Some light reading for anyone interested in this topic..... Enjoy!!!
Thanks to Brandon (bdawg6381 on CN)
http://www.cloudynights.com/index.ph...tach_id=282845
also much kudos and thanks to Mr Tamiji Homma for his permission to post this here:
Quoted from Tammy's great post on CN
Here is what I measured with Vixen ED80SF and Baader 2" MaxBright diagonal against several eyepiece focus distance when I focused to a target about 1 kilometer away, to focus to infinity, less than about 1mm inward distance required. The first column is distance between end of OTA and diagonal. The second column is relative distance, negative value shows need inward focus distance, positive value shows outward focus distance.
14.47 -16.94 Hyperion 31 1.25" mode
19.38 -12.03 LE 50
22.65 -8.76 Ethos 17
24.00 -7.41 Nagler 22T4
24.37 -7.04 Nagler 22T4
25.93 -5.48 Ethos 8 1.25" mode
26.09 -5.32 TMB SM 7
26.17 -5.24 Hyperion 24
28.62 -2.79 LE 30
29.57 -1.84 Paragon 40
29.58 -1.83 LVW 42
30.24 -1.17 Denk 14
30.37 -1.04 XW 40
30.88 -0.53 NAV-SW 17.5
31.02 -0.39 Paragon 30
31.09 -0.32 AII-16
31.14 -0.27 Hyperion 31
31.25 -0.16 AII-6
31.32 -0.09 LE 12.5
31.38 -0.03 XO 5
31.41 0.00 AII-4
31.41 0.00 XW 20
31.46 0.05 XW 30
31.53 0.12 AII-10
31.59 0.18 LE 7.5
31.61 0.20 NAV-SW 7
31.61 0.20 XW 30
31.61 0.20 XW 5
31.62 0.21 XW 10
31.65 0.24 XW 3.5
31.89 0.48 LE 5
33.52 2.11 Denk 21
34.09 2.68 UWAN 16
34.52 3.11 UWAN 28
35.75 4.34 TV PL 32
36.70 5.29 Panoptic 24
36.92 5.51 Panoptic 19
37.53 6.12 TV PL 15
37.72 6.31 TV PL 11
40.04 8.63 Zeiss 25
47.64 16.23 Hyperion 24 2" mode
51.15 19.74 Ethos 8 2" mode
note) unit is in millimeter.
PS: I used very low (less than 1mm) profile 1.25" -> 2" adapter to measure 1.25" format eyepiece.
Tammy