Ed Schlotzhauer

An artists journey

Tag: digital photography

  • The Histogram

    The Histogram

    Please permit me to rant briefly. I get incensed by the practice of most photo instructors to “dumb down” what we do. They assume people are incapable or afraid of anything technical. So they give a very short and often unintelligible description of something we, as photographers need to know, then go on. One example of this is the lowly histogram.

    I’m sorry to have to tell you, but all art has a technical component to it. Photography is one of the most technical.

    The histogram is like taking your temperature or looking at a graph of your portfolio performance. It is data that does not mean anything in itself but it is very useful to check. In this case, the histogram is just a measure of our image. It is valuable, but it is only one of many possible measures.

    What I hope to do here is do what your dad probably did (or should have done) in this situation – tell you to get over it. You need to know this, so get on with it. 🙂

    Not high tech

    The histogram is not a complex, fancy piece of technology. It is just counting and marking.

    Let’s say for simplicity that your image is black & white and is 8 bit depth. You know that this means the image is a grid of pixels, each having a value of 0-255. Now you decide to go through each pixel one at a time and keep track of a count of each pixel value you find. You come to a pixel that has the value 87. Go to your row of 87’s and increment it by one. You know, like

    Keep on going. If the next pixel is 127, go and increment the count for that bucket.

    After you count the values of all the pixels, you will have up to 256 groups of counts. Now, draw a graph (technically a column chart) or put the data in Excel and have it graph it. If you put the numbers 0-255 on the x axis (the horizontal line) and draw a point above each number corresponding to the count you made for that number, you will have a histogram.

    That’s all it is, just a count of the number of each pixel value. The actual number in each bin does not matter. What counts is the overall shape of the curve.

    An example

    Here is a fairly balanced black & white image and its histogram.

    People would call this a “good” histogram. It shows that the tones have counts from very close to 0 to almost 255, a full range from black to white The tones are spread fairly evenly. There is a bump in the distribution of the light tones – the right side- which is natural because there are big areas of snowfields and light gray clouds.

    There is no magic. You could manually follow the pattern I described and derive this yourself. It doesn’t “mean” anything of itself. It is just a way to get some information about your image.

    Descriptive, not prescriptive

    This is where people get confused, partly because they are misled by their instructors. The histogram does not tell you if you have a good or bad image. The histogram is descriptive, not prescriptive. That is, it is just information for you. It does not grade your image or tell you you exposed it wrong.

    IN GENERAL, if your histogram shows values bunched up far at the left or far at the right, that is a warning sign. It is telling you the image may be too underexposed or over exposed. Those values at the extremes show that you may be losing data that cannot be recovered.

    Whenever you see this situation it is a warning flag, not a stop sign. It may be necessary for the effect you want.

    Expose To The Right example

    You often hear the advice to “expose to the right“. This is good advice in general. It means bias your exposure higher – more histogram to the right – as long as there is no clipping of the highlights. This is because of some of that scary technical stuff you need to know. The dark areas of an image are more subject to noise. If you have to boost the dark areas that magnifies the noise. The best results are often obtained by overexposing a little and reducing the exposure of the whole image in post processing. Digital data retains more information when you are scaling it down than when you are scaling it up.

    Expose to the right is an example of a good way to use histograms. I always have the histogram view turned on in my viewfinder. As a matter of fact, possibly the single best reason to go to mirrorless cameras is to be able to get a real-time histogram. I always check it, before and after taking a frame.

    Let me emphasize again that this is information for you to use and make your own judgment. Do not let the histogram take your pictures. Keep artistic control.

    Yours can look anyway you want

    It is not unusual for me to shoot images that have a “bad” histogram. When I do this it is deliberate and I do not have to answer to the data police (yet).

    One class of very low key images is night photography. Often these are nearly all dark with only a few points of light. This is an example:

    It is hard to see at this size, but you can tell what is important from the histogram. Most data is clustered at the dark end. There is a spike at the brightest whites. These are the stars. Your instructor would tell you it is not a good histogram, but the image is exactly what I wanted. An image is properly exposed if it comes out the way you want.

