Pentax LX LX Manual - Page 45

SC-21 The standard screen featuring a central split-image SC-21 spot with a microprism collar on a matte field. SC-26 SA-21 A highly versatile yet simple screen comprised of a central microprism grid on a matte field. 0 SA-23 Similar to the SA -21 with sharper prism angles to aid focusing with high speed (f/1.2 - f/2.8) lenses. SA-26 A microprism screen with a matte field suited for telephotos longer than 300mm. A 4° prism angle SA-21 permits use up to f/8. SA-37 A screen of microprism field only for use with tele- photo lenses, or in ultra close-up photography. • SB-21 Standard split-image focusing center spot on a matte field. SC-26 A split-image/microprism screen on a matte field for use with telephotos in excess of 300mm. A 4° prism angle permits use up to f/8. The split-image spot SA -23 SA -26 diameter is 2.5mm while the microprism collar is 5mm in diameter. SD-21 An all matte focusing screen with central cross hairs for use in photomicrography, astrophotography and photomacrography in dim light. SD-11 Similar to SD-21 but with no matte. SA-37 SE-20 An all-matte screen especially suited for focusing small aperture telephoto or macro lenses. SE-25 An all-matte screen suitable for telephoto lenses longer than 300mm. For situations where the split-image and microprism are inadequate. SG-20 Similar to the SE-20 but with etched crosslines in 6mm squares. Excellent for architectural subjects SB-21 and multiple exposure composition. 51-20 Similar to SE-20 but with engraved scales for deter- e mining subject size with bellows and microscope photography. SD-21 SD-11 SE-20 SE-25 SG-20 O S I-20 430