100º AFOV zoom 30-104x / 41-145x!!!
Posted 06 August 2012 - 06:11 PM
Posted 07 August 2012 - 09:10 AM
Posted 07 August 2012 - 05:20 PM
From your comment regarding the light availability at 145x, I remembered that the 1rst lens of the FSA-L2 moves with zoom and that might would affect the zoom factor with the barlow. Today I did a quick test to verify the zoom factor and noticed that it's reduced when using the barlow cell (at maximum zoom position the first lens of the Nikon is closer to the barlow lens, so increase less...), and the resulting magnification should be 41-127x so more according the image quality and brightness I observed before and confirmed today...
I should add that with this combo, with the barlow, the resulting TFOV are much wider than the 30-90x zoom of the Optolyth 100...
Can you please confirm that the Ethos17 has better eye-relief than the Ethos13 and Ethos21? Thanks.
Posted 08 August 2012 - 07:56 AM
I don't remember seeing more eye relief in the 17mm Ethos vs the 13mm or 21mm but I will check that out the next time I use it. I know when I use my Celestron F6.3 focal reducer it cuts down the eye relief on them.
Can you please confirm that the Ethos17 has better eye-relief than the Ethos13 and Ethos21?
Posted 19 August 2012 - 10:52 AM
It's possible to reach >140x during daylight without obtaining a dark image but didn't tested the resolution neither did use it on field conditions.
Posted 24 August 2012 - 03:49 AM
That must be a dim daylight view @145x in a 92mm scope. I like using a pair of 13mm Ethos with my Denk II with Power X Switch in .66x focal reducer mode in my C9.25 with 45° 2" WO correct image prism diagonal as a spotting scope in the daytime. I also use my 17mm and 21mm Ethos in my scopes as a spotter in the daytime.
In the daytime, your pupil is probably open no more than 2mm so that puts a limit on the maximum brightness. I often use 120x in my 80mm apo, 145x in a 92mm is probably not as dim as it would seem.
Posted 18 September 2013 - 05:03 PM
Interesting that 20 years ago I started with a Nikon ED60 with a 20-45x zoom and nowadays I usually use my combo equivalent to a 41-124x 100º AFOV zoom and can also use a 53-178x 102º AFOV when higher resolutions are needed and it works well...