    At the other extreme, a high key image is almost all white. This fence in a snowy field is almost all bright values:

    The distribution (the arrangement of the data values) is skewed way to the right, but not overexposed. But there is a spike at the left representing the black fence posts. Very high contrast. This is the result I wanted, so it is correct.

    These 2 examples of “wrong” exposures should broaden your understanding of what is allowed. Anything that matches your intent is a properly done image.

    A great tool, but just a tool.

    I hope I have given you a better feel of what a histogram represents. It is just an overall look at the data values in the image. It is there for information to help you make the images you want. A histogram is neither good or bad. It is just information. Other people have given their own interpretation of histograms and their importance. This is a good one.

    I am very thankful for the invention of histograms and their availability in modern cameras and post processing tools. It is an indispensable tool. I use them every day. But remember it is a tool. It is not there to tell you what you can do. You are the artist. Only you can decide the result you want.

  • Behind the Curtain

    Behind the Curtain

    “Pay no attention to the man behind the curtain” is one of the classic lines from movie history. It is brilliant and captures a universal truth.

    If you don’t remember, or if you’re young enough to never have seen The Wizard of Oz, Dorothy and her friends are terrified and fascinated by the projected image of an imposing wizard with his booming voice. But her dog Toto pulls a curtain aside and reveals an old man who is controlling things through levers and buttons. He tells them to pay no attention to the man behind the curtain to try to deflect attention from what is really happening.

    Once revealed, the magic is not intimidating anymore. This is very true in most things. Even the Wizard of Oz turns out to be a nice guy.

    Magic

    The famous science fiction writer Arthur C. Clarke said “Any sufficiently advanced technology is indistinguishable from magic.” This is also very true and we are effectively surrounded by magic all the time. For most of us, the internet is magic, making a phone call is magic, even getting in our car and driving it is magic. These and many others around us everyday are marvelously advanced technology products that few people really understand. We use them but don’t understand how they work.

    But everyone who uses a tool or product forms a mental model to help us understand how it works. Some of the models we make are wild hallucinations with no basis in fact. These incorrect models quickly break down when we venture into new or advanced territory. They no longer allow us to predict behavior, which is the purpose of the model.

    The way to counter this is to learn more accurate models of what is really happening. Learning the reality in effect lifts the curtain and lets us see how the thing really works.

    Maybe it is not as romantic and fanciful to learn the reality, but it lets us become more expert in the thing we are using. The magic becomes just technology that now serves us well.

    Photoshop

    I want to use Photoshop as today’s example of magic. I’m afraid that to many artists Photoshop appears to be magic. This is an invitation to get over that by starting to peak behind some of the curtains.

    I will not downplay it or dumb it down. That would not be treating you like an adult. Photoshop is very complicated. At first it seems like looking in the cockpit of a jet aircraft. I have been at it since about Photoshop 4 (it’s on version 21 now) and I have been fortunate to have the benefit of live and video instruction from some master teachers such as Ben Willmore, Dave Cross, and John Paul Caponigro. But every week I study it more and learn new abilities and ways of combining things.

    But there is a good side to all this complexity, too. All that capability to learn means all that capability that can be used creatively for your art. I rate Photoshop as one of the finest software products ever created, and I have used a lot and I developed software for many years.

    It is almost true that Photoshop is not magic. Content Aware Fill and Content Aware Move and a few other features may actually be magic. But for the most part it is just a collection of relatively simple tools that can be combined together to create artistic results.

    Demystify

    Demystifying is what happened with the curtain. It will happen for you with Photoshop if you burrow into it and get past the fear factor. You will eventually have a moment when the mists lift and you understand how people create with tools like this and how you can use the tools to realize your own vision. This is a moment of enlightenment. There is no right or wrong way.

    If you just try to memorize all the tools and settings and features you will go crazy. There are an unimaginable number of combinations. It is important to first learn the principles of how to work in it. I’m just going to discuss the Photoshop features that are most important to photographers.

    Basics

    I can’t teach you to be a Photoshop expert here, but maybe I can help point out some important concepts. There are basically 2 things you can do: transform pixels or blend and combine them.

