Intuitively, again, we can pose an answer. A "prosumer" camera is one which, better than all others, has a serious and practical aptitude to satisfy both consumers and pros. In other words, the highest of the high-end before that great leap into the pure "professional" realm, however that's defined.
Okay, that was easy. Now then. What do we mean by "high end?"
Well, there's a sliding scale, too. At one time, such as in 1996 when most consumer cameras had VGA-or-so (640x480-pixels) picture size, a "high end" camera had one megapixel. The first one-megapixel consumercam came on the market in 1998, so "high end" then meant a two- or three-megapixel camera, or an interchangeable-lens DSLR. There had been 6MP cameras since the mid-1990s, and they, at their $15k prices, epitomized professionalism. With them in place at the upper end of the scale, representing a ceiling beyond which conventional wisdom said digicams would not rise, they used economics to quell the debates over the definition of "professional."
But oh, for the sylvan days of simplicity, when the number of pixels explained so much. Today, while plenty of "professional" DSLRs continue to provide 5MP and 6MP imagers, the past year has seen a deluge of "prosumer" models with 7MP and 8MP imagers. Indeed, in a year when more than a half-dozen different models offered 7MP and 8MP pictures to prosumers, only one 8MP camera, a Canon DSLR, could claim to be indisputably professional (with its $5k pricetag).
In this same year, consumer-market cameras, including entry-level models, have shown-up with 5MP and 6MP imagers. So if entry-level models have the same number of pixels as pro models, and high-end consumercams have more, what does the number of pixels have to do with being "professional" any longer?
Whatever we thought might define "professional" and "prosumer" in 2003 was quite different than our terms for 1996, but in 2005 we must revise our thinking again.
If variable ISO, variable white-balance, connectivity, and pixel-count can be found across all levels, from entry to general consumer to prosumer to pro, what's left to define "prosumer" this time?
There's an answer, but it raises more questions of its own.
Through the Looking Glass
If the integral body features and external connections of most digicams have been substantially standardized across market lines, the last real variable, one with a defining impact upon the performance of the camera and the range of pictures it can capture, is the lens.
Most of the first-generation digicams that had zoom lenses had 3x ranges like most of the zoom-equipped 35s before them, and like the majority of zoom-equipped cameras today. But today, in addition, there are digicams galore with much higher ranges—4x, 5x, 6x, 7x, 8x, 10x, and 12x, to be exact—which give anywhere from a little to a lot more flexibility and coverage to the cameras that have them.
Strictly speaking, extra-high-performance lenses have been with us since the beginning, too—Sony's DKC-ID1 had a 12x zoom. Yet by now, a dozen or two models with such high-performance lenses have come to the market, built permanently into digicam bodies. By so doing, they've reconfigured the relationship between permanent- and interchangeable-lens cameras.
The 35mm market contains few zoom lenses with more than a 3x range, and 2x is a popular standard—the 17-35mm range, say. The accessory-lens makers, such as Sigma and Tamron, both offer moderate-price, moderate-size zooms with nearly an 11x range (28-300mm), and as such may be spearheading a new revolution in interchangeable optics. But for the moment, and for the most part, 5x is as much as you're likely to get from traditional professional lenses. How many consumer and prosumercams routinely exceed professional standards in optical versatility?
If we accept that the lens is the delineating factor between "prosumer" cameras and others, and if they must equal or exceed other groups of cameras in a significant way, then we'd have to say that cameras with 5x lenses or higher may be called "prosumer."
This group would include all the cameras with 8MP sensors, though the highest-performance lenses—above 8x—are today all shipping with imagers in the 5MP to 6MP range (the exception being the Nikon Coolpix 8800. That range of imagers also accompanies lenses of the 5x variety, to 6x per the Fujifilm S20 (billed by the company as a "professional" camera), to 7x per the Konica Minolta Dimage A1 (5MP), A2 (8MP) and A200 (8MP in a simplified body).
The 7x lens in the current Minoltas has its roots in the original Dimage 7, brought out in the late summer of 2001. It was ahead of its time in one conspicuous trait, and held on to the honor for over two years, for it zoomed-out to the widest wide-angle in the prosumercam field—a "35mm equivalent" of 28-200mm.
At the PMA show last year, we got our first look at the same focal-length range in two newer cameras, the Canon PowerShot Pro 1, and the Olympus C-8080. More recently, Olympus has been quoting a wide-angle extreme of 27mm for its new C-7070, though with a 4x zooming range, it just misses our definition of "prosumer" (meaning, perhaps, that our definition is not perfect).