I sometimes have a hard time explaining certain things in a coherent and meaningful way. Like why it's okay for mommy to pick her nose but I'm always scolding my kids not to ("Because I'm an expert"), or like why it's okay for mom to have a few fries from the McD's bag but everyone else has to wait until we get home ("I'm just checking to make sure they're not poisoned"), or why mommy can say "holy crap" but the kids can't ("Because I'm already going to hell for all the other bad words I say").
I've also struggled with explaining the difference between my camera - the full-frame Canon 5D - and a non-full-frame camera like a point-and-shoot or a Canon XSi. I try to explain about the sensor size and the difference between what you might see through the viewfinder and what is actually committed to memory. So when I opened the latest issue of "Popular Photography" and saw an article about this very same thing, I knew that I had finally found something that I can share. So here it is:
This scan of page 56/57 in the April 09 issue shows the effect of the smaller sensor on a single photo. As the caption says, "even when both the viewpoint and the lens focal length stay the same" the result is different for different sensor sizes. Basically, having a smaller sensor acts as almost a zoom factor, which can be a benefit. One example given by the magazine is that a wedding photographer uses her 50mm 1.2 lens on her 40D (an APS sensor) which ends up giving her the effect of an 85mm focal length.
**ETA** Here's a
link to another fine example of what the heck I'm talking about. Thanks, Susie!
Anyway, I'm just a camera nerd and found this particular article fascinating and it helped me to better understand exactly what the differences in sensor size really are. So that I can better explain it to the next person who asks. And this is what I'll tell them: It's not the size that matters, but how you use it.