Understanding Luminance For Color Transparencies

[scott_fleming1]

I keep getting explanations couched in the terms of the zone system

to some of my questions. I am strictly focused on color

transparency work at this time in my photographic endeavors. Given

that I cannot play with my development and printing so as to

manipulate contrast all that much .... is it not really the case

that when a zone oriented photographer speaks of putting this

midtone here or this highlight there ... all I, as a color

transparency shooter can do, is darken or lighten my transparency a

stop or so in either direction?

[glenn_kroeger]

Scott:

 

You do have some control. Film choice is the main control. Provia has more latitude than Velvia... Astia probably the widest latitude. Choice of EI and processing can also have some effect. Provia100 pushed one stop has a bit more contrast than Provia straight.

 

The most difficult (although not that bad) approach is to use multiple exposures and blend them digitally. This works wonders and provides significantly more control that split ND filters, although requires considerably more work.

[eugene_singer]

Scott, besides controlling the exposure, you can also vary the selection of the make and type of transparency film you are using. Some films exhibit more contrast. Some are not as contrasty. Some display more pleasing flesh tones. Some look better with green foilage. Kerry Thalmann wrote a very informative article on the subject for View Camera last year. He tested several color trans.films and compared the results. He included illustrations showing the differences between them. You are referring to the available Quick/Readyload color films, aren't you?

[mark_sampson]

Transparency films do not really have the built-in flexibility of b/w materials. Studio photographers regularly 'push' or occaisionally 'pull' transparency films, that is increase or decrease development to alter density and contrast. It's expensive and in your case, a bad idea. One thing that might work for you would be to use an incident meter reading- that is light falling on the subject- instead of a reflected reading (meter pointing at the subject). Use one kind of film and keep the process normal. The learning curve isn't really that steep, but you still have to climb it.

[scott_fleming1]

Thank you. That helped. I can always count on you guys.

 

I'm still a little confused on the question of translating zone shooters comments into useful data for me ... a color transparency person.

 

It's hard to ask a question when one does not fully intellectually grasp a complex subject. I can look at my transparencies and realize that I prefer them a bit darker. I'm looking at one where the water in a creek is a beautiful dark green but you can still see into the water. I notice that the bark on the large cypress trees has a lot more contrast and thus apparent texture. The depth of the photo is much greater due to it's overall more rich appearance. But it's too dark. If I printed from it I get the feeling it wouldn't work.

 

What am I trying to say? I'm not sure. All I did to get this transparency was NOT listen to my meter regarding how to open up for the highlights and thus darkened the image by one full stop. How would a zone oriented shooter describe this process?

[glenn_kroeger]

Scott:

 

The deeper colors in a slightly underexposed transparency have always appealed to most photographers. This is why the photo magazines always talked about the "pros" rating ISO 64 films at EI 80. More saturation also looks better to many. I have to admit, that if I shoot a Velvia and an Astia transparency, I usually like the "punch" of the Velvia on the light table.

 

BUT, I know in my mind that a correctly exposed, lower contrast, lower saturation chrome will scan better and ultimatly produce a better print using a digital workflow.

 

So there is a battle between heart and mind, but I try to let the mind win, and keep my eyes on the final print, not the light table.

[steve_swinehart]

The reason you may be getting answers associated with the Zone System is that the ZS is a convenient way to visually associate the film's sensitometric response to how the subject's luminance range will be rendered. It also aids in making choices on tonal rendering.

 

In any photographic situation, the luminance values of the entire scene can be assigned Zone values with each Zone of the viewed subject equaling a one f/stop difference compared to the next Zone. Zone V equals an 18% grey, Zone IV one stop darker, and Zone VI one stop lighter, etc. Only when B&W film is developed do the Zones change that relationship if under / over developed.

 

As you also understand, there is further manipulation of the Zone relationships when printing through choice of paper contrast grade, dodging, burning, etc., so that the final B&W image rendering may bear no Zonal relationship resemblance to the actual luminance values when the film was exposed

 

In shooting transparency film, in general, one must work within the boundaries set by the film's characteristic curve alone (as you also stated). Although some modification of the curves can occur through under / over development of transparency film, the main attribute of this is to compensate for an ISO speed change, and really not contrast modification.

 

How do you use the Zone system with transparency film? Is is useful? I think it is because it gives you a way to relate the film's response to the subject's luminance range, and make choices for the final image rendering.

 

For example, I know that the lowest shadow value with detail is Zone III. Female caucasian skin looks best (to me) at about Zone VI with highlights approaching Zone VII. Snow in sunlight should be Zone VII if you want detail in the snow.

 

When evaluating a subject, I will find the darkest area where I want detail, the lightest area where I want detail, and then see if it will fit the total Zone range of transparency film - which is 5 to 5-1/2 Zones (or stops) depending upon the exact film type. Once that is determined, I look at my subject of interest, assign an area as being the "key value" and see where it will fall within that range.

