Introduction to Digital Photography, An Overdue Course Syllabus

Upper Garwin Falls, Wilton NH

Green River Falls, Guilford Vt

I am in the middle of my Introduction to Digital Photography Class at Keene Community Education. I have been offering this 4-week course, twice a year, for several years and I continue to be amazed at what seems to be an endless supply of local people who are desperate to learn about how to use their digital cameras. The class has never failed to be fully booked immediately after the course is announced.

The program includes 8 hours of class time and two photo shoots to nearby locations. Eight hours is not enough, but during that time I try to cover a broad range of topics. In the first class, I start with a discussion of the features offered by various classes of cameras and how to approach learning the mind-boggling array of features.  I show how and where to upload and archive images and the advantages of different image file types (emphasizing RAW of course). It is a lot to pack into the first two hours.

Rockport Ma

In subsequent classes I cover the control of exposure, approaches to composition and the opportunities and challenges of shooting in various kinds of light. Somewhere in there I try to squeeze in discussions of image sharpness, focus and control of color balance.

Old Home Day, Chesterfield, NH

It is a lot to explain and in preparing my classes I have drawn heavily on the discussions I have written in many of my blog articles. My students often ask whether I have a course syllabus and I generally direct the to my blogs. Most of the information and examples are there, but it is not always easy to find. Included here is a list of links selected from over 400 blog articles that cover the key areas of my course. They are organized to roughly match the order of the classes. Hopefully these chapters will also provide a helpful introduction to the amazing world of modern digital photography for those who will never be able to participate in any of my classes.

Central Square, Keene NH

Nuts and Bolts

My first class is generally the most challenging for the students and myself as it includes such a broad range of topics. The relative advantages of large sensors and small sensors, lossy vs lossless file types, and the long list of approaches to image archiving are just a few of the topics covered.

• What Camera Should I Buy (Part I)
• What Camera Should I Buy (Part II)
• Spray and Pray
• Digital File Types
• Image Backup for a Long Journey
• Dead Tree Photo Archiving
• Foot Photography

Intro to Digital Photo Class, Spring 2018

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Exposure

Exposure is not just about the brightness of the image. How we combine Aperture, Shutter Speed and ISO also effects important aspects of the imaging, including depth of field, portrayal of motion and image noise. 

• Exposure, the Basics and More
• Exposure - The Basics Part Two
• ISO Control
• Using the Histogram
• Exposing to the Right
• Diffraction and Best Lens Sharpness

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Composition

Lower Purgatory Falls, Wilton NH

The “Rules of Composition” should never be allowed to restrict your own creative vision, but they can provide some helpful starting points. The rules are all based on what looked balanced and beautiful to the eye of others, and what works for your eyes has equal validity. Picasso said “We all know that Art is not truth.  Art is a lie that makes us realize truth”.  Your compositions should be a path to realizing your own personal truth.

• Compositional Guides
• Cropping, Less is Often More
• Drawing the Eye
• The Power of Diagonals
• Head and Nose Room
• Avoiding Distractions
• Lets Get One Thing Straight
• Spacing in Your Photographs, Avoiding the Overlap
• A Vertical Rut ?

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Using Light

In New England, the light is always changing. Whether it is the warm beauty of the “Golden Hour” or the harsh brilliance of the midday sun, it is important to recognize the conditions, and plan your shooting to respond to the challenges and the opportunities that they provide.

• Working With the Light (Part I)
• Working With the Light (Part II)
• White Balance
• Favorite Light for Spring Foliage
• The Magic in a Sunny Day
• Photography in the Lead Hours (New England Photography Guild Article
• Flash Photography 1, Cute Little Owen!

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Sharpness and Focus

The apparent sharpness of and image is not only related to proper focus, but also the steadiness of the camera. These are important topics, but I never know where I will be able to slip them into my presentations. It usually depends on how many questions I must answer and how many images I end up critiquing. 

• Tips for Sharp Focus
• My Problem with Monopods
• Lens Cleaning, If You Must
• Back Button Auto-Focus
• Protecting Your Photographic Jewels
• Protecting the Equipment

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Final Thoughts

Here are some of my random thoughts about art, photography and the state of digital photography’s place in the world of fine art and media. It is the kind of “artsy” talk I pledged to never use when I started my blog more than 10 years ago.

