Archive for 2012
Thursday, October 4th, 2012
I got a request a few days ago about my thoughts re small/large format and digital vs film. It seems to be an active topic so I hope the following can shed some more “light” on the subject!
Dear Mr. Ross,
… was wondering if you would be kind enough to answer a couple of questions regarding your use of large format cameras. In particular, I was wondering two things:
1. Why do you continue to use large-format cameras for your art? Do you find some benefit in them that you cannot obtain from a 35mm camera?
2. It is my belief from what I have read that you prefer film over digital photography. For example, I noticed your comment in response to the Popular Photography article, Photoshop and Photography – What is Photography? “I have never seen an inkjet print that could match the depth of image in a traditional silver-print.” Is my assumption that you primarily use film correct? Is there ever a time (from a fine art standpoint) where digital would be more beneficial in your mind?
I am sure you are frequently inundated with questions from fans and fellow photographers, so I thank you in advance for taking the time to read these questions, and hopefully responding to them.
Camera size: First, consider that you can only cram a certain amount of information in a given amount of space. At 24x36mm (1×1.5 sq. in) a 35mm camera has a negative with 1.5 square inches of area. A 4×5″ negative has 20 square inches and 8×10 has 80! So, given an equivalent film in both cameras, a 4×5 negative has over 13 times the information (detail) as a 35mm. Also, most 4×5 cameras have all sorts of adjustments allowing controls of focus and image geometry not available with “solid-body” cameras. Further, there is only one exposure on each piece of 4×5 film, so each image can be developed according to its own merits. Lastly, I personally kind of like the slower, contemplative approach often associated with working with a bigger camera.
Film vs digital: They both have their merits. I got a Canon 5D MkII several months ago and think it is a wonderful tool. Digital can certainly do things film cannot do – capture color and BW at the same time, have different ISO speeds with the twist of a dial, record a staggering number of images on a single memory card and offer instant replay immediately after exposure among other things. Downside- there is nothing permanent about a digital image. If an image has not been printed and its storage drive fails without backup, the image is gone forever. Currently, digital recording has nowhere near the tonal scale of a BW negative, and to some degree, a color negative. With Digital, many common scenes would require multiple exposures and subsequent HDR processing to record the brightness range easily captured in a single exposure on bw film. That said, there is just something I intrinsically like about working with film. I have an Epson 3880 printer and think it produces quite lovely prints – but they still don’t have the tonal depth of a silver-gelatin print. And it’s more fun to see the image emerge in the developer than watch it get spit out of a printer.
I hope this helps – I’ve only scratched the surface of the topic! Bottom line, any camera is only a tool. Each style has its own merits and drawbacks – they are just different, not better or worse! One can drive a screw with a hammer – but it may not produce the most satisfying results!
Would Ansel Adams Shoot Digital?
Sunday, September 16th, 2012
How Do Light Meters Work?
Most of us can understand that a reliable light meter, either in-camera or hand-held is pretty essential to getting good film or digital exposures – but just how they work might be a matter of some mystery or confusion!
When light meters were first made, they were pointed from camera position toward a scene, measuring a rather broad area, evaluating the average brightness of objects either emitting light or reflecting some amount of light back toward the camera. The assumption was that if you mixed all the lights and darks in an “average” scene into one brightness, that mixture would be some sort of middle gray.
It was decided that that middle gray represented a neutral color reflecting 18% of the light falling on it. Photoshop-wise – that works out to a black set at about 55% opacity.
In photography, this works out fine so long as your meter (or camera) is reading an equal mix of lights and darks, or you are metering something that is itself middle-gray in brightness.
• But what if you are photographing a white horse in the snow? The meter thinks it is looking at something gray – and thus will give you the correct exposure to make that horse and snow GRAY! The solution is to give MORE exposure to your film or image sensor so that the scene is given enough light to look like a textured white in the image.
With film, this is about 2.5 to 3 stops more light than your meter reading.
With digital, this may be only 1.5 to 2 stops more light than the meter reading.
