Frequently asked photo questions for December

Have a question about digital photography? Send it to me. I reply to as many as I can--though given the quantity of e-mails that I get, I can’t promise a personal reply to each one. I round up the most interesting questions about once a month here in Digital Focus. For more frequently asked questions, read my newsletters from September, October, and November.

Managing Lots and Lots of Photos

I volunteer for a large nonprofit organization. They would like to take their photographs (which I suppose number in the tens of thousands) and organize/archive them. Can you be able to point me in the direction of software designed for this sort of thing?

--Jeff Ross, Kansas City, Kansas

What you're describing, Jeff, is sometimes called digital asset management, or DAM software. It's possible that a simple consumer program could satisfy the organization's needs; even Microsoft's free Windows Live Photo Gallery can easily manage thousands of photos, and can be configured to organize and manage images stored in multiple locations on different hard drives. If you need a more professional solution to do more advanced tasks like manage workflow, handle archiving, and generate contact sheets, then you should investigate programs like Microsoft Expression Media and Extensis Portfolio.

CCDs Versus CMOS

CCD and CMOS: What is the difference between these two technologies? Are there real-world advantages of one over the other? Should I care?

--John Taylor, Shelby, North Carolina

For the most part, John, I'll say that no, you needn't care. The important thing is finding a high-quality camera that takes good pictures; the particular way in which the pictures get made is, I think, kind of irrelevant to most people.

But since you ask, any given camera today will feature either a CCD (charge coupled device) or a CMOS (complementary metal oxide semiconductor) image sensor. Both are analog devices that convert incoming light into voltage, which is later converted again into a digital signal. In a CCD, all the pixels on the sensor send their signal to a central location for conversion. In a CMOS sensor, each pixel has its own charge-to-voltage conversion. Both of these chips have a laundry list of advantages and trade-offs, primarily only of interest to engineers and tech geeks. You can get a sense of some of the biggest differences at How Stuff Works.

Back in the 90s, CMOS sensors were unable to generate high-quality images, and were thus relegated to cheap, low-res cameras. But a few years ago, fabrication technology improved to the point that some of the highest quality cameras now sport CMOS sensors. These days, very-high-end digital SLRs are equally likely to have either type of sensor. I'd say it's far less important what kind of sensor a camera has than just finding a model that suits your needs and gets good scores in camera reviews like those at PC World.

Minimizing Lag

I'm buying a new camera and would like one that can take pictures quickly. If I take a shot, but I have to wait a few seconds before it's ready to take another, I've missed my shot. What should I look for to avoid this?

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