    Layers

    One of the most important capabilities you will use is layers. Get very comfortable with them. A layer is just what it says. Think of it as a perfectly clear sheet of plastic. You create stacks of layers and each one can contain pixels or mathematical operations on pixels. A layer can be an image from your camera or things you have drawn or painted or many other things, including all or parts of other images. You can add or delete or rearrange layers at will. The image you see in the main window is the view looking down through all the layers. You can never see layers. You just see the pixels on the layers.

    Pixels on a layer can just hide ones below or they can be combined with pixels below using what are called blend modes. Blend modes can cause the pixels of a layer to lighten or darken or influence just the color or luminosity or contrast of pixels below.

    In addition, a layer can have a mask. The mask can block parts of the layer from view. A phrase you will hear often is “black conceals; white reveals”. The black areas of a mask prevent the pixels of this layer from being seen in the stack. This lets us be very precise in making changes to select parts.

    Tools

    Operating across all the layers and masks you have a large set of tools. These are like paint brushes or erasers or means to select certain areas to operate on. The tools let you manipulate the layers and masks to work some of the magic.

    While layers hold pixels, tools allow us to do things to the pixels. Pixels on any layer can be added or removed or colored or sharpened or blurred or moved around to almost any level. Same with masks, which are also just pixels but just function differently.

    Principles

    Focus on these concepts. They are some of the powerful principles that make Photoshop such a marvelous tool for manipulating pixels. When you get comfortable with these basic things you will be surprised how much you can do in Photoshop and how simple it starts to seem.

    So the reality is that Photoshop is “just” a large collection of fairly simple tools. The beauty of this is that these tools can be used and combined in near infinite ways to modify or create digital art. Each user has complete ability to express his vision without being constrained by the tools to look all the same.

    There is no lack of training available in books or on the internet. Look around and find some that work for you. I recommend Ben Willmore and Dave Cross as excellent instructors to start with. They can present powerful concepts simply and make all this wondrous capability accessible to you. Buying some courses on CreativeLive is one way to get their training.

    Living without magic

    The adult world has less magic than you had when you were a kid. A side effect of growing up is there is less magic in your world. In a sense this is good. The tools we use to create our art should be just tools. No matter how powerful they are, they are just things to be wielded in our creative process.

    Save the magic for your creative vision and spirit of adventure. Keep a sense of wonder as you go through the world. You are surrounded my magic. Don’t make it less important by viewing your tools as part of the magic.

    What you see and perceive and create is the magic.

  • Far Enough

    Far Enough

    “You don’t know you’ve gone far enough until you’ve gone too far.” – John Paul Caponigro

    This very insightful quote by Mr. Caponigro has become important to me. But before getting too far into it, I need to deal with a basic assumption it is based on. It assumes that you will be processing your images heavily. Not everyone believes or practices this. I didn’t either for a long time

    Do I need to process images?

    Yes is the basic answer. The bits that come out of the sensor that you load into Lightroom or whatever you use to process your images are not just RAW, they are “raw”. It is a faithful data capture but it is not what you remembered or want to see.

    Any image needs basic sharpening, contrast adjustment, color correction, and usually tone mapping. In addition there are esthetic changes like removing distractions, cropping, vignetting, etc. All this is usually necessary just to create a “straight” version of the image that faithfully matches the scene you saw.

    Once you have bought in to the need for processing, now the question becomes “how much?”

    What is the picture?

    Every artist must be able to answer for themselves what their goal is for an image. Is it a faithful rendering of the scene as they remembered it? Or is it to create an interesting piece of art?

    The answer has a lot to do with the type and amount of processing they will allow themselves. The answer is a personal and artistic decision. There is no right or wrong.

    For me personally, the further I go as an artist, not just a photographer, the more tolerant I become of serious modifications.

    On the other hand, in an article in the September 2019 issue of Photoshop User Magazine, Ramtin Kazemi states “I will never change the permanent subject matter of a scene”. His self imposed limit is that he will not move a tree or remove a boulder, although he may make dramatic changes in lighting and color. He will also change “impermanent” things like clouds. This is his decision as an artist. I will not criticize his choice. That does not mean it binds any boundaries on my artistic vision.