• Conversely, if you are photographing something dark in a dark surround, the opposite approach comes into play. The meter will tell you how to expose to make that DARK scene a middle gray! You then need to give LESS exposure to force that scene to look dark.
With film: a 2 to 3 stop reduced exposure will run you from a textured dark to nearly black.
With digital: a 1.5 to 2.5 stop reduction will typically run you from a textured dark to nearly black.
(Pssst: that’s pretty much the real basics of the Zone System! Hint – that 18% “middle-gray” is Zone V…!)
A word of caution: Some, if not many, of the modern in-camera meters with computer analytics can come up with completely unpredictable exposures. First, they seem to all be calibrated towards acceptable exposures for color slides or digital – so if you are working with a bw negative film (and to some extent color neg) you are almost certain to get a good looking contact sheet with terrible shadow detail. Second, computer analytics are not the same thing as thinking! The most sophisticated metering system in existence has no idea of WHAT it is analyzing! If you want to be in control of image tonality, you need to have an understanding partnership with your metering system and equipment.
Tuesday, June 19th, 2012
Polarizing Filters – You can’t mimic these in Photoshop!
A polarizing filter is one of the few filters that is equally effective with color imaging and with black-and-white. It can:
• Minimize or eliminate reflections in glass, water or most any surface except metal.
• Darken skies in color photos as well as in black-and-white
• Cut through haze
• Increase the saturation of colors
Types: There are two basic types of polarizer, the original “linear” polarizer and the comparatively new “circular” polarizer. They essentially accomplish the same thing, but linear polarizers pose problems with most modern through-the-lens metering systems, so circular polarizers were developed to minimize or eliminate metering issues.
Filter Factor: Most filter manufacturers list polarizers as having a variable filter factor, usually 2 to 4 depending on the effect of the polarization. I personally just use a factor of 2.5 (1.3 stop correction) because any further darkening, say, of a sky is an effect I want, and do not want to override.
Use: The great thing about using a polarizer is that you can actually see the effect before taking the picture. When held up to the eye or placed on a lens and rotated in a clockwise or counter-clockwise direction, you can see gradual lightening or darkening as you rotate. You can pick just the degree of effect you want. At its lightest orientation, it is essentially just a 1.3-stop neutral density filter. If you are using aa non-through-the-lens camera (rangefinder, Holga, etc) you will need to hold the filter up to your eye and note what part of the filter is at “12 o’clock” for the effect you want, then put the filter on your lens in the same orientation.
Above, a polarizer effectively eliminating reflections in glass. Note that the reflections in the polished table are only moderately affected – that light was polarized in a different direction. Below, note how the polarizer has darkened the sky, increased saturation in the colors and reduced haze.
Using Polarizers with Wide Angle Lenses: Polarizers work by darkening light in the subject that is already polarized. If there is no polarized light, the filter has no effect other than neutral density. The light in a sky is not evenly polarized, so if you are using a wide-angle lens, you will capture part of the sky that may be highly polarized AND also include part of a sky that is less polarized. If you are using a wide-angle lens on a subject that does not include sky, you may not notice any odd effect.
In the end, no well equipped camera case should be without the versatile polarizing filter!
Monday, June 4th, 2012
Affordable Authentic Ansel Adams Prints
Thunderstorm, Yosemite Valley
One of Ansel Adams’ personal commitments was to share his energy and abilities in support of the things he believed in, most notably, photography and the environment.
In the cause of both, Ansel and his wife, Virginia, selected six photographs of Yosemite and offered them for sale through her family business, Best’s Studio, in Yosemite National Park. The year was 1958.
Ansel’s intent was to present photography as an affordable art and to showcase the environmental grandeur of Yosemite National Park. Never much of a fan of the “curios” that were the staple of most Park concessioners at the time, he also wanted to offer visitors a quality memento of their time in Yosemite.
The 8×10 prints would be made from the original negatives by an assistant under Ansel’s precise direction and be printed in sufficiently large batches to make them affordable.
This collection, entitled the Yosemite Special Edition Photographs, proved immensely popular and over the years, Ansel added more images to the set until the total was capped at 30 at the time of his passing in 1984.
