Ed Schlotzhauer

An artists journey

Tag: photographic technology

Photography is Technology
There is no separating photography from technology. That is its nature. Photography is technology as much as it is art. It is one of the most technical art forms.
What is technology?
One definition of technology is “the application of scientific knowledge to the practical aims of human life.” Other definitions I like refer to applying knowledge to achieve practical goals.
There is no getting around the fact that there is a tremendous amount of scientific and engineering knowledge packed in all the devices and tools we use in our photography.
Technology pervades most things in all parts of our life these days. But photography is steeped in it.
The technologies we use
When you step back and look at it, every part of the chain from initial image capture to a final print or post relies heavily on technology.
Our camera is a wonderfully crafted marvel. From the lens to the camera body and all that goes on in it. None of this would be possible without the almost magic technology behind it.
Just consider the sensor. It can convert incoming light into electrical signals in a tiny fraction of a second. These signals are read out and converted to digital data (yes, the sensor captures analog data) in milliseconds. Our tiny memory card takes in all this data, again in milliseconds.
And it does all this reliably and repeatably, day in and day out, in all kinds of weather, wherever we are.
And it is almost impossible to work with images today without a good computer and great software tools. Again, these are technologies that are marvelously better than what anyone had just a few years ago. We regularly and quickly color correct, remove distractions, change tones, and sharpen our images – with far better control and precision than in film days. If we choose, we can bend and stretch pixels in ways that could not have been imagined a few years ago.
Do. you post your images on social media for your followers to comment on? The scale and extent of the technology behind this is almost unimaginable. That post requires billions of dollars of cutting edge technology to happen.
It is impossible to do anything photographically without technology.
©Ed Schlotzhauer
Shiny things
This great technology that benefits us so much can be a liability. It is all too easy to get tangled up in the learning and the process of what is happening. A lot of specific knowledge is required to do our craft well.
So we get trapped in chasing the technology itself. There are always raging arguments about how many mega pixels we need. Or which sensor has the lowest noise and best dynamic range. And are zoom lenses evil? Do we have to only use prime lenses?
Is Lightroom Classic the best place to be managing and editing our images or should we use Capture One? And Photoshop is a life-long learning experience all by itself.
Resolution, color accuracy, modulation transfer functions, RAW image processing – it can make our heads ache.
A good or bad thing about technology is that there is always more of it we “need”. Studying reviews and specifications of gear can become an obsession. So much so that some spend all their time thinking about what they would do with the next big thing if they could get it and little time actually going out and making images with what they have.
Don’t get me wrong. I’m an Engineer. I love to compare specs and I can swim in data all day. It would be a pleasant journey for me to spend a day lost in details of acutance or chromatic aberration or dynamic range. For nerds like me, comparing lenses is kind of like shopping for cars. We could talk all day about which one is best and go into great detail about why, even if we do not intend to buy one.
©Ed Schlotzhauer
Accumulating
A problem with this focus on technology for its own sake is that we feel the need to always be searching for the “best”. New equipment always comes out and it is a little better than the old. We believe that to do the best job of our photography, we need the best new stuff. So it is an endless treadmill of acquiring shiny new things that will make us a better photographer.
And it can get to the point where we get into a state of analysis paralysis. Have you seen someone out in the field lugging a huge, heavy pack with most of their “must have” gear? After all, no telling what we may encounter. So we bring the full range of ultra fish-eye to extreme telephoto lenses. And, of course, macro and perspective control lenses. A backup body (or 2) is a must. And a computer for checking our images on a larger screen and maybe doing a quick edit. Just to be safe.
This person may spend more time trying to decide what to use and fiddling with equipment than they do finding subjects and composing and capturing images. Yes, “fiddling” is a technical term. ☺
From what I have seen, when painters and sculptors get together with their peers and “talk shop”, there is a certain amount of discussion of technology and tools and equipment. But not like photographers. It can be an obsession with us.
©Ed Schlotzhauer
Make it disappear
I don’t want to paint a gloomy picture of technology. I like it and need it, at least when it works right. It would be impossible do my art without technology.
But go back to that original definition that technology is about applying knowledge to achieve practical goals. Its purpose is to help us do things better. It should not become an end in itself.
Great technology used right should “disappear”. It is not about the wizard’s wand or the warrior’s sword. It is about what they can do with them. One way to make it disappear is to learn to use it so well that it is fluid and natural.
