SIGMAKOKI Reasonable Achromatic Lens Focal Length 60.2mm　S-DLB-20-60PM

Feature

• This is a product that lowers the surface quality by one rank from spherical achromatic lens (DLB).
• It can be used for optical systems that do not require high surface quality, such as telescope lenses and microscope imaging lenses.
• Specifications other than surface quality are almost the same as DLB.
• I recommend this lens unless you want to use it for high-precision experiments with lasers.
• Optimized to minimize aberration and reduce focal length deviation across the visible spectrum.
• It is corrected not only for aberrations of the on-axis object point, but also for off-axis coma and astigmatism.
• * Use an achromatic lens when you want to focus an image at infinity or when you want to use a point light source that is parallel to the image.
• Sufficient optical performance cannot be obtained when the camera is used for close-range imaging.
• * The chromatic lens has an orientation that allows parallel light to enter the lens.
• * This function allows parallel light to enter from the side of the face with a small radius of curvature (the face pointed to by the arrow).
• * When parallel light is incident from the opposite side, chromatic aberration and spherical aberration occur, and the condensing spot becomes larger.

Specifications

• [ common specification]
• Material: BK7, SF2
• Design wavelength: Blue: 486.1nm, Green: 546.1nm, Blue: 656.3nm
• Eccentricity: ＜3′
• Coating: Reflective prevention film
• Scratch - dig: 60-40
• Effective diameter: 90% of the outer diameter
• [Individual specification]
• Outer diameter φD: φ20mm
• Focus distance f: 60.2mm
• Edge thickness te: 5.4mm
• Center thickness tc: 7.4mm
• Back focus fb: 56.6mm
• RoHS conform product