Today, Best’s Studio is known as the Ansel Adams Gallery, and continues as a family-run business. Ansel’s Special Edition Photographs of Yosemite are a mainstay of the Gallery’s offerings and heritage. Each print is still made by hand directly from Ansel’s original negatives, using his approach and methodology to ensure strict adherence to his standards and aesthetic.
And while Ansel’s archives eventually became part of the permanent collection of the Center for Creative Photography at the University of Arizona at Tucson, he made special provisions for the Special Edition Photograph negatives to be held back from the archive so that the tradition of offering high-quality original art at affordable prices would continue as his personal legacy in support of the arts and the environment.
Making the Special Edition Prints: Chosen by Ansel
I became Ansel’s assistant in the middle of 1974, working with Ted Orland, who had been Ansel’s primary assistant for the previous two years.
When Ted left in early 1975, I inherited not only the responsibility of keeping all of Ansel’s photographic operations running, but also the making of the Special Edition prints. Don Worth, Gerry Sharpe, Liliane DeCock, and Ted had all served in this capacity before me, all of us working as Ansel’s eyes and hands in the darkroom. Not easy, but an immensely rewarding challenge.
Although Ansel’s hands were not in direct contact with the Special Edition printing, his vision always was. He was consulted through test and sample prints, and the challenge was to be able to anticipate and respond technically to his requests.
”Make it a little darker over here,” he would suggest, or, ”Can you make it a bit more contrasty?” he would ask. The final approval was a slap on the back along with a hearty, “Ya got it, man!”
In 1979, I left Ansel’s employ to open my own studio in San Francisco, but he liked the way I was printing his negatives and asked me to continue making the Special Edition prints. In his autobiography, Ansel said, “Alan was my photographic assistant from 1974 until 1979, and he continues to make the Special Edition Prints with sensitivity. He knows those negatives thoroughly and interprets them as closely as possible to my original fine prints of those images.”
Making the Special Edition Photographs is an assignment I continue to this day, with Ansel’s vision and standards always in mind as I work. The prints are still made directly from Ansel’s negatives and in the “traditional” way: in a wet darkroom with amber safelights, chemicals and running water. The prints are still silver-gelatin prints, meaning that the image-forming element is literally metallic silver. Precious.
And after nearly 40 years, I can honestly say that I never tire of seeing these images come up in the developing tray. It’s an honor and privilege to play a small part in continuing Ansel’s legacy.
To see the full selection of the Yosemite Special Edition Prints, please visit the Ansel Adams Gallery website.
For the technical details on the making of the Special Edition prints, click here.
Alan Ross Photography would like to acknowledge the assistance and support of the Ansel Adams Gallery staff and Freestyle Photographic Supplies.
Sunday, May 6th, 2012
A previous post discussed the basics of how and why colored filters can change the relationships of different subject colors in black-and-white photography. This writing will give some visual examples of the effects of filters in BW work.
The example above shows a still-life scene containing a wide range of neutrals and colors, rendered in color, black and white with no filter and then with four strongly colored filters. The effects are commensurate with the color-wheel in the previous post:
#12 Yellow. The lemon and banana are lightened significantly. The near-yellows – red, orange, green are lightened somewhat. The cyan bowl is darkened. Neutrals unchanged.
#25 Red. The lemon and banana are not quite as light as with the yellow filter, but the tomato, radishes and apple have become quite light. The cyan bowl is now quite dark. Neutrals unchanged.
#58 Green. It has turned its opposite and near opposites, radishes, tomato, apples near black. The lettuce is lightened somewhat. Neutrals unchanged.
#47B Blue. Wowzer! But consider – yellow is opposite blue, and red and green are adjacent to yellow. It darkened everything – except the cyan bowl, which it lightened because that color is its neighbor!
A note: Red or Green with foliage. Green plants and trees don’t always behave the way one might think! Living plants also reflect a great deal of infrared. Broad-leaf plants usually lighten with a green filter, Junipers and piney growths usually do not.