I recommend that we choose a small set of equipment and learn it well. Learn its strengths and weaknesses. Yes, weaknesses can become strengths if used artistically. Think of film grain for example.
Have you noticed that a lot of music pushes an instrument to its highest or lowest range? Pushing the limits can lead to interesting effects. And it tests the skill of the performer. Our photography can be a little like that. Push the limits.
Practice with your equipment frequently. Go overboard with it. Pick up your camera every day and run through scenarios. It should be automatic. Learn to operate it in pitch dark, relying on familiarity and feel to guide you. Even if you only use one lens, get to know what it can do and learn to see like it sees. You do not always need to carry a full range of lenses. That is what feet are for. Move.
If we develop this intimate knowledge of our technology, it becomes a tool we can wield for our creativity. It “disappears” in our creative process. Great things happen.
I love the technology we have available today. It allows us to create great things. Always remember that the technology is for us to make art. Use it. Don’t be controlled by it.
April 16, 2025
Be The 1%
We can choose to be the 1% of photographers. Those who make prints. A print is a special thing with its own life.
The 1%
I’m not talking about that 1% we hear talked about in the news – the richest people in the world or the country. The latest data I could find for the USA says that, on average across the country, to be in the 1% financially you need a salary of about $600,000 or a net worth of $11 Million. Another article said that 1% of the people in the world own over 50% of the total household wealth.
I am not bringing this up to get into any discussion of income inequality, investing practices, demographics, or anything related to that.
No, I am referring to a group of photographers we can easily choose to join. Peter Eastway speculates that only about 1% of photographers make prints. Why do you think we don’t print more?
©Ed Schlotzhauer
What is a print?
First, what do I mean by a print? This may seem obvious, but I want to make sure we are on the same page, so to speak.
By a print I am referring to an image presented in a fixed physical medium. A print is an object with weight and space and presence. We can hold it and touch it. We perceive it with our physical senses. And it is “permanent”. That is, it persists unchanged over time.
A print is an enduring expression of the artist’s intent at the time. I say at the time, because it is quite possible for my intent to change with time. The print I make today may be quite different from one of the same image file 5 years ago, or even a few months ago. My vision changes and I often come to see it different. That is natural. I am the artist. Ansel Adams, for example, is famous for drastically changing his vision of how some of his famous images should be printed over time.
What is a print not? It is not an image on a screen. Not your computer monitor or an iPad or your phone. It is not a fleeting image scrolled by on social media or your web site.
Screens are important in the production of our art, but I hope they are not the main goal. Psychologically, we know that what we see on a screen is ephemeral. It has no permanence. We discount it easily. Being on a screen, we subconsciously consider it fluid and flexible.
Why a print?
A print is tangible. It is an artifact that persists in time and space. That is, it is physical. It is an object. We can hand it off to a client who buys it, and it becomes their possession.
By giving the print this life of its own, we are creating a new piece of art. It is no longer under the control of the artist. Kind of like a child growing up and going out on their own. They are your family, but they have their own life now.
As the artist, I can no longer “huddle over it” and protect and explain it. It is on its own. Now it is hanging on a wall. Maybe in someone’s home. Maybe in a gallery. But no matter where, it is now perceived for itself in isolation. It must explain itself, justify itself, fend for itself.
©Ed Schlotzhauer
New thought process?
Deciding to make a print changes our perception of what we are doing.
For one thing, we must commit our interpretation of what we see or feel in the image. We must resolve the “it could be like this or it could be like that” questions in our mind. Once we make the print, we can’t come back next week and change it. If we do, it becomes a different piece of art.
And we will go through a more stringent selection process to pick it. Out of thousands of good images, why print this one? Does it do a better job of representing my view on the subject? Is it a more perceptive representation of something I feel? Will this give my viewers more insight than the many other images I could have picked? Is this an image I will hand to the world and say, “this is me?”
New creative decisions
And making a print involves new creative decisions. What size should it be? Some images seem to call to be large while others seem to prefer being small. Should this be a paper print or canvas or metal or acrylic? Will it look best as glossy or matte? Sure, some of the decisions will be dictated by the intended application. But many are purely artistic.
And there are technical considerations that come in now. Does the file have the quality and resolution to make a large print? Can I print it and mount it myself or must I send it out to a service bureau to be done? The selected media imposes constraints on the image itself. If the desired effect is soft and ethereal then a matte finish may be best. But if the image relies on sharp detail a glossy substrate will make that pop more.