 

If the key value is not rendered at the Zone that I think it should be, then I have to make a choice as to giving more or less exposure, and evaluating what that will do to the rest of the image. Do I care that shadows will block up or highlights will lose detail? How far can I push the exposure? Can I squeeze in a 1/2-stop more exposure to move the rendering of the subject up to the Zone where I want it without totally losing highlight detail?

 

These, as you know, are the decisions you have to make with transparency film. Knowing and using the Zone system is not imperative for making a good photograph, but for people who use it or have used it regularly in B&W photography, it is a very convenient tool for subject luminance range anlysis, and predicting what the final image rendering will be, prior to making the exposure.

[eugene_singer]

Scott, the only thing you need to apply from the Zone system when you shoot color transparencies is the ability to identify a Zone V (18%-middle grey) area in the scene. Take your reading off of that area. Don't complicate matters by using the "H","S", and "A" buttons on your Minolta Spot Meter F. You can rate the ISO of the film differently from the manufacturers recommendation,if you want. Or, you can bracket your exposures and shoot a few extra films. Color trannies cover a smaller range of Zones than B&W films. They don't print the same way as color or B&W negatives. If you want prints, you will need to use color or B&W print film. Then, the controls of the Zone System will come into play.

Follow Jack Dykinga's method. He shoots his trannies for publication or digital scanning and printing.

[steve_swinehart]

"If you want prints, you will need to use color or B&W print film."

 

Unless, of course, you want an Ilfochrome print or a LightJet print - then you need a transparency.

[john_luke]

The best way is to shoot some different emulsions and compare. I personally do not like Velvia because it turns black too quickly in the trees if you are shooting near high noon on a sunny day. I like Provia. It seems to see into these deep areas a bit better. Consider all the above posts. Processing is very critical also. The lab can make or break the quality.

 

Also, bear in mind that the chrome is an intermediate step. Are you making light-jet prints from drum scans? Coffee table books? A good drum scanner can see into the dense areas of the film better than a CCD scanner will. Just because the chrome has a particular look and feel on the light table doesn't mean it will look like that when done.

 

It's pretty hard to move the scale up and down because the film is so touchy. I usually process 1 sheet and look at it to see if the other ones I held back need to be pushed or pulled. Pushing or pulling the processing can effect the gamma and color, so you may want to consider bracketing so all the film goes through the process at normal development

[eugene_singer]

Steve, you quoted my sentence out of context. Read the next sentence. You will realize the point I was trying to make about using the Zone system for color tranny work. It's very difficult to get Ilfochromes printed by a lab. nowadays. Many of the commercial labs. in the Dallas-Ft. Worth area no longer do wet prints of any type. Color transparencies are printed digitally most of the time.

[leonard_evens]

I was one of the people suggesting that you study the Zone System. I think that Steve Swinehart has pretty much covered it, but let me reenforce what he said. With transparencies, you don't have the controls used in b/w photography and associated with the Zone Xystem. But it is still true that any particular luminance will result in a certain density on your film. Since you have a spotmeter, you can identify the different luminances in the scene in terms of traditional zones. If you look at a scene, for example, you may see detail in a deep shadow, but checking it with your spotmeter will show you that you can't record that detail without clipping highlights you want to keep. You would know that if when you set some highlight with detail on Zone VII then the shadows are below Zone I. From what you have said previously, you are already trying to do something like that. Understanding zones simply gives you a more refined and sophisticated way to do it.

[philip_sweeney]

Scott I know I responded to a previous post using zone language. Although development controls for color are somewhat limited as others have pointed out we can still describe the scale of our transparencies and SBRs (subject brightness range) with zones (or stops, or EVs). As I described before E100S has a 3 stop scale (or Zones IV, V, VI, VII) that will be open and luminous. Scale = VII-IV= 3. Although I prefer to consider E100S a 4 stop scale. Zone VII holds highlight detail well and at VIII it is blown out (or starting to). III is getting dark.

 

With a 3 stop SBR one could underexpose by one stop very accurately with a spotmeter and hold detail throughout. I own a spotmeter and would not trust capturing a wide SBR with a wider angle averaging meter. It would fail me metering city lights etc. I consider the spotmeter just as important for color as B & W. I only use color transparencies when I do color.

 

If you were to undertake a little study of sensitometry and/or the zone system, I think you will find that using a spotmeter is actually less complex than using a wider angle averaging meter. If all the light and dark values are even about the middle your meter reading is perfect (theoretically) or is it? Let's not even go there BTZS.

 

Zones are a good language for SBRs and film scale, just as math is the language of physics!

[www.graemehird.com]

Steve's answer was spot on (pun intended...) and so eloquently put.

 

As a transparency shooter, you set your exposure based on the desired highlights (place them on zone VII) and let the shadows fall where they will. If they are too low (less than zone III) they won't record any detail. If they are important, change your film, your filtration or the lighting (or take a second exposure to suit and digitally blend).

 

With transparencies, the zone system is really only effective for the exposure portion of the equation. But it does work.

