Themes Keep Emerging

Blowing snow in the Colorado mountains

Quite a while back I talked some about themes in our work. I mentioned that one theme I come back to is wabi-sabi. As I reflect on my work I find that there are common themes that keep emerging.

What is a theme?

In the previous article I gave the simple dictionary definition of a theme as “a subject or topic of discourse or of artistic representation”. This is right, but inadequate. I have come to believe that for artists, themes are ingrained and consistent.

That is, unless we are doing commercial work for clients, themes represent what we are drawn to. The things that have meaning or symbolism to us. They probably don’t mean anything in themselves, but they disclose something about us. What we see and the way we think.

So perhaps, for a fine artist, themes are the ideas that tweak our passion, that spark our creativity. It is important to keep in mind that the theme does not have to be deeply meaningful. It just grabs us for some reason.


I am at a stage where I think more and more about projects. These self-assigned projects help focus me and exercise my creativity. Without them I tend to run wild and shoot everything in sight. That is OK, but a project helps me get deepen into an idea.

I have a list of project idea I think I would like to do. Sometimes, though, when I try to start one, it turns out to be Meh… It is difficult to really get into it with any enthusiasm. I have come to recognize that this is a symptom of the project not aligning with any of the themes that channel my interest. I usually abandon these, unless there is a compelling reason to push on through it. There seldom is.

On the other hand, when a project aligns with my innate theme interests I can really get into it. It is energizing and exciting rather than being dreary work.

Look inward

So I have learned to look inward more to keep projects aligned with my natural themes. This can be hard for some of us cold, analytical types. After all, it is easier to talk about composition or exposure than it is about feelings. But as I have said before, art is primarily about feelings. I have to get in touch with my feelings??! Well, maybe not in that sense. But I have to become a lot more sensitized to them.

The unique nature of photography is that it is a subtractive art. The world is swirling all around us in unbelievable detail and complexity. When we lift a camera we engage in a process of reducing, filtering, limiting what we show to make a pleasing and coherent image. This takes discipline and a good sense of what we find important in the frame at the time.

Self discovery

This self-discovery process sounds hard for some of us, especially guys. But maybe not. Our own work can often tell us, if we listen.

If you have a body of work (a fairly large collection of images you think are good) you probably have the data you need already – your own images. As an exercise in self discovery, pick out around 100 of your best images. The ones that you feel you are most proud of and that represent the work you are doing now. If I were doing it right now, I would use Lightroom to go through my catalog of top picks and pull 100 of them into a collection to examine.

As painful and time consuming as that is, that is the easy part. Now it is time to think and reflect. Study this set of images. Write down the themes that come to mind as you look over the collection. Just do a free association, stream of consciousness at first. Write these theme ideas on sticky notes and lay them out on a table or a white board or your monitor or wherever is convenient. Look for groupings of related ideas. Put them together. Come up with a term to represent each grouping.

Hopefully you now have no more than 3-6 theme ideas. Go back to your image collection and try grouping them according to these ideas. Don’t worry if it is not perfect. A single image may overlap more than one idea. But it is a test to see if you believe the groupings you came up with.

Now you have a clearer map of the big ideas you are drawn to. This is enlightenment.

Rocket Science?

No, this is not rocket science. It is not really science at all, in the sense of being objective and repeatable. If you repeat the experiment you would probably select a different set of images, because they seemed meaningful to you at the time. You would probably label them differently and come up with different themes. Same but different. That is, there should be a lot of overlap, because themes are much more broad than a particular subject.

Does this make it invalid? No. The process gives you insight about yourself and your interests. It is turning your sights inward and trying to understand more about yourself. The fact that you get different results proves you are a complex and varied individual. That’s good. Be proud of your complexity.

What am I drawn to?

I mentioned wabi-sabi as one of my themes. Some others are time travel, weathered, force of nature, and black & white. I haven’t figured out if black & white is a theme or just an attribute of a lot of the art I like to do. Still working on it.

The image with this article I just shot yesterday (as I write this). This is in the force of nature theme. We just had our first good snow here in Colorado and I couldn’t resist getting up in the mountains to see it. This is not cloud or fog or smoke. It’s blowing snow. It’s not snowing. As a matter of fact the sky is a boring bright blue.

When we get sandwiched between a high pressure system to the west and a low pressure system to the east, we can get violent winds across the mountains as the pressure tries to equalize. When I shot this, it was about 18 F with about 40-50 MPH gusts. Very cold! But I hardly noticed. I love scenes like this showing the power and majesty and force of nature! I was in the zone. I didn’t even remember to put my gloves on, and I hardly noticed.

