Has anyone had a chance to compare Vixen LVW and Pentax XW eyepieces of similar focal lengths? Are the Pentaxes considerably better? Is it just the obvious differences, i.e., 5 degrees extra AFOV & twist eyecup, or are they clearly superior optically? Any comments most welcome, thanks.
ps: I saw what could be very good deals on Vixen LVW and Pentax XW eyepieces, but I haven't followed them up yet. Just dreaming at this stage.
I have the 10.5 and 14mm XL's and havent seen an eyepiece yet that I'd trade them for
Well I pretty much agree with Geoff. I have the 7mm,10mm,14mm and 20mm Pentax XW's and I won't be trading them on anything either. The 7mm and 10mm are about as good an eyepiece as I have ever used in these focal lengths and that includes everything uncle Al has ever made. The 14mm has a little bit of field curvature and the 20mm has slightly more field curvature in faster scopes. However, this is a necessary compromise to achieve 20mm of eye-relief and 70 deg AFOV at these focal lengths with this design. It is not obtrusive and you don't notice it in general observing, you can detect it if you specifically look for it. It causes stars in the outer 10% to 15% of the FOV to "bloat" in size by about 5% from best focus. They stay perfectly round and DO NOT become elongated astigmatic slits that are commonplace in $50 eyepieces. The upside is that on axis sharpness, contrast and light transmission are superb and superior to any premium widefield eyepiece I have used.
That having been said the Vixen LVW are also a superb eyepiece. Clearly superior to the LV's that others have mentioned as being great. They are also a completely different design to the LV's FWIW. Any observer would also be very happy to have a box full of Vixen LVW's in his observing kit.
In conclusion I possibly rate the 22mm Vixen LVW as superior to the 20mm Pentax XW. In all of the shorter focal lengths I think the Pentax XW's are about as good as it gets and superior to anything you care to throw at them. I rate them above the Nagler T6's and Radians also by a very small margin.
Whichever you choose between the Pentax XW's and Vixen LVW's you will end up with an excellent eyepiece. So don't get involved too deep in "paralysis by analsysis". If you can afford the shorter focal length Pentax XW's grab 'em, if not take comfort from the fact that the Vixen LVW's are also superb. Something else that may be important to you depending on the scopes you own is that the LVW's all have the dual 1.25"/2" barrel and fit either size focuser. This is no benefit to me but may be relevant to you.
Thanks heaps, John. Re the dual 1.25"/2" barrel size, don't the XWs have the same thing? I always thought they did.
Nope they dont in the shorter focal lengths, 1.25" only, and the 30mm up are 2" only.
Dual 1.25/2" configuration eyepieces can be a pain depending on focus point and travel of your focuser. If forced to use the 1.25" part in a barlow, it can be hard to get a firm mechanical coupling with the 2" section in the way also.
Well maybe I'd possibly swap for an XW, but I havent looked through any myself. DanielSun has a 22mm LVW that I looked through at the star camp, and that seemed very nice.
For those brave enough to buy second hand via astromart, I think the Pentax XL's are still a good bargain.
Came across this old thread. So, replying to Steve's original post, I thought I'd share some of my own experiences with some of these eyepieces.
LVW: These are probably the most forgiving eyepieces I know. Forgiving in that they can be used in just about ANY telescope design and perform very well in all of them across their whole range of focal lengths, with the 30mm being the odd man out. I've used them in my fast Newtonians, in fast refractors and slow SCTs and Maks, and the only major change is a slight eye relief change with some. To ask an eyepiece to perform exactly the same way in a fast Newtonian to an SCT, to a Mak and to a fast refractor is a big ask. Very, very few eyepieces can do this and do it well, and even fewer across their whole focal length range. The 30mm is the weakest member, and this is also noted by Vixen with its different appearance despite the "LVW" label - it does not perform well in fast Newtonians.
XW: These are much more varied in their performance as they are very much telescope design sensitive. They do no all perform the same as the LVW's in different scopes. As an example, the 10mm XW is fantastic in fast Newtonians, but its performance in an SCT is no where as good - eye placement becomes much more critical and difficult. The 14mm shows significant field curvature in fast Newtonians, but it is a better optical match in slower Maks and SCTs [a coma corrector will improve the 14mm in a fast Newt, but the need for a coma corrector to improve field curvature in this eyepiece/scope combo shows a deficiency in the eyepiece/scope match]. One or two other XW's also show eyepiece/scope design optical mismatch. But when there is an optical match, damn they are good!
Which gives the better image? This is very subjective, but I would say there really isn't anything much between them as they are all stonking great (setting aside any optical mismatches). For me to split hairs is just too subjective for this post.
Which to get? Well, my cop-out phrase here is 'it is upto you'. Performance wise I would say the LVW's are stronger as they perform well in different scope designs. The XW's have a wider AFOV, but are more scope sensitive for which you need to figure out which is best for your scope/s.
Last edited by mental4astro; 21-11-2013 at 09:31 AM.
As you resurrected this very old thread I started, let me share my experiences of the past 6 or so years.
