50mm Pentax Achromat Objective Lens (Binocular model 16x50 XCF) For Sale
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50mm Pentax Achromat Objective Lens (Binocular model 16x50 XCF):
We have salvaged a couple of these lens from one Pentax 16x50 XCF binoculars. They are in prestine conditon and are great for a DIY project like a finderscope.Its medium aperture (2" or 50mm) makes it great for observing deep sky objects at low magnification.
The approximate 200mm of focal length makes it a very fast optical system (f/4) so some color (achromatic aberration) may be seen at high magnification
We recommend not to go over 25x in magnification but some costumers have built their own instruments and go over 40x.
Use it in combination with a 10mm eyepiece and you will get 20x which is a great magnification for scanning the milkyway and finding large deep sky objects.