As I mentioned in the previous post, digital images are best “filtered” post-capture. The examples shown here should suggest the post-process effects.
Next time – polarizing filters! You can’t mimic these in Photoshop!
Friday, April 6th, 2012
Filters – How to Choose and Use
I think the thing I like most about working in black-and-white is the fact that it’s much more an expression of how I feel about a subject than a representation of “reality.” The world doesn’t exist in Black-and-White (my mother told me that…) so a b/w image is by its very nature an abstraction of the things we see.
The judicial use of filters can greatly enhance the impact of how a subject appears, and in black-and-white we can even skew the way colored subjects relate to each other.
I normally like to be fairly subtle about my use of filters; a photograph shouldn’t look like a filter was used, just as a print shouldn’t look like it was dodged and burned! One of the most generally popular choices, a #8 Yellow, is usually so subtle that I don’t see much point in using it. Another popular choice, the #25 Red, is often too strong, rendering skies and day-lit shadows illogically dark.
My two favorite filters, a #12 Yellow (“minus blue”), and a #23 Red, respectively, have both more strength and finesse than the ones found in most camera bags. The #12 yields an effect almost as strong as a #15 orange, but with only a 1 stop filter factor, only slightly greater than the #8. The #23 tends not to make skies quite so artificially dark as the #25.
Understanding the relationships of different colors of light to each other is key to choosing a filter. A standard color-wheel is shown below. The numbers in various color areas are Wratten filter-number designations, an industry standard utilized by many filter manufacturers. A #12 filter, for example is pure yellow, a #8 is a light yellow. The capital letters in bold are called Additive Primary colors, and the lower-case letters are Subtractive Primaries.
Red is opposite Cyan
Green is opposite Magenta
Blue is opposite Yellow
In Black-and-White photography the practical effect of a filter is to lighten its own color and darken its opposite color.
In purely scientific terms, a filter has no effect on its own color and darkens everything else, including “neutral” colors. When we apply a “filter factor” to the exposure, neutral colors remain unchanged and then the filter’s own color becomes lighter and its opposite becomes darker.
What we commonly call a “blue” sky is technically a bit more cyan, which is why a red filter will darken the sky more than a yellow filter. Orange is in between. Keep in mind that outdoor shadows are illuminated by the sky, not the white light of the sun. Any filter that darkens the sky will also darken the shadows!
Green or red filters can be quite useful in the Southwest, for example, where we might come across a brilliant green plant in front of a red sandstone wall. With no filter used, the b/w film will see the green and red as being largely the same: gray mush. A strong green filter will make the plant light and the sandstone dark, the red filter will do the opposite.
For workers using digital cameras for b/w, my tests indicate that it is better to use a computer-simulated “filter” after a RAW capture, rather than an actual filter for the capture itself. While this may only approximate the effect of using a filter with film, the effect ought to be similar – without any need for exposure compensation for the filter’s own density.
Polarizing filters are also extremely useful for both B/W and color work – but we’ll cover that in another post!
Friday, March 16th, 2012
Where do you focus, and how does the aperture affect an image?
In a certain way, the opening question should be the other way around! There is a law of physics that governs the relationship between shutter speed and aperture (f-stop). Shutter speeds are pretty easy to understand: 1/60 second is one half as much time as 1/30. F-stops are a little different: f8 is one half the light of f5.6, which is half the light of f4! The point is, for any shutter speed/f-stop combo, one-half the exposure time with twice the light equals the same total amount of light given to the film – or pixels. 1/60 @ f4 = 1/30 @ f5.6 = 1/15 @ f 8.
There is always the inescapable relationship between exposure time and aperture. If you are photographing a sports event, you will likely go with a fast shutter speed and let the aperture fall as it will. This article will “focus” on aperture as primary.
F-stop #s versus depth-of field. A lens can only truly focus on ONE plane. With a perfect lens, that plane would be equally sharp at any aperture – but everything nearer or farther would rapidly become unsharp. Increasingly smaller apertures reduce this apparent unsharpness, increasing what is called depth-of-field. The smaller the aperture (f16 is smaller than f4), the greater the apparent sharpness.
