Jump to content


Photo

Celestron Ultima LX?

  • Please log in to reply
12 replies to this topic

#1 daveyfitz

daveyfitz

    Explorer 1

  • -----
  • Posts: 82
  • Joined: 02 Jan 2013
  • Loc: Utah

Posted 01 February 2013 - 02:22 PM

I'd like to hear some opinions on the Celestron Ultima LX EPs.

I've searched extensively for reviews and not come up with much.

To me, the feature set is EXTREMELY enticing:

---Fully Multi Coated

---70° FOV

---16mm eye relief

---Parfocal

---ALL the focal lengths can be 2" format, by removing the 1.25 barrel, and ALL accept 2" filters.
-(ZOW, no adapters needed, no 1.25" filters needed)

---Twist up eyecups

---Price near $100

I suppose it's too much to hope for that they are also bright and crisp edge to edge,
but (dare I dream?), who owns them and loves (hates?) them?

Thanks to any who would share their knowledge.

#2 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 22880
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 01 February 2013 - 07:08 PM

You don't have to remove any 1.25" barrel to convert these to 2". Except for the 2"-only focal lengths, all the others are 1.25" eyepieces with 2" skirts, so they are usable in either 1.25" or 2" focusers and accessories without modification.
They are a "mid-grade" eyepiece, so somewhere in-between the edge correction of a Panoptic or Delos, say and a QX70.
Where they stack up will be determined by the focal ratio of your scope and your preferences.

#3 rguasto

rguasto

    Viking 1

  • *****
  • Posts: 800
  • Joined: 18 Nov 2010
  • Loc: Long Island, NY

Posted 01 February 2013 - 09:06 PM

Perfect description. I own the Astro Tech version (AF 70). In my 8" F8 reflector they produce nice round stars to the edge. In a friends 8" F5 reflector ~75% (last 10% is obvious and likely the mirrors coma, but doesn't bother me) They work very well on DSO's. I really like the large eye lens. Very well made.
-Rob

#4 ThreeD

ThreeD

    Apollo

  • -----
  • Posts: 1029
  • Joined: 23 Dec 2008
  • Loc: Sacramento suburbs

Posted 02 February 2013 - 02:11 AM

The 32mm wasn't great in an XT8 and I'm not just talking about the exit pupil being a bit on the large size. Then again for the price it wasn't too bad. I picked it up as a (relatively speaking) budget eyepiece when I was starting out and kept it for about two years until I found a deal on a 31mm Nagler. Once I bought the Nagler I sold the Ultima LX and never looked back but for the price difference I wouldn't expect it to compare.

I was just starting out so didn't know a lot but if I remember correctly it suffered from a little bit of what I now understand is field curvature. I could have the edge or the center in focus but not both. Actually I'm not sure the edge would ever get perfectly sharp but it would get better with the center a bit out. This could be unique to the 32mm as that is the only focal length I've seen.

I actually seem to prefer eyepieces with less eye relief. To me eye placement is much easier on my 31mm Nagler than it was on that 32mm Ultima LX. I only had one of the line so I had no benefit from them being parfocal but I agree that it makes life in the field easier. I lost many an object when I first started out due to the time it took to switch eye pieces *and* refocus when using my undriven dob.

#5 maroubra_boy

maroubra_boy

    Vendor - Gondwana Telescopes

  • -----
  • Vendors
  • Posts: 531
  • Joined: 08 Sep 2009
  • Loc: Sydney, Australia

Posted 02 February 2013 - 06:56 AM

I've been trying for ages to find more user experiences on these EPs. I've even started some 3 separate threads on this range with only a little feedback.

I have the 8mm and I like it. Certainly not the best EP I've used, but no where near the worst. The eye relief is very nice and comfortable. I also find it very easy on my eyes to use for extended periods - eye strain is something rarely mentioned, and few EPs can claim a real ease of use this way, even expensive ones.

I too have read the 32mm is the runt of the range. But it is also unfair to damn an entire range just on one experience with one of the models. Take the Pentax 14mm XW, it shows a lot of field curvature in fast Newtonians, where as the other models in the range have this much better controlled.

The only other LX I've read about is the 17mm. Reviews on this one are mixed, though no one out right dismiss's it. From what I can gather it performs ok. Not an LVW, so if you are after exceptional performance, this is not the EP for you.

What also appeals to me from this range is the AFOV which as wide as I like to go.

I am very keen to find out how the others in the range do. I'd love to weed out the real gem or two in this lot.

Alex.

