How much did I pay for this one-time superstar? An affordable $286 (plus shipping)--less than 10 percent of its original price.

I ordered the camera late on a Friday afternoon, so I had all weekend to obsess about the things that I was certain would go wrong. Although the condition was described as "excellent," it was not new, so I braced for the worst. I feared that my skinflint quest for a bargain digital SLR body might teach me yet another lesson about being "penny wise and pound foolish." A desirable digital SLR for less than $300? Who could be that stupid?

Your experience may be different, but in my case, what I thought might be a self-induced nightmare quickly turned into a delightfully sweet dream. Canon has done a remarkable job of protecting legacy customers. Other camera manufacturers may not be as diligent, so beware. Here is what I checked, and what you should check, too:

Lens compatibility--that's always a potential problem. In most cases, using film camera lenses on a digital SLR does not create any problems. Going the other way, that is, trying to use one of the new "digital only" lenses on a 35mm film SLR, can be disastrous. Certain digital lenses are designed to throw a circle of light that is just large enough to cover an APS-C sized sensor--far too small to cover a full 35mm film frame. But the bonus here is that when you use a legacy film camera lens on a digital camera you are utilizing only the sweet spot in the middle and sidestepping the slight unsharpness and vignetting that often occurs at the extreme outer edges of the frame. In the case of my classic Canon EOS D30 I was able to use the latest Di offering from Tamron, their terrific 17-50mm f/2.8 zoom. It has a constant f/2.8 aperture and is a real joy to use, so I was delighted that there were no compatibility issues.

Software--that's often the biggest bugaboo. It's almost guaranteed that a camera's firmware will be upgraded at least once or twice during its lifetime, but that's a non-issue as long as you have access to the Internet. However, proprietary file formats and obsolete raw processing software present serious potential problems. What if you're left with a file format that's unsupported? Chuck Westfall, Director of Media and Customer Relationships at Canon USA, assured me that the latest version of their raw workflow management software, Canon's Photo Professional 2.1, was compatible with all Canon digital SLR cameras--from the latest to the oldest. I could shoot raw with absolutely no problems. Of course, he was right.

The battery can be an issue as well. If you go for a used digital SLR be sure that the battery and charger can still be had for a reasonable price. Once again, my EOS D30 earned five stars--it uses the same battery as my Canon EOS 10D, a 511 lithium ion. So, I had a couple of backups.

The "old" Canon EOS D30 handled contrasty lighting with ease. (Canon's EOS D30, Tamron's 17-50mm zoom.)

On the downside, the Canon EOS D30 is slower (of course) than the Canon EOS 30D. If it wasn't, that would mean we have not progressed very far over the last 60 months. The CMOS imager is "only" 3 megapixels and the AF sensors are arranged as three linear points instead of being in a multiple pattern. Truth be told, however, the only real compatibility issue was the cable. Instead of having a USB port the EOS D30 requires a special cable with a proprietary connector. This issue was quickly resolved by taking a quick look at Canon's website (www.canonusa.com) where I learned that it's the same cable that my old Canon PowerShot S230 uses--so I owned one and didn't even know it. The cable was a critical component, so if you're thinking that an easier workaround would have been to use a card reader and avoid the cable altogether, think again. I wasn't interested in downloading images. In order to set and store the three Parameters (Contrast, Sharpness, and Color Saturation) on my used digital SLR it's necessary to access the camera directly through software. Once set, the Parameters can be selected via the Main menu, but without the cable--and software--it's impossible to set up the values.

In the final analysis, the most important aspect is image quality. Judge for yourself. Every image in this article was shot with the Canon EOS D30 and the Tamron 17-50mm zoom. I've been using digital cameras since before they existed commercially and I must say that I'll be using this camera on a regular basis. I like how it performs and it works with all of my Canon lenses. I usually don't make enormous prints, but when I need to, I own other digital SLR cameras that deliver higher resolution. Like you, I like to shoot raw but I don't like to deal with humongous image file sizes. I appreciate sharpness, correct exposure, and the ability to use raw format so that I have greater control over the final work product. The Canon EOS D30 fulfills all of my requirements.

This brings us to the final question. How long do cameras last? The parts and components inside a camera, particularly the mechanical ones, have a finite life. We assume that a camera body accumulates visible battle scars as it approaches the end of its usefulness, and we assume that we can guess its age by examining its condition. This is not a foolproof method, but it generally works. Some cameras (even some film cameras) keep a running count of the number of times the shutter has been actuated. The data is available only to trained service technicians who have the proper equipment to access the chip. If you have the opportunity to physically inspect the secondhand camera before purchasing it, be sure to check the heads of the screws for signs of tampering or amateur repair. Also look carefully for dents and dings that can indicate that it has suffered impact damage. Cameras that exhibit any of these symptoms or show excessive wear, scratches, or other obvious defects are not worth taking a risk--even if the price is irresistible.