Ed Schlotzhauer

An artists journey

Category: Technology

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

  • Is Black & White a “Thing”?

    Is Black & White a “Thing”?

    Is Black & White photography an art form in its own or is it a way to salvage images that just didn’t work in color? Hear me out before you flame me. I love B&W and believe it is a special medium.

    History

    Black & White is where we started. It is our history and beginning. Looking only at commercial films, the early world was totally black & white. There were a variety of film designs, with tradeoffs of speed, contrast, fog level, etc. Because processing was done chemically, the entire roll had to be exposed at the same speed. Generally, a photographer became familiar with a handful of films. Lots of work was required to become familiar with the film’s exposure characteristics. Different films were selected for different uses and effects.

    In the black & white days lots of work was done in camera to adjust the tone values. Filters, usually red or orange, were used while shooting. Their selection was based on the artist’s subjective judgement of predicting the outcome.

    The system worked pretty well for decades.

    Color

    Then along came color. It really took off in the 1950’s with the introduction of Kodachrome.

    Finally ordinary consumers had what they thought they were missing – a color image. Color film sales dominated black & white.

    Digital

    In the early 2000’s digital cameras became practical and affordable. Now color film was eclipsed and it virtually disappeared from the market. Digital had better resolution, better dynamic range, it was cheaper, and we could print our own pictures on cheap inkjet printers.

    So why, with all these advances, does anyone care about black & white anymore?

    Digital saved black & white

    The technological benefits that made digital imaging take over mainstream photography also brought huge advances to black & white images. A modern sensor is amazing. It captures more information than black & white film and it captures and retains the color information. This can be used later to tailor the tonality of the b&w image. And it allows far more control than color filters and a chemical darkroom.

    The tools we have, like Lightroom and Photoshop, are very advanced and are able to exert a degree of control that would have been unthinkable in the film days. At the same time we have highly mature multichannel inkjet printers with sophisticated inks giving us archival prints. Added to that the development of many types of papers for printing and the options available to a black & white artist today makes this a golden age.

    Why black & white?

    But color is readily available and everyone can print it cheaply. Why would anyone still want black & white?

    This gets to the heart of the issue. A black & white print is perceived as an entirely different experience. Black & white sheds the distraction of color. What is left is tones, shades of gray. These emphasize the shapes and forms of things. Composition and graphic design comes more to the fore. It is an alternate view of reality. That causes us to look at the image differently.

    This difference is the beauty of it. It is a different interpretation of the world. The viewer immediately sees it is different and the artist can lead them through his composition more easily to see what he wants to emphasize.

    I have heard photographers say “this didn’t work in color, lets try black & white”. That is a very limited perspective. I would turn it around and say “this image really needed the color information to make it work, so we can’t do it in black & white”.

    Ansel Adams once said “the negative is the score, and the print is the performance”. This is still true, except the negative is a raw file and the print and processing are all done digitally. No dark room. No chemical mess.

    So is black & white a thing in its own right? Definitely! It is a great art form with a long and glorious history. Today is the best time ever to be doing or viewing black & white images!

  • The Sensor

    The Sensor

    Putting up a nice safe technical post this week. What is the sensor and why do I care? If we just click the shutter button and expect to see magic happen on our screen, isn’t that enough? No, I obviously do not think it is enough or I wouldn’t be writing about it. The sensor is the heart of the technology of image capture. Without a great sensor none of this would be possible.

    History

    Going back, there was rubbing pigment on the wall of caves – Oops, too far. Photography as we would recognize it started in the early 1800’s. Motivated photographers had to mix their own chemicals and wet coat their own glass plates, in the field, in the dark, right before exposing them, then processing them quickly, in the dark, in the trailer they brought. Not for the short attention span crowd.

    In the late 1800’s Kodak produced commercial coated transparent film, on a nitrate base. Keep it away from your candles – poof. A few years later cellulose based safety film was invented and replaced the dangerous nitrate film.