I encourage you to make your own prints when you can. A good, medium size desktop pigment ink printer costs about the same as a mid-range lens for a 35mm camera. Having your own printer encourages you to experiment more. And the immediate feedback you get is gratifying.
©Ed Schlotzhauer
Technical considerations
Creating a good print is a specialized process that requires some detailed knowledge. The fundamental problem is one of basic physics. Screens generate light and emit it. It is an RGB mix, and it is additive. That is, red + green makes orange.
We see prints by reflected light. Light hits the surface of the print and what bounces back is what we see. It is a subtractive process. The ink absorbs some colors. We see the reflected light that is not absorbed. To reduce the red you add cyan. Cyan is the opposite of red. More cyan absorbing red means less red reflected.
This and other differences mean that a print will never look exactly like the image on screen. How close we can come is one of the challenges. How close we need to come is an artistic judgment. A print is another art form.
Editing the image for printing is a task on its own. We load profiles for the media and printer and inks that we are using. A special profiling view is switched on so we see a simulation of what the final print will look like. This is, at best, a fair but not exact model. The reality is it may require several rounds of test prints and re-edits to get to a final print we like.
It can be a lot of work, but it is part of the artistic process. This is work we must do to “birth” the print as its own entity.
I usually have a number of prints hanging around my studio. Some because I just like them. But often it is to live with them a while to see if I like them long term. Results vary.
©Ed Schlotzhauer
Viewing it
We have gone through all this work and expense to create a print. Why? Was it worth it?
This is a personal evaluation.
Sometimes you are disappointed with the result. Some images just do not seem to print well. That could mean we did not choose the best medium or size. Maybe it would have worked better in black & white.
But most of the time you will feel the satisfaction of creating something new. Because the print is a new work of art. It is a distinct physical object with a life of its own. It lives in the world and is evaluated by viewers.
We did our best job of composition and subject selection and lighting and a host of other things. We edited it carefully and prepared it for printing. Now it passes into another realm. We have tried to guide the viewers to see what we saw, but now they are on their own to discover it.
The child leaves home and starts its own life. We are proud of it, but we cannot control it. It is not ours anymore. Likewise, a print becomes an independent entity. The viewers evaluate it on its own by their own criteria.
Something tugged their interest enough to spend more than a passing look at it. Maybe we can draw them in and take them on a journey they did not anticipate. That is joy for the artist and the viewer.
Take the leap. Be one of the 1% of photographers who make prints. It can change your art and give you a different relationsip with your images. And it can be a legacy.
April 9, 2025
The Color Is…
Color is one of the major considerations in our photo processing. And it can be hard. Have you ever considered how many tools and settings there are to control color in Lightroom and Photoshop?
But where are you on the color concern spectrum? For you, is color:
1. Critical. It must exactly match
2. Important
3. An annoyance
4. Just a design variable
5. Don’t care
Why do we need to change it?
Despite all of the great technology we have, color is still an imprecise and slippery thing to deal with. Different camera manufacturers often create their own unique ‘look”. Fuji, for instance, has profiles built in for some of their famous films (remember Velvia?). But because of different technology and processing tradeoffs, there are subtle differences between, say, Nikon and Canon. There are even small variations between samples of the same camera model,
The color variations are magnified as we move further along the processing chain. What we see is greatly influenced by the decision to shoot RAW or JPEG, and if JPEG, what color balance is chosen. And is our monitor calibrated to ensure it correctly represents the colors in the digital file?
Finally, when we make a print everything can change drastically. The print is strongly influenced by the paper we choose and the printer’s ink set. Using good profiles for the printer and paper combination helps to produce an output that is “similar” to what we edited on screen, but it will never be the same. Just the move from illuminated pixels in RGB space to reflected light from a paper substrate in CMYK space means they can never be exactly the same. The physics is completely different.
The variations along the way are the process of color correcting the image.
Most of us do not see or pay much attention to these differences. The importance to us depends on our application.
©Ed Schlotzhauer
Tools
The color correction tool chain starts back in our camera. Specifically, the color balance setting.
The color of the light on our scene varies greatly in different conditions. Bright sunlight is completely different from open shade, as is a cloudy, overcast day. Indoors under tungsten or fluorescent lighting and. even LED’s give different color casts.
