Today, weathersealing is taken for granted as a common, although not ubiquitous, feature in cameras. Over 30 years ago, however, it was rare in professional SLRs (the Pentax LX being the only model with what would now be considered to be even a modicum of such protection) and non-existent as far as any enthusiast or consumer-level 35mm model went. A plastic bag and some elastics were the standard means of improving the survivability of your rig in the rain or at the beach, with all of the compromises that implies. The time was ripe for innovation. And who better than Olympus to shake things up?
By 1986, Olympus, as was their wont, was looking for an edge in the red-hot 35mm point & shoot market. Having failed to increase their market share with the AFL model (and its ill-conceived non-user-replaceable lithium battery, like...duh!), they were looking for a more consumer-friendly feature to differentiate themselves from the competition. They were not alone in this, but it would be their adoption of weatherproofing (video caption is incorrect ;-)) for the Infinity, as opposed to waterproofing (the route taken by Nikon with their Action Touch/L35AW AF in the same year and Minolta with their Weathermatic DL of 1987) which would prove to hit a sweet spot with consumers.
Obviously, waterproofing is much more comprehensive than weatherproofing, with removable gaskets that must be periodically cleaned and re-lubricated with grease to maintain performance. Waterproofing also involves the capability of submergence for the camera, versus merely being able to shrug off splashes of water or rain. Weatherproofing offered two advantages: 1) it was less costly to integrate into the construction of a camera, and 2) it did not require the user to perform the gasket maintenance that the waterproof models needed. This made for broader appeal and would become commonplace on Olympus' top point & shoot models into the 21st century and would prompt their competitors to introduce their own weathersealed challengers to the Infinity and Infinity Stylus (aka mju) lines.
More Than Just a Few Gaskets
Although Olympus heavily emphasized weatherproofing in their advertising for the Infinity (it was nicknamed "Nurepika" in Japan, translated as "Wet Flash"), it was packing some serious improvements in other areas over the AFL (1984) and its replacement the AFL-S (1985). The AFL-S did allow the user to replace the battery (CR-P2/DL-223A) and also added DX film coding but was otherwise identical to its predecessor. The Infinity added:
Holding Infinity in Your Hand
Being an Olympus, the Infinity has to have a quirk (or two, or three ;-)). Probably the most noticeable being its focus lock procedure. Rather than use a half-press of the shutter button to lock focus and then allow the user to re-frame, the Infinity used a separate Focus Lock button on the rear left shoulder of the camera in concert with the shutter button. You could call this feature a variety of things, but convenient and ergonomic are not two of them. The procedure goes something like this:
See, nothing to it ;-).
You may be wondering why Olympus went with such a complicated procedure, while everyone else was content to use the simple half-press/re-compose method. One possible explanation is that Olympus did not want to pay royalties to the patent-holder(s) for the viewfinder AF-confirmation LED or the half-press-focus-locking shutter button as its competitors evidently did. There was plenty of behind-the-scenes patent horse-trading that went on between the Japanese camera companies, but in this instance, Olympus was perhaps unable or unwilling to swing such a deal. Interestingly, by the time they introduced the Infinity II (AF-1 Super) in late-1989, there was a green AF-confimation LED in the viewfinder and a half-press shutter button focus lock :-).
Less of a quirk than a straight-out omission on the original Infinity was the lack of an override for the flash (to either force it OFF or ON). It was all-AUTO all the time. This is evidence of Olympus' belief that their target demographic for this camera was not going to be concerned about flash control. What they failed to realize was that many SLR-toting photogs also liked to have a decent P&S handy and they did want more control over flash. To their credit, Olympus also rectified this with the Infinity II and its Flash OFF and Fill-in Flash settings. Along with those improvements the Infinity II could also focus down to 50cm (20") in macro mode, and shoot four-frame bursts. It also added a small top-deck LCD for the flash, macro, drive, and film status settings. And all of this in a nicely-tweaked ergonomic package.
The Infinity II was quickly supplanted by the Infinity Stylus in 1991 and slid into relative obscurity with the incredible success of the Stylus line that culminated in the Stylus Epic of 1997 (over 5 million Stylii and 3.8 million Stylus Epics were sold). With the nutty prices that the Infinity Stylus (mju) & Stylus Epic (mju-ii) are fetching nowadays, the Infinity II makes for an intriguing alternative. I find that it's larger size is more manageable for my hands, and while the Epic will beat it in a straight-out specification shootout, in the real world the elder model gives up very little. It has a great lens, that 1/750 sec. top shutter speed, over-rideable flash control, and pretty decent AF. The relative rarity of the Infinity II makes for a bit more effort to find one, but by the same token, you will pay a LOT less when you do because they are definitely off of the "trending" point and shoot radar. And it will see you through the rain just as well :-).
Olympus History of Cameras - Autofocus Cameras: Weatherproof Compact Cameras
Olympus History of Cameras - u[mju:] (Stylus) Series: Attractive and Stylish Design
Owners Manuals for Olympus AF-1, Infinity Stylus, & Infinity Stylus Epic
Suffers from a quarter-century and counting film and manual focus SLR addiction. Has recently expanded into 1980's AF point and shoots, and (gack!) '90s SLRs. He even mixes in some digital. Definitely a sick man.