    How far is enough?

    When you give yourself permission to dramatically alter the basic image it opens up significant artistic opportunities. The digital tools we have today are marvelous. Artists today can do far more post processing than ever before; vastly more than chemical darkroom users ever could.

    We have such an embarrassment of riches that it can be a challenge to know when to stop. This is part of what Mr. Caponigro was talking about. How do you know you have taken your artistic vision to its limit?

    You do it by taking it beyond your limit and them backing off. I believe you will only know what your personal limit is in any dimension by going to the point where you say “too much”. Now you have found a limit for this image for where you are right now. In other words, the limits are moving targets and you need to keep pushing to find where they are today.

    And that is just talking about post processing. The same applies to how we approach all of our art. Push the boundaries. Keep trying new things.

    Use the tools

    The marvelous tools we have usually allow non-destructive editing. Most of the tools have a workflow that can be adopted to allow us to remove or modify changes and make different decisions in the future.

    For instance, Smart Objects in Photoshop allow most adjustments to be edited at a later time. Using new layers and adjustment layers prevents making permanent changes in the basic image information. Lightroom is inherently non-destructive for al its adjustments.

    So assume you do your basic image correction in Lightroom. Push all the adjustment to the point where you say “I don’t think so”, then back them off to the point that seems best. This works for all the controls in Lightroom. You can come back to an image months later and visualize it differently. You can re-process it with no loss of fidelity. I do this often.

    I occasionally see artists doing tutorials who still do destructive editing. That is, they do things like making a couple of adjustments in Photoshop and then merging them down. This commits them as a permanent, uneditable part of the image. Their work is beautiful. They must have such confidence in their artistic vision that they know they will never change their mind.

    I admire them, but that doesn’t work for me. I am forever learning and seeing differently. I like doing “what if” exercises, where I take an old image and try new things with it. I am sometimes amazed at what I discover.

    Is there a “too far”?

    If there a “too far” point, it can only be decided by each individual artist. I know I lean towards a lot more processing of my images now than I did a few years ago. I also realize it is a moving target for me.

    On any individual adjustment I can usually find a “too far” point. But in the larger sense, I do not believe there is a fixed point beyond which we should not go. There is no edge of the earth point where we fall off into chaos. The limit for any image is determined by my current artistic vision and my intent for the image. It is fair game to use any and all of the tools available to create the art I visualize. Ultimately, the far enough point is a personal judgment.

    Your mileage may vary.

  • Is Digital Imaging Going to Stick Around?

    Is Digital Imaging Going to Stick Around?

    Got ‘ya. 🙂 Sorry to disappoint, but this is not a rant against digital imaging or a plea for a return to the “good old days” of film. Digital imaging is a technology. As such it should be a neutral consideration. It doesn’t matter if our art if it is created “digitally” or by some other means.

    It’s just a technology

    Art, by its nature, is created with a medium using specific technology. Digital imaging is the currently popular medium and technology used by most photographers. If I were writing this 30 years ago, the medium would be film and no one would give it a second thought.

    That is one reason I think it strange that people feel the need to qualify it most of the time. It is said to be digital photography using a digital camera and modified using digital post processing. To me that is putting undue emphasis on the technology.

    Pushing the limits

    Any medium or any technology has limits. Artists are inspired by pushing the limits of the medium. Whether it is painting or music or photography, a great craftsman knows the capabilities of the medium he is using. It becomes a game, a quest, to push the limits of the technology to create new art.

    But photography is fairly unique in that the technology is advancing rapidly. I don’t think people are inventing new cellos ( well, there are the electronic ones…). The quality and capability of oil paints is probably improving slowly, but not being revolutionized. Digital photography is a much less mature technology and it is based on the electronic and integrated circuit industry, which is huge and rapidly moving. Consequently we tend to think of getting a new shiny gadget that pushes out the boundaries rather than learning the limits and using them as part of our art. That is a problem for photographers.

    I love the quality of my equipment and the things I can express with it. But there is a tendency for most people to focus too much on the technology. The resolution, the dynamic range, the focusing, the low noise are easy to see as the important thing. I am glad these things are improving all the time. Too often, though, we get caught up in looking at what the technology can accomplish rather than focusing on what the artist is doing with it.