Out eye/brain automatically adjusts for most of these differences, but the camera does not. The color balance setting in the camera is a means to dial out the color casts. But this is only useful for JPEG images and the preview we see in camera. Color balance has no effect on RAW images. Those compensations are made in our image editing software.
My camera stays set to Auto White Balance. I only shoot RAW, so it has little effect on my processing or results.
Lightroom
When I say “Lightroom” that is a shorthand for “Lightroom Classic”. That is the only version I care about. But I”m pretty sure everything I say about it applies to both applications. There are differences in color representations in other RAW image processors like Capture One, but I do not have enough experience with them to say much.
Lightroom is packed full of ways to change the color of our image. In the Develop module you are never far from something that can modify color.
Some of the controls change color globally, that is, for the whole image. Just scanning down from top to bottom (I think my controls are still in the default order), we start with profile. This can be a simple selection of default balance or you can set any of the many provided color effects, including black & white toning.
Next there is the white balance adjustment to allow us to adapt the image to a color that should be neutral. Next to that is the color balance selection to partially compensate for lighting conditions.
Right under them is the Temp and Tint sliders. Vibrance and saturation do not actually alter colors much, but they have a strong effect on the look of colors.
Then there is the Tone Curve, where we can adjust red, green, and blue channel properties directly, followed by Color Mixer and Color Grading. Finally there is the Calibration group where we can control hue and saturation of each channel.
All of these are only the control that affect the whole image. We have many of the same controls to perform selective adjust color in regions (like a linear gradient) or spots (e.g the brush tool).
©Ed Schlotzhauer
Partly driven by the application
Hopefully, you get the impression that Lightroom gives us a lot of control of color. It must be important. I won’t even go into Photoshop with its many adjustments. I trust the point is made. This is not a “how to”.
Color adjustment is a large part of what we may deal with in post processing.
Maybe.
It depends on our application and needs.
If you are doing product photography, the customer is very concerned that the color of their logo or product absolutely matches their specification. Portrait customers have a fairly narrow tolerance for off colors in people’s faces. Or you may have a self-imposed rule that the final color must exactly match the original scene.
In these cases you are probably using gray cards or Color Checker swatches to ensure you faithfully match the original. You may even be calibrating your camera to minimize discrepancies. You will probably be using many of these Lightroom controls to adjust the colors to balance out shifts or color casts.
I’m a Fine Art Photographer
But I’m a Fine Art Photographer. I dislike that term and I’m not completely sure what it means, but I do know that what I create is art. Art is not tied to a real scene. Maybe someday I will get into a discussion on indexicality, but not today. By my definition, anything I want to do as art is acceptable.
I may not care at all about the color of the original scene. I’m certainly not fanatical about matching it or balancing color casts. My consideration is how the resulting image looks (to me) and what effect it has for the viewers.
Yet I do use most of the color controls I listed earlier. Except I very rarely use Calibrarion to adjust color, but that’s just me and my thought process. All the other controls, in global and regional and spots, are tools I use frequently.
Color is a subtle thing. Almost imperceptible shifts can create large perceived changes. It can be tricky, or impossible, to achieve an effect I have in mind. But I try.
©Ed Schlotzhauer
Not an absolute
Breaking the assumption that my image must look like the original was difficult for me. Coming from a very technical, engineering background made me think in absolutes. Precision was important. But now that the assumption is broken, it is freeing. The realities I started with no longer hinder my vision (as much).
Even so, I do not usually create comic book-like pop art. Unless I want to for some reason. But, on the other hand, I do often enjoy making images that are so extreme you will think I modified them too much, even if I did little at all.
Sometimes color is the subject. Sometimes an image “needs” to be a different color than the original. An extreme use of color modification is black & white. Yes, taking away all color and just leaving tonality is extreme color manipulation.
In the questions I posed at the start, I’m usually operating at about 4 or 5. It is a tool I can apply to accomplish my vision. Not something I am stuck with because that’s what the original was.
©Ed Schlotzhauer
Do what you need to do
Color perception is one aspect of a visual image. But it is a powerful one. With our technology, we are blessed with extreme ability to control or modify color. Don’t be afraid to use it creatively.
Unless you are working in an application that demands absolute fidelity to the original, color becomes just another design element to be used for art.
Make your art. The color is… what you need it to be.
