ES LER 92°

[spaceboy]

http://www.telescopehouse.com/eyepieces/explore-scientific-eyepieces/explore-scientific-92-ler-eyepieces/explore-scientific-92a-argon-17mm-le-eyepiece.html

It will be interesting to hear users comments to if the stated 22mm eye relief is actually 22mm. I know with all my ES eyepieces 82° & 100° I have to use them with the eyecup folded down to get the whole FOV in and even then it can be tight. As has already been noted time and time again by users of ES eyepieces the recess of the lens is the culprit of the eye reliefs being far shorter than on paper with their eyepieces.

[John]

These are creating a bit of a "stir" on the Cloudynights forum:

http://www.cloudynights.com/topic/528192-new-explore-12mm-92-degree-is-in-game-changer/

Heavy and very large eyepieces !

 

 

 

[John]

FWIW I've read that the usable eye relief is 20mm. Close enough though.

 

[bish]

We just need John to review one now...

[spaceboy]

20mm sounds about right given the usual recess to lens found in other ES. I assume it is going to always be the case when having to have a sealed lens assembly for purging. Definitely an improvement over the 12.5mm - 14.5mm (more like 10mm - 11mm) eye relief of the 100° range and the new shallower 92° fov should make them all together easier to take in the views.

[Chris]

1 hour ago, John said:

These are creating a bit of a "stir" on the Cloudynights forum:

http://www.cloudynights.com/topic/528192-new-explore-12mm-92-degree-is-in-game-changer/

Heavy and very large eyepieces !

 

 

 

I've just read the entire CN thread, tangents and all. Jeez! did you see the pics of the eyelens compared to the ethos and the Nav, it's like some kind of 'Super Delos'!

[michael.h.f.wilkinson]

These sound very interesting indeed. Maybe the 12T4 will be replaced by a 12 deg ES 92 deg? Some state the 17mm version is actually a touch sharper than the superb Nagler 17T4. Sounds very interesting (if expensive )

A bit cheaper than the Naglers too

[John]

3 hours ago, bish said:

We just need John to review one now...

I very nearly clicked the "buy" option on one a couple of hours back but I'm hesitating for some reason

 

[Doug]

I just like to say as I normally say to friend look on OPT USA site they are usually cheaper but not time even with our 20% VAT (tax) it is £26.00 cheaper here thats $37.00 for our American friends at 

Telescope House 

Oh ,I have no affiliation with this company except I brought my scope there   

[bish]

10 hours ago, John said:

I very nearly clicked the "buy" option on one a couple of hours back but I'm hesitating for some reason

 

your subconscious is telling you that you don't need it - not that it stops us buying astro kit....

[Stu]

These do look interesting. Is the 17mm the longest focal length or is/will there be a 20/21mm?

[michael.h.f.wilkinson]

I think I will keep the Naglers for now. Cracking EPs and I would gain more putting the money towards more aperture at some point

[RikM]

I would also like to see if they come out with a 20mm ish version. 

[russ.will]

Ooh! Interesting and some very positive comments from TV users too. Near 100deg AFOV and 20mm eye relief? Are we seeing a paradigm shift where the pupil starts to push past the master?

Let the dust settle and we''l see where this bottoms out.

Russell

[estwing]

interesting stuff....wonder if Tele-vue have a ethos 2 in the pipeline??

[spaceboy]

I won't be buying anytime soon as I find it a chore to use the 100° eyepieces because of the weight and these LER eyepieces are even heavier. I'm sure I'm not the only person who prefer the scope staying put when you change from one focal length to another. I do enjoy the views in the ES 100° but despite the dent they made in my bank balance at the time I could never bring myself to let my set of ES 82° ep's go to fund them. I use the 82° ep's far more than I do the heavy 100°s because there is almost no need to counterweight or keep one eye on the scope when swapping out ep's. Even balancing the scope and just using the ES 100° no sooner you take the one ep out the scope lens/mirror wants to go south. I know a lot of ethos owners manage fine and I'm sure with practice I could get in to some sort of routine that supports the scope throughout the swap but I think a momentary loss of concentration using an LER 92° @ 2.5lbs and your offset or counter weighted scope would swing like a wreckers ball. I know a lot of people have had scopes slip through the clamps on their mount as the night time cold shrinks stuff or they didn't tighten the clamps as much as they thought due to cold hands or fumbling in the dark. A swinging scope isn't going to be forgiving of loose clamps or tripod legs getting in the way.

[michael.h.f.wilkinson]

Much depends on scope and mount, of course. My SCT on its sturdy Great Polaris mount doesn't flinch when I swap from Vixen SLV 5mm (165 g)  to the 1kg Nagler 31T5 "Panzerfaust".  Especially in a Dobsonian, the balance issues can be rather more profound

[Stu]

1 hour ago, spaceboy said:

I won't be buying anytime soon as I find it a chore to use the 100° eyepieces because of the weight and these LER eyepieces are even heavier. I'm sure I'm not the only person who prefer the scope staying put when you change from one focal length to another. I do enjoy the views in the ES 100° but despite the dent they made in my bank balance at the time I could never bring myself to let my set of ES 82° ep's go to fund them. I use the 82° ep's far more than I do the heavy 100°s because there is almost no need to counterweight or keep one eye on the scope when swapping out ep's. Even balancing the scope and just using the ES 100° no sooner you take the one ep out the scope lens/mirror wants to go south. I know a lot of ethos owners manage fine and I'm sure with practice I could get in to some sort of routine that supports the scope throughout the swap but I think a momentary loss of concentration using an LER 92° @ 2.5lbs and your offset or counter weighted scope would swing like a wreckers ball. I know a lot of people have had scopes slip through the clamps on their mount as the night time cold shrinks stuff or they didn't tighten the clamps as much as they thought due to cold hands or fumbling in the dark. A swinging scope isn't going to be forgiving of loose clamps or tripod legs getting in the way.

