K9 Double-Convex Lens

General-purpose, cost-effective solution for visible light imaging and focusing.

Premium Optical Material
Precision Optical Specifications
Rigorous Tolerance Control
Versatile Specifications
Protective Design Details

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Data Sheet

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.

Parameter	Specification
Material	K9 Grade A Optical Glass (N-BK7 equivalent)
Shape	Bi-Convex (Symmetric)
Design Wavelength (λ)	546.1 nm
Diameter Tolerance	+0.0 / -0.1 mm
Focal Length Tolerance	± 1%
Surface Quality	40-20 Scratch-Dig
Surface Flatness	λ/4 @ 632.8 nm
Centration	< 3 arc min
Clear Aperture	> 90% of Diameter
Chamfer	0.25 mm x 45°
Coating	Uncoated (Standard) / AR Coating (Optional)

Item No.	D (mm)	f (mm)	tc (mm)	te (mm)	fb (mm)	r (mm)	Centration
VLGLB4-4	4	4	2.16	1	3.21	3.73	≤ 3'
VLGLB6-6.4	6	6.4	2.5	1	5.6	6.23	≤ 3'
VLGLB6-8.4	6	8.4	2.1	1	7.6	8.3	≤ 3'
VLGLB6-30	6	30	1.3	1	29.8	31.14	≤ 3'
VLGLB10-10.8	10	10.8	4.6	2	9.2	10.38	≤ 1'
VLGLB10-15.6	10	15.6	3.6	2	14.4	15.57	≤ 1'
VLGLB15-16	15	16	5.9	2	14	15.57	≤ 1'
VLGLB15-30.6	15	30.6	3.8	2	29.4	31.14	≤ 1'
VLGLB20-21.2	20	21.2	7.1	2	18.8	20.76	≤ 1'
VLGLB20-26	20	26	6	2	24	25.95	≤ 1'
VLGLB20-31	20	31	5.3	2	29.1	31.14	≤ 1'
VLGLB25-25	25	25	8.96	2	21.846	24.19	≤ 1'
VLGLB25-31.2	25	31.2	7.2	2	28.8	31.14	≤ 1'
VLGLB25-50.8	25	50.8	5	2	49.2	51.9	≤ 1'
VLGLB25-100.6	25	100.6	3.5	2	99.4	103.8	≤ 1'
VLGLB25-150.5	25	150.5	3	2	149.5	155.7	≤ 1'
VLGLB25-200.5	25	200.5	2.8	2	199.5	207.6	≤ 1'
VLGLB25-250	25	250	2.5	2	248.35	257.97	≤ 1'
VLGLB25.4-50.8	25.4	50.8	5.1	1.9	49.2	51.9	≤ 1'
VLGLB25.4-100.6	25.4	100.6	3.5	1.9	99.4	103.8	≤ 1'
VLGLB25.4-190	25.4	190	2.8	2	188.16	195.8	≤ 1'
VLGLB30-31.7	30	31.7	9.7	2	28.3	31.14	≤ 1'
VLGLB30-51.1	30	51.1	6.4	2	48.9	51.9	≤ 1'
VLGLB30-80.8	30	80.8	4.7	2	79.2	83.04	≤ 1'
VLGLB30-120	30	120	4	2	119.5	124.58	≤ 1'
VLGLB30-150.6	30	150.6	3.4	2	149.4	155.7	≤ 1'
VLGLB30-180	30	180	3.2	2	179.5	186.5	≤ 1'
VLGLB30-200.5	30	200.5	3.1	2	199.5	207.6	≤ 1'
VLGLB40-51.7	40	51.7	10	2	48.3	51.9	≤ 1'
VLGLB40-101	40	101	5.9	2	99	103.8	≤ 1'
VLGLB50-52.7	50	52.7	15.8	3	47.3	51.9	≤ 1'
VLGLB50-101.5	50	101.5	9.1	3	98.5	103.8	≤ 1'
VLGLB50-151.2	50	151.2	7	3	148.8	155.7	≤ 1'
VLGLB50-201	50	201	6	3	199	207.6	≤ 1'
VLGLB50-251	50	251	5.4	3	249.1	259.5	≤ 1'
VLGLB50-300.8	50	300.8	5	3	299.3	311.4	≤ 1'
VLGLB50-400	50	400	4.3	3	398.58	412.7	≤ 1'
VLGLB100-202.5	100	202.5	15.2	3	197.5	207.6	≤ 1'

K9 Double-Convex Lens

Overview

Ideal Solution for Finite Conjugate & 1:1 Imaging

Dimension:

Qualification

K9 Double-Convex (Bi-Convex) Lenses Specifications

Selection Chart

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

Serivce & Support

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