Ed Schlotzhauer

An artists journey

Category: Technology

Ideas about the mechanics, techniques, and technology behind image making.

Know Your Masks
We all put on masks (not Covid ones, thankfully) all the time. Our masks make us look better to other people. But I’m not talking about our social interactions. We are image makers, so we also use masks in our editing tools to make our images look better. Both Photoshop and Lightroom have masks, but they are very different. Understanding the differences helps us better understand our craft.
What are they
In their simplest form, masks limit the extend of the edits we make to an image. All of our editing software lets us make global adjustments to an image, like increasing or decreasing the overall exposure. Most of our editors also allow us to restrict edits to selected parts of the image by masking.
You know the situation. After we get the overall look of an image balanced the way we like we often have to “drill in” and work on smaller parts. For instance, maybe a part needs to be brightened to make it stand out the way we want or darkened to call less attention to itself. No matter what your software calls it, masks are used for this.
But how we do it and how they work on the image can vary greatly.
©Ed Schlotzhauer
A mask
In the general sense, a mask allows us to isolate part of an image so that we can make selective edits.
Without masks all of our edits would be global. That is, what we do would affect the entire image. To selectively modify only parts of the image, though, we need the ability to restrict the area to be edited. In a sense, a mask is kind of like a stencil that keeps us from painting outside of an area.
For photography, the concept of masks comes from the darkroom. In the traditional darkroom, printers used bits of paper or sheets with shapes cut out to hold light back from selected areas or to add light to selected areas during exposure of a print. This was called dodging and burning. It required a lot of planning, and it was a very tedious and labor-intensive process. One mistake and hours of work could be ruined. I personally am very glad we do not do that now.
Lightroom vs Photoshop
I’m going to use Lightroom Classic (which I will just call “Lightroom”) and Photoshop as my examples. They are what I know, and I think they are the most commonly used editors of their specific kind. Yes, kind, because for all their similarities they are 2 different kinds of thing. These differences are important to us, and we need to have some understanding of how they work in order to use them better.
The most fundamental difference is that Lightroom never modifies pixels while Photoshop will gladly do anything you want to your pixels. Because of this basic difference, the way they deal with masking and editing is also completely different.
In a sense, Adobe has created a problem for their users. They sell the 2 premier image editors. The products are tightly linked, and users often have to use both of them to accomplish their goals, but they are so different that it causes confusion.
©Ed Schlotzhauer
Photoshop
Photoshop was the first capable and widely used image editor. It springs from the days when images were only pixels. It is a pixel editor, even with adjustment layers and blending modes.
Photoshop is a bare knife. It eagerly does whatever you tell it to do to your image. Like a sharp knife in skilled hands can do great work, the same knife in unskilled hands can be dangerous. Photoshop will shred your pixels with no remorse.
Inside Photoshop, a mask is a black & white image that is attached to a layer. Whatever adjustment you do on the layer is restricted by the mask. The mantra is “white reveals and black conceals”. That is, where the mask is white the adjustments are made on the underlying image. Where the mask is black, the adjustment is ignored.
But note that the mask is just another bitmap image. It can contain any set of pixels including shades of grey. For instance, sometimes frequency separation editing is done by doing something like taking, say, a copy of the green channel and pasting that into an adjustment layer as a mask. That is a complex mask, but Photoshop handles it easily.
Also, we modify images by building up layers of changes. The order of the layers is very important in Photoshop. The changes are always applied in the order you specify in the layer stack and the results will probably change if the order is changed.
So in Photoshop you can do anything you want to the pixels. They can be stretched and blurred and painted over and, well, there is little limit. Masks are just another kind of bitmap that lets us limit the area modified by a layer.
©Ed Schlotzhauer
Lightroom
Lightroom Classic is the newer product and it brings a completely different design and technology approach. It is specialized to be the editor of RAW images like Photoshop is specialized to be the pixel editor.
Lightroom has become my first and often only step in editing images. One reason I go to Photoshop less is because Lightroom has added very capable masking ability and they continue to enhance it.
But masks in Lightroom are a totally different thing from Photoshop. Since Lightroom is designed to be incapable of destroying pixels, they have adopted a technology of keeping track of descriptions of the edits to be done rather than actually doing the edits. Same for masks and their edits. These descriptions are separate from the image. They are applied to the original RAW file whenever it needs to be viewed. And the order of edits usually does not matter.
Generally, Lightroom masks are constructed by combinations of gradients and shapes and range selections and brush strokes. The shapes can be composed together to make complex and useful masks. Some “AI” aids are available as shortcuts for selecting the sky, or people, for instance.