In the example above, figure A is focused approximately on the line of traffic in the foreground. The chain-link fence is way out of focus, as is the distant railing. The wide-open aperture (f 1.4) necessitated a very fast shutter speed resulting in the cars frozen in time. Figure B is with the lens stopped down 4 stops (f 5.6). The point of focus was not changed, but the fence is now a good deal sharper, as is the distant railing, but at the now much longer exposure time, the nearby car, while still sharp in focus, is blurred in time. Figure C is still focused in the same place but the lens is now stopped down 3 more stops to f 16. The fence now appears to be quite sharp as does the distant railing, but the car is now quite blurred at 1/15 second. (Note: it is a total coincidence that the images seem to show the same car!)
Most fixed-focal length lenses have an engraved scale allowing you to evaluate how much apparent sharpness (depth-of-field) you can get at various apertures. The example above shows a Hasselblad 80mm lens set at f 22. As the lens aperture is stopped-down, the depth of field increases in the proportion of 1/3 toward the lens from the plane of critical focus and 2/3 beyond the plane of focus. Figure A above shows the lens focused at about 3.3 feet, and at f 22 the depth of field runs from 3 feet away to 4 feet. Figure B shows what would happen if we did a landscape with the lens focused on infinity. The image would only be “sharp” from about 17 feet away to distant mountains. If we instead focused at 17 feet (this is called the “hyperfocal” distance) the image would now be sharp from about 9 feet to the mountains (Figure C).
There are two ways to plan how to make this work. One way is to choose your aperture first and see how much depth-of-field you get, and the other is to find out what aperture you need to work with and then see how much depth of field you need to work within. Let’s say your camera is on a tripod, and you want as much as possible near-and-far to be sharp. Take the Infinity mark on the lens and place it over the engraving for your smallest aperture. The lens is now focused automatically at the hyperfocal distance and you can read the depth of field on the focus scale of the lens. In this example (Figure C), f 22 gives you a pretty sharp image from about 9 feet to infinity. Lets say the camera is NOT on a tripod, and you can’t manage to stop down to f 22, but only to f 8. In this case, you would place the Infinity mark over the f 8 index. You would now see that the image would only be sharp from about 20 feet to infinity (see green arrows, figure C).
What if your lens doesn’t have markings? A lot of modern zoom lenses have distance scales, but no depth-of-field markings. If this is the case, you can find the hyperfocal distance by putting the nearest subject and distant subject marks on the lens an equal distance from the central focus mark. If your camera has a “depth of field preview” button, this can be a useful aid in seeing just how much is sharp – or not! But the actual depth of field for any given f-stop will just be a guess.
One bit of fun with f-stops: Selective Focus! Sometimes, you can make a stronger statement by limiting how much is in focus. Just leave the lens at its widest aperture. The figure on the left was done with a 200mm lens at f 4.5 focused exactly on the near marker, and the figure on the right was done at f 22 with the lens set at the hyperfocal distance.
One last thing I’d like to comment on in this writing: lens quality. Photo gear can be expensive, no doubt about it. Especially at an entry level, the prospect of getting an off-brand lens for a lot less than the brand that has your camera’s name on it can be awfully tempting. In these days of computer-aided engineering design a “Brand X” lens can be quite good – but there is an equally good chance that it will not measure up to the quality or durability of a top brand. One of the reasons being that the Brand X lens manufacturer can cut a lot of production cost by using much looser manufacturing tolerances than the top brands. The glass itself may well be of lesser quality. If you need to save dollars, look for quality used gear from a reputable source.
Hopefully, all of this will help you have a better understanding of the relationship between your vision, your lens, and your results!
Friday, March 9th, 2012
As I discussed in a previous blog, effective application of the Zone System (ZS) really requires the use of a reliable hand-held spot meter. There are basically two kinds of spot meters, those with analog dials for calculating exposure and those with digital displays. While both can afford effective results, the ones with analog dials make it FAR easier to evaluate exposure (and development, with film) than meters with LCD read-outs.
