One Ethos or two XWs?

[coliea]

I've posted this on CN also folks, so if you reply here no need to bother there

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I never thought buying an Ethos would be the cheap option, but let me explain...

After following the advice in this CN thread http://tinyurl.com/4ad57z I picked up a Pentax XW10 for my SV102 f7 scope. I also sold my 1.6x Barlow and replaced it with a 2.5xPowerMate. My intention was to follow up the 10XW with the 14 and 20, which along with the PowerMate would give me mags of 36x, 51x, 71x, 89x, 127x and 178x with just 3 eyepieces.

Then I did something stoopid... I threw the Ethos 13 into the mix

I had originally written the Ethos off as too expensive, but having looked at the specs I’m now wondering if the Ethos could replace the 20XW and 14XW and actually save me some money?

My initial reasoning for picking up the 14XW and 20XW? The 14 would give me an exit pupil of exactly 2mm in my SV102 (at 51x) and the 20XW would deliver a TFOV of 1.9 degrees (at 36x). Looking at the Ethos 13 however I notice it will also deliver the supposedly sweet 2mm exit pupil (1.9 actually) of the 14XW while providing the TFOV of the 20XW (or close enough at 1.8 degrees). One Ethos instead of two XWs = money saved... right?

But... the 13E and 10XW (+2.5PM) would give me a range of magnifications of 55x, 71x, 137, 178x, so now I seem to have gap between 71 and 137. This could be filled with the 7XW (101x) but then I’m not really saving financially and am back to where I started – paralysis by analysis anyone?

I realise I’m pretty lucky that my “problem” is choosing between Ethos and XW eyepieces... at the end of the day it’s not much of a dilemma. But I thought I’d ask for arguments for both sides:

1. 20XW, 14XW, 10XW + 2.5xPM

2. 13E, 10XW, 7XW + 2.5xPM

Whatcha think?

Col

[Andrew*]

I wish I was in your position!

The 13E would work beautifully in your scope, no question. You would use it so much to justify it. The 7mm on the other hand would get less use.

So have you considered filling the ~100x gap with something a bit more budget? Say a 7mm TMB Planetary or 8mm Hyperion? Afterall, you don't NEED to be very picky with an f/7 scope...

Question: your range only goes to 178x. Do you not feel teh need for a higher power eyepiece - I'm sure the SV102 could easily go to 250x? Or are you not into lunar/planetary.

Andrew

Andrew

[coliea]

Afterall, you don't NEED to be very picky with an f/7 scope...

Yeah Andrew, I spoke with Steve @ FLO before purchasing the 10XW and he told me the exact same thing, saying I could get by with "lesser" EPs in an f/7. I really appreciated the honesty and genuine advice but I decided to go with a few premium eyepieces, my thinking being they're a lifetime investment even if I change scopes in a few years time.

Question: your range only goes to 178x. Do you not feel teh need for a higher power eyepiece - I'm sure the SV102 could easily go to 250x? Or are you not into lunar/planetary.

Nope - I'm deffo into lunar/planetary observation also, and would get 254x with the 7XW + 2.5 Powermate, which was another reason I'm thinking of the 13E, 10XW and 7XW.

Col

[Ben Ritchie]

Col, I went through this recently, although in my case I was looking between the 8E vs 7XW and 10XW - i've owned both of the XWs before and they're among my favourite eyepieces ever, pre-Ethos only the 20mm T5 Nagler ranks up there. The 13mm Ethos was an automatic choice for me once I could raise the £££, and once I looked through that any thoughts of XWs went out the window, I had to have the 8E too. In my setup (130mm f/8 refractor) both Ethos eyepieces are stunning.

So my vote would certainly be for the 13mm Ethos rather than the longer focal length XWs. If you didn't already have the 10mm XW then i'd be voting for the 8E too. The gap between them doesn't bother me a bit.