Today’s feature image
Is this the “right” color? I don’t know. First, I didn’t have a gray card with me. Second, even if I did, I couldn’t have held it out the window at 40,000 ft. Third and most important, I don’t care.
This is what I remember seeing at the time. It is the way I chose to make the image look. It is art. I like it like that.
March 26, 2025
It’s Just a Camera
That piece of technology we use to make images, it’s just a camera. Not magic or sentient or automatic. It still needs someone to take the picture.
Brushes
I really like my camera. It is a good tool to use to make images I like. When I’m in the field, my camera is the vehicle for my creative expression.
Have you ever had someone look at one of your pictures and say “Wow, you must have a great camera”? Or see you taking pictures and say “You must be a professional, since you have a big camera.” I have. Many times. Now, I basically just smile and go on.
But if you see a painting hanging in a gallery, who looks for the artist and tells them “Man, those must be some great brushes you have.” Or, seeing a nice wood carving, tell the sculptor “you must have some really sharp chisels”.
The public has a tendency to attribute a good photograph to the camera more than to the photographer. Being a piece of technology, somehow there is the implication that the camera somehow made the picture.
As artists, we should not encourage this attitude.
©Ed Schlotzhauer
A box
At it’s most basic, a camera is a box that keeps out light. The name comes from “camera obscura”, which was a dark space, often a room, with a small opening to let in light. This caused an inverted and reversed image to be projected on the back wall. It is believed this technique has been used since 500 BC.
The first “modern” cameras were wooden boxes that had a lens on one end and a holder for coated glass plates on the other. This is how many great historical photographs were exposed.
They have certainly become much more sophisticated now, with auto focus, camera shake compensation, exposure measurement, ability to automatically set exposure parameters, etc. Too much to list. The user manual for my Nikon Z7 II is 823 pages. Astounding, but it still doesn’t take the pictures. At it’s most basic, it is still a closed box to keep light off the sensor until time to record the image.
I appreciate many of the features in modern cameras. They make my art easier and extend the range I can operate in. It is great to have our little “dark spaces” getting smaller all the time. Even to becoming little flat things we can put in our pocket (phone).
I fear there will come a point where we will face some major decisions.
It’s still a tool
Right now our cameras and phones have amazing capabilities. Some of them are just basic technological advances. Some are deemed “AI”. Many of the best features are appearing first in our phones.
The ability to “sweep” our phone across a scene and have it automatically stitch together a panorama is very useful. Face detection is common now and can be useful for some types of work. An interesting feature I have seen is where, when taking a group shot, some cameras actually take many images and pick out and merge together the “best” look for everyone. At least, ones when they are smiling and their eyes are open.
Features like these make shooting pictures less technical and less stressful. Anyone can get “professional” level results. That is probably a good thing. It is an aid.©Ed Schlotzhauer
A coming “revolution”
There are still some of us who want to make the artistic decisions ourselves. Even if it is difficult and requires lots of training. Even if we make mistakes and bad choices. Those don’t matter. It is our art, our decisions, our responsibility. The technology is likely to get a lot more intrusive.
Probably right now most major camera manufacturers and all phone makers have teams of smart people trying to go all in with AI. People who actually believe in it and confidently think AI actually is or will become intelligent. Some who actually think AI can do art.
I can imagine one of the user stories they are working from: “(Camera speaking) Attach the 24-70 lens. It is best for this shot. Move me 34.7 inches left and lower me 9.3 inches. I detect a glare. Attach the lens hood. Place the subject at the Rule of Thirds point I am illuminating in the viewfinder. I will shoot it now and remove the non-subject person traversing the frame. I am also correcting the 3° tilt to the right and the overall color. Done. “
To me, this is a dystopian scene. I do not want to relinquish my artistic vision to anything, especially a machine. I am very willing to use smart tools to assist my work. In-camera features like eye identification and focus tracking can be very handy. On the computer, making it easier to make selections or to remove distractions is useful. But I do not plan to give control over to the camera to make it’s own decisions
Plasticity.
In The Interior Landscape, Guy Tal states
For any medium to be useful to an artist, it must allow a generous degree of plasticity. It must lend itself readily to subjective expression of concepts and feelings originating in the artist’s mind and not just those inherent in or commonly associated with the subject.
Mr. Tal was not referring to AI here, but I believe it applies. An AI controlled camera could probably expose images that would be regarded by most consumers as pleasing. The pictures would be a faithful and well exposed depiction of the subject. Most users would be happy. Unfortunately, the AI could not know the subjective expressions that are in my mind. It cannot know my vision and intent.