©Ed Schlotzhauer
Lightroom markup example
The edit descriptions are just text that is kept separate from the image and is processed by Lightroom as needed. Here is a sample of the instructions for one of my images. This is only part of the text file, it defines one mask:
<crs:MaskGroupBasedCorrections>
    <rdf:Seq>
     <rdf:li>
      <rdf:Description
       crs:What=”Correction”
       crs:CorrectionAmount=”1″
       crs:CorrectionActive=”true”
       crs:CorrectionName=”Mask 1″
       crs:CorrectionSyncID=”4F05D072D78C40239D264FC0F8F45469″
       crs:LocalExposure=”0″
       crs:LocalHue=”0″
       crs:LocalSaturation=”0″
       crs:LocalContrast=”0″
       crs:LocalClarity=”0″
       crs:LocalSharpness=”0.215228″
       crs:LocalBrightness=”0″
       crs:LocalToningHue=”0″
       crs:LocalToningSaturation=”0″
       crs:LocalExposure2012=”0.27395″
       crs:LocalContrast2012=”-0.100282″
       crs:LocalHighlights2012=”0″
       crs:LocalShadows2012=”-0.188717″
       crs:LocalWhites2012=”0.127177″
       crs:LocalBlacks2012=”-0.061475″
       crs:LocalClarity2012=”0.730341″
       crs:LocalDehaze=”0.631532″
       crs:LocalLuminanceNoise=”0″
       crs:LocalMoire=”0″
       crs:LocalDefringe=”0″
       crs:LocalTemperature=”0.274462″
       crs:LocalTint=”-0.102011″
       crs:LocalTexture=”0.169762″
       crs:LocalGrain=”-0.100026″
       crs:LocalCurveRefineSaturation=”100″>
      <crs:CorrectionMasks>
       <rdf:Seq>
        <rdf:li
         crs:What=”Mask/CircularGradient”
         crs:MaskActive=”true”
         crs:MaskName=”Radial Gradient 1″
         crs:MaskBlendMode=”0″
         crs:MaskInverted=”false”
         crs:MaskSyncID=”780243712C904039AF01C58DADCB61FA”
         crs:MaskValue=”1″
         crs:Top=”0.219066″
         crs:Left=”0.694605″
         crs:Bottom=”0.301111″
         crs:Right=”0.787517″
         crs:Angle=”0″
         crs:Midpoint=”50″
         crs:Roundness=”0″
         crs:Feather=”34″
         crs:Flipped=”true”
         crs:Version=”2″/>
       </rdf:Seq>
      </crs:CorrectionMasks>
      </rdf:Description>
     </rdf:li>
    </rdf:Seq>
   </crs:MaskGroupBasedCorrections>
It looks intimidating, but it is not made for us to read. We never see this unless we go looking for it. Computer Science people call this a markup language. Computers process it efficiently.
It’s our technology
Photoshop deals only with pixels, and it can change the actual pixels of your image in any way you would like. There is no limit, and it can make changes that are unrecoverable. Lightroom edits are more limited in scope and only deal with information about the adjustments you would like made to your image. A benefit of Lightroom is that it refuses to destroy any pixels.
This applies to masking, too. Masks in Photoshop are bitmap images that can be as complex as the image itself. The mask is another layer to paint or edit like other images in Photoshop.
©Ed Schlotzhauer
Masks in Lightroom are more limited, but still absolutely useful. The masks are combinations of the shapes Lightroom knows about and lists of changes to make within the shape. It does not matter what order you do adjustments in Lightroom.
We need to be aware of these basic design features as we are using the products. Photoshop works directly on pixels. Lightroom keeps information about how to change the look of pixels. They are fundamentally different in design. When we do not keep these behaviors in mind, we can become frustrated when switching between the tools.
It is part of the technology we use to create our art. The better we understand how it works the more skilled we can be at using the tools.
June 11, 2025
Photography is About Light
Stating the obvious? I think we sometimes forget the fundamentals of what we are doing and working with. No light, no photography. Photography is about light.
Writing with light
Remember that our word “photography” comes from 2 Greek words that together mean “writing with light”. So, from the beginning of our art form, it was understood that we were recording light on some type of photo sensitive material. Glass plates or tintype or film back then. Mostly digital sensors now.
Technology changes but still we are recording light.
Embrace that. It is what we are all about as photographers. Photography is about light.
Low light is not no light
Our technology improves all the time. It is possible to get sensors that do a fair job of imaging at 250,000 ISO. Maybe more. I don’t track the latest. The highest ISO I found with a quick scan was the Nikon D6 at 3,280,000!
A 250,000 ISO is about 11 stops of additional exposure above a nominal ISO 100 setting. Eleven stops is a huge amount as exposures go. I haven’t tried it, but at ISO 250,000 I bet you could make a properly exposed landscape shot lit only by starlight.
But the point is that very low light is not the same as no light. Have you ever been in a cavern deep underground where they turned off all lights at some point? Then we encounter the eerie experience of actual, total blackness. In those conditions it is impossible to see anything. Put your hand right in front of your face and you can’t tell it’s there. There are absolutely no photons to impinge on our retina.
We could do no photography in total blackness. Of course, other artists would be almost equally disadvantaged. I suppose, theoretically, painters could make marks on their canvas in total blackness, but they would have no way to know what they were creating. Sculptors could mold clay by feel, but they would have very limited feedback on what they were doing. But photographers cannot do anything without light.