    Around this same time roll film was also invented, so more than one exposure could be made before changing film. This was a contribution to most photographers. Leica’s adaptation of the 35mm film size and the development of an excellent, small hand held camera system greatly advanced the use of photography. In 1935 Kodak released one of the greatest advances in photography – Kodachrome film. Color photography was finally practical and it became very popular. A very large market for both color and black and white film developed with Kodak, Fuji, Agfa and many other brands vying for position.

    This is not an exact history of the development of photography and all of its branches. The point is that the technology of recording images has always been central to photography and it has been a subject of heated discussion/argument by photographers. I have witnessed people almost coming to blows about Kodachrome vs Fuji Velvia.

    Film Was Our Sensor

    Most “serious” photographers had their 2 or 3 favorite films that they used regularly. They learned the characteristics of each well enough that they could predict the results. This is very important, because photography has always been a mixture of technology and art. How the sensor (film) records light is necessary to know so the artist can determine how to use it to achieve the results they want. Pushing the limits of the sensor technology was a common artistic effect.

    But then photography’s “shot heard around the world” happened in 1975. From Kodak’s web site: “Kodak invented the world’s first digital camera. The prototype was the size of a toaster and captured black-and-white images at a resolution of 10,000 pixels (.01 megapixels).” From that trivial sounding start, Kodak killed it’s own business and the multi-billion film business around the world. Digital sensors forever changed the course of photography. And this was a good thing for photographers.

    Digital Image Capture

    Image capture in a digital sensor is completely different from film. Instead of photons of light causing a chemical reaction in the film, the photons caused the emission of electrons in the sensor chip. These electrons are accumulated over the duration of the exposure, then transferred out serially and sampled to “count” the electrons. From this, complex and high speed processing reconstructs an array of “pixels” (picture elements) which is so dense it fools our eye into seeing a smooth image. This constructed data set is recorded onto a memory chip in the camera. Then usually transferred to a computer.

    Over the years, good engineering has improved the process so much that few people still argue that images from film are superior to digital captures. My personal transition happened in about 2004. I finally concluded that the Nikon D70 was at least at parity with 35mm film. That was a 6 Mega Pixel sensor. The image accompanying this post was shot with that camera. Now, when I look at a good quality scan of a 35mm slide compared to a capture off my 47 Mega Pixel Nikon Z-7 sensor I have to shake my head and marvel at the improvement of our photographic technology. Yes, some of this comes from greatly improved lens design, but the sensor is one of the biggest effects.

    So with digital sensors I am free to push the limits more, to experiment more, to have more fun with photography, to post process to a much larger degree. Sensor development has removed many of the barriers of resolution, dynamic range, reliability, noise, etc. Photography now can be driven more by artistic vision than by a struggle to produce a usable image.

    Do We Need To Understand the Technology Anymore?

    Do we as artists need to know about the technology of our sensors? I believe YES. Photography is unique in being a strong mix of technology and art. A good craftsman cannot ignore either of them. These marvelous devices must be understood to be used to their full potential. Digital sensors have limitations and their own quirky characteristics. Dig in; understand the transfer curves; understand the dynamic range; understand the behavior at maximum brightness or darkness; understand noise; understand moire patterns. Understand other related things like the focus system in your camera. Nothing is trivial. But have a very high regard for the sensor.

    Much more can be written about the sensor. I may in the future if requested. As an engineer I enjoy digging into the technology.

    To the sensor developers at Kodak and Nikon and Canon and Sony and Fuji and all the others – Thank you!

  • Does DPI Matter?

    Does DPI Matter?

    People sometimes get hung up on DPI like it really matters. It doesn’t, at least not in the way you may think. The number of pixels matters. The scaled resolution of an image to print matters. DPI is just a setting and an indication of when scaling is required. Where I’m really going is to say an artist must be a craftsman with his tools and technology.

