The Difference Dolland Made
Taken by Wayne Wooten on November 16, 2018 @
Pensacola, Florida
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Details:
I replaced the 50x600 simple convex lens in Tasco's 50x500 red refractor with a Surplus Shed achromat (L14811) for $7, and gave it a 1.25 star diagonal. Results on the first quarter moon were an impressive display of what a difference Dolland's invention made!
The first image is the moon with the original Tasco 50x500 objective, equivalent to Galileo's best long refractor around 1618. It was made with my iPhone 5c and the iOptron smartphone adapter. Note the fuzzy image and blue fringe due to chromatic aberration.
Here is the scope made with the Tasco objective and a -30mm negative eyepiece for a Galilean style erect image.
Here is the much sharper image made with the 360mm f.l. achromat, same setup. No color distortion, much shraper detail.
The revised scope used the same 50mm lens mount, but shortened the tube 140 mm, and used a 1.25" star diagonal.
Photographer's website:
http://https://www.facebook.com/groups/80860174301/photos/?filter=albums
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