K9 Double-Convex Lenses

Overview

Ideal Solution for Finite Conjugate & 1:1 Imaging

Our K9 Double-Convex (Bi-Convex) Lenses are precision-manufactured from high-quality Grade A K9 glass, the industry standard equivalent to N-BK7. Featuring two symmetric convex surfaces with equal radii of curvature, these lenses are specifically optimized for finite conjugate applications.

They deliver superior performance when the object and image distances are roughly equal (e.g., 1:1 imaging systems), making them a cost-effective choice for visible and near-infrared (NIR) focusing tasks.

Dimension:

Qualification

K9 Double-Convex (Bi-Convex) Lenses Specifications

Parameter	Specification
Material	K9 Grade A Optical Glass (N-BK7 Equivalent)
Design Wavelength	546.1 nm ($n_d$=1.519)
Surface Quality	40-20 Scratch-Dig
Centration	≤ 3 arc min
Clear Aperture	> 90%
Diameter Tolerance	+0.0 / -0.1 mm
Focal Length Tolerance	± 1%
Bevel	0.25mm x 45°
Coating	Uncoated (Standard)

Selection Chart

K9 Double-Convex (Bi-Convex) Lenses Selection Chart

Item No.	D (mm)	f (mm)	Tc (mm)	Te (mm)	fb (mm)	r (mm)	Centration
VLGLB4-4	4.0	4.0	2.16	1.0	3.21	3.73	≤ 3'
VLGLB6-6	6.0	6.4	2.5	1.0	5.6	6.23	≤ 3'
VLGLB6-8	6.0	8.4	2.1	1.0	7.6	8.3	≤ 3'
VLGLB6-30	6.0	30.0	1.3	1.0	29.8	31.14	≤ 3'
VLGLB10-10	10.0	10.8	4.6	2.0	9.2	10.38	≤ 1'
VLGLB10-15	10.0	15.6	3.6	2.0	14.4	15.57	≤ 1'
VLGLB15-15	15.0	16.0	5.9	2.0	14.0	15.57	≤ 1'
VLGLB15-30	15.0	30.6	3.8	2.0	29.4	31.14	≤ 1'
VLGLB20-20	20.0	21.2	7.1	2.0	18.8	20.76	≤ 1'
VLGLB20-25	20.0	26.0	6.0	2.0	24.0	25.95	≤ 1'
VLGLB20-30	20.0	31.0	5.3	2.0	29.1	31.14	≤ 1'
VLGLB25-25	25.0	25.0	8.96	2.0	21.85	24.19	≤ 1'
VLGLB25-30	25.0	31.2	7.2	2.0	28.8	31.14	≤ 1'
VLGLB25-50	25.0	50.8	5.0	2.0	49.2	51.9	≤ 1'
VLGLB25-100	25.0	100.6	3.5	2.0	99.4	103.8	≤ 1'
VLGLB25-150	25.0	150.5	3.0	2.0	149.5	155.7	≤ 1'
VLGLB25-200	25.0	200.5	2.8	2.0	199.5	207.6	≤ 1'
VLGLB25-250	25.0	250.0	2.5	2.0	248.35	257.97	≤ 1'
VLGLB25.4-50	25.4	50.8	5.1	1.9	49.2	51.9	≤ 1'
VLGLB25.4-100	25.4	100.6	3.5	1.9	99.4	103.8	≤ 1'
VLGLB25.4-190	25.4	190.0	2.8	2.0	188.16	195.8	≤ 1'
VLGLB30-30	30.0	31.7	9.7	2.0	28.3	31.14	≤ 1'
VLGLB30-50	30.0	51.1	6.4	2.0	48.9	51.9	≤ 1'
VLGLB30-80	30.0	80.8	4.7	2.0	79.2	83.04	≤ 1'
VLGLB30-120	30.0	120.0	4.0	2.0	119.5	124.58	≤ 1'
VLGLB30-150	30.0	150.6	3.4	2.0	149.4	155.7	≤ 1'
VLGLB30-180	30.0	180.0	3.2	2.0	179.5	186.5	≤ 1'
VLGLB30-200	30.0	200.5	3.1	2.0	199.5	207.6	≤ 1'
VLGLB40-50	40.0	51.7	10.0	2.0	48.3	51.9	≤ 1'
VLGLB40-100	40.0	101.0	5.9	2.0	99.0	103.8	≤ 1'
VLGLB50-50	50.0	52.7	15.8	3.0	47.3	51.9	≤ 1'
VLGLB50-100	50.0	101.5	9.1	3.0	98.5	103.8	≤ 1'
VLGLB50-150	50.0	151.2	7.0	3.0	148.8	155.7	≤ 1'
VLGLB50-200	50.0	201.0	6.0	3.0	199.0	207.6	≤ 1'
VLGLB50-250	50.0	251.0	5.4	3.0	249.1	259.5	≤ 1'
VLGLB50-300	50.0	300.8	5.0	3.0	299.3	311.4	≤ 1'
VLGLB50-400	50.0	400.0	4.3	3.0	398.58	412.7	≤ 1'
VLGLB100-200	100.0	202.5	15.2	3.0	197.5	207.6	≤ 1'