It is important to keep in mind that light meters (computer-evaluative meters in modern cameras are unpredictable) are designed to yield an exposure to render the metered area middle gray (Zone V). If the subject is light, you need to MAKE it light by giving more exposure than the meter suggests. This is called PLACING the subject on a higher Zone. Dark subjects are just the opposite.
In the illustration above, figures AA and CC were made automatically using the built-in meter in a Canon 5D MkII. The camera was set on Program Exposure and the meter set on Averaging. The background in figures AA and BB was a white card, and the egg in figures CC and DD was on a black card. Left to it’s own devices, the camera assumed the subjects were both gray and rendered them that way. Using Manual Exposure, I took a reading on the white card, PLACED it on Zone VII-2/3 knowing from my test (previous blog) that the card would then be rendered near-white, and the figurine would retain excellent detail. With the egg on the black card, my intent was to keep the egg from being overexposed, so I took a reading on the top of the egg and PLACED it on Zone VII-1/3, so I would be assured of recording some texture in the shell.
I have three spot meters: two Pentax Digital meters (these have analog dials) and a MeteredLight Pocket Spot. All three meters are matched to each other, so it doesn’t matter which I use.
The illustration above shows how a meter can help plan how to deal with subjects ranging from easy to extreme.
Figure A on the left shows a simple still-life with the spot reading’s EV values ranging from 10-2/3 on the brightest part of the glass, to 5 on the front face of the bowl. Just a bit under six stops range, and this fits my camera’s dynamic range almost perfectly.
Because I wanted to make sure the highlights were not burned out, I took the 10•• reading for the reflection and placed it just less than Zone VIII. Here is where I let the meter do the work for me. At a glance I can see my Exposure Index, an array of equivalent exposure settings, and how EV values fit in the scale from dark to light. This meter has a “window” that shows three stops above and below middle gray, so I can see the range from Zone II at the left and Zone VIII on the right. I turned the EV ring until the 10•• was positioned a bit below the Zone VIII extreme. All I had to do now was choose the particular exposure combo the meter rings displayed. On the top of the barrel I could see that one option would be 1/30 at f 3.2, but my lens wasn’t that fast, and I wanted more depth of field anyway, so following the exposures around the right side of the barrel, I could see that an equivalent exposure was ½” at f 13. Click!
Next I decided to work with a broader composition, so used a wider focal length to include a window scene along with the fruit. Figure B. The light had not changed, so using the same exposure as before, the tonalities of the bowl of fruit and surrounded areas recorded the same, but the window was completely blown out. The only way to deal with a scene like this is to use HDR techniques: make a number of exposures holding detail in the shadows and on up to the brightest high tones, then use a computer program to combine them. The ZS and a spot meter can take the guess work out of this, too.
Taking a reading on the front of the dark bowl, it still reads EV 5, so if I place that on Zone II I know it will have tonality. I see that an exposure to hold the shadows is still ½ at F 13. I now measured the brightest value outside the window and note that the sky measured EV 15. I want the sky to render well below near-white, so I’ll take that EV 15 and turn the EV ring so the 15 is placed just below Zone VII. I don’t want to change my f-stop, so I see that 1/80” will safely hold tonality in the sky.
So, a series of exposures ranging at least from ½” to 1/80” will hold all the tones in this extreme scene. Assembled in Photoshop CS5, the full range is held, figure C. This looks a bit dull because of the compression of such a wide range of tones, so figure D shows the combo with the mid-tones brightened up a bit.
Sadly, Pentax seems to no longer be making spot meters, though they can often be found on-line. So far as I know, the only spot meter still being made with an analog dial is the Metered Light Pocket Spot.( http://meteredlight.blogspot.com/ ) It is only 2×2-1/4” in size and has a ZS-ready dial, engraved from Zone I to Zone X. For the illustration, I put a couple of pieces of magenta tape over the scale, leaving a “window” equivalent to the scale of the Canon 5D.