#6 eklf

eklf

    Apollo

  • *****
  • Posts: 1450
  • Joined: 12 May 2007
  • Loc: Carrboro, NC

Posted 02 February 2013 - 08:30 AM

I had the 22mm and found it to be a decent performer in my F6 dob. Performance-wise it appeared to be on par with 22 pan and 22 LVW, (although both the latter were more comfortable to use) and a definite step above Hyperion 21mm (better edge correction and a sharply defined field stop, just like lvw and pan).

The only reason I let it go was, given the architecture of my face - big nose and deep set eyes) - poor nose relief.

If it were not for the nose relief issue I would gladly have considered the entire line. Recommended.

#7 maroubra_boy

maroubra_boy

    Vendor - Gondwana Telescopes

  • -----
  • Vendors
  • Posts: 531
  • Joined: 08 Sep 2009
  • Loc: Sydney, Australia

Posted 02 February 2013 - 04:11 PM

Good to read about the 22mm.

Dave, I've just re-read your original post. The 1.25" barrel doesn't come away to leave just the 2" on those dual barrel models. They are intergrated. Unfortunately it means ONLY 1.25" filters can be used directly on the EP. I too had understood that the 2" filters could be used, but to me it seems that the marketing lads at Celestron have never actually touched and used this EP and have made a claim that isn't the case.

One way to use 2" filters is by fitting them into the end of your 1.25" adapter if it has a thread for accepting them. Another is threading them into your 2" diagonal if you are using one. The only other way is to thread them onto the end of the draw tube of your focuser via a step-down ring placed onto the draw tube. This last way is how I use my 2" filter on my big dob. Only thing is not all draw tubes have a thread cut into them at their "scope side" end, and this is only an option with reflectors.

#8 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13776
  • Joined: 26 Dec 2004
  • Loc: Canada

Posted 02 February 2013 - 05:28 PM

Good to read about the 22mm.

Dave, I've just re-read your original post. The 1.25" barrel doesn't come away to leave just the 2" on those dual barrel models. They are integrated. Unfortunately it means ONLY 1.25" filters can be used directly on the EP. I too had understood that the 2" filters could be used, but to me it seems that the marketing lads at Celestron have never actually touched and used this EP and have made a claim that isn't the case.

One way to use 2" filters is by fitting them into the end of your 1.25" adapter if it has a thread for accepting them. Another is threading them into your 2" diagonal if you are using one. The only other way is to thread them onto the end of the draw tube of your focuser via a step-down ring placed onto the draw tube. This last way is how I use my 2" filter on my big dob. Only thing is not all draw tubes have a thread cut into them at their "scope side" end, and this is only an option with reflectors.


Or you can do this...

1.25" yepiece plus Antares Twist Lock adapter with 2 inch filter.

Attached Files



#9 Scanning4Comets

Scanning4Comets

    Markus

  • *****
  • Posts: 13776
  • Joined: 26 Dec 2004
  • Loc: Canada

Posted 02 February 2013 - 05:30 PM

Or.....

Eyepiece plus 2" filter permanently screwed onto a 2" extension tube. I prefer this way, but my 2" Orion Ultrablock filter threads won't go onto the extension tube deep enough, so I use the first method for the 2" Ultrablock. I may be able to use the second method for my 2" Lumicon O-III once it arrives. The second method is the best, unless you can't reach focus. I can reach focus either way.

Another thing you could do, is leave the 2" filter permanently mounted onto a Twist Lock adapter if you only use 1.25" eyepieces and only have 2" filters.

I think a filter holder is the ultimate IMHO. No fussing with threads in the dark or cold.

Back onto the original topic: The Celestron Ultima LX eyepiece I had was the 17mm. For the money it's great if you need long eye relief, and don't mind a bit of FC if you have a short FL scope.

Cheers,

Attached Files



#10 daveyfitz

daveyfitz

    Explorer 1

  • -----
  • Posts: 82
  • Joined: 02 Jan 2013
  • Loc: Utah

Posted 03 February 2013 - 11:22 AM

Good to read about the 22mm.

Dave, I've just re-read your original post. The 1.25" barrel doesn't come away to leave just the 2" on those dual barrel models. -------


Alex: Are you sure about that?

If you look at the images of the dual-barrel models, there is a compression screw in the outer barrel, which I would assume releases the inner barrel.
That would allow access to 2" threads, if present.

Attached Files



#11 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 22880
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 03 February 2013 - 11:44 AM

Good to read about the 22mm.

Dave, I've just re-read your original post. The 1.25" barrel doesn't come away to leave just the 2" on those dual barrel models. -------


Alex: Are you sure about that?

If you look at the images of the dual-barrel models, there is a compression screw in the outer barrel, which I would assume releases the inner barrel.
That would allow access to 2" threads, if present.

