Rules, schmules...

It's amazing how often I find myself breaking the "rules" these days. I still read blogs, many from "pro" photographers that try to make sure you've got the light coming from over your shoulder, i.e. front lighting your subject. More times than not, I'm working with (sometimes strong) backlighting.

Don't have your subject looking OUT of the frame? Says who.

Always trying to have your photographs tack-sharp? Why?

Using high shutter speeds to freeze motion? Why?

Cranking the aperture to maximize depth of field? Why?

Staying away from high ISO's to prevent grain? Why?

Attach lens to the front of your camera? Why? (try free-lensing).

Shoot subjects at eye-level? Why? (depends what you're trying to say).

Use only natural light? Why?

Don't shoot in the middle of the day? (already covered this one in another post).

This is safe. FORGET ABOUT THE RULES AND PLAY. You're not likely to be arrested if you break any of these rules (...I suppose it's possible depending on how far you take things...).

Look at the photography that inspires you and speaks to you. For me, these days, the pictures that really resonate are almost always rule-breakers. You can't get there if you don't.

Conversion factors and shutter speed...

People often ask about why they took better pictures with their point-and-shoots than with their DSLR's. The complaint is that pictures turn out blurry and out-of-focus. While there are many potential reasons, one of the most overlooked is related to lens conversion factors on other than full frame sensors.

The long standard rule for hand-holding (yes I know, we should ALL be using tripods ALL the time...) is that shutter speed should be equal to, or faster than the inverse of the focal length of the lens being used. That may sound complicated but is actually quite simple. If you are using a 100 mm fixed lens or have your zoom set to 100 mm, you can only get sharp pictures with a shutter speed of 1/100 second or faster. An 85 mm lens would allow you to hand-hold at speeds down to 1/85th of a second, and so on. Where there isn't a shutter speed that matches your lens' focal length, use the next fastest available.

Where we run into problems is with DSLR's that have smaller than full-frame sensors. Full frame models correspond to traditional 35mm cameras and the rule above holds true. Smaller sensor cameras have a magnifying effect on lens. Usually called a digital conversion factor, it makes the effective focal length of a lens some multiple (usually 1.4--1.6x) of its named length. A camera with a 1.4x conversion factor makes a 100mm lens the equivalent of a 140, and a 300mm lens...a 450mm! While this is terrific for photographers that need longer glass, it creates a problem for everyone when it comes to shutter speeds.

Remember our rule? Good. Now remember this: the rule applies to the EFFECTIVE focal length of your lens. This means that higher shutter speeds are necessary to hand-hold your camera if you don't have a full-frame sensor. The 100mm lens mentioned above needs to be used with a 1/140 second or faster shutter speed to get sharp pictures. The 300mm must be shot at over 1/450th of a second.

With enough light, increased shutter speeds don't pose a huge problem. At low light levels and in close-up work additional light or higher ISO's will be needed. The biggest problem is REMEMBERING that higher shutter speeds are needed. I've fallen into the trap of thinking shutter speeds are fast enough, only to be disappointed with results later on.

AND, vibration reduction (VR) lenses should not be considered a fix. In some ways they're used as a crutch to compensate. While they can be of some assistance with minor, barely detectable camera movement; they are no substitute for shooting with appropriate shutter speeds.

When in doubt, lug the tripod out. If you can't, or don't want to, be aware--and REMEMBER to apply conversion factors to your shutter speed consierations...