Connect with your heart

So I find that scenes that excite me when I am shooting them are usually in one of my themes. If I am not excited, I’m probably trying to shoot something that doesn’t inherently draw me to it. By understanding my preferred themes I can more easily decide what to shoot and what to avoid.

Someone once said “if it doesn’t excite you, why should it excite your viewers?” This is generally true. Have you ever made a technically perfect image of a beautiful scene and then later thrown it away? I have. Lots.

Art is about showing other people what we felt; what we were excited about. If we’re not in love with an image why should we ever show it to someone else?

What’s Your Motivation?

Blurred intentional camera motion.

What’s your motivation? What compels you to do what you do as an artist? If we understand more about our personal motivation it will help carry us through hard times.

Motivation vs. creativity

Just so we’re on the same page, let me differentiate motivation from creativity. I wrote recently on creativity. To me motivation is the “why” behind what you do and creativity is the viewpoint or fresh approach you bring to your work. The ideas or substance behind our art.

Motivation gets us up in the morning or keeps us out shooting after the sun is gone or when the weather is miserable. Something drives or compels us to do our work. Creativity may give us a new idea of something that would make a good image. Motivation gets us off the chair and our the door. They work together to create our art.


We are all motivated by something, but each of us is motivated by something different. My wife is one of those who is motivated by a check list. Getting everything checked off at the end of the day is her goal. I like to get things checked off, but it doesn’t really motivate me. I need to create, to make things that brings my unique viewpoint to the world.

There are many

Some other possible motivators that come to mind are:

  • People’s expectations. We like to please others. For some of us, that can be more important than pleasing our self.
  • Money. This is why some of us work. Now obviously, we all need to support ourselves, but for some, the money itself is how we “keep score”.
  • Fame or recognition. This can be powerful, but realisticaly, few of us artists actually become famous. There is the dream, though.
  • Helping people. An example is Beth Young who, after battling cancer, discovered that peaceful, relaxing images help soothe people’s pain. Now she tries to produce that to help others.
  • Fear. This is sneaky, but do you ever feel you’re being left behind and want to work really hard to catch up? Perhaps you look at other photographer’s work and feel inferior. Maybe you don’t even know where you need to go, but you are plagued by fear. I think this is a lot of what social media is about.
  • Personal drive. Some of us are driven to look around at the world and see things and we need to capture them and bring them to other people. Maybe it’s ego, or maybe it is just the knowledge that people would miss these scenes unless we show them. Either way, it is a motivation.

I’m sure there are many more motivators. Like I said, we are all motivated by different things. But my point is that, when you think about it, something motivates you.

Study yourself

Introspection or self inspection is hard for some. Learning to do it helps us grow and understand our self better. Do you ever sit back and reflect on your motivation? When you don’t feel like doing anything, what gets you going? Can you detect a cause/effect relationship? That is, when an idea comes into your head that seems to push or pull us to expend the energy to do something.

If we understand our motivation we can accept it and embrace it. Use it to propel us toward our goals. If we can recognize it we might be better at it’s care and feeding.

You’re not always motivated

Like creativity, motivation is not always around when we would like it to be. Like most things in life, it has cycles. It ebbs and flows like a tide. Unlike a tide, it does not have a predictable schedule. We can’t control it. We just accept it as our reason for doing what we do.

What to do when you’re not

Sometimes we have to recharge. Sometimes we are so drained that we have to rebuild. Maybe we are at an inflection points in our life when our subconscious understands we need to change direction but our conscious mind is still struggling with it.

Be patient with yourself. Let it work. Feed your mind – read, study, be with people to keep from spiraling into depression. Wait for the motivation to re-engage and push you along. Motivation is a force. It is neither good or bad, right or wrong. It just is and it works on us.

But don’t just sit passively and watch TV while you wait. Work. Keep doing your art. Shoot; process; market. Stay busy. You may not be happy with what you are creating right now, but doing something is better than sitting around feeling sorry for yourself. Picasso famously said “Inspiration exists, but it has to find you working.” I believe it is the same for motivation. When we are working we are more receptive.

There is a “why” behind what we do. Sometimes we have to re-discover it. Occasionally, but rarely, it changes. Reflect on your motivation. Understanding it will help you understand why you feel it necessary to do what you do. That understanding can carry us through the dark times when we do not feel inspired.

