Viewing Mars, Extra Disk--The Eyepiece Factor

Viewing Mars with the Meade 25mm provided eyepiece with the LXD55 AR6 gives something like two
disks, one brighter than the other. I've seen this before with SCTs and other scopes. Possibly it
has something to do with the brightness of Mars. I've seen it with Jupiter. I've been told that the
effect is reduced by using shorter length eyepieces. I noticed this effect with an 11" C-11 f/10
last night and going to a Televue 9mm eyepiece helped somewhat. I'll try it on the AR6 tonight. Any
thoughts on this? Maybe a Barlow would reduce the extra circular glare?
--
Wayne T. Watson (121.015 Deg. W, 39.262 Deg. N, 2,701 feet, Nevada City, CA)
-- GMT-8 hr std. time, RJ Rcvr 39° 8' 0" N, 121° 1' 0" W

Remember to drink an adequate amount of dihydrogen oxide each
day.

Web Page: home.earthlink.net/~mtnviews
Imaginarium Museum: home.earthlink.net/~mtnviews/imaginarium.html

In article ,
Wayne Watson wrote:

Viewing Mars with the Meade 25mm provided eyepiece with the LXD55 AR6 gives
something like two
disks, one brighter than the other. I've seen this before with SCTs and other
scopes.
SNIP_

Wayne,

The only telescope I ever used that showed this ghost image was a 4"
Unitron that I owned for a few years back in the mid 90s. I brought it
to Winter Star Party once, and when Roland Christen looked through it,
he was not surprised. According to Roland, In this case it was due to
surfaces R2 and R3 not being coated, apparently a common occurence in
Unitron objectives. As with you, it was only seen at low powers.
Roland offered to coat the uncoated surfaces but I never took him up on
it. I have no idea what may be causing the ghost image in the scopes
you mention.

Starry Skies,
Rich

Sometimes I think it's my eyes, but I had a friend check it on his Dob once, and he confirmed it.

Richard DeLuca wrote:

In article ,
Wayne Watson wrote:

Viewing Mars with the Meade 25mm provided eyepiece with the LXD55 AR6 gives
something like two
disks, one brighter than the other. I've seen this before with SCTs and other
scopes.
SNIP_

Wayne,

The only telescope I ever used that showed this ghost image was a 4"
Unitron that I owned for a few years back in the mid 90s. I brought it
to Winter Star Party once, and when Roland Christen looked through it,
he was not surprised. According to Roland, In this case it was due to
surfaces R2 and R3 not being coated, apparently a common occurence in
Unitron objectives. As with you, it was only seen at low powers.
Roland offered to coat the uncoated surfaces but I never took him up on
it. I have no idea what may be causing the ghost image in the scopes
you mention.

Starry Skies,
Rich

--
Wayne T. Watson (121.015 Deg. W, 39.262 Deg. N, 2,701 feet, Nevada City, CA)
-- GMT-8 hr std. time, RJ Rcvr 39° 8' 0" N, 121° 1' 0" W

Remember to drink an adequate amount of dihydrogen oxide each
day.

Web Page: home.earthlink.net/~mtnviews
Imaginarium Museum: home.earthlink.net/~mtnviews/imaginarium.html