Refractor objective lensPosted By James Koerth |
Could I put a 127mm 1200mm focal lens achromatic doublet objective lens in a refractor that currently uses a 127mm 1180mm F9.3 doublet objective lens. How would the 20mm affect draw tube focus if it could be done? Thanks for your advice.
Jim Koerth
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Jim Koerth
[email protected]