I ended up owning and using both types of EPs. Generally I prefer XW's, except for the 22mm LVW, which I prefer to the 20mm XW. The 22mm is definitely the queen of the LVWs; 10mm of the XWs.
But I no longer own any XWs or LVWs. I got sick of heavy and bulky EPs. My EPs now are the two Pentax XFs 12 & 8.5 mm & a couple of Masuyama style plossls. I also have a generic ultra-wide 30mm which is crappy on its own, but very good in a long barlow & very versatile for public astro events. The XFs are the best EPs for me: small, light, good FOV, outstanding optics, great ergonomics.
Now that it has surfaced, I find it interesting to see that the old Vixen LVWs are still up there as far as quality of views is concerned.
I now have the full set and can see no reason to look elsewhere, I think the difference between these and the Pentax XWs is so small that I would not bother mixing and matching brands. The LVWs for me are the perfect amount of eye-relief, nicely parfocal, all fit into a 2" diagonal (or a 1.25" bar the 42mm). They do have a little bit of warm colour out at the very edge of view but are very sharp across the view.
Although when they were introduced they were 'heavyweights' the more modern TVs et al have taken over for their mass. I have not tried the XFs but hope to in the near future.
At the moment the 13mm and the 22mm are getting most use. The seeing hasn't supported the 5 and 3.5 lately even in my little 900mm Tak.
Hi Matt! What ausastronomer (John Bambury) said above over 7 years ago took me around 5 years to confirm - and he was spot on. I never met John - he is just a bunch of informative posts to me - but my long term experience seems to show that everything he says about visual astronomy is always correct. LVWs are excellent EPs indeed! Forgot to mention that 13mm LVW is also preferable to 14mm XW for my eyes.
The main weakness of the LVW series is the gap between the 13 and 8mm, where having a 10mm XW alongside the LVWs is well justified if you own an f/5-ish instrument.
I agree Steve, a 10mm LVW would be nice to have.
I agree also about John (ausastronomer), when I came back to this obsession, after a long sabbatical, I spoke to John at length as all the gear that is now available at a modest price was just a pipedream 20+ years ago, what a very helpful pleasant fellow he is. I must get down to Kiama and buy him the beer I promised !!!
I recently bought the 42mm LVW, a beautiful piece of glass for low power viewing. I know there are eyepieces in the top-tier like the Ethos line that are better but for my money, I shall stick with these LVWs.
I have the XF12 and 8.5 and they are really superb Pentaxes, very sharp on and off axis and cost considerably less than the XW.
They are my favorites ep.
Some may disagree but the feedback I have generally received over the years is that the pick of the Vixen LVW range is actually the 22mm.
This being the case I would be very curious to know what are everyones views in terms of what might be a better option between a Vixen LVW 22mm or a Televue Panoptic 24mm.
I don't think the 2mm difference between them is a significant issue and both are said to have flat fields without curvature on fast scopes (unlike what is supposedly encountered in the Pentax 20mm) consequently if you had to pick between the two which way would you lean and why?
All thoughts, opinions, perspectives would be most welcome.
I can't find any difference in the quality of views between the 13mm, 17mm or the 22mm other than the level of magnification. In my 900mm f/l scope the 8, 13 & 17 get the most use.
Hoping for some clear sky tonight to really try out the 42mm.
Can't compare to the Pan24 though, but can't fault the 22mm LVW. I'm not an eyepiece junkie so am happy to stick with the one brand (they look so nice all together in the case too .....
I had a full set of Vixen LV's and I found the 20mm was as good as my 19mm Panoptic except the TV pan had a larger field of view that I liked .
The smaller focal length LV's were almost identical to my Radians , but I like the softer views the Radians give on the moon and planets , especially in my Tak M210 .
Its really down to personal choice , I found the Vixens excellent in all ways .
I would have kept the Vixen's in a heart beat but I decided my TV's were the ones to keep , my personal choice .
Brian.
(they look so nice all together in the case too .....
Show off....
But seriously....I just bought a Vixen LVW 22mm from OPT for $209.00 + Postage.... discounted from $269.00......there has been such a ' rave ' about this particular eyepiece...I wanted to find out myself...
Should go very well with my new Vixen NA140....left Japan last Friday...wooohoooo....!!!!
Flash............
Last edited by FlashDrive; 27-11-2013 at 03:22 PM.
Re Pano24 vs LVW22. They are both great EPs in pretty much any scope. The Pano is smaller and lighter, nice traveller EP with slightly greater TFOV. Eyeglass wearers will likely prefer the LVW. The Pano has more pincushion distortion. They are different animals and you have to take them both for a walk to decide for yourself. There is no point telling you which one I prefer, because this is really a personal preference thing (like say pasta or risotto) & depends on scope/focusser you have also. I let go of my LVW22 because of its bulk and weight; let go of my Pano24 cos I needed money at the time & it was not getting used often enough to justify having it in my EP case. I got the most use out of the Pano while travelling around Eastern Europe with my 8" f/4 truss Dob.
If you're unsure, toss a coin and get either one. You'll be happy.
Pentax XW vs Vixen LVW
I had a full set of Vixen LV's and I found the 20mm was as good as my 19mm Panoptic except the TV pan had a larger field of view that I liked .
