Celestron X-Cel LX v BST Explorer Eyepiece

[johninderby]

A brief comparison

I have been very impressed with the Celestron X-Cel LX eyepieces and was curious as to how the BST Explorers would compare as they are both 60 degree 1.25" eyepieces with similar specs. I got hold of one of the 8mm BST Explorers and have been comparing it to a 9mm X-Cel LX. I compared them in an f/5 80mm achro and an f/7 80mm APO to see if the performed differently in a fairly fast scope and a medium one.

They are both well made eyepieces that have a quality feel about them, although the LXs are slightly better finished. I definitely prefer the twist-up eyecup of the LX compared to the screw-up eyecup of the BST though. The LX eyecup can be adjusted to the right height instantly whereas on the BST it takes quite a few turns to raise it up. A minor irritation that of course has no effect on the performance of the eyepiece, but still something I like to see them improve on the BST.

Distortion

Well controlled in both eyepieces although the LX was slightly better. In the f/7 the LX had some distortion at about 90% and the BST at about 85% and in the f/5 the LX was at about 85% and the BST at about 80%. Perhaps I'm being a bit particular as I was really looking for distortion, and in practice distortion isn't a problem in either eyepiece. Both perform well in an f/5 scope.

Sharpness & Contrast

While both eyepieces were excellent this is where the LX pulled ahead. For instance when observing the moon and switching from the BST to the LX at first glance the views looked the same, but then I realised that I could make out more detail and the contrast was better. Not miles better perhaps, but definitely that one step better. The difference was similar on Jupiter, just that bit more detail and contrast.

Glare Etc.

Internal reflections weren't a problem in either eyepiece. One thing that was noticeable though was that with the full moon halfway into the FOV in the BST there was a bright ring (glow?) around the edge of the FOV where the moon was. There was no trace of this in the LX.

Conclusions

I think it's the coatings that account for most of the difference in performance, although I also think they've spent that bit more on quality control with the LXs. If price wasn't a consideration then it would defiantly be the X-Cel LX. However the BSTs are only £40.00, so if that's your budget you wouldn't go wrong in buying one. I suppose I'm saying they're both winners.

John

PS

Before anyone asks yes the 8mm BST Explorer will be going up for sale in a week or two @ £30.00 delivered.

[nightfisher]

nice little comparison john, thanks for posting

[andrew63]

Yes, im sure the review will be of interest to many John - thanks for an informative comparison. I saw some where a review comparing a 9 and 12 x-cel lx and the 9 was considered the stronger.

andrew

[johninderby]

Few photos of the eyepieces.

In the last comparison photo it makes me question the fully edge blackened claim of the BSTs judging by the reflections, or is something else causing them?

Couple of other things. The BST needs more out-focus travel. Weights are similar with the BST 8mm being 168g and the 9mm LX being 182g.

John

[spaceboy]

Very interesting review John.

[nicnac]

Good read.

i am very impressed with the LX range, i wonder if the quality is the same with the ultima LX?

[Damo636]

Nice write up John. Judging by the reflections the LX would appear to have the more lustrous coatings.

[Jiggy 67]

Good review, it just so happens that I've been agonising between the LX, BST and a couple of others for weeks.....I was leaning towards the LX and this has now made my mind up.....now...where's that list for Santa??

[great_bear]

I'll wager that if you reviewing the ones at either end of the focal-length range - such as the 5mm or especially the 25mm - the LX would roundly beat the BST by a good margin.

- just guessing though!

[sunshine185]

This has made my mind up, going to get a high power x-cel lx for the dob, at about 70 quid if memory serves me correctly, was a toss-up between this and a bgo.

[nicnac]

69 quid from flo