For sale: 1 ACCU-FOCUS focusing aid/scope dust cap. * REDUCED AGAIN*
Similar to Kendrick Kwik-FOCUS, but has open slot for secondary mirror access. Includes 4 easily removable dust caps.
Measures: 13 5/8" inner diameter, 13 3/4" outer diameter.
I bought this for my 11" Nexstar, but it is a bit too big. Perhaps useful for someone with a 12" or larger scope - (should work just as well on a reflector of similar size). Please measure your scope before buying, but also take into consideration that velcro or felt padding can be added to firm up the fit.
For those unfamiliar, this is a simple device (Hartmann Mask) for fast and easy focusing:
1) Remove 3 smaller, outer dust caps
2) Place on front of OTA
3) Locate a bright star
4) Through the EP you will see 3 stars instead of one (if out of focus).
5) Adjust your focus until the 3 stars merge into one. Now you're in focus.
Can also be used as:
* a dust cover
* an aperture step down to reduce light from bright objects (moon, planets).
* a solar filter by adding an off-axis solar filter on one or all openings - DO NOT USE THE ORANGE DUST CAPS TO BLOCK THE SUNLIGHT, ANY NON FILTERED OPENINGS MUST COMPLETELY BLOCK THE SUN!!!
$42 shipped in CONUS. Paypal welcome - no additional fee.