Whilst in the process of setting up an astronomy club for my students (I'm a primary school teacher) I soon came to the realization that people only ever give away telescopes or EPs if they are low quality or broken. Can't say I blame them!
My biggest problem has been EPs. Every one I have is of the Huygens design, the type that came standard in the 80s and 90s with cheap Tasco style telescopes. Obviously these are pretty dreadful to say the least. But in researching EPs two comments stuck with me:
1) Having a shiny/chromed inner barrel is bad, all that light bouncing around kills contrast.
2) High quality EPs (and mirrors for that matter) have their edges painted black to help minimize the effects of scattered light.
My thought process went something like, "Well...I own black spray paint and a Sharpie...may as well give it a go!"
Step 1: Disassemble a 12.5mm 'H' style EP.
http://s30.postimg.org/igkrghfht/CSC_0082.jpg
Step 2: Rough up the inside of the barrel with some sandpaper and then spray as much primer as possible everywhere but where I want it...
http://s29.postimg.org/b2r4sxacn/CSC_0081.jpg
Step 3: Repeat the process with some matt-black paint (it looks shiny in the pic, it's not)
http://s29.postimg.org/f0eeibx5z/CSC_0080.jpg
Step 4: Blacken edges of lenses with a sharpie. I wrapped the ends of some tweezers in Scotch tape to hold the lenses. Once half of each edge was colored the other edge went noticeably grey. To be expected, but still cool to see. I did a quick lap first and 'colored' the edge then a second lap 'dabbing' the Sharpie so that there was a thick layer of ink.
http://s29.postimg.org/mdtshah7r/CSC_0079.jpg
Step 5: Clean outside of barrel with turps and lenses in the usual fashion, reassemble.
Everything went smoothly and the process took about 15 minutes of work with some waiting in between for drying time.
The result? Well, a noticeably better EP. Better contrast all round and the appearance of being slightly 'sharper'. Still rubbish though, still annoying to use, but not so bad as to put one of my budding astronomers off of star-gazing for life!
Clear skies and good seeing,
Clockdrive