Again in The Interior Landscape, Guy Tal states
There are well-established compositional templates knows to impress viewers, requiring only mechanical skills but no expressive intent. Art raises the bar. Art requires from the artist a degree of emotional investment and an elevated subjective experience, as well as the skill to express visual concepts beyond “here’s something pretty,” “look where I’ve been,” or”see how lucky I was”.
I resonate with this concept of plasticity. It gives structure to my desire to create images that are not simply representations of what is there. I want to use the camera and other parts of the technology of photography simply as tools to help me capture what I visualize and feel.
©Ed Schlotzhauer
Make art
You might get the impression that I am not a fan of AI. Well, I definitely am not a true believer. It could be a useful tool for some things. One of the big problems is that most people do not understand its limitations, so they believe it is something it is not.
By it’s nature, AI cannot be creative. It is a compendium of what it has been trained on. The output of AI is a statistical prediction of a response given an input. So, at best, it is an average of what it has been given. It cannot think or feel or have inspiration.
I am a human. I do think, get depressed, find inspiration, feel love, and see things in my own quirky way. If those are faults compared to AI, then I readily admit to being deeply flawed. But from those flaws, and all the other strange bits of my makeup, I can create art. Because my art comes from my unique human understanding and viewpoint.
I like my camera. It is a great tool. I have actually read most of the user manual in order to know what features it has and to pick which I choose to use. The reality is that I probably only use, I would guess, less than 20% of its capabilities. That’s OK. It’s a tool, not the center of my attention.
I know that designs have gotten so good that camera manufacturers are up against boundaries of physics. It is easier to add value through new “intelligent” tricks than to expand resolution or dynamic range or reduce noise. AI is a hype magnet and a path of least resistance. I get it.
Who/What is in charge?
But if the next camera I select is bloated with AI features and the price is double because of that, I will pass. I can even envision them wanting me to pay a monthly subscription to use the features in my new camera. If these things happen, my next camera is likely to be an older, used camera with less features but better raw performance and easier manual operation. Yeah, I’m an old curmudgeon. I get to be. I’m the artist in charge.
The camera does not make images. The artist does. It will continue that way for me as long as I have something to say about it. And I do. 🙂
So modern cameras are wonderful tools. I would love to have a new one. But are you an artist or just someone who takes pictures? If you are an artist, do not forget that the camera is basically just a dark box that holds the lens and sensor in the right positions. It is an instrument allowing us to create art. The artistic intelligence is in you. Do not surrender your artistic vision to a machine.
Photography is based on technology more than most other arts. That does not mean the technology makes the art.
“The equipment of Alfred Stieglitz or Edward Weston represents less in cost and variety than many an amateur ‘can barely get along with.’ Their magnificent photographs were made with intelligence and sympathy – not with merely the machines.”
Ansel Adams
February 12, 2025
Why Do We See 255 Everywhere?
Do you ever wonder about the magic number 255 you see all over Photoshop and even in Lightroom Classic if you look? It seems like 255 pops up everywhere. Why is that? It is a strange number to choose.
It’s just a number
First let me say that at this point in time, 255 is just a number without meaning. It is the number chosen to represent the maximum value of a channel or color. Something has to be used to represent the maximum value. Looking back, 100 (as in 100%) would have probably made more sense. But we have 255.
Think of it like Fahrenheit and Centigrade scales. The boiling point of water is 212 in Fahrenheit and 100 in Centigrade. Either way, it represents the same thing, the boiling point of water. That does not change no matter how the number is represented.
So when you see 255 just read it as the maximum value of that thing. If that is the level you wish to understand, this would be a good point to stop reading this article. 🙂
Personally I hope you continue. Understanding some of the history and details of our tools can only help improve our craft.
Roots in binary
Before we go deeper I need to justify where the number 255 comes from. It is rooted in binary coding. You are probably familiar with digital notations. We have lived with it for so long it seems to permeate everything around us.
Please pardon me for going full on Geek here. I so seldom get to use my training that it is fun. A very, very brief background: when digital computers were being developed, it was found to be simpler and more reliable to create circuits that were either on or off, no in between states. This was called a bit. A piece of data that was either off or on, noted as 0 or 1. The advantage of this seemingly silly decision is that the bits could be made very small and can be operated on very fast.
