Pentax XW vs VT ortho`s

[nightfisher]

I have heard many good things about the pentax ep`s, this leads me to want to try them, but, i am very happy with my Volcano top circle T`s, having the full set of these classics, do the pentax offer any better  views other than being 60 degree field of view?

[AlexB67]

Hi Jules, I can't really comment on a comparison, but the XWs do offer 70 degrees, the XFs I think are 60 or 65 degrees.  If you can get your hands on an old XL, the predecessor of the XW. I can certainly recommend the XL from my limited experience. The XLs offer 65 degrees and sometimes can be got for similar sort of price as second hand radians, but they are very rare. I've never seen one crop up again since I bought the 10.5mm, people just do not seem to sell them ! Perhaps that says something about their quality.

I did spot a longer focal length one once on the bay, but it was over 200 pounds, when it gets that close in price you may as well buy a new XW for around 250 IMO. 

One comment I can make with the XWs you'll have that luxurious 20mm eye relief to play with, the XLs have that too.

[dweller25]

Jules, I have Pentax XW's and VT Orthos.

On axis they match each other for sharpness and contrast.

The Pentax XW's offer the same sharpness across a wider field of view and VERY comfortable eye relief - and that's what you are paying for.

HTH

[nightfisher]

Thanks David, i might have meant the pentax XF range but i think i will be stopping with my VT set for time being

[alan potts]

I would say Pentax XW and especially the shorter one offer much better eye-relief and a much wider field of view. They are however much more expensive and heavier, from the optical point of view there is little in the Pentax and a BGO of similar focal length, so I am guessing the CT's will be much the same.

I do find BGO's the slightest bit better for light scatter and contrast than many of the highend eyepieces (Pentax XW, Delos Radians) I own but it is so small a difference, where they win though is viewing comfort.

Alan

[John]

I would say Pentax XW and especially the shorter one offer much better eye-relief and a much wider field of view. They are however much more expensive and heavier, from the optical point of view there is little in the Pentax and a BGO of similar focal length, so I am guessing the CT's will be much the same.

I do find BGO's the slightest bit better for light scatter and contrast than many of the highend eyepieces (Pentax XW, Delos Radians) I own but it is so small a difference, where they win though is viewing comfort.

Alan

I've compared the XW's, Baader GO's and the VT orthos quite a few times and reached the same conclusions as Alan has. I thought the XW 5mm a little better on light scatter than a VT ortho.

[alan potts]

John,

Yes I know you have and of course it is great to see you add to the thread. I have only compared my 5mm XW with a 6mm BGO and a 9mm BGO Powermated and I really cannot see a lot of difference. I would like to lay my hands on a 5mm XO and put that against the Pentax 5mm XW, I say the XO as there is a chance I could at least get one one day, I think Zeiss ZO II are out of my reach in more ways than one.

Paying 400 plus for an eyepiece that will have a very short eye-relief and so tax the user is not an area I wish to explore.

Alan

[John]

Paying 400 plus for an eyepiece that will have a very short eye-relief and so tax the user is not an area I wish to explore.

Alan

I tend to agree Alan. The TMB Supermono's change hands for similar amounts now but when I had the 5mm of that range and was comparing it with a £50 University Optics HD (similar to an Astro Hutech / Baader GO / Fujiyama) I can remember how often the two just seemed identical and it was only on the nights of best seeing, say 10% of sessions, that the very slight improvement of the TMB Supermono started to emerge when searching for very subtle planetary details. Even then, the UO HD would show said detail, it's just that I had to work a little harder to see it 

As we so often say, at these levels, the differences are very subtle indeed and, often very expensive to acquire !

[alan potts]

The other thing that I believe you told was the FOV of the Supermono is so small at 30 degrees, I am not sure I could live with that, I do not know what the Zeiss FOV is not that it really matters as I can't see myself buying one, I think for the amounts we are talking the 4.7mm E would win hands down.

I think going back to the original post if I had a set of very good orthos, and lets face it if you use them all the time you would get used to them, I am not sure I would go the expense of buying either Delos or XW's as they are not an optical improvement, just much easier on the eye. We both know you do not have to spend a packet to get optics up there with the very best, but then you told me that.

Alan.

[John]

Yes, the TMB Supermono AFoV is around 30 degrees. An ortho seems really quite expansive in comparison !

One that I would love to try though is the Pentax XO 5mm. These are very rare too although I think more in the ~£250 region rather than ~£400 if you can find one.

Again though, the differences would be subtle and need good conditions to reveal themselves I think.

Given the current sky conditions in my part of the UK, seeing any stars though any sort of eyepiece is a minor miracle though 

[alan potts]

The Xo is one that I am on the look out for and if I never get one, well you can't miss what you have never had.

I was watching the Bulgarian weather forecast last night and they did a section on the UK weather, I can't say it looked very nice, I rather got the impression if you were lucky enough to have clear sky the wind would put the mockers on things.

I am suffering too so far February has only yeilded 1 night clear and that is terrible for me.

Alan