Focal Distance

Woo-hoo!  We’re finally there!  Focal Distance is the final basic term/area we need to cover before we can start talking about how we put the five variables to work for us to create fun and exciting images.  In my very honest opinion, based on a ton of experience teaching those who have been to “photography schools”, taken “Photography 101 and 102” in college, and even those who have “read the manual”, if you truly understand even the basic explanations we’ve covered in Shutter Speed, Aperture, Focal Length, ISO and now Focal Distance, then you’re further along in your understanding and knowledge of photography, and ready to make great photographs, than the above graduates.  Sure, they cover this material in-depth in such courses.  Often too much depth.  More often the student cannot visualize what they’ve learned which makes it extremely difficult to apply it in a practical sense.

Purposely I’ve kept the explanations of these areas simple, brief (I know it doesn’t seem like it considering my tendency towards verbosity), and visual.  As we start using these variables to discuss composition I’ll be feeding in more bits and pieces of information exactly where the information can be applied.  Hopefully this will work better than having everyone read the book, memorizing, and hopefully remembering much later during application.  If needed please review the five variables in the appropriate weekly columns as often as you need to maintain.  Most likely you’ll find you need to re-read certain sections during the discussion of application more than a few times.  This is normal, stick with it and soon the information will be tattooed on your frontal lobes.   It will starting being a load of fun when even those of you with no previous photographic experience start turning out some really good works!

Focal Distance.  This one is easy.  It’s the physical distance from the film/sensor plane (in a film camera the actual film, in any SLR or DSLR from the mirror) to the subject.  The subject could be a person standing ten feet away, or the mountains being the standing person which are ten miles away.  Looking at the scene you as the photographer decide what the subject(s) in your scene will be, and then you’ll expose and focus for those subjects.

Focal Distance determines perspective.  Most people, even many professional photographers, are under the impression that “focal length” (of the lens) determines perspective.  It doesn’t.  Focal length merely allows you to fill the frame with the subject at a further or closer distance.  This is all focal length does.  Focal distance, is how far away from the subject you are and this is what determines perspective.  For some reason many find this a hard concept to swallow, try not to make this more difficult than it needs to be.   Keep it simple and you’ll be able to visualize it much sooner.

Usually the next question I get is “why do we have different focal lengths then?”   Good question, why the vast array of lenses ranging from the super wide, to the super telephoto?  Working distance is a big factor.  You’ll probably want some distance between you and the hungry tiger, but maybe not so much between you and the pretty nude model in your studio.  Using perspective control (by varying focal distance) you can make a human subject appear to have a bigger nose and ears and flatter face than you’d normally notice in real life, or on the other end a slimming effect better known as a compressed look.  For instance, if I want to photograph a crusty old man and accentuate the features that make him crusty then I’d probably choose a wide angle lens that makes his ears, eyes, and nose appear large along with his other facial characteristics.  If I wanted to photograph a beautiful swimsuit model and accentuate her great shape and make her look a tad bit slimmer, then I’d use a telephoto lens.  Almost 100% of the time when I photograph swimsuit models outdoors I choose my Canon 300mm F2.8 IS lens.  This gives them a slimming / compressed effect which is normally desirable.  And you should never underestimate the instant respect and cooperation you get when you pull out that long/big white lens which sets you apart from those with average sized lenses.  It sounds funny, but the models do perk up and become more willing to work harder and more cooperative because you’re giving the appearance of looking more professional.

Sometimes you’ll have two subjects in a scene, and two focal distances, sometimes more.  In the below sample I had a focal distance from my camera to the big log on my left, and the focal distance from my camera to the ocean background.  By adding the log, and keeping it in sharp focus, I added a reference point and an additional dimension to a rather bland scene.  This doesn’t work and doesn’t have the right effect unless both the log and the background are in sharp focus.  This is where a very wide lens (in this case a 12mm) and a very small aperture become necessary.  The focal distance between my camera and the log was less than six inches!  The focal distance between my camera and the horizon was probably about eleven miles.

Horizon with 12mm Sigma

In the below example I used the same 12mm wide angle lens to “encompass” the passageway.  When using such a wide lens controlling perspective becomes critical.  Perfect 90 degree angles from the floor, against the walls, and more becomes necessary other wise what appears to be severe distortion takes effect.  In this shot I set up my tripod, carefully leveled the camera, and took the shot.  The full size version shows every detail of every brick and piece of wood in the scene and it feels like you’re standing right in it.

Temple corridor in black and white

In the example below I wanted to get the very tip of the elephants trunk in focus, as well as his eyes and other parts.  This was shot at 14mm with a focal distance of less than two inches!  Yes, his trunk was actually touching the front of my lens at times while I was taking this shot.  If I had tried to take this shot with a 50mm lens and not the 14mm lens, I would have achieved getting the front of the trunk in focus, but only being able to get about half way up his trunk in the scene.  The wider coverage of the 14mm lens allowed me to get the entire elephant in the scene.  A fun shot I’ll always remember taking.  It won’t win any awards, but it will make me laugh every time I look at it and remember his trunk bumping my lens in curiosity.

Big trunked elephant

My final example was shot with a 300mm lens and a focal distance of approximately 100 meters.  The young lady looked lovely and I didn’t want to intrude on her private thoughts as she looked over the river while standing alone.  The working distance was so great she didn’t even realize I took the photo until later when she turned away I approached her and asked for her email so I could send her a copy of the picture I took.  My habit is to email images to as many of my subjects as I can, a way to say thanks for the enjoyment they’ve provided.  You end up amassing a lot of names, phone  numbers, and email addresses, so a good system to keep track of them is necessary.  I find the voice tag recording feature of the professional series DSLRs to be very handy for this.  It attaches a small sound file to the appropriate image of your voice recording the pertinent information.  You also make a lot of new friends by sharing the images.

Lone girl at a temple

Focal Distance controls perspective.  Focal length controls focal distance.  You use perspective in the composition of your image.  This is all you really need to know about focal distance and I’ve given you some fun examples of how it’s used.  Next week we’ll be discussing how to use all five variables to get the desired depth of field in our composition.  Until then review as necessary.