©Ed Schlotzhauer
A single bit by itself isn’t very valuable. To represent realistic information and do calculations bits were combined together in larger units. The next widely used unit was 8 bits. This came to be called a “byte”. Eight bits is a byte – Geek humor.
It turns out that 8 bits is enough to start encoding useful information. For instance, it will hold 1 character. A byte is big enough to code all the upper and lower case letters, punctuation, and some special symbols. At least in English. And we will see that it holds a useful amount of image data.
Let me give a very simple description of digital value coding using 3 bits:
Each combination of the 3 on/off values is assigned a value. The encoded values range from 0 to 7.
Going back to the unit we called a byte, the 8 bits can encode 256 values, 0 to 255. This is the origin of the magic 255.
History of Photoshop
It is hard to think that there was a “before Photoshop”. Thomas Knoll needed to develop ways of doing analysis on images for his PhD thesis. In those days, nothing was available, so he taught himself programming and developed a library of operations. Here is an interesting interview with Thomas.
His brother John worked for Industrial Light and Magic. He saw applications for image processing in some things they were doing, so he encouraged Thomas to enhance his library. Eventually they decided to try to make it a product. Adobe was interested. It is amazing how things come to be.
In the days when the library, later Photoshop, was developed, the state of the art of image representation was to code each pixel as 3 8 bit values. One byte each for red, green, and blue. Each color had the value range 0 to 255. This number scheme became baked in to Photoshop and a standard metaphor of the user interface.
©Ed Schlotzhauer
Today’s data
Early digital cameras shot 8 bit images. Today, though, images and Photoshop has grown well beyond that. As an example, my Nikon Z7 II captures 14 bit data. Each red, green and blue channel is 14 bits. That is 16384 values per channel instead of 256. Some other cameras have even more bit depth.
Photoshop allows us to select if we will treat our files as 8 bit or 16 bit or 32 bit. With all these variables it could impose a huge burden on the user to deal with the actual value range of the data he is editing. Some of these numbers get to be staggering (for 32 bit data each channel has 4,294,967,296 values). Adobe chose to keep the maximum number we see at 255. In effect, it became an arbitrary measuring scale we work with across the apps.
By the way, Lightroom uses 32 bit data internally. You do not get a choice. But even in Lightroom (Classic at least) the 255 illusion peaks through in one place. Look at the Tone Curve tool. The scale is 0 to 255.
Still, it’s just a number
Fahrenheit or Centigrade. It is just an arbitrary number to represent the same thing, the boiling point of water. Adobe has kept that historical number 255 and given it the implied meaning of “maximum”. It no longer has a tie to the actual size of the data you are editing or the maximum value of an 8 bit chunk of data.
©Ed Schlotzhauer
They have done us a service in this. I would hate to think of the mental complexity I would have to go through if this number changed all over the place to be the actual values I am working with. But a simplification comes with some challenges. People tend to forget why the simplification was made. Even that one was made at all.
When you are using the curves tool and other things, freely accept 255 as meaning “maximum”. Do not forget and think that your data only goes to 255. Or that it has somehow discarded all those other wonderful bits our modern cameras give us. When someone tells you that white is 255/255/255 and seem to think that is the actual value of their data, remember that is just a number on a scale. Smile to yourself knowing you probably understand it at a deeper level than they do.
I don’t have many images in my catalog that are actually 8 bit data. I am very glad the technology has moved on in wonderful ways. And I am grateful for the simplified scale that normalizes what I see when I am working with all this data. Thank you Adobe. This is something you did right. It doesn’t matter what the number is, something had to be defined as a convenient value for “maximum”.
Today’s image
The image at the head of this is actually 8 bit. An 8 bit jpg file. All the data is actually 0 to 255. Back in 2006 that was about the best I could do with the camera I had. It’s not terrible. I like the image, but I wish I could shoot it again with a modern camera.
As a matter of fact, all the images in this article are 8 bit. I wanted to emphasize that it was a very workable system.
Side note
In today’s digital systems we seldom worry much about a few bytes. Every time I press the shutter on my camera it writes about 50 million bytes to my memory card.
I mentioned that digital bits could be made very small. As an example, Apple’s M4 processor, which is their main CPU as of this writing, has 28 Billion transistors. On one chip. That is hard to comprehend. It certainly wasn’t anticipated when Thomas Knoll developed Photoshop.
December 25, 2024