High power widefield eyepiece.

[Guest]

I am using my new Celestron C925 and enjoying it very much.My high power eyepieces are The 8.5 and 12mm Pentax XF and a Celestron X-Cel LX 7mm.Because I use with a non driven mount,the planets on view does travel across the 60 degree field quickly.I have for that reason comtemplating just one high power eyepiece with a much wider fiels,say 80 degrees.I think that either of 7.5mm or an 8mm focal length would fit the gap.Some people have said that wider field eyepieces with numerous elements add glare and loses contrast.Would this be the case with Televue,Explorer Scientific or Pentax?

Does anyone have any experience using very wide field eyepieces for planetary observing?

Thanks

Martin.

[damnut]

Hi Martin,

The 8mm will give nearly 300x in your scope, even at best seeing conditions in my 10"lx200 would I rarely go above 250x. A colleague has the 9mm 120 deg ep and it is awesome! I have a myriad 9mm 100 deg and it is fine for planetary. There is an 8.8mm  82 deg ES which is a lovely ep.

[John]

I tend to use wide field eyepieces all the time for planetary observing Martin. With my scopes being on undriven, alt-azimuth mounts I find wide fields of view help reduce the need for "nudging" a bit

Having compared wide field eyepieces a lot with simpler designs such as good orthoscopics I don't feel that there is much, if any downside to modern more complex designs as long as they are well executed using quality materials.

Specifically I've found the Pentax XW eyepieces from 10mm down to 3.5mm perform really excellently on the moon and planets so those are my favourite eyepieces currently for that purpose. I believe the Tele Vue Delos is just as capable and, from the early reports, the new Tele Vue Delite is also likely to excell at this. 

The only eyepieces with 82 degree fields that I've used for this purpose are the Tele Vue Nagler Type 6's and the William Optics UWAN / Skywatcher Nirvana range. Both these types gave very nice planetary performance but I feel the Pentax XW's just show that bit less light scatter around bright objects and a slightly sharper, more contrasty image to my eyes. I also found these qualites in the Tele Vue Ethos eyepieces but those push the budget up a significant amount.

Those are just my findings and preferences currently. Others will have their favourites as well of course and some will still prefer the simpler "low glass" designs over the more complex types.

[jetstream]

Hi Martin, glad you are enjoying the new scope.  I have a question- how critical of a planetary observer are you? Widefield can give very good views, but if you get to the nitpicking stage ( like me), they fall short a bit. My 18mm ES 82 and 16mmT5 barlow very well for some great planetary views.

Another question could be is how much mag will your seeing allow? If the sky prevents the fine detail from being seen, then the narrower more specific planetary eyepieces won't give much extra.

[MarsG76]

Hi Martin, among my collection I have a TeleVue 11mm Type 6 Nagler and it's absolutely awesome for planetary observing. The contrast is super, clarity is among the best I've seen and it 82 deg AFOV. On the clearest nights I combine it with a 2.5x powermate and with baader contrast booster and moon & sky glow filters stacked it has delivered the best, most detailed views of Saturn, Jupiter, the moon, mars, Venus.... Also it is a great eyepiece with its wide field and high power for nebulae like Orion Nebula and the carina nebula and star clusters such as the jewel box.

I can't recommend this eyepiece enough.

[alan potts]

A fine answer by John.

I would only like to add that the Meade 6.7mm UWA or 8.8mm UWA, a touch more power the former, would be very good eyepieces as well or  ExSc do the same eyepiece  elements in a different tutu with gas, so I would have thought was just as good.

I have a 7mm Nagler which is very good and have used the 7mm XW which is excellent but dear. As said there are not that many at 7mm in the ultra wide zone but as said this is high power..

Alan.

[Tinker1947]

These EP have been talked about as being good, i don't have one so can't comment.....

http://www.firstlightoptics.com/explore-scientific-eyepieces/explore-scientific-82-degree-series-eyepieces.html

[estwing]

8mm ethos....super piece of glass...

[kurtz9]

If you want a straight use EP the ES82 in 8.8 or the ES100 in 9mm would work great for you...

Another option if you have a 2x barlow of some kind would be the ES14, which comes in both 82 and 100 AFOVs and barlows down to 7mm at 2x (and as an owner of a 9.25 myself, 7mm works just great on moon/planets even in average/not great seeing- your skies may vary of course)

And if you DON'T have a 2x right now, well, you can get the 14mm 100 degree ES -and- a 2" 2x ES focal extender for less than what a comparable Ethos by itself costs....  and most folks find the ES100s and Ethos equal in visual quality (especially given you're using a slow scope)

[jetstream]

Martin, my much maligned 7mm Luminos performs very well on the planets and the moon - here it rivals some more expensive hyperwides- but is still softer than dedicated planetary's. Most will say these eyepieces are junk, but my example performs well with a nice wide field. No ghosting, scatter is not bad...

If I was going to buy a fixed fl widefield planetary today it would be the Pentax XW, the 7mm might be friendlier than the 5mm...

[andrew63]

For me these would be colossal amounts of magnification - 300x to 400x - to use successfully with such a long focus telescope on an un driven alt az mount.   I have a picture of trying to track the ISS - there one second gone the next 

andrew