I have had a lot of students with the do-everything Sekonic meter pictured above. It is a great meter, but a bit awkward to easily use the ZS. I made a simple little accessory card that makes it a lot easier to evaluate Zone placement and exposure. The example above shows a shadow exposure of 1/60 at f 5.6, and a highlight exposure of 1/60 at f 64. If I want to place the highlight on Zone VII-1/2, I put the VII-VIII on the card over the f64 mark and see that the reading under the Zone V on the card is f22-23, so that’s my exposure at 1/60”! I also see that my shadow now falls between Zone O and Zone I, so that area and subjects up to a stop or so brighter will not be recorded.
Bottom line. There are many reasons to avail yourself of the automated features in today’s sophisticated cameras. Computerized metering modes can work wonders in fast-changing lighting situations or if your subject is evenly lit and the sun is behind your shoulders. Autofocus can save the day with moving subjects, and auto-bracketing can help explore the nuance of exposure shifts. But if your camera is on a tripod or if you have a moment to reflect upon your subject, you may well find that with just a few seconds spent with spot meter and thought will give you more successful first-exposures than letting the camera make the decisions. It’s a snap!
P.S. In black-and-white, the “extreme” scene discussed above could be easily recorded with one exposure, on negative film. ;>)
Tuesday, February 21st, 2012
In a word: YES!
The Zone System (ZS) can be an integral and important part of any digital photographer’s workflow because it allows you to plan and predict an image’s tonal values rather than letting the camera make the decision.
The computerized metering systems in modern cameras are really amazing, and a lot of the time they will give you practical exposures, but in difficult or extreme lighting situations, the scale of the subject’s brightness is simply greater than the camera’s technology can handle.
The Zone System:
- Lets you be aware of whether, or how much, the scene brightness exceeds your camera’s limits
- Lets you make an intelligent decision about how to expose when the tones/contrast in a scene are “bigger” than what your camera can capture
- Helps you avoid blown-out highlights
- Lets you know how much exposure range you need for successful HDR captures
The Zone System 101
To use the Zone System effectively in the digital world, you need to understand a few of its basic principles:
The ZS was originally conceived by Ansel Adams and fellow photo instructor Fred Archer as a tool to give photographers working with black-and-white negative film (no digital back then!) the ability to plan and control the effects of exposure and development. They created a “scale” of tones from black to white and assigned each one a number, with “I” being almost pure black and “IX” or “X” being nearly white or white. Zone “V” is middle gray, and each “Zone” is one stop lighter or darker than its neighbor.
In the digital age, image contrast can be easily increased post-capture, but there is no practical means of reducing image contrast in a single capture. Pre-exposure can enhance shadow tonality, but this requires the ability to double-expose, and High Dynamic Range techniques (HDR) require three or more exposures for best results.
Sophisticated “evaluative” metering modes in modern cameras can handle many complicated shooting situations, but if the contrast of the scene exceeds the recording scale of the camera, something’s gotta give. This is where the ZS can help.
Step One: You Need a Reliable Hand-Held Spot Meter
A 1° measuring spot lets you measure important areas precisely and with ease. Using a camera’s “spot” metering mode is not always practical: the size of the spot depends on the focal length of the lens and generally requires a lot of button-pushing and pointing the camera this way and that – an exercise in frustration and wasted time.
Without a spot meter, you may know that you will lose tonality at one end of the scale or the other, but you have no way of knowing which, or by how much, at least until examining an after-the-fact histogram. By then, your scene might be gone!
Step Two: Your Spot Meter and the Zone System
By design, a spot meter will give you an exposure to make the measured area middle gray. This gray is called Zone V. If you measure snow in sun, the meter will give you the exposure to make the snow Zone V gray. If you measure a black speaker grille, it will give you the exposure to make that grille Zone V gray. If you want the snow to look white (not paper white but a very light gray) you need to PLACE it on a higher Zone. If you give one stop more than the meter says, you are placing the snow on Zone VI, two stops more than the basic meter reading places that value on Zone VII, and so on. As for the speaker grille, it is just the opposite. You would need to expose the grille two or three stops LESS than indicated in order to make it look dark. This would PLACE the grille on Zone III or II respectively. You can only PLACE one value. Everything else, then, FALLS in natural relation to the placed value.
