the way a printed I projected a 4x5 step wedge on my paper of choice and read the reflection densities. From then on I knew that a negative that had a certain DR could be printed in such grade paper (that being grade 2 or 3, etc). Did I need to know the paper's LER, or the flare factor? Not at all! then after doing all that testing and plotting all those curves etc, I moved to developing by inspection....N+, N- etc, are a thing of the past for me. Sure I did mess up some negs while I was learning but since I got the hang of it, it has been great. So my point is that it is not necessary to get the exact placement of Zone VII to the last 2 decimal points to get a workable negative.

A very telling example is Ramiro, who in another post was confused by the shape of the H&D curve he had drawn as a result of developing tmx. My response was there is nothing strange in this curve, tmx responds this way. How I knew this, because many years ago I did the same exercise. How was this knowledge useful? only to advice Ramiro, it did not do a damm thing for my pictures.

 

I guess in the end we are of two different minds and will have to agree to disagree, IMO all that testing is a waste of time and the end result is a book full of H&D curves. Some testing is good, but to become so enmeshed in the zone placement, DR and curve plotting just causes more confusion in a very simple process, as a chemist I can tell the KISS principle is the most valuable advice I can give anybody in this art.

[stephen_benskin]

Jorge,

 

Instead of responding to your last post point for point, I'm just going to agree to disagree. Let me leave you with two things. First of all, where should the line be drawn between useful information and worthless information and who should be the one to draw it? Second, I've attached another image.

 

BTW, I just heard Herb Ritts died Thursday. While I've never been drawn to his images, he has been a large presence in photography.<div></div>

[jorge_gasteazoro4]

Stephen, you seem to be attaching images as if to prove your point. This is really moot as I could post my images of pt/pd prints which are just as good. These prints do not make my statements any more true or false. As to who should decide, it is the person doing the testing, but there is nothing wrong in telling people not to get their hand in the fire or they will get burned. Is up to them to do it and ending up agreeing.

[stephen_benskin]

Jorge,

 

The first image was, in part, to prove a point, but the second was just for fun. I feel seeing someones work helps to get to know them better. I'd love to see something of yours.

[jorge_gasteazoro4]

Ah ok, as soon as I find out how to scan pt/pd prints that look half way descent I will upload one. In the mean time here goes one from the slot canyons. The only one I took there just to get it off my system, since I think these type of slot canyons pictures are just way over done.

[stephen_benskin]

Great image! Thanks. I know what you mean about getting a deceit scan. Plus, what looks good on my screen may not look good on yours. It's a curse to a control freak like me.

[stephen_benskin]

Ramiro,

 

I've attached a family of curves for HP5P. The film was processed in Xtol, but it should give you a general idea on the look. Yours looks very similar.<div></div>

[jorge_gasteazoro4]

<i>Plus, what looks good on my screen may not look good on yours</i><p>

Exactly, I have seen many uploaded pt/pd prints which look awful, washed out and no contrast. I imagine it makes people think, what is the big deal about this process?

[ramiro_aceves]

Hello all,

 

Thanks for you responses, all of them have helped me in understanding this issues better. I also understand both points of wiew. My poor english do not allow me enter into the discussion. The tone reproduction curve sent by Stephen have clarified me all. I have understand that flare can not be discarded. The worst thing is that flare depens on the lens and on the secene, so it can not be quantified. But we can use average numbers or what is better: I WILL NEVER NEGLECT THE LENSES FLARE! . Camera Lens manufacturers should give us some numbers to be able to compare. It is amazing to see that there are some many variables playing around that is almost impossible to predict the final tones in the print, but I think we can be quite close, and understanding how each part of the process works, I mean, from the subject to the final print, we will be able to better control the whole process.I think it is very important to have a solid understanding intead of beleiving in what others say, think or feel. I do not understand when some one says "good tonality", I prefer seeing a H&D curve. In photography there are a lot of miths and misunderstandings, that can propagate to the newcomers as me. The same occurs in other hobbies. My other hobby is amateur radio, and also there are at least three kinds of persons. The first likes only to talk trough the air without understanding anything,how radio waves propagate and how electronic circuits work. the second likes building radio equipment, antennas and so one without understanding anything. The third is the same except for he understands or try to understands how thing works . Some people also build antennas following some designs without understanding anything, and if the design does not work, do not know how to correct it. I think this analogy is aplicable to photography. I know that if I develop using manufacturer development times and press shutter release button on my camera without thinking in spped and aperture setting in auto mode, I will get decent prints. But If we want to control in the way we think, we must know how things work.

