Celestron Xcel LX first light

[F15Rules]

Quick First Light Celestron Xcel lx 7mm and 18mm

As per my short thread yesterday regarding these new eyepieces..I had an all too rare experience last night: having received the above eyepieces yesterday, the same evening the sky was beautifully clear, so got a quick first light (30 minutes).

Conditions:

Good transparency, seeing moderate with noticeable unsteadiness with intermittent better steadiness. Local light pollution from neighbour’s conservatory and light dome up to c 0 degrees latitude due to surrounding towns in all directions.

Scope: Vixen ED103s F7.7 refractor

Objects viewed:

Double Cluster

Pleiades

Gamma Arietis

Comparison eyepieces:

Celestron 7mm barlowed x1.5 to give c4.7mm compared with Pentax XL 5.2mm

Celestron 7mm native compared to Pentax XL 10.5mm

Celestron 18mm compared to Morpheus 14mm

ES 24mm 68 used mainly as a finder eyepiece this evening, to locate objects.

Key points:

First impressions using both Celestrons on their own were excellent. Very good contrast, very sharp stellar points and nice field of view. Reminded me of the view through Televue plossls but with noticeably bigger field of view. Looked sharp to the edge (see below).

Easy to use, very comfortable. I really like the adjustable eyecup. Filter threads readily accept the barlow element. The knurled rubber grip around the body of the eyepiece is a good feature, I wore gloves last night and had no problems holding the eyepiece or adjusting the eyecup (I was using a click lock 2”-1.25” adapter which I think is unbeatable to hold the eyepiece firmly in place). The optics look excellent and have high quality coatings applied. I could see no sign of any dust or debris but note other's comments and will make sure to keep them well covered with dust caps (I routinely do this anyway with all my eyepieces).

Both eyepieces are smaller than the comparator eyepieces, but feel solid and well made. I did not need to adjust the balance of the scope between eyepieces. All the eyepieces used tonight apart from the ES24 68 are parfocal, which is a real bonus. The ES 24 needs just half a turn of my fine focus 1:7 microfocus knob.

7mm Celestron Xcel Lx

The 7mm barlowed compared with the Pentax XL 5.2 delivered lovely sharp views at cx 169. I spent some time with this comparison on Gamma Arietis, a beautiful binary with equal components, rather like a brighter version of Epsilon Lyrae, slightly wider split. I moved the image with my motors to each side of the fov, up and down, side to side, and the image stayed sharp and clear to the edge of the field. This surprised me and exceeded my expectations. The Pentax XL gave ever so slightly a darker background, slightly less scatter (a known strong point of the Pentax range) and a bit wider fov being a 65 deg eyepiece, but the Celestron got remarkably close to it.

I didn’t view the Pleiades with the 7mm. I did look at the Double Cluster and in particular NGC 884 with the tiny circlet asterism at the centre. The contrast was excellent both native at 7mm and at c4.7mm with the barlow element. At these higher powers (x113 and x169 respectively) the darker sky background helped the fainter stars surrounding the circlet to become much more obvious with direct vision.

18mm Celestron Xcel Lx

The 18mm held up very well. I looked at the Double Cluster in Perseus first, and got a lovely view with both cluster centres easily contained in one view at x44, with good contrast and pin sharp stars. The circlet asterism was well defined with one bright star, 4 less bright and one faint component best seen with averted vision, although this does get easier with higher magnification, I find. The Pleiades were similarly well presented, but I couldn’t get all the cluster into one field of view in the way I can with the ES24 68. Contrast was very good and I felt I saw slight hints of nebulosity around Merope. Light scatter was well controlled.

 

Comparing to another eyepiece was more difficult, as my Morpheus 14mm was the nearest I could get to it, and the latter has a 76 deg fov which is very noticeably larger. The Celestron again stayed sharp almost to the very edge of the field. The Morpheus stayed sharp to I would estimate 2-3% of the edge, but of course it was a much wider field of view, so was probably sharp out to about 73-74degrees, which is why I like this unit so much.

 

In some senses these features are unimportant as I use a driven mount which holds the object centred more or less indefinitely. But it is of more importance when using a Dob type scope where it has to be regularly adjusted manually. I cannot say how sharp either of these would be at F5 or faster, but I will test them in my F5.5 90mm refractor next time out.

 

Contrast was better in the Morpheus, but this was as much to do with the difference in magnification I feel. Light scatter was also very slightly better in the Morpheus, but I was very happy with the Celestron’s views.

 

Summary

Based admittedly on just a short session on limited objects, I am very happy with these new eyepieces, especially at the price paid. They get remarkably close in my Vixen to the Pentax and Morpheus, giving up some field of view and just a little on contrast and light scatter, but the differences are small. On the basis of what I saw last night, I would recommend these and may well consider another at some point.

Dave

[YKSE]

Nice first light Dave

Edge sharpness and scatter level in 7mm Xcel-LX is prety much in agreement the tests I've, it should work very well in f4 scopes without much deteriation in the edge.

[billyharris72]

Nice review Dave. I'm a fan of these too. While I've always liked Plossls, and think the Ex-Cels may have a touch more light scatter, there is not much in it and the edge correction is superb. I find it sharp to the edge in my f5 scopes. These days the Ex-Cels are prety much my go to eyepieces for most things.

[John]

Good and useful review Dave.

