The Canon T70 was introduced in 1984 as the successor to series progenitor T50.  The T-series was originally intended to bridge the gap between SLR cameras and compact, point and shoots.  In the mid 1980s the market share enjoyed by SLRs was on the decline while compact 35mm cameras were enjoying a surge in popularity.  Canon figured they would try to introduce some of the ease of automation found in that latter category into the SLR.  Hence, the T50 was a camera that looked like an SLR but operated like an automatic compact.  The T70 built upon the success of that camera while introducing a richer array of features.  The general idea remained in place: keep it simple, keep it automatic.  But should the user be of a more advanced nature and wanted greater functionality or control, the T70 was capable of offering that as well.  

At its heart, the T70 is meant to be used in a fully automatic mode.  It was capable of not just one full program mode, but three!  There are standard, wide and telephoto Program options.  The wide mode prioritized depth of field while the telephoto mode favored higher shutter speeds for freezing action.  In addition, the camera could be set to an Shutter Priority AE mode or a metered Manual mode that functioned similar to the Canon AE-1 or A-1 cameras (the desired aperture based on shutter speed selection is displayed in the viewfinder via red LED lights). To compliment these advanced exposure modes, the T70 also offered two different metering styles.  The user could choose either an average pattern or a partial - which is similar to a spot meter but with a larger area of measurement.

It is easy to overlook these days but other innovations of the T70 (and T-series as a whole) included motorized film advance and film rewind, the latter introduced to the series on the T70.  And LCD screen atop the camera became the source of camera setting information and the standard shutter speed dial was replaced for an up/down button toggle.  Canon also introduced an advanced data back that could replace the standard back on the T70 and offered even more functionality such as interval shooting and data recording.  Lastly, all this was powered by only two AA batteries, which helped keep the profile of the camera smaller and its weight lower.

Of course, we need to mention that despite the T70's advanced nature it still used the Canon FD-mount lenses.  In this sense, the T70 can really be seen as a bridge camera, bringing some of the advanced features that would become standard on autofocus SLRs to the manual focus Canon FD system.  In fact the T70 even has an AE exposure mode that will function with stopped-down Canon FL-mount lenses.  Perhaps the fact that the T70 straddles two worlds makes the camera easier to overlook these days.  Photographers tend to prefer the really old school look and feel of Canon's A-series or F-series cameras, or they go for the more technologically advanced, autofocus, EOS cameras.