    Art is made by an artist, not a camera

    It is easy to get blinded by the brilliance of the technology and loose sight of the fact that ultimately, we should be talking about the art. Art is made by an artist, not a camera. An artist can make exciting art with a cell phone or a disposable film camera. Resolution and dynamic range do not make art.

    I am delighted to admit that my main camera is a mirrorless 46MPix wonder. The image quality is remarkable. I will confess that in one part of my work I like super detailed, crunchy sharp images. But I also, more and more, find myself making extreme abstracts that are unrecognizable from the original capture. The technology enables this, because the images have such depth and fidelity to begin with that they can survive serious processing. Pushing the limits. The technology lets me do these things. It does not do any of them for me.

    I love the technology and I make use of it, but it is not digital art, it is just art.

    It’s not perfect

    Saying that digital is just a technology also admits that is is not perfect. It is so good that it has displaced film, but it is not ultimate truth. Someday it too will be displaced by something else.

    A digital image is simply an array of pixels. That means there are artifacts that become obvious at extreme magnification. The sensors are getting better all the time, but that is a built-in limitation of the technology.

    A digital sensor can only capture about 14 bits of dynamic range (+/- 2). This is 16,384 brightness steps for each color. It is amazing how good this looks, but it is far short of the capability of the human eye. And the sensor is linear while the eye response is logarithmic. Again, the eye had a significant advantage.

    Technically, current digital imaging products are the best photographic devices that have ever been made. Technically. That does not mean they produce better art.

    Ephemeral

    Another important consideration for digital imaging is that it is and has promoted an ephemeral view of images. Digital images have fed the huge social media, entertainment industry, online viewing trend. People have become used to glancing at images for about 1 second or less and moving on. This has tended to devalue most images. Especially if they are on a screen.

    I don’t believe this short attention span culture is healthy for the viewers or artists.

    But there is a still more insidious problem with digital images: they have no physical presence. Did you at some time end up with a shoe box of family pictures that brought important memories back? Did you discover and enjoy a drawer full of negatives and old prints at your parents? Those do not exist any more.

    Digital images only exist on your computer or in “the cloud”. E.g. once the computer dies or you stop paying for the cloud, they are gone. Totally. No record of their existence. A career of art, a lifetime of family memories can disappear in an instant.

    This is a dark side of digital imaging.

    Prints are even more important

    Because digital images are so ephemeral, I believe it is even more important now to make prints of important images. Prints have substance, weight, physical presence. They seem much more real than an image on the screen. And they are.

    A print is “permanent” – well, maybe 100 years for a good quality pigment print on professional paper. When you handle it it has weight and the image seems important. It is something that can be displayed proudly on your wall to view often and for others to see. It can be handed down to others later. A print is a real material thing, not just a bunch of bits.

    Some photographers say an image isn’t finished until it is printed. More and more I’m coming to agree with that view.

    Will it stick?

    So, will digital imaging stick around? Sure. It already has. It is really hard to find film any more. Even harder to get it processed. Digital has become so clearly superior to the alternatives that it has displaced them all. That is not to say it does not have faults. Everything does.

    But digital is just a technology. It will dominate until something better comes along. A technology does not make art. What an artist does with the medium is art. A super high tech digital camera is not a requirement to make art.

    I would much rather be remembered as an artist than as someone who was very proficient with digital technology.

  • Ansel Wasn’t an Oracle

    Ansel Wasn’t an Oracle

    Ansel Adams famously said that the negative is the score and the print the performance. Ansel was one of the great lights of 20th Century photography and his writings are generally very good. In this case, though, I think this famous quote has become a little outdated by technology changes.

    I love this quote and have been guided by it for a long time. As I began to understand it more deeply, it was empowering. For a long time my work was basically a documentary or reportage style. It was very literal photography of scenes in the natural world. I even for a time subscribed to the false doctrine that if an image was altered in any way it was no longer pure and virtuous.

    Ansel’s quote helped me understand that that had never been true and was not a worthy or even useful goal. At least for me. I truly believe that the negative (raw file now) is only a start. It usually must be perfected by the artist to become art rather than just a record of something.