 

Well, taking this apart, I am goind to tell you some last "discoveries":

 

***

Yesterday I made some contact prints of my Stouffer 3110 step wedge into Ilford Ilfospeed RC grade2 paper, over the enlarger base. Then, I put the step wedge in the negative carrier and made some prints. I ended with the same exposure range on the paper. So, I conclude that in MY difussion enlarger Durst M601 with MY color head, the contrast is the same for MY prints that for MY contact prints.

***

 

***

Yesterday I found a film that behave different from the others. While I have always found that EI speed is lower than ISO speed , here is the exception. I developed NEW kodak TMAX400 at EI 400 and developed in Ilford ID11 1:1 for 10 minutes, and zone I is 0.2 over the film base and fog!!!. I have to retest to confirm!! This are the densities from zone 0 to X. I think that if there was not error, EI can be stimated on EI 565 (half stop higher)

 

0,05

0,2

0,325

0,48

0,625

0,775

0,925

1,14

1,33

1,48

1,65

 

I have compared and the grain was the same that TURA 100 ISO film shooted at EI50 into rodinal 1:100 20 minutes and this film is 3 stops and a half slower!!!

 

I do not know why I still use rodinal?¿?¿?¿?

 

****

 

 

***

Now a question. I always do this tests with daylight. Some times I want to make tests and it is at night. Is it possible to make a film test using the light from a slide proyector

on a white card, or the different light temperature can influenciate the tests?

***

 

 

***

Another question. Is it posible to make the film tests by contact copying the step wedge onto the film and eliminate shutter problems? If true, how to calculate the exposure time. I would do it on the base of the enlarger. It will be also useful to make slides from negatives.

***

 

For Stephen :Great pictures, I like the Castle picture, very good!!!

Is the HP5 curve made by you? Very good.

Also very good picture from Jorge.

 

Thanks to all for your help.

 

Happy 2003 and enjoy till silver halides extint!

 

( I do not want to start another digital-alalog photography discussion!!) :-) :-) :-)

 

 

 

 

[stephen_benskin]

" Now a question. I always do this tests with daylight. Some times I want to make tests and it is at night. Is it possible to make a film test using the light from a slide proyector on a white card, or the different light temperature can influenciate the tests?"

 

Sure, but the light sources at night are more than just tungsten. There is, of course, the spectral sensitivity of the film, but if you want to test the spectral sensitivity of the meter, why not set up a white card in daylight, put the meter on a tripod. Take a reading off the card, then place a filter with a known filter factor over the meter and take another reading. You will probably discover a number of things. First, most meters are overly sensitive to warmer light. A red filter with a three stop filter factor, e.g. Wratten #25, will only register as a two stop difference. In addition, most meters are sensitive to infrared. If you meter grass or leaves, the meter will read them as brighter than they really are leading to underexposure. Try this little test. Point the meter at a TV remote. Take a reading. Then take a reading while pushing a bottom on the remote. If there is a change in the meter reading, the meter's photo cell is sensitive to infrared.

 

The problem about applying all this to night photography is the incorporation of reciprocity. This makes most night work more educated guess work. But understanding the meter's spectral sensitivity is definitely handy during day shoots.

 

"Another question. Is it possible to make the film tests by contact copying the step wedge onto the film and eliminate shutter problems? If true, how to calculate the exposure time. I would do it on the base of the enlarger. It will be also useful to make slides from negatives."

 

It's very hard to determine film speed from a step tablet unless you are using a sensitometer. A sensitometer is simply a very accurate light source. My EG&G Mark VI is an intermittent type. It must occasionally be calibrated to ensure its accuracy. The problem with sensitometers is that, to my knowledge, no one currently makes one for continuous tone photography; however, since the military went digital, used ones are floating around if you look hard.

 

You can get close though, either by metering the enlarger light source or by using relative exposure. While I have some reservations with some of his ideas, Phil Davis' Beyond the Zone System outlines the enlarger approach. The advantage with curves is that you can see the film's characteristics and how the film responds to development. Using CI as a contrast determinant is, in my opinion, the best way to go. The thing about film curves is that they just sit there unless you learn how to approach them. Then they are full of information. I've learned so much after creating a number of plotting programs which enable me to play with the data. There's no way I'd ever do a tone reproduction by hand.