Do you not use an Ercole mount Nick? I'm getting another very soon but from memory the top lock works very effectively at stopping any motion when changing eyepieces? Balance during use needs adjusting still admittedly

[RT65CB-SWL]

On 19 March 2016 at 09:10, bish said:

your subconscious is telling you that you don't need it - not that it stops us buying astro kit....

Or as my lady friend says... "Do you really need it?" and I answer with... "It may be useful!"

[michael.h.f.wilkinson]

14 minutes ago, Philip R said:

Or as my lady friend says... "Do you really need it?" and I answer with... "It may be useful!"

Alternatively, reply: "do you really need that pair of shoes"

[bish]

36 minutes ago, Philip R said:

Or as my lady friend says... "Do you really need it?" and I answer with... "It may be useful!"

That's why I never throw things away too ..."it may come in handy one day."

[spaceboy]

8 hours ago, Stu said:

Do you not use an Ercole mount Nick? I'm getting another very soon but from memory the top lock works very effectively at stopping any motion when changing eyepieces? Balance during use needs adjusting still admittedly

I do Stu and the top lock does a good job of holding the scope between changes but find depending on where I'm looking in the sky I have to button up both the lock and the ALT screw pretty tight if I don't want that 6" of glass half a meter off the axis to start drooping south. It's large eyepieces in general that I have never really enjoyed using. You go from a 1.2lb 100° eyepiece (imagine 2.5lb with the 92° LER) to a 60g ortho and you then got no choice but to faff around in the dark re-balancing your scope. If you then find seeing isn't up to the magnification of the ortho you got to go through it all again in reverse. I can go all night long with my ES 82° ep's and ortho and only have to make adjustments to the ALT tension ( again depending how far off the horizon I'm looking) &  top lock between changes.

I am considering something similar to your Vixen's sliding counterweight but can't help but think it is adding yet more weight to an already heavy scope. 

[Commanderfish]

19 hours ago, spaceboy said:

I do Stu and the top lock does a good job of holding the scope between changes but find depending on where I'm looking in the sky I have to button up both the lock and the ALT screw pretty tight if I don't want that 6" of glass half a meter off the axis to start drooping south. It's large eyepieces in general that I have never really enjoyed using. You go from a 1.2lb 100° eyepiece (imagine 2.5lb with the 92° LER) to a 60g ortho and you then got no choice but to faff around in the dark re-balancing your scope. If you then find seeing isn't up to the magnification of the ortho you got to go through it all again in reverse. I can go all night long with my ES 82° ep's and ortho and only have to make adjustments to the ALT tension ( again depending how far off the horizon I'm looking) &  top lock between changes.

I am considering something similar to your Vixen's sliding counterweight but can't help but think it is adding yet more weight to an already heavy scope. 

Here's what I've got to address this problem on the Ercole.  You attach it to your dovetail and slide it around to counteract the change in eyepiece weight.  Mine isn't on yet as my stock dovetail has a protective plate on it which makes it too wide for the counterweight, and I'm waiting for the correct countersunk 1/4" UNC 20 screws to be delivered so that I can mount a longer dovetail.  I'll post when I've had a chance to experiment.  It's cheaper if you get it from Teleskop Service  in Germany by the way.  

http://www.firstlightoptics.com/counterweights/baader-dovetail-bar-levelling-counterweight.html

Teleskop Service also have a 31cm vixen dovetail on sale for 22 Euros.  I've got one and it's solid.

https://www.teleskop-express.de/shop/index.php/language/en

[F15Rules]

For heavy EPs I find that Baader clicklocks really help. I go from Meade 14mm UWA big boy to 7mm ortho and although I still have to rebalance my scope, I don't have to worry about the EP dropping out of the focuser. I also have a 69mm Vixen to 2" clicklock attached to the back of the scope so there is no weak link :-)

 

Dave

[spaceboy]

Thanks commanderfish but £87 is a little rich for me if I'm honest.

My method when I eventually find the correct OTA ring (astroboot lists this but this is not the actual one they have) was to have a set of 3 OTA rings along the scope.

2 that do the usual job of holding the dovetail but 1 of which will have an 'L' bracket fixed to the top. The 3rd OTA ring will again have an 'L' bracket and this http://www.firstlightoptics.com/skywatcher-star-adventurer/skywatcher-star-adventurer-counterweight-kit.html fixed between the 2 'L' brackets allowing me to slide the counter weight between the 2nd and 3rd OTA rings. Total cost should be no more than £30.