Saturday, June 7, 2014

60mm Refractor Lunar Geography: Aristoteles, Archimedes, Plato

I'm working on some lunar geography with my Meade 285 refractor. It's not amazing, but it gets the job done - the 6mm eyepiece I got for Christmas is providing some nice views.

moon 60mm telescope with iphone
Single shot taken with iPhone 5 through 6mm eyepiece handheld

My DIY telescope adapter mount doesn't work with this 6mm eyepiece because the light cone focuses further away from the surface of the eyepiece - which is great if you're looking through the eyepiece while wearing glasses, but bad for trying to take photos while resting the camera directly on the eyepiece.

Ok that was me trying to describe it, and then I looked it up... it's called "eye relief" and it "measures the spacing from the last surface of the eye lens of an eyepiece to the plane behind the eyepiece where all the light rays of the exit pupil are visible" (Celestron.com). My 6mm eyepiece has 14.8mm eye relief which is comfortable so you can blink and not worry about touching your eye directly to the glass.

archimedes with iphone
Note, the image appears flipped and rotated because of the diagonal mirror
I labeled several prominent craters, including Aristoteles, which appeared on this month's observing list. Archimedes is such a cool name, and it makes me want to watch the Disney version of the Sword in the Stone.

meade 285
Meade 285 refractor on my balcony
I always like it when people provide some context shots so I can see their gear and location, so I did that here. Speaking of gear, I didn't even know this rubber lip on my eyepiece folded up until I started writing this post. I read that eyepieces with eye relief more than 12mm or so usually have a rubber or plastic cuff or shield around the eye lens. Who knew!

eyepiece eyecup folding rubber shield
Folding rubber eyecup lip cuff thing that makes a shield around the eye lens to prevent glare

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