 

 

"Is the HP5 curve made by you?"

 

Yes, it's from one of my programs. The version posted is slightly modified though.

[jorge_gasteazoro4]

<i>Yes, it's from one of my programs. The version posted is slightly modified though.</i><p>

You mean is this a program you bought or one you made? I need to plot some reflection curves for my pt/pd printing and this program looks like a great solution.

[stephen_benskin]

Jorge,

 

It's one that I made. They tend to be very specific as well as buggy. I'm probably the worlds worst programer, but if careful, these plotting programs will work. There's one for film entry, and individual curve analysis. There's one for paper entry, and individual curve analysis, and then there's the tone reproduction curve program which is always going through modifications. Recently, I completely rewrote it and am still adding in variables (whenever I feel masochistic).

 

They are written in visual basic and can only be run on a PC. With some modifications to the program, I think I can make it work for people without sensitometers.

[jorge_gasteazoro4]

Thanks Stephen...bummer, I hate xcel.

[ken_hughes3]

stephen, your picture posts have confirmed everything that I suspected of you. get out and shoot more.

[ramiro_aceves]

Hello all and Stephen Benskin

 

I have tested today a cheap handheld exposure meter against the TV remote control. With the meter at 5 centimeters and 2 EV reading, I can measure an increase of 2.5 EV when pussing the buttons. If I put the meter closer, It can reach an increment of 4 EV.

I have also tested with a Pentax P50 and Zenith 12XP with NO increments. (perhaps the infrared emiter does not cover all the frame and the Zenith camera sensitivity is about only 1/30 sec and f2 -> 7 EV)

 

I heard about making tests with an electric kitchen. Testing the cheap meter in the dark at 10cm over the kitchen, its needle starts moving when the resistor starts showing red light. At full power it reads 6.5 EV. Pentax P50 with 50mm lens reads 1/4 sec and f2 (EV4). The zenith ZP12 it is not sensitive enough).

So the cheap meter seems to be more sensitive to red light than the pentax TTL meter.

 

 

I do not have red filters to do the tests, only a polarizing and yelow Y1 filter.

 

What do you think?

 

Thanks for your help.

[stephen_benskin]

I hadn't heard of the electric burner on the stove approach. It sounds interesting. As for the TV remote, your findings sound about right. I've done it and found a change even with my modified Zone VI Pentax spot meter. It's just one more fun element to work with and another reason why ultimate control is beyond our grasp.

 

Today I was out on a day shooting trip (happening way too infrequently lately), and haven't had time to look into modifying the plotting programs I mentioned. Hopefully, I will be able to make some head way by the end of the week and the file size won't be too large to upload.

[stephen_benskin]

Ramiro,

 

I've been looking for this file for a couple of days. It shows how to derive the value of the transmitted light through a step tablet. Then how to calculate the film speed. The file is saved as a PC Word document.

[stephen_benskin]

I'm attempting to upload the film plotting - input program. It will archive, plot, and figure CI from data derived from a 21 step tablet. I've disabled the speed calculation which was based on known exposure values from a sensitometer. The family of curves program will be able to determine relative film speeds. There is a blank data base and one with some files. I will soon attempt to upload the family of curves program so that you can interpret the curves. If anyone wants to only play with some curves, wait to upload that program. This one is only for data input. It is in a Zip file and will only work with PCs. The file size is around 4 MB.

 

Like I've said, I'm the worlds worst programmer. Let me know what problems you have. There are no help files. It will probably crash if you do anything it doesn't like. Good luck.

[stephen_benskin]

This is a Family of Curves program. It allows curve analysis. There are a number of film files to play with included in the data base. The file is Zipped and is approximately 5.5MB. Let me know what you think. Please don't expect a robust professional program. However, it works (most of the time).

[steve_bingham]

Of course all this is moot if you are photographing different subjects using roll film, 35mm or 120! The simplist explanation, and an old maxim, is expose for the shadows (you want) and develop for the highlights (you want) excluding spectral highlights. Having said that, it is interesting to note that Adams spent a lot of time dodging and burning his prints, trying to fit all those zones onto paper! Getting 8 honest zones out of paper is a real art form. Getting 8 zones from Tri X is realatively simple. There lies the problem. My advice - try to keep it simple and don't get wrapped up in the science of it all. At best, it is an inexact science.