Dodging and Burning

Classic Rocky Mountain Balck & White. This exhibits strong use of traditional dodging and burning.

I have mentioned dodging and burning before, but usually in the context of black & white images. Dodging and burning is much more general than that these days. They are techniques that should be known by all photographers.


We usually think of dodging and burning as something associated with black & white photography. This is because this is where they were invented and first applied. Ansel Adams and the masters before him used dodging and burning extensively to achieve the artistic look they wanted.

The technique has its roots in the chemical darkroom. Photographers discovered that during the sometimes minutes long exposure of a print, they could change the tonal values of the print by withholding or adding light to selected areas.

Remember that these black & white processes were built around negatives. That is, on the print material, the more light it receives the darker the area is and the less light it receives, the lighter it it. In the limit no light at all will give the white base of the paper.

Hence the origins of the names. The printer (a person creating a darkroom print) might use a small tool, usually a circular or oval shaped piece of paper on a stick, to shield a region from some of the light. This holding back some light was called dodging. It made the dodged region of the print lighter. The printer could also add light to a region, usually by cutting a small hole in a sheet of paper and using it to shield everything except the hole from the light. This was called burning. It made the region receiving extra light darker.

In today’s digital processing, the terms are archaic. I remember them by thinking that burning sounds like it would make it darker. They might better be called just lightening and darkening. In my LIghtroom process, I call these layers just “light” and “dark”.

What are they now?

In the more general sense, dodging and burning are a means of selectively changing the tonal intensities or other properties of regions of an image. We can do this in great detail now and it is not at all limited to black & white images.

I am fairly confident in saying that all images you see a professional fine art photographer print use dodging and burning. The artist may spend hours tweaking the relationships. It is so easy now and we have so much control relative to the chemical darkroom days that it would almost be foolish not to. It would be passing up a great opportunity to enhance the visual experience for your viewers.

Digital post processing

Virtually all software tools that photographers use have the ability to selectively adjust tones in regions. The different tools may use their own names for it, but they all do about the same thing. I will discuss Lightroom Classic and Photoshop since I am familiar with them.

Since we edit on a computer using software tools, we are no longer limited to it being a real-time “performance” in the darkroom. Artists back in the day had to repeat the lengthy dodging and burning process for each print. Now we can do it once to create our “digital negative”. Editing becomes a pleasant creative process we can enjoy in our office with a nice glass of wine and some relaxing music playing.

And because we are no longer limited to black and white and chemical processes, the range of what we can adjust is greatly increased. We use the same techniques to selectively adjust colors and sharpness and contrast. It is even almost trivial to remove distracting elements.

It’s a great time to be to be a photographer!

Lightroom Classic

Ah, a marketing blunder by Adobe. Renaming “Lightoom” to “Lightroom Classic” was an affront to photographers and a thinly disguised attempt to push most users to the (reduced capability) online version. Thanks. Now that I have that off my chest let me just say that I will call the product just “Lightroom”. Know that I mean the desktop version where I have all my images stored locally.

That out of the way, Lightroom is a fantastic product that is vitally important to a large percentage of photographers. It is where we store and catalog and search for and edit our image library.

In addition to everything else it does, Lightroom has very capable dodge and burn tools and they are being enhanced all the time. At the time I am writing this, Lightroom version 12 was just released. It adds some significant new features.

Lightoom has several selection tools for dodging and burning and general editing. They are called the linear gradient, the radial gradient, the brush, and color and luminence range. In addition, there are “AI-based” features to aid in selecting the sky, the subject, people, and objects.

The purpose of all these tools is to select a certain region of an image to modify. Once we have a selection there is a range of editing that can be applied, such as exposure, contrast, texture, clarity, dehaze, temperature and tint adjustments, saturation, and sharpness. This gives us a very fine degree of control of the look of our image, down to arbitrarily small regions. And a wonderful bonus is, all adjustments in Lightroom are non-destructive. Everything can be modified or rolled back however much we want, even all the way to the original image.


Lightroom gets more capable all the time and is used as the exclusive editing tool for many photographers. But Photoshop is the granddaddy, the patriarch. While Lightroom makes it easy to do a lot of things, Photoshop does not restrict us from doing anything. We can mash, bend, distort, replace and modify any of the pixels in an image. You can combine multiple images together. You just have to know how.

Adjustment layers with masks are a primary means of local adjustments. These layers can be used to do traditional dodging and burning adjustments. There are even tools in the Photoshop tool bar that do dodging and burning, but I would not suggest using them, since they directly modify pixels. The ability to use a non-destructive workflow is important in Photoshop. At least, it is important to me. Some people disagree. Do whatever works best for you.

