|Version based on Cosina CT1EX|
image by bokina90 (Image rights)
German distributor Porst used the naming Carena CX-300 on two different (but closely-related) 35mm SLR cameras, both made by the prolific Cosina. Both use the common K-mount bayonet for interchangeable lenses; have a match-LED ( - o + ) exposure meter indicator on the left of the viewfinder; and were the cost-reduced alternative omitting a self timer.
The less common CX-300 flavor seems derived from the Cosina CT1G with the restyled flatter pentaprism cover; its top shutter speed is 1/1000 second. Its grip for the shooter's right hand is a distinctive, oddly angular shape. The more commonly-seen CX-300 appears identical to the Cosina CT1EX (also sold as Exakta HS-10) and increases the top shutter speed to 1/2000 second.