Celestron have been known in the past to be a little hit & miss where eyepieces are concerned. While their telescopes are of an exceptional quality their eyepieces are somewhat more sporadic in how they’ve been received. So where does the Ultima LX lie?
Aesthetically this is an unusual looking eyepiece, with it’s almost hour glass profile the body is made of a springy rubber to protect the vulnerable lens elements. The shape is such that it stops the eyepiece from rolling freely around when placed on a flat surface and little divots cut into the soft rubber aid gripping, especially useful when observing with cold and stiffening fingers. The eye cup is a twist-able kind made from the same soft rubber as the body.
Celestron have used a whopping 8 elements in the Ultima’s design. This is to reach the 70 degree field of view the LX offers. All those lens elements have made for a heavy eyepiece (just over 700 grams) so balance issues can crop up when swapping between this eyepiece and other lighter eyepieces. Each lens has been fully multi coated to improve light transmission.
As well as producing a wide field of view the extra elements have gifted this eyepiece with a very comfortable eye relief for this focal length, 16mm means you won’t have to feel like your eyeball is superglued to the lens, it also makes the LX suitable for spectacle wearers.
When you couple the long eye relief with a large objective lens (28mm) the Ultima is certainly a comfortable eyepiece to look through but comfort alone is not enough to make a good eyepiece, it must also perform well optically.
With 8 pieces of glass between the object and the observer you could be forgiven for being a little sceptical about the Ultima’s optical prowess. Amazingly, views are sharp, clear and contrasty despite all these extra elements, a testament to the excellent coatings Celestron have used. The outer 10%% of the field does start to degrade slightly but this is a common ailment of the wide field eyepiece and isn’t noticeable enough to mar this eyepiece. Optically the Ultima LX is very solid indeed.
To summarise this eyepiece is comfortable to look through and yields high quality views with excellent colour rendition and only a nominal break down in image quality is present in the outer fringes of the field. It’s well designed but the only slight flaw is in the heaviness brought about by the 8 elements used, it may require readjustment of the telescope to regain balance when switching the LX with other, lighter eyepieces.