17.3 mm Delos in a GSO Newt.

[Varangian]

Hi all,

I am seriously considering one of three EPs - the 17.3 Delos, 17 mm Vixen LVW and the 16 mm ES 68*. I own the 10 mm Delos and I love it although I have established that the 17.3 mm is not parfocal with the rest of the Delos range (from 12 mm down). I intend to use the 17.3 mm in a 12" GSO Newt and was wondering if there are any other IISers who have viewing experience with this combination (or simply with the 17.3 mm with a fast Newt). I have scoured both IIS and CN for reviews and most seem to be very good re. the Delos and LVW and more variable with the ES but still quite good, although I'm struggling to find good reviews of the ES in a fast newt.

I have just two questions I would like to ask and if anyone could assist it would be greatly appreciated.

1/ I would like to know whether the 17.3 Delos will reach focus in my GSO focuser without the need for an extension tube (or lack of inward travel).

2/ Does anyone have experience with the 17.3 in a fast Newt and can you please provide a brief opinion on this combination?

Thanks all in advance.

[astro744]

See Column F at http://www.televue.com/engine/TV3b_page.asp?id=214#.U3wXfvmSy5I

The 17.3mm Delos has a field stop 0.48" (0.25+0.23) above that of the 10mm Delos. Therefore you will have to rack the focuser inward 0.48".

I have not used the Delos range and cannot comment on their performance other than to say the quality will be similar to the 10mm Delos as you would expect from Tele Vue.

[Allan]

TeleVue make such consistent eyepieces across the whole range. I have not looked through the 17.3, but can't believe it would be anything other than a great eyepiece. If you buy it and find you can't reach focus, then get the TeleVue in travel adaptor which was made for the 17.3 and 14 Delos. That should fix the problem for you.

[MattT]

I do have the 16 ES 68º and with a coma corrector of some kind (mine is the ES) it is refractor like views, as is the other ES 20 24 28 and 34 eyepieces in my 10" f4,8 Newt. Do you have a CC?
Matt

[bytor666]

Hi John,

I've tried the 17.3mm Delos in my 10" F/4.7 and it is in dire need of a coma corrector BIG-TIME. I own the 17mm Vixen LVW, and while it also shows some coma, I can safely say that I am happy with it in my scope without a coma corrector.

The 17.3mm Delos starts to show coma about 50% of the way out. The 17mm Vixen LVW starts at around 75% of the way out, but it is not distracting at all. What I really like about the 17mm Vixen LVW is such easy eye placement, and excellent eye relief. The 17.3mm Delos however, does have a bit more "pop" to it and a really big "immersion" factor. If you own a coma corrector, I'd say to go with the 17.3mm Delos. If you do not own a coma corrector, you'd really like the 17mm Vixen LVW!

CS!