    I get information from people all the time requiring image previews at a certain DPI. One client even required images at 72 DPI stating that it was for my protection – implying that a lower DPI image wouldn’t be copied or stolen.

    The number of pixels is what is important. DPI is just a setting. You get it by taking the dimension of the image in an axis and dividing it by the desired print length of the axis. So if I had an image that was 3000×3000 pixels and I wanted to make a 10×10 inch print, 3000 / 10 gives 300 DPI. This is a good resolution for printing. I know from looking at the DPI that no additional scaling or interpolation needs to be done.

    But what if I wanted to print that same image at 30×30 inches? In this case the DPI would be 100. I know that is too low. To print it well I should scale and interpolate it to at least 240 DPI. This is simple to do in Photoshop and Lightroom and various other tools are available to do it. So the DPI is really only useful as a metric to the person making a print or for a designer creating a layout. How did I know 100 DPI was too low? I have to know that. That is where I’m going.

    What’s the use of even bringing it up then? Well, I believe it shows a certain lack of rigor or even understanding by the people using the digital products. Too many artists say “I’m not technical. I just do things by feel.” That is too simplistic in the digital world. It is great to say you’re more interested in the artistic outcome than the technology. I agree with that. But pixels and sensors and lenses are the tools and resources we work with to create. An artist has to be a craftsman who knows his tools well. He has to know when and how to scale a collection of pixels to create an excellent print. He has to know when and how to sharpen an image to make it look great without introducing artifacts of over sharpening. He has to know how to do black & white conversions. He has to know how to do color corrections and tone mapping to achieve the look he wants. These things are specific technical skills and require knowledge of what is being done and why.

    I’m not saying an artist or craftsman must use the latest, best, most expensive tools. No, use the tools that you’re comfortable with and that work for you. But master them. Whatever your tools, you should be an excellent craftsman with them.

  • Technology is Important

    Technology is important in photography, maybe more than most other arts. I sometimes hear photographers say “I’m not interested in the technology; I just want to make pictures.” This seems to usually have one of 2 meanings: either they really do know the technical side but they are making an exaggerated statement to say that artistic considerations are more important, or they really don’t consider the technology. This later group is needlessly limiting their potential.

    The term “photography” comes from Greek words meaning “writing with light”. It is a good name. Photography is unique among arts in that (for the most part) we start by capturing something that is there in front of the camera. Most other visual arts start with a blank canvas and the image has to be built from scratch by the artist. I’m not arguing that this makes photography more of less valuable than, say, painting. Just that the process is different.

    Since we are capturing something that exists, we must know how to use the tools we have to maximize our success. Taking digital image capture as the norm, there is the lens, the camera body, the image correction process, and the creative manipulation process. Modern photography absolutely requires a good computer system.

    • Lens : The focal length and maximum f/stop determine the envelope of what can be captured for a certain scene. The focal length sets the magnification or “cropping” or framing of the subject. The f/stop choice determines the depth of field — the relative amount of the field of view that is in acceptable focus. They also interact to control the amount of light entering in to the camera sensor.
    • Camera body: In a typical modern camera this controls the exposure, the focus, the shutter speed, the image capture, and the initial image processing. Exposure is a combination of the ISO speed (the relative sensitivity setting of the sensor), the aperture, and the shutter speed. The image is captured on the sensor, a large silicon chip. The sensor is perhaps the most critical piece of technology in the system. It has a maximum number of pixel it can capture and a dynamic range — the range of brightest to darkest data it can record. The data coming from the sensor is not the image ready for viewing. It must have sophisticated and high speed processing done to it before it can be written to the memory card or even previewed on the back of the camera.
    • Image correction: Even after the processing done in the camera, every image needs some correction. This is not a flaw, it is a required part of the process. Typical processing at this stage include color correction, a little bit of sharpening, some tone correction (e.g. reduce highlights and/or raise shadows), and cropping.
    • Creative manipulation: This is a later stage of processing, maybe using in the same software; maybe not. This may include tone mapping, black & white conversion, removing extraneous objects, compositing images together, blurring, sharpening, and many other operations.
    • I’m not even considering here the final output. This can be prints, web postings, stock images, etc.

