Objective Lens， 50 51 52 53 57 58mm Cemented Doublet Objective Lens Achromatic Optical Focal Length 182mm-987mm DIY Refraction Telescope,for Doublet Convex Lens(51F225)

=========High-concerned chemical : NoneModel Number : YT102319121Diameter : 50 51 52 53 57 58mmfocal length : 182mm-987mm

• Made optical glass with precision polishing, ensuring stable performance and long service life.
• This cemented doublet objective lens is available in 50/51/52/53/57/58mm diameters, with focal lengths from 182mm to 987mm, designed for DIY refracting telescopes.
• The achromatic optical structure effectively corrects chromatic aberration, delivering sharp, high-contrast images for clear astronomical observation.
• Made optical glass with fine polishing, it ensures high light transmittance, low distortion and stable long-term performance.
• Multiple sizes and focal lengths offer flexible choices for telescope assembly, modification and upgrading to meet different observation needs.
• Standard structure and good compatibility make installation easy, ideal for astronomy enthusiasts to build and improve refracting telescopes.