Some astro accessories

Stuff is expensive, but preconceptions aside, astronomical equipment doesn't always cost an arm and a leg. Also, optics can last forever if treated well. This stuff has embellished my telescopes for some time.

Plössl eyepieces
  • 40 mm, 26 mm, 10 mm, 7.5 mm focal lengths
  • No-name, yet high quality, eyepieces from Teknofokus
  • These are truly excellent eyepieces and have served me a long time with my 200 mm telescope
  • Celestron achromatic Barlow lens—for those select evenings when the atmosphere seems to have disappeared. Saturn at 350x, yum!
  • But once you've looked through a Nagler, Plössls just seem so... narrow.
TeleVue eyepieces
  • 27 mm, 24 mm Panoptic
  • 13 mm Nagler Type-VI
We all know the name TeleVue and drool at Nagler eyepieces (well, nowadays we drool at Ethos eyepieces). After all the time and expense I put into my new 400 mm telescope, I decided to complement it with only the best.

The 27 mm Pan is maybe a bit too wide, showing just too much coma in an f/4.5 Newtonian scope. The 24 mm shows less coma, and it comes in a 1 1/4" barrel (the 26 has a 2" barrel), and therefore fits better in my filter adapters.

  • Astronomik 2" O-III visual filter
  • Astronomik 2" UHC visual filter
  • Both in their own 1 1/4"-2" adapters
Most my eyepieces (all except the 26 Pan) are 1 1/4" size. Therefore it may seem a waste of money to buy 2" filters. But in our arctic climate, attaching expensive filters to eyepiece threads with fingers frozen numb is something of a hazard. It is so much more convenient to leave each filter to its own dedicated 1 1/4"-2" adapter. Not only is changing filters a lot easier, but eyepieces can likewise be exchanged to change magnification, without having to move the filter from one eyepiece to another.
  • Lumicon 1 1/4" O-III—my old deep-sky filter—after 10+ years
    of use, it has developed a spotted appearance–that can't be good.
  • Baader 1 1/4" Neodymium filter—Very good for
    improving contrast on Jupiter and Saturn! (Also great fun
    for eyeballing daytime surroundings, some shades of red are
    strikingly emphasized!)
  • 1 1/4" Neutral density lunar filter, 2% transmission
  • 1 1/4" #21 orange filter, which I bought once when Mars was in opposition (not that effective, really)
Laser collimator
  • Really the easiest way to collimate a newtonian
  • Funny, inside this contraption there is a laser pointer! Those things must be cheaper than the laser diodes they contain!
Home-made Telrad copy
  • Since I built myself a Telrad-clone, I've never wished for a finder scope, although I once had a very good one (home-made also) on my 200 mm scope (before rebuilding it from aluminum)
  • The optics comprise a microscope slide, a lens, a first-surface mirror, and the bullseye pattern photographed onto black-and-white negative film, illuminated from behind with a LED
  • I rarely make use of the bullseye ring pattern, so a red-dot sight would do almost as well

Antti J. Niskanen <uuki@iki.fi>