• Why I Photograph
• Is Photography Art ?  Is it a Craft
• Find Rather Than Search
• "No Budget for Photography", The Devaluation of Photography

Jeffrey Newcomer
www.partridgebrookreflections.com

Diffraction & Best Lens Sharpness

As a landscape photographer, I am frequently striving to capture the maximum depth of field possible, but as is true of all photography, compromises need to be made on the path to the sharpest images.  The widest DOF is obtained at high f stops (small apertures), but with ever smaller apertures diffraction begins to affect sharpness, making images progressively softer.

Yikes, Physics

http://innovativescience.blogspot.com/2011/02/diffraction.html

Diffraction is a property of light related to its behavior as a wave.  Light passing through a lens does not focus sharply to a point, but spreads out as it is bent around the hard edges of the iris. The result is a soft bull’s eye, which is called the “Airy disk” and results in a softening of the detail in an image.  The name “Airy disk” may seem remarkably fanciful, especially originating from optical

Airey Disk:Wikipedia

engineers, but it does not come from its soft airy appearance.  The fact is that the guy who discovered the disk was named “George Airy”.  Diffraction is an innate property of light and not a defect in the lens.  It is present in even the most precisely constructed and expensive lens and grows worse as the aperture becomes smaller.  A few weeks ago I demonstrated the star burst effect created by diffraction on Christmas lights when small apertures are used.  The effect is minimal when the lens is wide open, but other optical defects such as spherical aberration, diminished sharpness at large apertures.  The balance of these competing effects means that the sharpest f

Starburst Effect

stops tends to be those a few stops smaller than wide open.  A lens is “Diffraction Limited” at the f stop beyond which the image begins to soften.   This is a property of the lens and not the camera, but since a lens’ Airy disk is the same absolute size on any camera, the effect tends to be relatively larger and therefore more prominent in cameras with smaller sensors and with higher resolution.   It is great to have all those pixels, but crowding all those smaller elements on the sensor means that the lens will be diffraction limited at a wider f stop.  Physics sucks doesn’t it ?  The properties of every lens/camera combination are different and the only way to determine optimal sharpness is to test it.

The Test

Fortunately, testing lens' for their sharpest f-stop is not difficult.  You start with a target that is flat and has sharp detail.  I used an antique map of Vermont and New Hampshire.  I taped it to the glass on a photograph hanging in the kitchen and then set my camera on a tripod, aligning it so that the plane of the sensor was parallel to the target. I precisely focused on the map using the camera's Live View and used mirror lock-up and a cable release to avoid any vibration. With the camera set on aperture preferred, I  recorded a series of images covering the full range from wide open to the smallest aperture.  The result was a collection of images that I could quickly scan to find where image sharpness began to break down as the f stop increased.

 

The Results

Actually I was pleased to find that the loss of sharpness at small apertures was not as bad as I had expected.  I was able to identify the optimal f stop (usually between f/10 & f/16), but I also got a feeling for how far I could reasonably push the aperture when I needed more depth of field.  For my 100mm Macro, I found that the images were sharpest around f/8 - f/14, but that I could still get reasonable results up to at least f/22.  It is important to remember that this analysis does not take into account the power of sharpening algorithms to salvage sharpness when the results are marginal. 

 

Landscape Dilemma

So what can we do when extreme depth of field is needed?  Sadly I can’t afford a tilt-shift lens, but, now that I know how far I can stop down before diffraction significantly rears its ugly head, I can more intelligently balance the impact of DOF vs. Sharpness and I can apply post processing sharpening to correct some of the problems.  This is also a situation where focus stacking becomes extremely valuable. Multiple images at lower (and sharper) f stops, progressively focused through the scene, can be stacked and blended to get deep DOF with consistent sharpness.  The digital camera once again defeats the apparently immutable laws of physics – take THAT Newton!


 Photography is always a matter of compromise as our artistic vision collides with the limitations imposed by the physical properties of light, optics and camera sensors.  How these limitations are balanced has much to do with the outcome and knowing the most about the capabilities of your equipment is the key to striking the best balance.  Testing your lens' for their optimal sharpness is just one piece of the necessary homework required to get the most from your equipment and the best expression of your vision from the digital Camera.