Objective Lens， 21mm 23mm 25mm 28mm Cemented Doublet Objective Lens Blue Film Green Achromatic Optical Lenses Telescope Accessory,for Doublet Convex Lens(D23f213 Blue Film)

=========High-concerned chemical : NoneModel Number : YT102319Diameter : 21mm 23mm 25mm 28mmfocal length : 24.5-262mm

• Made optical glass with precision polishing, ensuring stable performance and long service life.
• These cemented doublet objective lenses come in 21mm, 23mm, 25mm and 28mm diameters, with blue and green coating, serving as practical optical accessories for telescopes.
• Adopting achromatic optical design, they effectively reduce chromatic aberration and provide clear, sharp imaging for astronomical observation and optical experiments.
• Blue and green film coatings enhance light transmittance, reduce reflection and stray light, ensuring brighter and more stable viewing effect.
• Made optical glass with fine polishing, they feature low distortion, reliable performance and long service life.
• Multiple sizes are available for flexible selection, easy to install and compatible with various small optical telescopes and projects.