 

Cheers,

Graeme

[emrys]

I am going to throw an additional spanner into the works. I shoot 100% transparency but I would consider myself a zone system man. I don't obviously do any darkroom manipulation, but I do *think* zone system when I'm out in the field.

 

Here's a snippet of my inner dialogue when I'm sizing up an exposure. NOTE: before I get people telling me my exposures are wrong, this is not an actual example.

 

I look out onto the scene. There's a bunch of green grass, some fence posts, a wooden barn that's dark cos it's had creosote applied, some blue sky and some fluffy clouds. The sun is off to the side somewhere and everthing is lit up with nice long shadows (lucky me!)

 

The first thing I do is take a spot reading of some sunlit grass. I know from experience that green grass makes a good mid tone and so once I take a reading here I can use this as an 'anchor' around which I can 'place' (and hence evaluate) the other elements in the scene.

 

I reckon I've got another 10 minutes before the sun goes so I meter off the illuminated side of the barn and the shadow side of the barn. The illuminated side of the barn is 1.5 stops less than the grass and the shadow side is 2.5 stops less.

 

I know from experience that the illuminated side will show up just fine and that the shadow side will still show some detail (but not much). I decide that this will be ok and continue...

 

I meter off a fence post. It's 0.5 stops brighter than the grass. Looking at the fence post I see that it's made of reasonably light wood and decide that 0.5 stops above a mid tone will not look unnatural for this.

 

Lastly I deal with the sky. The blue sky area is 2 stops above the grass. The white fluffy clouds are 3.5 stops above the grass. I decide that I'm going to have to use a grad here.

 

I decide from experience that for the clouds to look natural I should place the white areas 1.5 stops above the mid tone. A 2 stop grad is required. This two stop grad will lower the blue sky value to a mid tone. I decide that the contrast difference between the clouds and the blue sky is sufficient and a polariser won't be needed.

 

I take the shot.

 

Now while I haven't explicitly mentioned Zone V or Zone VI or whatever, I've been thinking in terms of placement and how variations around a mid tone will be rendered on the final transparency. All of my judgements have been based around the latitude of the film I'm using.

 

Had the blue sky been lighter I may have used a polariser. Had the shadow area of the barn been darker I may have used pre-exposure (do a search for this if your interested). Had the grass been Autumn gold rather than green I may have placed it 0.5 stop above a mid tone. And so on.

 

I agree that in the end all you are doing is increasing or decreasing exposure, but what you are also learning along the way is how specific elements (grass, sky, light wood, dark wood etc.) relate to one another in terms of their reflectance (and hence exposure values).

 

I hope this helps (it may not cos it's still early here),

 

Mike

[robert_lawrence]

Peter Norquist used to have a useful reference called "The Zone System in Color Transparency Photography" but all the google links I tried were dead.

 

It is however worth checking out Charles Campbells site at

http://www.photonaturalist.com/chromozone/index.asp

[david_goldfarb]

It's not really true that you can't control contrast with development time using transparency film. You can, but if you're not developing it yourself, you need to do find a lab that can produce consistent results, and you need to figure out how much expansion you get with their standard pushes, or alternately (if they are willing and able to push in 1/2 or 1/3 stop increments), exactly how many stops push to ask for to get the expansion you want.

 

I don't do this so scientifically, but if I think the lighting is too flat, I'll push one or two stops and adjust speed accordingly to increase contrast with transparency film. Pulling I haven't done so much, so if I need to reduce contrast, I try other methods.

[jim_galli4]

Scott, this will be anecdotal as you've got about all the great info above that you will need. I also grew up in the world where fabulous light meters were built into the camera and you never gave the camera's choice much thought. When I graduated to MF I simply bought a twin camera platform, set the Nikon FE next to the Mamiya, and set the mamiya to whatever the Nikon was doing. Both had Velvia and it worked great. Then came the 4X5 and Minolta F and it was finally time to be weaned. Bottom line is you're going to have to set a dumpster in close proximity to the darkroom and figure on filling it up. Best thing you can do is write down what your meter told you about different areas of the scene so that later you can look at the left side of the trash can that you placed 1 stop below center and the right side which fell 1 stop above center, and see if how you predicted the picture would look is working. You'll get to the end of the learning curve much faster. I work at a gov't test range where we expose 6-12,000 feet of 35mm ektachrome in any given scenario. Imagine 13 different cameras looking 13 different angles making up a full 360 degrees, a customer that's spending 1/2 a million dollars to get data and one guy gets to calculate the exposure that ALL of the cameras will be set to. That would be me. No pressure right? Most of the time I do it without a meter. Your tax dollars at work buddy. You see I just happen to know that at this particular piece of real estate when the sun is out from 8 AM to 6 PM it's going to be EV 14.6. I do double check that usually. I may be crazy but I'm not stupid.

[w_byrn]

You can make an exposue and quickly turn over the film holder and make the identical exposure.Label them correctly and process only one.If adjustmens need to be made process the next one accordingly, pushing or pulling to get the right density.

Walt Byrnes

[w_byrn]

I would call that informed bracketing.

Walt Byrnes