Decided to make the switch to a digital SLR camera? Here are a few commonly asked questions.

QI'm starting from scratch. What will I need after I buy the basic camera body and lens?

AHere's what the pros suggest:

* Shoe mount flash. The little built-in flash is designed for snapshots only. A more powerful flash ($110 to $350) can allow you to bounce the light off another surface, like a ceiling, for a more natural-looking light without the blowout that makes people in flash photos look as if they're wearing pancake makeup.

* A specialty lens. Where SLRs shine is in their adaptability. Pick a lens expressly for the photos you take most often. For kids' sports -- the most popular use of the digital SLR -- a 75-300mm zoom is good. Zoom prices start at about $150 and climb quickly; it's worth spending a bit more for a fast lens if it will be your main one. For candids and portraits, a 28-90mm will work, but a 50mm f/1.4 is probably most flattering. Panoramic outdoor shots (or claustrophobic indoor spaces) call for a wide angle. A 14mm lens will capture your environs amply.

As long as you're talking lenses -- does it make sense to purchase the 55mm starter lens if I already have a 50mm lens for my regular SLR?

Yes. The ratio of lens length to recording surface is different for digital SLRs. To find out what lens gets the same effect on your digital camera as your film camera, use a focal length multiplier, which for these cameras is about 1.5 (Nikon) and 1.6 (Canon). The 18-55mm f/3.5-5.6 lens made specifically for the Digital Rebel, for example, covers roughly the same ground as a 28-90mm lens in 35mm format. The Nikon D70 18-70mm f/3.5 lens is much like 28-105mm in 35mm.

Okay, go on.

You'll also need:

* Extra batteries. There is nothing more heartbreaking than missing the perfect shot because you're out of power. The Nikon D70 and Canon Digital Rebel use rechargable batteries; buy an extra for about $50. If your camera takes an external pack that lets you use store-bought conventional batteries, you might want one of those too, just in case.

* More memory. Memory cards are the film of digital photography -- it's where the images are stored. The more memory, the more pictures you can save, especially important when shooting at memory-munching high quality. These cameras both accept CompactFlash cards, which come in several capacities (measured in megabytes), speeds (measured in megabytes per second) and brands. You'll want at least a 256 megabyte card, which can hold about 75 jpegs of the highest quality; the price difference between two 256MB cards of the same brand will generally be due to how fast it "writes" your photo. A Lexar 256 MB 40X CompactFlash High Speed Series card, for example, can record up to 256 MB of images at a speed of 6MB per second, and retails for about $60. Memory card prices are steadily dropping. If price is no object, pros are buying 1 gigabyte cards, which start at about $200.

* Buy a dust bulb, not canned air. Because the digital sensor is electrically charged, it will attract dust when you change lenses. Wiping it can damage it, but a whoosh of air from a $4 dust bulb can help. Pressurized cans of air sometimes spray tiny bits of lubricant, which can bond to the sensor. You'll have spots in the same places on every photo.

Anything in particular to keep in mind when traveling with a digital SLR?

The Digital Rebel and the Nikon D70 battery chargers are both dual voltage, so skip a converter but buy a plug adaptor when traveling overseas. Shoot high-resolution images (you can't enlarge a low-resolution image without major fuzz) and, if possible, have a store burn them onto CDs while traveling, to free up memory.

And finally, digital repair is expensive; consider purchasing insurance that specifically includes damage protection.

-- Roy Furchgott and Anne McDonough

A memory card.