The screw in the 2" outer skirt presses against the 1.25" focuser to hold the eyepiece in place. Though there is a slit in the 2" skirt to allow access to the setscrew in the 1.25" focuser, many screws are not long enough to use when the eyepiece is used in a 1.25" focuser.
Hence, the setscrew transfers to the eyepiece and presses against the outside of the focuser.

When the eyepiece is used in a 1.25" adapter in a 2" focuser (not too likely, but possible if you desire using 2" filters on the adapter), the setscrew of the adapter presses against the 1.25" barrel in the eyepiece and the 2" skirt merely rests on the top of the adapter.

When the eyepiece is used as a 2" eyepiece, the screw in the eyepiece's barrel is removed.

If the 1.25" barrel is removed, the correction in the eyepiece is eliminated, similar to removing lenses in nearly any fully-corrected eyepiece. For example, when the bottom lenses are removed from Baader Hyperion eyepieces, the focal lengths get a lot longer, and correction at the edge of the field goes kablooey. They're designed to be used WITH the lenses in the 1.25" barrel. The 2" skirt is merely for convenience to the 2" focuser user.

#12 daveyfitz

daveyfitz

    Explorer 1

  • -----
  • Posts: 82
  • Joined: 02 Jan 2013
  • Loc: Utah

Posted 03 February 2013 - 01:37 PM

The screw in the 2" outer skirt presses against the 1.25" focuser to hold the eyepiece in place. Though there is a slit in the 2" skirt to allow access to the setscrew in the 1.25" focuser, many screws are not long enough to use when the eyepiece is used in a 1.25" focuser.
Hence, the setscrew transfers to the eyepiece and presses against the outside of the focuser.

When the eyepiece is used in a 1.25" adapter in a 2" focuser (not too likely, but possible if you desire using 2" filters on the adapter), the setscrew of the adapter presses against the 1.25" barrel in the eyepiece and the 2" skirt merely rests on the top of the adapter.

When the eyepiece is used as a 2" eyepiece, the screw in the eyepiece's barrel is removed.

If the 1.25" barrel is removed, the correction in the eyepiece is eliminated, similar to removing lenses in nearly any fully-corrected eyepiece. For example, when the bottom lenses are removed from Baader Hyperion eyepieces, the focal lengths get a lot longer, and correction at the edge of the field goes kablooey. They're designed to be used WITH the lenses in the 1.25" barrel. The 2" skirt is merely for convenience to the 2" focuser user.


Dang.

That is a WHOLE lot less attractive than being able to remove the 1.25" and having a set of 2" barrels that accept 2" filters.

Thanks for clearing up my misconception.

Note to EP designers: Get on this.

#13 Starman1

Starman1

    Vendor (EyepiecesEtc.com)

  • *****
  • Vendors
  • Posts: 22880
  • Joined: 23 Jun 2003
  • Loc: Los Angeles

Posted 03 February 2013 - 02:29 PM


The screw in the 2" outer skirt presses against the 1.25" focuser to hold the eyepiece in place. Though there is a slit in the 2" skirt to allow access to the setscrew in the 1.25" focuser, many screws are not long enough to use when the eyepiece is used in a 1.25" focuser.
Hence, the setscrew transfers to the eyepiece and presses against the outside of the focuser.

When the eyepiece is used in a 1.25" adapter in a 2" focuser (not too likely, but possible if you desire using 2" filters on the adapter), the setscrew of the adapter presses against the 1.25" barrel in the eyepiece and the 2" skirt merely rests on the top of the adapter.

When the eyepiece is used as a 2" eyepiece, the screw in the eyepiece's barrel is removed.

If the 1.25" barrel is removed, the correction in the eyepiece is eliminated, similar to removing lenses in nearly any fully-corrected eyepiece. For example, when the bottom lenses are removed from Baader Hyperion eyepieces, the focal lengths get a lot longer, and correction at the edge of the field goes kablooey. They're designed to be used WITH the lenses in the 1.25" barrel. The 2" skirt is merely for convenience to the 2" focuser user.


Dang.

That is a WHOLE lot less attractive than being able to remove the 1.25" and having a set of 2" barrels that accept 2" filters.

Thanks for clearing up my misconception.

Note to EP designers: Get on this.

TeleVue eyepieces with similar skirts have the 2" skirts threaded on the inside. You can attach a 2" barrel extender that goes beyond the 1.25" section. At that point, the eyepiece is a pure 2" eyepiece and accepts 2" filters.

But, the Ultima LX skirt is not threaded, IIRC, so the barrel extender idea won't work.

What would work is to buy a 1.25" adapter and simply attach it to the eyepiece in a semi-permanent fashion. Many adapters are threaded on the bottom for 2" filters.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics