The Pentax ME line of cameras had these distinctions, according to Wikepedia article:
- 1976: The smallest and lightest SLR camera (Pentax MX and ME)[4]
- 1979: The world's first camera to incorporate the concept of push-button shutter speed control. This camera was the Pentax ME Super[4]
- 1980: The world's first through-the-lens autofocus camera. This camera was the Pentax ME F[4]
A clue as to the positioning of the ME line:
"The M series cameras were noted for their compact size, and are among the smallest 35 mm SLRs ever made, though they are quite heavy when compared to the plastic SLRs of the 1990s. Except for the MX, all were based on the same basic camera body, and featured aperture-priority exposure automation. While superficially resembling the ME, the MX was designed as a manual-only SLR system targeted to the advanced amateur or professional photographer, and had its own set of accessories that were mostly incompatible with the other M series cameras. Conversely, the other M-series cameras were targeted squarely at casual users. None of the M-series, with the exception of the MX, featured a depth of field preview."
Contrast the ME vs the LX
IOW, what marked the 'professional' camera was the availability of specific
features and accessories expected by a pro photographer...the lack of DOF Preview in the ME series is such an example. And the MX had accessories not compatible with the ME.
Ken Rockwell summarized, in a review of the Pentax ME
"
What's Missing
The ME is a very basic camera. It has most of what you need, except it has:
- No depth-of-field preview button. No display of aperture in finder.
- No AE Lock (use the exposure compensation dial instead, or look at the meter and use the manual 1/100 setting).
- Unlike premium cameras which use all sorts of dynamic dampers and counterbalances, the ME transmits mirror slap to the body. "
The above are examples of things 'defeatured' in lower level products, to differentiate it from its more expensive brothers.
The Pentax ME was Pentax response to Olympus OM size, which then resulted in the immensely popular mass market Canon AE-1, and Nikon EM, and Minolta 'small body' series, all of which were attractively priced for the consumer.
The fact that all bodies of same mount shared the same lenses, optional lenses were not a differentiator, but which 'basic normal' was often a key indicator of the market that a camera was aimed at...a standard f/1.8 or f/2 normal was provided with the 'price leader' for the mass market, while the f/1.4 might be the standard lens provided with the 'pro body'.
(Back in 1970's, a normal lens came with the body, unlike later decades when bodies without lens were commonly offered.)
Someone remarked:
"The Pentax ME and MX I considered then were $299 and $349 for bodies. By 1980 I worked in a camera store and remember quite well some of the prices. ME Super came out at $389 w/50 f/1.7."
Someone else posted:
"From the Oct 1981 (Vol 88 N10) issue of Popular Photography the
B&H ad lists
- Pentax LX body $449.90 with the M f/1.4 50mm lens $543.90. The M 50mm f/1.2 lens is listed for $175.00.
- MX body $154.90. Add $15 for black body.
The PRICE of the camera body is NOT a factor in its ability to capture super images...the PHOTOGRAPHER is the key determinant of that! A more expensive and more fully featured camera expands the RANGE OF SITUATIONS in which the same photographer might or might not be able to make an image. A good photographer would be able to make most images equally 'good' with a $170 body with lens or a $470 body with no lens.