phantom-thought

wekilledamandapalmer:

In the Bag of Photographers tricks there are about ten easy technical techniques that make people think your photos are better than most other people’s. One of these, and it’s a big one is depth of field.

Depth of Field (or DOF if you’re writing it) refers to the area that’s in focus in any given photo. DOF can either be “deep” or “shallow”. A shallow DOF is one where very little of the image is in focus, a deep DOF is, well, where things from near the lens all the way out to the horizon are in focus. If you leave your camera set on “program” it selects both the shutter speed and the aperture, assuring you that your images will be properly exposed but not giving you control over the depth of field, moving the camera off of “program” does two things — 1) it gives you more control over the final image and 2) more of your photos will probably be blurry or improperly exposed — you live and learn.

Anyway, today modeling DOF we have the Fabulous Cabal, K9 extrordinare.

This is a deep depth of field — Cabal’s in focus, the house is in focus. To most people this looks pretty “snapshotty”.

Now, a similar shot with a very shallow depth of field (Cabal seen here with his person, Neil Freaking Gaiman):

Here Cabal’s in focus, his person is in focus, but the ground in front of them is blurry and the house behind them is very blurry. This serves to isolate the subject and, for some reason, we go “wow” when we see photos like this. As you can see, this technique isn’t just useful for photographing dead Amanda Palmers but very useful for all sorts of photography (including dog portraits). Learning how to do it isn’t difficult.

OKAY, YOU SOLD ME, HOW DO I DO THIS?
There are two factors that influence depth of field, one is the distance from the lens and the other is the aperture of the lens. The closer the subject is to the lens the shallower your DOF and the wider the aperture of your lens the shallower the DOF. If you’re using a point-and shoot that doesn’t allow you to control the aperture of your lens, you’re mostly out of luck. But one of the reasons that you blew your graduation money on an SLR is because of all the extra control it gives you over your images. The trouble with SLR’s is that they usually come with a very unremarkable zoom lens and most people never get more lenses, significantly reducing the usefulness of the camera.

A really great lens to have for shallow DOF shots is the venerable, inexpensive, and much overlooked 50mm f 1.8. If you don’t have one, I recommend picking one up — like today — it makes a very nice second lens to go with the zoom lens that came with the camera.


you can find these for any of the major camera manufacturers in the $60-100 range used and not terribly much more new.

DESCRIBING LENSES: WHAT THE HECK DO ALL THESE NUMBERS MEAN?
Lenses are described with two numbers their “focal length” which tells you how wide or narrow the field of view will be, and an “f-stop” which will tell you the amount of light the lens lets in. So a 50mm f 1.8 is a lens with a focal length of fifty millimeters which is a pretty “normal” field of view (28mm is a “wide angle” and 100mm or more is “telephoto”), and has a maximum aperture of 1.8

The aperture or “f-stop” of a lens is the size of the hole through which the light passes. This is adjustable though the numbering system used is a little weird. The smaller the number, the larger the hole (and the shallower the DOF) which seems a bit counter-intuitive. f 1.8 is a big hole, it lets a lot of light through:


conversely, f 22 is a very SMALL hole that lets not much light through and gives a deeper DOF


USING YOUR LENS FOR SHALLOW DOF
If you don’t have a 50, you can use the maximum extension of your zoom lens at the smallest f-stop it has (which will probably be something like 120mm at f 5.6) this will do until you get something better). So set your camera on manual, set the f-stop as low as it goes (smallest number) and then adjust the shutter speed until the image is properly exposed (you can either use your camera’s meter or do what i do, take a picture, look at the image on the camera’s screen and adjust accordingly) once the image is properly exposed, get close to your subject and get them a good distance from the background to give it a chance to blur out. After that — start shooting.

BEST LENSES
If you like this technique and want to investigate it more fully, you’ll be spending some money on lenses. Lenses with extremely shallow depth of field are the 50mm f 1.4, the 85mm f 1.4 (or the 1.8 which is about half the price) and anything over 100mm that has an f-stop of 2.8. (most companies make an 80-200 f 2.8 which is the workhorse of photojournalism). You can often find inexpensive 100 or 135mm f 2.8’s — these make great portrait lenses.

Now go take some photos of your friends playing dead using a shallow DOF and send them on in.