Cosina CT-1A

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The Cosina CT-1A is a manual-focus 35mm SLR from Cosina.[1] It accepts K mount type lenses. It is nearly the same as the Cosina CT-1 but replaces that model's analog meter needle with a match-LED exposure indicator ( + O - ) at the side of the viewfinder. This also necessitated the use of two LR44 or SR44 batteries, rather than the single mercury cell of the earlier model.[2]

The CT-1A has a vertically-traveling focal plane shutter with speeds from 1s to 1/1000 with B. Flash sync is at 1/125 a sec. The self-timer is mechanical with a delay of approx 10 sec. It features a open-aperture TTL metering in a center-weighted pattern, utilizing two CdS cells. The meter has a range of 3 to 18 EV at (ASA 100). Film speeds from 25 to 1600 ASA can be set on the ring surrounding the rewind crank.

Following the CT-1A Cosina offered two models: the CT1G is essentially the same as the CT-1A but without a self-timer (and at one time the two were included in the same owners manual); while the CT1 Super increases its top shutter speed to 1/2000 second. Both of the latter models also add an angular plastic handgrip.


  1. It appears to have been announced in late 1980, and was going on sale by the time of this news item about Cosina introductions in the April 1981 Popular Photography, pg. 222, via Google Books.
  2. A green LED requires about 2.0 volts to light up; a single mercury cell only provides 1.35v.