There are probably 2 main ways to do dodging and burning in Photoshop: 2 curve layers or 1 overlay layer. The first uses 2 curves adjustment layers, one set to lighten about a stop and the other set to darken about a stop. Each has a black mask. By painting in white areas in one of the masks we can selectively lighten or darken.

The method I more often use is to create a layer filled with 50% gray and a blend mode of Overlay. Then when I paint lighter than 50% gray on the layer it lightens or darker than 50% grey it darkens. I like this better because it is only one layer and it is more intuitive to me to use white to lighten and black to darken.

Either method is easily alterable and non-destructive. Each can be set up by a simple Photoshop action.

It has been edited

So in today’s photography world, assume any image you see has been edited – a lot. It is easy. It makes our images better. We are making art, not documentary.

There are photographers who think any modification of an image is wrong. They are, of course, free to feel that and act on their beliefs. I feel sorry for them. They are severely limiting their artistic potential. And they are probably “stretching the truth”. They do some color and contrast correction. Maybe a little dodging and burning and vignetting. Take out an errant twig sticking in from the side. Be skeptical when someone tells you an image has not been modified. What is the limit of “purity” vs. “artifice”? Who sets the rule? Why should there be a limitation?

Dodging and burning and related transforms have been used since the early days of photography. Masters like Ansel Adams would never have become famous without them. That is why it took many hours to print an Ansel Adams print. Most people would say it was worth it.

If you are doing photography today, I believe you need to master dodging and burning and all the related tools we have to work with now. The tools are there for us to use to make our images better. The concepts are timeless, only the technology changes. The editing controls are there because we need to use them to achieve our vision for our images. Not using them is like tying one hand behind your back. Maybe it makes a statement, but it artificially limits you for no good benefit.

How Big Can I Print It?

A VERY low resolution image (3 MPix) that would print surprisingly well

One of the things we have to wrestle with when we want to make a print is how big can I print this image and get good results? And how large should I print it? There is a lot of advice out there. Some of it is good.

Film vs. Digital

Virtually all images have to be scaled up for printing. The print you want to hang on your wall is many times larger than the sensor or piece of film you start from. Hardly any of us are shooting 8×10 negatives these days. Even if we are, we still usually want to make larger prints.

The technology has changed completely from the film days. Enlargement used to be optical. By adjusting the enlarger lens and the distance from the film carrier to the print surface, the image was blown up to the desired size. If the lens is good, it faithfully magnifies everything, including grain and defects. If the lens is cheap, it enlarges and introduces distortion and blurring.

Digital enlarging is a totally different process. A digital image is an array of pixels. My little printer at my studio likes to have 300 pixels/inch for optimum quality. So if I want to make an 8×10 print and I have at least 2400×3000 pixels, it will print at its best quality without changing a thing. Digital enlarging is a matter of changing the number of pixels.

Digital enlarging

But usually I want to print a larger size than the number of pixels I have. Here the digital technology gets interesting. And wonderful. Going back to my example, if I want to make a 16×20 print and maintain best quality, I would have to double the pixels in each dimension. It would have to go to 4800×6000 pixels.

Photoshop has the ability to scale the number of pixels in your image. There are several algorithms, but the default, just called “Automatic”, usually does a great job. Here is the difference from film: software algorithms are used to intelligently “stretch” the pixels, preserving detail as much as possible and keeping smooth transitions looking good. Lightroom Classic has similar scaling for making a print, but it is automatically applied behind the scenes. Smoke and mirrors.

The result is the ability to scale the image larger with good quality.

Print technology

In a recent article I discussed a little of how an inkjet printer makes great looking prints using discrete dots of ink. There are other technologies, such as dye sublimation or laser writing on photosensitive paper, but they are far less used these days.

It should be obvious, but to make a really big print, you need a really big printer, at least in the short dimension of the print. Really big printers are really expensive and tricky to set up and use. That is why most of us send large prints out to a business that does this professionally.

Why do I say the printer has to be big in the short dimension of the print? Past a certain size, most prints are done on roll feed printers. They have a large roll of paper in them. Say you have a printer that prints 44″ wide. The roll of paper is 44 inches wide and many feet long.

