The Ricoh TLS 401 was introduced in 1970 as an innovative successor to the three year older Ricoh Singlex TLS, having a combined eye-level and waist-level finder. Selection of either is by twisting a knob on the right-hand side of the finder housing. The vertical finder window has a removable black plastic cover, which, if turned the other way round as the practical minded will discover, may sit on permanently and just slid towards the accessory shoe when not needed. The original Singlex of 1964 was a further development of the Nikkorex F made by Mamiya for Nikon, the only Ricoh SLR having a Nikon F lens mount, the ensuing models having a 42mm screw mount throughout most of the next decade.
The TLR 401 has a match needle stop down TTL CdS meter with average or spot selector switch situated just below the wind lever on the back of the camera. Correct exposure is obtained when the meter needle is brought inside the brackets at the lover right in the finder. Also in the finder, to the left, is an indicator for the selected meter mode, S for spot and A for average. The exposure meter is activated by sliding a chunky knob on the left-hand side of the mirror housing upwards, also stopping down the lens to the selected aperture, meaning the meter is of the stop down variety, like the Pentax Spotmatic of 1964, but unlike most other contemporary SLR cameras of the principal brands using bayonet lens mount. The camera is equipped with the sturdy vertical running focal plane Copal Square 1 to 1/1000 second metal blade shutter.