Soviet projectional lens F-92 1:2/92 mm, for LETI-60 slide projector, *409

Description: Item details Quantity: 1 piecesWeight: 423 grams Description Soviet projectional lens F-92 1:2/92 mm, for LETI-60 slide projector. Made in USSR. ---------------------------------- A slide projector (filmoscope, slide projector, frame projector) is a type of projection apparatus for demonstrating slides, filmstrips and other media on a transparent basis. Gained the greatest popularity in the 20th century. The USSR produced slide projectors "Etude", "Svet", "Svityaz", "Alpha 35-50", "Ekran", "Sputnik", "Proton" and many others. Overhead projectors designed for viewing only filmstrips made on 35 mm photographic film with a frame size of 18x24 mm were traditionally called “filmoscope”. Lens F=92 1:2 manufactured by KOMZ (Kazan Optical-Mechanical Plant). The lens is from the Soviet overhead projector 'LETI-60' (a.k.a 'Leti-60'), and possibly from 'LETI-60M' (a.k.a 'Leti-60m'). This lens was produced in two main versions. Differences between models 'F=92 1:2' and '2/92': -Different case frame. The front lens '2/92' is set much deeper into the lens body, thus creating a kind of small hood. Also, '2/92' has a different focus ring with zebra markings. -Different identification marks. So, on the ‘F=92 1:2’ there is a mark from the KOMZ plant, while the ‘2/92’ was presumably produced at the LOMO plant. I would like to add that there are lenses labeled 'F-92 1:2' and without a manufacturer's mark (see example). -Different enlightenment. Version '2/92' has a pronounced orange coating on the front lens, 'F=92 1:2' has a pronounced lilac coating. However, I want to clarify that some ‘2/92’ lenses also had lilac coating (see example). The lens of the LETI-60/60M F=92 1:2 overhead projector is a simple six-lens anastigmat, made according to the classic 6/4 scheme of the Helios/Planar type. In comparison with projection “Triplets”, this lens is both faster and of higher quality, but its design is much simpler than that of cinema projection anastigmats of the PO500-1 type. Due to its prevalence and low cost on the secondary market, it has become one of the most popular lenses for homemade products, but it is quite difficult to find a truly high-quality and complete adaptation option for this lens: often during adaptation, an aperture of the wrong size is installed (or not installed at all), which leads to the loss of the relative aperture , an unsuccessfully selected focusing mechanism with a small stroke is used and no work is done to additionally blacken the internal parts of the lens unit. Specifications: Optical design – 6 lenses in 4 groups, “Helios” / “Planar”. Focal length – 92 mm; Relative aperture – 1:2; Covered frame – 44×33 mm, calculated frame – 36×24 mm; Features - the lens does not have a camera mount and an adjustable aperture. ---------------------------------- The buyer will receive exactly the same item as in the photo. Come visit us again. Thanks and Regards.

Price: 29 USD

Location: Pereyaslav

End Time: 2024-09-12T16:40:11.000Z

Shipping Cost: 24 USD