Pentax Electro Spotmatic (ES)

This was the screw-mount Spotmatic that finally let go of the needle. Pentax had built its reputation on the all-manual Spotmatic, the camera half of every photography class learned on, and then in 1971 it dropped an electronic shutter into the same body and called it the Electro Spotmatic. Set the aperture, let the camera pick the shutter speed. It was Pentax's first aperture-priority electronic SLR, and it brought TTL open-aperture automatic exposure to the M42 screw mount, which for a screw mount was a strange and slightly heretical thing to do.

In the hand it feels like a Spotmatic, because it basically is one. Same chunky brass-and-chrome build, same satisfying density, same bright ground-glass finder with a microprism collar that snaps focus in well enough in daylight and gets vague in dim rooms. The CdS meter reads through the lens, center-weighted, and on aperture priority the shutter steps continuously rather than clicking through fixed marks, so you get speeds in between the printed numbers; in manual the settings return to the usual clicked marks. The focal-plane shutter runs from a long 8 seconds out to about 1/1000, with flash sync at 1/60. The release is quieter and smoother than the purely mechanical Spotmatics.

The real advance hides in the mount. With the new SMC Takumar lenses, an extra aperture-coupling pin let the ES meter wide open and only stop down at the moment of exposure. That open-aperture metering was the headline feature, the thing the older Spotmatics could not do, since they made you stop the lens down by hand just to take a reading. A brighter finder while you composed, automatic exposure when you fired. For 1971 that was genuinely new.

Then there is the cost of the electronics. The auto exposure leans on the battery and on circuitry that was never built to survive five decades, and when an Electro Spotmatic fails, it usually fails in the meter or the auto-shutter. A repair person who still knows these boards is hard to find. The match-needle Spotmatics are simpler and cheaper to keep running, which is part of why this one lives in the shadow of its manual siblings. The M42 mount did not help its longevity either: lens changes are slow, and Pentax moved to the K bayonet in 1975, after which the screw-mount bodies were gradually phased out. The ES ended up a bridge between Pentax's manual past and its automatic future.

Today it is a budget pick. People cross-shop it against the plain Spotmatic and usually buy the manual one, because a working manual body will outlive a working automatic one. But a clean Electro Spotmatic that still meters is a pleasant thing to shoot. Choose your aperture, point it, and let the shutter find the speed, with a deep catalog of cheap Takumar glass waiting on the front. It rewards a relaxed, aperture-first way of working.

When the auto exposure starts drifting, or the meter goes dark, you can still run the body in manual. An incident or spot reading from the Zone Light Meter app gives you a number you can trust, then you set the aperture and stop the shutter down by hand. The electronics no longer have to be the thing you rely on.