bgo v,s pentax

[faulksy]

any thoughts on theses i know a lot love both and i no what tight eye relief is on the bgo but the views are great. the pentax are great as well so i believe just wondered what would be the better bgo,pentax xf or pentax xw i know the fov is narrow on the first 2. the reason for the question is its my birthday soon lol. cheers in advance. regards mike:confused:

[John]

I've recently moved from BGO's in favour of a Pentax XW 5mm / Ethos 6mm. The BGO 5mm (actually a UO HD 5mm but optically the same) was as good as the XW across it's 42 degree FoV. I feel that the Ethos just pips the BGO 6mm for light scatter control and contrast but that ones is not on your list. In the end it was viewing comfort that has moved me away from BGO's (but goodness knows I tried enough of them over the past 12 months )

I've never tried a Pentax XF.

[faulksy]

so in other words apart from tight eye relief and smaller fov in your opinion the bgo is that good. was looking at the pentax but quite dear was thinking of the bgo around 12mm. thanks for the honesty john

[John]

so in other words apart from tight eye relief and smaller fov in your opinion the bgo is that good....

Yes - in terms of sharpness, contrast and light scatter control, you have to fork out £hundreds to get anything better, in my view, and then it's only a tiny improvement under the very best of observing conditions.

I owned a TMB Supermonocentric 5mm for a while which are often listed alongside Zeiss and Pentax Ortho's as one of the optimum planetary eyepieces. I compared it directly with the 5mm UO HD ortho over a number nights and the TMB only showed a tiny advantage in showing subtle planetary detail just a little easier on the very best nights (of which there were 2 out of the 10 nights I compared them on).

The TMB Supermono's have just 32 degrees of apparent field of view and are highly specialised planetary eyepieces.

While there are compromises in viewing comfort with the BGO's (or any ortho for that matter) in terms of pure planetary performance they are a very tough act to improve on.

I hope Baader's replacements for them, assuming that the production of BGO's is at an end now, are as good

[nightfisher]

I must admit that i have found favour with BGO`s having had the 18mm for a little while, i have added the 7mm as a new purchase, just need the clouds to vanish so i can try it out

[Moonshane]

I completely agree with John. I have eyepieces ranging from BGOs, through Televue Plossls to a Nagler and and Ethos. Personally I find they all fit together and there's no real difference at this quality level in the field that they have. Obviously the Ethos and Naglers have a much wider field and more stunning wide field views as a result. The BGOs to me give a slightly whiter view than the Televue eyepieces I have, some of which have a very very minor yellow cast in comparison.

I presume like John that you are mainly considering planetary/lunar/double star observing when looking at this purchase? If so then I am sure that all of the eyepieces mentioned will make you happy.

personally, the BGOs are the first eyepieces I would reach for when observing planets. the 12.5mm is very comfortable to use and I would say easier than a 15mm plossl (I have a 15mm TV plossl) so assuming you are happy with using the 9mm that you have, the 12.5mm will be really quite comfy.

[faulksy]

thanks guys and yes it will be mainly for planets and doubles and i find the 9mm eye relief fine once you get used to it, so like you said moonshane the 12.5 will be a walk in the park to use.thanks for your comments to nightfisher as im tempted with the 18mm as well glad you like it.and to you john hope your right about the replacment, cant see it being worse though. thanks guys you have made my mind up, i do love my 9mm bgo, so need to get some more now lol

[iwatkins]

18mm BGO is perfect for me. Crisp, contrasty image on my 180Mak.

Bought it as the 12.5mm was out of stock. But I still want a 12.5mm BGO.

Can you get one? Nope. Seems everywhere is sold out and no more coming.

Cheers

Ian

[michael.h.f.wilkinson]

I can vouch for the Pentax XF 8.5. Outstanding value for money, pipped the Radian for sharpness, and definitely better in terms of light transmission and colour neutrality. And 60 deg FOV is by no means narrow.

[Dunkster]

Sorry to piggy back, OP... how do the XF/XW rate compared to a Delos or Nagler at the shorter FL?

[faulksy]

good question dunkster

[Damo636]

Sorry to piggy back, OP... how do the XF/XW rate compared to a Delos or Nagler at the shorter FL?

I haven't had much time with the Pentax XW but I have had enough to determine it is every bit an equal in all but fov to my 8mm Ethos. The on axis sharpness is amazing and continues all the way to the very edge. The Delos is reported to give a similar experience to the Ethos but with a smaller fov so i would guess the XW and the Delos are very very evenly matched. I have owned a couple of t6 Naglers and found them to excellent but would say that both the Ethos and the XW are a definate notch up optically so I guess the Delos would also outperform the Nagler.