    The darkroom process

    Let me talk a little about the darkroom process, as I understand it. This is so I can contrast it to the current workflow. I will confess that, although I built a darkroom in my basement, I only ever used it for a few black and white images. About that time I discovered a new program called “Photoshop”. 🙂

    The image captured on film is generally considered “read only”. It is never modified. There are exceptions to every rule, but this is by far the typical case.

    The extensive set of transformations and modifications that can be applied to the negative in the course of printing are done in “real time”. That is, it is a dance involving adding or holding back light from certain areas during the time the paper is exposed to light. It can also involve variations of development time or chemicals and even manual operations like bleaching or spotting of the print.

    Given this workflow, it is completely appropriate for Ansel to describe it as a score that will be performed by an artist. The outcome will vary somewhat with each performance, depending on the feelings and inspiration of the performer. Each print is a unique creative process.

    The digital workflow

    Fast forward now to the current generation of digital imaging. Digital imaging is wonderful in too many ways to list. I absolutely believe it is superior to film in almost all important respects. There is no reason for most artists to ever want to go back to film and chemicals. Your mileage may vary, but that is a personal artistic decision.

    One of the places where digital processing is most different is in the post processing to complete the image. The raw file (the “negative”) is processed in the computer using software like Photoshop.

    The software allows extensive, non-destructive manipulation of the image. The great dynamic range captured by modern sensors now gives us far more information to work with and more freedom to transform the image. It is easy to remove distracting elements, composite images together, and vastly change the tone and color profiles and even exposure.

    Ansel had to select a type of film to use prior to taking an image. He also had to use color filters to change the tonality of his black and white images. It was a guessing game based on lots of experience. He called it “pre-visualization”. Now we retain all the color information until processing time and we can convert to black and white via multiple types of software transforms and with extensive control over tonality. Much more subtle artistic decisions can be made. He would have loved it.

    Furthermore, these changes are built on the computer and recorded as a complete package. All the modifications can be done slowly and I can backtrack, undo things I don’t like, try alternatives, even easily create multiple versions of an image.

    The “performance” aspect of Ansel’s darkroom manipulation now becomes a considered, one-time transformation. All the artistic decisions are immediately seen on my nice color corrected monitor. I can study the effects at leisure and decide to change them. When I am done, I have virtually a finished image.

    The print

    It almost sounds like printing has been reduced to a minor step. Not so. It is still a complex artistic process. But again, the digital world gives many new options.

    Choice of paper is a big deal. It controls a major part of the look of the resulting image. A glossy Baryta has a very different look from a matte watercolor paper. Paper with varying textures and base color can be selected.

    This is assuming you are printing yourself. I recommend it. It is a joy and it connects you with the final product. But many other options are available. You can have your image rendered on canvas, metal substrates, acrylic, transparencies, cloth – too many to list. All vary the look and potential use of the final image.

    But the thing that is ultimately the most different from film days is that the artistic result has been determined prior to hitting Print or sending the file to the producer. Each time you print the image, the results should be so repeatable as to be indistinguishable. As Alain Briot said, somewhat tongue-in-cheek I think, this is one of the problems with printers: they do not need our help in any way while they do what they do.

    So, in a way, a print is like a good illusion. The magic happens before we ever see the print appear. This is a huge contrast to the film days where creating a print required a virtuoso performance in the darkroom.

    Was Ansel right?

    I believe Ansel was completely right and very insightful when he wrote this famous quote. Like with many things, though, time and technology changes. Since he was describing a particular technological process, it is not surprising that it will change.

    The real genius of the quote, and the reason I believe it is still useful, is to point out that the captured image is only the starting place. I am free to apply my vision to complete the image. Without that injection of originality, it is too easy for it to just be a snapshot.

    How that is done is not that big of a deal. Art is a physical product and expressed via currently available technology. The technology should not determine an artist’s vision. Make it your own.

    The quote was an observation by a great and experienced artist. It did not come down from heaven written on stone. Don’t be limited by changes of process or technology. Understand that it frees you to create!