Omega 3-Lens Turret
Technical Memo

Two different types of turret were supplied with Omega D-6 enlargers. The two types look very similar but are not interchangeable. Early D-6 enlargers were fitted with part #404-866. Due to thickness of this early turret, some 50mm lenses were not able to focus properly. As a result, both the lens stage of the D-6 and the turret were modified to bring the lenses slightly closer to the negative. This redesigned lens stage was carried over to D-5 enlargers, which also accepts the later 404-867 turret. It is therefore important for D-6 owners attempting to replace a turret to determine if they have an early or late type of chassis in order to select the matching turret. D-5 owners intending to purchase a used turret must avoid the early turret.

The early type 404-866 turret can be identified by the unpainted aluminum mounting flanges, which measure about 1 cm high. The stock number does not appear anywhere on the turret. On later 404-867 turrets, the mounting flanges are anodized black, about 0.6 cm high, and the turret catalog number is usually screened on the inside edge of the flange as can be seen in the photo.

The lens stage on early D-6 chassis is illustrated in the main picture and close-up in the upper circle. The lens mount slot is approximately 1/4" high, compared to the thinner 1/8" slot of the later D-6 and D-5 chassis shown in the lower circle. Additionally, on early D-6 enlargers the bellows is mounted to the flat upper surface of the lens stage, while on the later chassis the bellows is fitted into a recess in the casting.