Quality Planoconcave lenses Planoconcave lenses have one inward curved face and one flat face. Planoconcave lens bend parallel input rays so that they diverge away from one another on the output side of the lens. They have a negative focal length.  Planoconvex lenses are mainly used for image reduction or to spread light. Planoconcave lenses are also known as a tube-length correction lens in microscopy and as a Barlow lens in astronomy. These Planoconcave lenses are stocked uncoated or with a multilayer AR coating for 450-900nm except SF11 which are SLAR.
Knight Optical > Lenses > Concave lenses - Quality Grade > Uncoated Only UK and EU customers are charged VAT at 17.5%, customers outside the EU and EU customers based outside the UK who have a valid EU VAT number will not be charged VAT Bulk Discounts! Where (B) appears next to a price below, bulk prices are available, click the (B) button to view! PDF Part No. Focal length (mm) Material Diameter (mm) Back focal length (mm) Centre thickness (mm) Edge thickness (mm) Radius of curvature (mm) Price Qty Buy LNQ04025 4 SF11 2.5 4.4 0.75 1 3.14 £15.65 LNQ0604 6.3 SF11 4 6.9 1 1.4 4.95 £15.65 LNQ1006 10 SF11 6.3 10.8 1.5 2.2 7.85 £13.49 LNQ1610 16 BK7 10 17 1.5 3.2 8.27 £13.49 LNQ2510 25 BK7 10 26 1.5 2.5 12.9 £13.49 LNQ4010 40 B270 10 41 1.5 2.1 20.9 £13.49 LNQ2516 25 B270 16 26 1.5 4.2 13.1 £14.25 LNQ4016 40 B270 16 41 1.5 3.1 20.9 £13.85 LNQ6316 63 BK7 16 64 1.5 2.5 32.6 £13.85 LNQ10016 100 BK7 16 101 1.5 2.1 51.7 £13.85 LNQ2525 25 SF11 25 25.8 1.5 6 19.6 £19.00 LNQ3225 31.5 BK7 25 32.5 1.5 7.4 16.3 £16.75 LNQ4025 40 BK7 25 41 1.5 5.6 20.7 £15.00 LNQ5025 50 BK7 25 51 1.5 4.7 25.8 £14.45 LNQ6325 63 BK7 25 64 1.5 4 32.6 £14.45 LNQ10025 100 BK7 25 101 1.5 3 51.7 £14.45 LNQ16025 160 BK7 25 161 1.5 2.4 82.7 £14.45 LNQ25025 250 BK7 25 251 1.5 2.1 129 £14.45 LNQ30025 300 BK7 25 X X X X £17.45 Knight Optical > Lenses > Concave lenses - Quality Grade > Uncoated
Specification   Material: BK7 (or B270), SF11 for lower spherical aberrations (See spherical aberration calculation section) Material Data: (see materials section)  Diameter: +0.0 / -0.10mm  Centration Accuracy: < 0.1mm (F.L 40mm) < 2.5mrad (F.L > 40mm)  Focal Length (@587nm): ± 0.2% (<10mm) ± 2.0% (10-1000mm)  Centre Thickness: ± 0.15mm  Surface Quality: <40-20 scratch/dig (see quality section)
Specific requirements We can manufacture Planoconcave Lenses to any size or focal length at short notice, so if your requirements are not listed please contact us by telephone/ fax or email: stockrequirement@knightoptical.co.uk Coating Planoconcave lenses with suffix “AV2” are coated on both faces with (multilayer antireflective coating <0.5%@450-900nm, except SF11 which have a SLAR (see coatings section). Options available   · Mounting (all items)   · Special AR coating   · Stock lenses can be edged to smaller diameters See also Negative Doublets: Achromatic Doublets