Step Three: Know Your Limits
In order to plan a ZS approach to exposure, you need to know what tonal range your camera can and can’t handle. The composite image below shows nine images made with the Canon 5D set on MANUAL exposure. The target was a Kodak Gray Card with white and black patches that I made many years ago for testing the tonal range of slide film. I set my Pentax Digital Spot Meter to the same ISO as the camera, took a reading of the gray card and exposed according to the meter (a Zone V middle gray). I made four darker exposures one stop (Zone) apart and four lighter one stop apart.
At three stops under the Zone V exposure, I had made the gray card almost as dark as the black patch, so that told me the camera could hold some tonality for a subject on Zone II. On the bright end, the gray at two stops brighter than Zone V was still a noticeable light gray compared to the white patch, but at three stops (Zone VIII) the gray had turned as white as the white patch. That told me that my upper limit for recording highlight tonality is about Zone VII-1/2, or five and a half stops total range.
Step Four: Measure Your Subject Highlights
In general, with digital (and color transparency film), images look their best when the highlights are not blown out. If a photo opportunity is fleeting or moving, and I only have one chance for a shot, I will take a quick spot reading of an important high value, maybe a white dress or bright cloud, and give it an exposure of about 2-1/2 stops brighter than the basic meter reading (Zone V). This PLACES that dress on Zone VII-1/2. Having already done the test above, I KNOW that it will be very bright, but not “blown out”!
With digital, there is nothing evil about some subtle bracketing, so if you have the opportunity, go ahead and give some + and – exposures. With some practice and your spot meter, though, you’ll be surprised how often you get it right the first time! You might not need step five!
Step Five: Measure Your Subject Range
If you suspect the range of brightness in the scene is significantly beyond the range of your camera, AND you have the opportunity to make multiple exposures of a stationary subject, you can use HDR techniques. The ZS can be a big help here, too. Rather than making random plus-and-minus exposures to cover subject brightness (dynamic range), you can quickly measure exactly how much range you need to cover.
Let’s say I have a tree in the foreground in deep shade with some textured charring on its trunk. In the same composition I have bright sun glaring off some pale boulders.
With just two spot readings I can determine the range and how to deal with it. First I’d read the charred trunk. Based on my test above, I would know that if I gave it a Zone II exposure it would still have tonality. That determines the shadow exposure. Then I’d read the bright rocks. Let’s say they measured 8-1/2 stops brighter than the trunk. That is 3 full stops brighter than what my camera can record. So I now know that AFTER my first shadow exposure, I need to make 5 or 6 more exposures each at ½ or 2/3 faster shutter speed than the exposure before, until the last exposure is at least 3 stops darker than the first. Then it’s time to let Photoshop CS5 and/or other preferred software combine the exposures.
Bottom Line: Keep in Mind that the Zone System is Not Dogma!
Its application should be considered as something deeply personal. If you simply have a hunch that you like a certain shadow two stops darker than a basic meter reading (Zone V) rather than three, do it that way! It’s really a lot like cooking. If YOU like YOUR veggies al dente, don’t “expose” them to so much heat that they are over done! Bon appétit!
Thursday, February 9th, 2012
News Flash: Experience the Leica S2 in Yosemite!
Students attending my April Ansel Adams Gallery workshop, “Ansel Adams’ Yosemite: The Art of Seeing,” will have a rare opportunity to photograph with the Leica S2, a premier medium-format digital camera that retails for approximately $28,000 and was developed exclusively for digital photography. It’s based on a totally new image sensor that gives you 37.5 million pixels to work with, all with the size and handling of 35 mm.
Interested students will have a chance to use this state-of-the-art instrument as we visit some of Ansel Adam’s favorite spots in Yosemite and learn to connect his approach and mastery with today’s tools and technologies.
If you want to take your photography to new levels, better realize your photographic vision, learn to translate the literal to the expressive and use optics and exposure to best effect, join us!
Check out the Leica S2 here