Digital cameras 101

[bobrobinson]

I think this question is simple, but I don't know the answer so that tells you how proficient I am with cameras.  The actual physical size of a lens, that thingie that sticks out the body of the camera:  Does it take "better" photos if it's bigger, that is, has a wider opening to the world?  OR, is the light controlled by something else?  Thank you.

[ShutterbugGail]

Hello bobrobinson,

Welcome to the Q&A Board!

The quality, not the physical size of a lens, is a very important factor in the quality of images a camera takes. To be honest, unless you buy a real cheapo camera, most digital cameras have a very good lens that should take fine photos. Obviously, a $250 camera may not have the lens quality of a $1000 advanced digital camera, but it will produce fine images for most of us.

What will take better photos as far as the lens is concerned, is if you use the optical rather than the digital zoom. Most cameras have both optical and digital zooms (only the least expensive have only digital zooms). Digital zooms are not true zooms, so the optical zoom is the zoom of choice. I avoid using the digital zoom on my camera.

You can learn about the important differences between digital and optical zooms here:

http://www.digicamhelp.com/digital-camera-features/digital-camera-lenses.htm

Please let us know if you have additional questions.

[Deb]

Hi Bobrobinsin, I wasn't sure if you were referring to the built-in lens of a digicam or the detachable lens of SLR's. So, in addition to ShutterbugGail's dandy comments, the quality of the glass and the speed of the lens (its wides aperture) are also important. With regard to lenses for SLRs, you'll notice that a 300mm F5.6 lens is smaller in size than a 300mm F2.8 lens. The 300mm F2.8 being the faster lens. If you were to use a 2x extender with this F2.8 lens, the loss of 2 f-stops wouldn't be a big deal but if you tried to use the 2x extender with the F5.6 lens, you'd wind up with a slow lens (it would be the equivalent of an F11 lens). You would find your depth-of-field greatly affected as would the range within which you could get a proper exposure at a fixed ISO/ASA value.