Nightspore Posted June 16, 2021 Share Posted June 16, 2021 (edited) The Celestron X-Cel LX has an apparent field of view of 60º. There are six internal elements. I have no information on the amount of groups. The eyepiece body is made of black anodised aluminium with orange and white lettering. Celestron declares that it has a 16mm eye relief. They also claim the X-Cel LX are parfocal with the others in the range. Although this is not strictly true in my experience with them. I paid £109 for the 25mm back in early April. The housing (including barrel) is approximately 85mm in length and 95mm with the ‘twist-up’ eyeguard extended. It has a generous eye lens and I make the field stop about 26mm. The housing sports a novel equatorial treaded rubber grip reminiscent of a tractor tyre. The barrel includes a filter thread, adequate baffling and a shallow undercut. The eyepiece weighs around 170g according to my scales and is supplied with its own bolt case. I now own several X-Cel LX eyepieces. About six years ago I acquired the 9mm. It was the first X-Cel LX I bought. As it had a 60º FOV, I tended to use it predominantly as a planetary eyepiece, often in conjunction with a Barlow. It was only years later that I discovered just how good the 9mm X-Cel was for rich field observing, particularly in short tube refractors. The original Celestron X-Cel eyepiece range were reputedly among the worst designed eyepieces in the world. They were not successful. Celestron eventually released a new range with the X-Cel brand name but with the letters ‘LX’ added. So, no confusion there then! These LX versions generally have a very good reputation. Although I have had quality control problems with them in the past. Three or four years ago I had to return three 7mm focal length LX’s consecutively due to visible debris in the field. This was a known problem with some other focal lengths as well. Apparently due to a bad batch. I’ve not had the same problem with recent purchases. X-Cel LX eye lens dust caps are very close fitting. This seems to be the same throughout the range. The upside is that the cap won’t come off if the eyepiece is in your pocket. The downside is that you may lose a fingernail trying to remove the cap in the first place. Okay, maybe it’s not that bad. The field lens caps are fine. I got first light with the 25mm X-Cel LX in my 72ED DS Pro Evostar around 00:30 BST on June 13th. It gave 16.8x for 3º, 34’ FOV and a 4.3mm exit pupil. My main observing was in the Summer Triangle and the rich star fields within and around it. Collinder 399 (Coathanger Cluster), M57, M29 and M27 were all duly observed. I used an Explore Scientific broadband OIII filter for the Dumbbell/Applecore Nebula and the Veil Nebula. The overall sharpness and colour separation were superb. It is a well corrected eyepiece and showed very little edge astigmatism and no lateral colour. I’d say it had a slight edge on my 25mm TS Optics Planetary HR which has a similar field of 58º. I found the eye placement excellent with no problems, although the 16mm eye relief is a little long for me. The twist-up eyeguard helped with ameliorating this however. I’ve always liked the X-Cel eyeguards. They have an elegant simplicity that works well during actual observing. Overall this is an enjoyable eyepiece to use and I specifically bought it for the 72ED, primarily due to its comparatively light weight. I’ve had it out in the field for three sessions now. It’s definitely a keeper. Edited June 16, 2021 by Nightspore 3 Quote Link to comment Share on other sites More sharing options...
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