O

Index

[A] [B] [C] [D] [E] [F] [G] [H] [I] [J] [K] [L] [M] [N] [O] [P] [Q] [R] [S] [T] [U] [V] [W] [X] [Z]

O'Neil Photo and Optical
O-III filters 2nd
objective lens
observing
     charts 2nd 3rd 4th 5th 6th
     clothing
     drinking and
    DSOs (deep-sky objects)
         averted vision
         dark adaptation
         elevation
         enhancement with filters 2nd 3rd 4th 5th 6th 7th 8th 9th 10th
         eyes 2nd
         instrument size
         motion and visibility
         patience and persistence
         tapping the tube
         varying magnification and FoV
    etiquette (see etiquette)
         nebula filters
     geometric navigation
     horizon obstruction
     impact of light pollution
     lens cleaning and
     naked eye versus astrophotography
     observing notebooks 2nd 3rd 4th 5th
     risks and safety guidelines 2nd 3rd 4th
     seating for 2nd 3rd 4th
     sketching and 2nd
     star hopping 2nd
     techniques
     temperature and equipment
     urban environments 2nd 3rd 4th 5th 6th 7th 8th
         appropriate targets
     urban observing 2nd 3rd 4th
observing notebooks
    observing
         design
occultations
occulting eyepieces 2nd
Oceanside Photo and Telescope
off-axis sub-aperture masks
optical collimation
optical finders
     aligning 2nd 3rd 4th
     designs
     determining field of view
     dovetail mount
     two-ring finder mounts
optical tube assembly (OTA) 2nd
opticals finder
    designs
         drift-testing method
    determining field of view
         drift-testing method
optics
     at observing sites
     cleaning fluids
Orion Mini-Giant series binoculars
Orion Scenix binoculars
Orion StarBlast 2nd
Orion Telescope and Binocular Center
Osypowski
OTA (optical tube assembly)
Oxygen-III filters