    This is neither a tutorial of digital processing or meant to scare you away from photography. It is just stating what is involved to do a better than average job.

    The point is that a good artist will have an excellent working knowledge of every one of these steps. Each one is an important factor in determining the final outcome. You have to become very familiar with your tools. It is necessary to work with them over and over for so many repetitions that they are second nature. An artist must make dozens of conscious decisions, often in a fraction of a second, in the dark, or in bad weather, to get the result they envisioned. This might be heresy to many, but my opinion is that an old camera you are intimately familiar with is better than a sophisticated new camera that you don’t know how to use quickly. (So get the new camera and spend a lot of time learning it 🙂

    Any visual art involves making things. Making things requires tools. A good artist learns their tools well. This is one of the things that separates the good ones from the mediocre. When I hear someone say “I don’t do technology” I interpret it to mean “I’m not serious about my art.” Is that unfair? Not to me, but let me know what you think.

  • Yes, You Need to Backup

    Sorry. I know no one wants to think about this dirty subject, much less talk about it. But is is a necessary part of a digital artist’s process.

    Back in the “good old days” images were created on film. You kept the film in holders or sleeves in a file of some sort. Barring major fire or flood, you were pretty well backed up. The negatives or slides were fairly insensitive to water, tolerated a wide storage temperature range, and would last for decades or longer.

    Forward to today. It has been many years since I exposed a piece of film. ALL my work is digital. And all the derivative works I create are digital. There are significant advantaged to digital images, but there is one glaring, horrible downside: when the disk they are on dies, they are gone. They are not a physical object.

    Oh, but disks are very reliable. You can’t remember the last time one of yours crashed. (Cue whistling in the graveyard music). Here’s the reality: your disk is about to fail and there is little ability to predict when. After it fails is not the time to be doing a backup.

    In a past life I was an engineer, so I know something about this technology. I’ll try to keep it pretty basic. Most of us use rotating magnetic storage (e.g., the hard disk). This is an amazing technology. Bits are stored as microscopically small magnetic blobs on platters of metal spinning at, typically, 5400 or 7200 RPM. The data is read and written by “flying heads” that fly above the surface of the platter a few micro inches away. This is like a fighter jet flying at supersonic speed 10 feet off the ground. It’s a wonder it works, but it has been engineered with enough layers of protection to make it very reliable. The other fast growing technology is Solid State Disk (SSD). It is completely different and usually much faster. Just because it is smaller and faster does not make it more reliable. There are many more failure modes associated with SSD than rotating disks.

    What does this matter to me? My disk drive is rated at 1,000,000 hours MTBF (mean time before failure). It should be good practically forever. There is a reason disk makers throw out numbers like that. They are very impressive without really meaning much. It is a statistical measure of a large population of devices. It does not mean yours or mine won’t fail tomorrow.

    What to do? The ugly “backup” word. I won’t recommend specific software or hardware, except to say if you are using Macs, please turn on Time Machine immediately. Instead I will give you an idea of the paranoid extremes I go to.

    Yes, I use Time Machine for one level. It is a marvelous invention. It backs up my images and the computer every hour. My images are actually stored on a RAID drive. This means the information is redundant and one drive can fail with no loss of data. My drive is also very fast. The data on this RAID disk is also backed up daily to 2 other RAID drives. All of this is completely automated and requires no attention from me. About once a week I rotate a copy of my image data to off site storage, so it is backed up in another physical location.

    I’ll confess it again: I am paranoid about this. But the last 2 times my computers crashed I didn’t lose anything. I use (and love) SSD as my main computer storage. I have stacks of rotating disks with many terabytes of data on them. With a good backup plan I don’t worry at all about losing data.