It's hard to pry decent eyepieces apart in performance terms these days. When I was doing reviews for the forum I found I needed several sessions to start to understand where the differences lay and their exent.

I think you have done very well to produce some comparitive results in the single session 

[F15Rules]

12 minutes ago, John said:

Good and useful review Dave.

It's hard to pry decent eyepieces apart in performance terms these days. When I was doing reviews for the forum I found I needed several sessions to start to understand where the differences lay and their exent.

I think you have done very well to produce some comparitive results in the single session 

Thanks John,

I'm very aware that a 30 minute test is not at all exhaustive, and I need to spend much more time with the new eps. But I wanted these two specifically to fill gaps in my line up, with budget at this time being constrained.

The nice thing is that I really don't feel that whenever I put one of these new units into the scope during an extended session, that I am likely to see significant deterioration in the views compared to my proven XLs, Morpheus and ES eps. Apart from the smaller fov, which at 60 deg is still perfectly adequate for my tastes, I think the views will be reasonably close to my "better" eyepieces.

I'm especially impressed with the edge of field sharpness in the Xcel's...if I had had eyepieces as good as the Xcel's available back in the 80s at these sort of prices, I would have thought I was in eyepiece heaven! When you think what prices were charged back in the day for eyepieces from BC&F etc for humdrum eyepieces, we are so lucky nowadays with the choice and quality on offer.

Dave

[Mak the Night]

Very interesting and informative review. I have a 9mm X-Cel LX and saw it as an interim eyepiece until I could get something else. At first I though it was aesthetically a little weird, but the design is very ergonomic with the rubber grip making it easy to manipulate in the dark and in cold conditions. The draw tube undercut is fairly shallow and interacts well even with my Baader helical focuser.

I was so impressed with it that I decided that it was a keeper. I even like the eyecup, and I'm not usually a fan of twist-up cups. The X-Cel can suffer from a tiny bit of light scatter though sometimes I find, but the views are crystal clear, bright and defined that belies the unit cost of these eyepieces.

The Barlows are good as well.

[John]

1 hour ago, F15Rules said:

...if I had had eyepieces as good as the Xcel's available back in the 80s at these sort of prices, I would have thought I was in eyepiece heaven! When you think what prices were charged back in the day for eyepieces from BC&F etc for humdrum eyepieces, we are so lucky nowadays with the choice and quality on offer.

Dave

That is SO true Dave

 

[YKSE]

1 hour ago, John said:

Good and useful review Dave.

It's hard to pry decent eyepieces apart in performance terms these days. When I was doing reviews for the forum I found I needed several sessions to start to understand where the differences lay and their exent.

Absolutely, when there're many aspects of eyepiece performance to be evaluated, some, like colour fidelity, may needs more time, also when more eyepieces are involed, ranking them for the small differences can be quite time comsuming.

Some characters of an eyepiece though can be quickly evaluated, such as scatter, astignatism in the edge or latteral colours, a bright star like Vega or Capella makes the job easy. To evaluate vignetting and distortion, we don't even need night sky, day time targets are more suitable and easier for the job.

[Highburymark]

Praise indeed for the Celestrons to compete with the rest of your excellent EP collection Dave. Thanks for a very informative report

[Knighty2112]

I was looking at getting a 9mm Xcel LX the other night, but also considering the Baader Hyperion 10mm also which is about £40 more. As this EP will be a self gift for both my birthday & Christmas I'm leaning towards the Hyperion more, but could still be persuaded yet. Nice review!  

[Mak the Night]

I always wanted a Hyperion. I ended up choosing a 10mm Luminos over a Hyperion and eventually regretting it. The Hyperions have been described as the 'Lego set' of eyepieces as you can alter the focal lengths with spacer rings amongst other things.

Even when I finally decided to get a Hyperion I ended up with a 14mm Morpheus. Although I certainly don't regret buying the Morpheus.

[John]

Hyperions are thoughtfully designed and well constructed. They are also comfortable to use. The only dissapointment that I found with them was that they show a surprising (for a £100 eyepiece) amount of astigmatism in the outer parts of the field of view when the scope focal ratio dips below around F/8.

I tried the Fine Tuning rings with them and the system does work. I'm not 100% convinced about the wisdom of a system that requires the optics of an eyepiece to be opened to insert the spacer (which is what the FT ring is) though

 

[des anderson]

Nice review,lots of information and as Christmas is only an heartbeat a way,you have helped to make my mind up on getting some Xcel LX`s for my sct.Des

[Knighty2112]

4 hours ago, John said:

Hyperions are thoughtfully designed and well constructed. They are also comfortable to use. The only dissapointment that I found with them was that they show a surprising (for a £100 eyepiece) amount of astigmatism in the outer parts of the field of view when the scope focal ratio dips below around F/8.

I tried the Fine Tuning rings with them and the system does work. I'm not 100% convinced about the wisdom of a system that requires the optics of an eyepiece to be opened to insert the spacer (which is what the FT ring is) though

 

So it'll be fine in my f11 frac, but not so great in my f5? I could live with that.  

[John]

1 minute ago, Knighty2112 said:

So it'll be fine in my f11 frac, but not so great in my f5? I could live with that.  

Fine in the frac (most EP's are !). Your Maxvision 20mm would do somewhat better in the F/5 I reckon.