We want to take our same 8×10 aspect ratio image and make a 44×55 inch print. If it was film, we would require an enlarger with at least a 44×55 inch bed and a cut sheet of paper that is 44×55 inch. But an inkjet printer prints a narrow strip at a time across the paper. The heads move across and print a narrow 44 inch long strip of the image, the printer moves the paper a little bit, and it prints another narrow strip. Continuing until it has printed the entire 55 inch length. Then the printer automatically cuts off the print.

But if we naively follow the recommendations for optimum quality, we have to scale our poor little 2400×3000 pixel image up to 13200×16500 pixels. Even the best software algorithms may introduce objectionable artifacts at that magnification.

Viewing distance

Maybe we don’t have to blindly scale everything to 300 (or 360) pixels/inch.

A key question is: at what distance will the image be viewed? Years of studies and observation led to the conclusion that people are most comfortable viewing an image at about 1.5 to 2 times the image diagonal length. This lets the natural angle of the human eye take in the whole image easily. For the example we have been using of the very large print, people would naturally choose to view it from about 105 to 140 inches.

Along with the natural viewing distance there is the acuity of the human eye. I won’t get into detail, but the eye can resolve detail at about 1 arc minute of resolution (0.000290888 radians for the nerds). Simply, the further away something is, the less detail we can see.

Going through the calculations, if our audience is viewing the large print from 1.5 times the diagonal, it only has to be printed at 33 ppi! Finer detail than that cannot be seen from that viewing distance.

I have heard photographers who have images printed for billboards or the sides of a large building talk about inches/pixel. It would look like Lego blocks up close, but it looks sharp from where the viewer is.

Nature of the image

This is true unless the audience is photographers. They are going to get right up to the print, as close as their nose will allow, to see every blemish and defect. 🙂 But normal humans will view it from a distance.

There are modifications to the pixels vs. viewing distance calculations depending on the nature of the image. If the image contains highly detailed structure it will encourage viewers to come closer to examine it. If the image is very low contrast, smooth gradations, it could be even lower resolution.

Printing at the highest possible resolution that you can for the data you have is always a good idea.

Your mileage may vary

How big of a print can you make? It depends – don’t you get tired of hearing that? It is true, though. The real world is messy and simplistic “hacks” often don’t work well. It is better to understand things and know how to make a decision.

When it comes down to it, these are great times for making prints, even large ones. My normal print service lists prints as large as 54×108 inches on their price list. I know even larger ones are possible.

How big should you print? How big can you print?

Conventional wisdom is that scaling the pixels 2x each dimension should usually be safe. My camera’s native size is 8256×5504 pixels. Scaling an image 2x would be 16512×11008 pixels. This would be a “perfect” quality print of 55×36 inches on a Canon printer. I have yet to need to print larger than that.

Given the perceptive effects of visual acuity, I am confident I could create much larger prints. Larger than is even possible by current printers. And they would look good at a reasonable distance.

A key question is who are you printing for? A photographer or engineer will be right up to the print with a magnifying glass looking at each pixel. Most reasonable people will want to stand back at a comfortable distance and appreciate the image as a whole. Who is your audience?

Learn how to scale your image without artifacts and how to use print shapening to correct for problems. Know the perceptual effects of human visual acuity. This is part of the craftsmanship we have to learn in our trade. Given those tools, the rest is artistic judgment. With today’s equipment and careful technique and craftsmanship we can create wonderful results.

Your mileage may vary.

The image with this article is very small – 3 MPix. I would not have a problem making a 13×19 print of it. I doubt you could see the pixels.

Have you tried to make large prints? How did it go? Let me know!

Pixels, PPI, DPI

Intentional pixelation

Pardon me, but sometimes the Engineer in me has to rant. I see so much confusion about pixels and how to scale them to an output size. Pixels are just an RGB dot. How they are presented is up to the output driver. It is complicated at a technical level, but it does not have to be complicated to us poor users. So let’s see what pixels and PPI (pixels per inch) and DPI (dots per inch) really mean mean.

What are pixels?

A digital file is just a rectangular array of pixels. The term “pixel” is a contraction of “picture element”. It is the smallest dot the sensor can resolve or the smallest point of light a display can produce.

Getting to the array of pixels is complicated, since camera sensors don’t read them directly. See my article “How We Get Color Images“. Regardless of what magic actually happens, by the time you view an image on your computer monitor, it is an array of pixels. Conceptually each pixel is represented as a triplet of (Red value, Green value, Blue value). Each of the values is a number from 8 to 16 bits in size. So each value has a magnitude of 0 to 255 or 0 to 65536. What sizes you actually have is determined by the capability of your sensor (the dynamic range) and camera and the color space you are using.