©Ed Schlotzhauer
Computational photography
One clever way to get better results in low light is used in your cell phone and by astronomers. It is generally called “computational photography”.
Computational photography does not rely on the result of one frame. Instead, tens to thousands of shots are taken and processed by computer to bring out detail.
This is how your phone takes decent pictures in low light despite having a tiny sensor. It is actually shooting bursts of dozens of frames. Then it quickly processes them in the phone. It uses averaging and other more sophisticated techniques to reduce noise and bring out the desired detail. I am surprised at how well it works.
Astronomers have special needs in photographing distant galaxies. The light levers are so low that there is nothing to see with our eye. So, they instead take hundreds, maybe thousands of images with the regular sensor on their telescope and run them through dedicated processing software. Using combinations of specialized image processing algorithms and AI, their computers “reconstruct” what is probably there.
My astronomer friends have shown me some of their new “telescopes” they got recently. These surprising instruments are generally about the size of a moderately thick hard cover book. They rely on small, cheap optics and lots of computation, but produce amazing results.
Techniques like these let images be created in what seems like black conditions. But the reality is, it is not black. Just very low levels of lighting. If it was actually black, no photography.
©Ed Schlotzhauer
See the light
As I said, the purpose of this is to remind us that our art is based on light. We need to develop a heightened awareness of the light around us, because it is critical to our art. It changes all the time and is different in different conditions.
it has been observed that a fish probably does not think about water. But we need to think about light, which is almost as important to us as water is to a fish.
Light has many characteristics and most all of them affect our photography.
We need to be intensely aware of the quantity of light at any time, its color, is it direct or diffuse, its angle, whether it is steady or changing, is our subject lit directly or indirectly, and many other properties. It sounds complicated. But learning the light is part of the craft. Learning to apply it creatively is part of the art.
For instance, it is almost an axiom of photography that you do not photograph in the middle of the day. Like the “rule of thirds”, this is one of those rules I take pleasure in violating. The reality is that it completely depends on what subjects you are shooting, the nature of your light source, and what your goals are. Shooting at midday often enhances the texture of materials. In a dense forest it can create interesting dappled light patterns. In a slot canyon or a cathedral, it can create beautiful light beams. And diffuse overcast light may be perfect for many subjects, with high brightness and soft, even illumination.
©Ed Schlotzhauer
And as a practical matter, I am not a National Geographic photographer on assignment. I can’t spend a week in the field waiting for the “perfect” shot I went out to find. I have to be creative enough to make the best use of what I find at the time I’m there.
There are no rules, only what you can do with what you have.
Tonality
Tonality is one of those important things we need to think about and know how to use. It simply refers to the difference of luminance of the parts of our image. The tonality is what lets us distinguish all the parts. It creates separation of various areas.
Think of a blank white piece of paper. This effectively has zero tonality. There is no image, because without tonal separation we cannot resolve anything. Any actual image we create has a range of tones.
If the tones are squished together, our image is low contrast. Not much tonal separation. Maybe this is what you want, like a foggy scene.
On a sunny day there is a wide range of tones. We refer to it as high contrast. Sometimes it can be too much. Do we need to use exposure or editing techniques to tame the contrast? But that is our creative choice
A low-key image involves pushing most of the tones down towards dark. But the remaining light tones stand out. Likewise, if we create a high-key image, with most of the tones pushed toward light, the remaining dark tones stand out.
Our eyes are very sensitive to tonality. We perceive tiny differences in illumination levels. Use of tones is a creative process. It should be part of our thought process and toolbox.
One of the ultimate expressions of pure tonality is black & white photography. All color is stripped away, leaving only tonality to create the image.
©Ed Schlotzhauer
Color
Our eyes are an incredible design. The rods and cones have different purposes but work together to give us sight. But overall, our eye is less sensitive to color than to illumination levels.
Think of being in a dim room at night. We can make out the objects around us, but the colors are hard to distinguish. Turn the light on fully and the colors pop.
Similarly, in our images, good color requires good light. We can’t see vibrant, saturated color in dim light. I mentioned low key art. Have you noticed that most of it is black & white? This is a practical result of not being able to see much color in low light.
I believe some people’s artistic vision is drawn to color and some to black & white. If you are a color person you have to be doubly aware of light. Not enough and our brilliant colors fade.
©Ed Schlotzhauer
Creativity
All art processes are defined by their technology. Photography is based on light. We cannot do photography without light. To be a photographic artist, we need to be intensely aware of light and how to use it to our advantage.
Recognize it not as a limitation, but as a creative tool. Light is a marvelously varied thing. We are artists. We paint with light. Learning it and being constantly aware of it and deciding how we want to use it for any image is part of the art.
We are seldom in a place where there is no light, like the underground cavern I mentioned earlier. There is always light around. It may just be moonlight or city lights or a flash. We may decide there is not enough light to make the image we want sometimes, but there is always light to work with. Recognize it. Use it creatively.
Light is fundamental to photography. Learn to see it for what it is and learn to use it creatively. It is what you are photographing.
May 7, 2025
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
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