In digital photography, 2007 was a strong year for higher-end digital SLRs.

Already, single-lens reflex cameras were disproportionately popular as photographers moved to models that responded quickly and worked better in dim conditions. The bulk and expense were worth it.

But a panoply of new models arrived to satisfy the needs of experts and professionals in 2007. First was Canon's $5,000 EOS-1D Mark III, a rugged 10.1-megapixel photojournalist model unveiled in March that can shoot 10.5 frames per second. Alas for Canon, the camera's record was blighted with concerns about its autofocus performance.

But the floodgates opened in the second half of the year with Canon's top-end, $8,000 21.1-megapixel 1Ds Mark III. Canon hopes this full-frame model not only wlll keep professional SLR shooters loyal but also to woo studio photographers using even more expensive medium-format cameras. Announced at the same time in August and aimed at the serious enthusiast was the 40D, a $1,300 10.1-megapixel model.

A week later, Canon's biggest rival, Nikon, shot back with the $1,800 D300, and, more significant by far, the $5,000 D3, the first digital SLR to follow Canon's lead with sensors as large as a full frame of 35mm film. Large sensors are expensive, but the extra real estate means that individual pixels can be made larger for a given resolution, and larger pixels can work better in low light. The ISO sensitivity rating of Nikon's D3 goes up to a whopping 25,600.

Olympus, too, released a new top-end model, the $1,700 E-3, and two SLR newcomers expanded their ambitions with their second models: Panasonic's $1,300 (including a lens) 10.1-megapixel DMC-L10 and Sony's $1,400, 12-megapixel Alpha A700.

Makers of compact cameras had a harder time coming up with breakthrough models. Features such as face detection and image stabilization, which most agree genuinely help improve photos, spread from the high end to the mainstream, but those gains were offset by the silliness of the unending megapixel.

Higher-end compact cameras jumped up to 12 megapixels this year, which helps folks who like to crop images but hurts the vastly larger number who want to get something other than multicolored noise speckles when shooting in anything less than broad daylight.

In software, Adobe Systems delivered the biggest changes. For those using the higher-quality "raw" images that good cameras supply, Adobe released Photoshop Lightroom in March, and in just a few months it surpassed in popularity the earlier Apple rival, Aperture. Adobe announced an even more dramatic departure in February by declaring that it would make an online version of Photoshop. Photoshop Express is due in 2008.

Microsoft, meanwhile, made gains with its HD Photo format, built into Windows Vista and designed to replace JPEG with better compression, color, and dynamic range. In November Microsoft said the Joint Photographic Experts Group, which oversees the JPEG standards, would turn HD Photo into a new one called JPEG XR.