Pixels have no physical meaning. In the main camera I use, the array is 8256 x 5504 pixels. Again, it is just a number. It has no physical meaning. It has no relation by itself to a print size or the size of the image on screen.

What PPI should I use for display?

This is the thing that annoys me the most. I constantly see museum and gallery directors put out requirement that we have to send in electronic samples sized to 72 PPI. PPI stands for pixels per inch.

Way back in the dim distant past, computers only did text. Then Apple came along and wanted to do graphics. They did research and decided 72 PPI looked good on screen. This set the standard, but hasn’t been the case for eons of computer age. The display on my fairly old iMac is about 218 PPI, physically. But the magic 72 PPI stuck with a lot of people.

The increases in PPI density and bit depth and speed of monitors is one of the great technological advances of computers in recent years. All those pixels on screen makes for very sharp and smooth images. We can see so much more.

Worse, many people have been led to believe that the PPI sizing of the image files means something. It doesn’t anymore. Actually, it never did for images displayed on screen. The PPI setting has little or no meaning for an image displayed on screen.

Try it

Try an experiment: take an arbitrary, fairly large jpg file of your choosing. Let’s say the filename is MyFile.jpg. Load it into Photoshop and resize, WITHOUT RESCALING, to 72 PPI. Save it as MyFile-72.jpg. Now reload the original file.jpg and size it to 360 PPI. Again without rescaling. Save it as MyFile-360.jpg. Rescaling changes the number of pixels in the file. We just want to change the PPI setting. These 2 files now have the same number of pixels but different ppi scaling.

Now use whatever image preview application you like and view the 2 sized files. Is one of them 5 times larger than the other? On my system, they are exactly the same size on screen. Even though one is set to be 72 PPI and one is 360 PPI. They are displayed as the same size and the same resolution.

Why is this? Because the file PPI setting means nothing. The display app just looks at the number of pixels and decides how large it is going to make it. If it is a tiny image, say 300×200 pixels, it will probably make it very small to avoid pixelization artifacts when an image is enlarged too much. It it is a reasonable sized file, it will just pick a good output size. It makes these choices based on the number of pixels. If the image is in a web page, the web page code determines the size the image will be.

What PPI should I use for print?

Now we head into an even more confusing area, and here the confusion is somewhat justified. Printing is it’s own special world. The technology and perception is very different from displays. Displays emit light. Prints reflect light. The effect to the viewer is very different.

Printers don’t have pixels. Instead, we refer to the output scaling as DPI – dots per inch. This recognizes that we are now talking about physical marks on paper (or your substrate of choice).

The printer manufacturers have created tremendous confusion in customer’s minds because they overload terms. The Canon Pro-1000 printer I have at my studio has a specified print resolution of 2400 DPI horizontally and 1200 DPI vertically. Yet the optimum print resolution is 300 DPI. That is, when I am creating a print, I should try to set the output resolution to 300 DPI. This is bound to confuse most people. Why not set the output to 2400 dpi for maximum resolution?

How inkjet printers make nice prints

We come to one of the secrets of printers. We customers want prints with crisp lines and smooth gradations of color and tone. As natural as film used to be, or as smooth as the original artwork we are copying. An inkjet printer sprays dots of ink onto the paper. A dot or no dot. At the level of a single dot, this is not smooth. Inkjet inks do not “mix” to create new colors.

So take my Canon printer as an example. Each “dot” (at 300 per inch) is actually subdivided into an 8×4 grid – 8*300 is 2400 dots per inch horizontally. Any position in this 8×4 sub-grid can contain any combination of printer dots of any of the 12 colors. The print driver uses a magical algorithm called “error diffusion” to cover the sub-grid with a blend of printer dots of the available colors that simulate the color and intensity of the pixel to be printed there.

It is mind bending in it’s complexity. One reason they don’t talk about it much is that it is proprietary for each manufacturer and printer, a closely kept trade secret. The good news is that they take over this complexity so we don’t have to. And they do a very good job. So I set my image to print at 300 DPI and magic happens.

It usually doesn’t matter

In summary, PPI settings do not matter for images displayed on your monitor or on the web or sent to your social media account. If someone tells you they need their images scaled to 72 PPI, just smile and do it, but secretly know they do not know what they are talking about. Only the total number of pixels affects the size of the image. And without going into mind numbing detail, I hope this takes a little mystery out of the way printing works.

I feel better now. 🙂 How about you? Are you more or less confused?