Hyperion zoom vs UWAN (WO/Nirvana)

[omega3]

Hi,

I have been using the Hyperion Zoom with my 10" Skyliner. Would I get markedly better view (apart from the wider FOV), in particular the contrast, with an UWAN eyepiece, say 7mm or 16mm. I live just outside the M25, so suffer from quite a bit of light pollution, my limiting magnitude is around 3.

Alan

[michael.h.f.wilkinson]

I do not know the Hyperion zoom myself, but in general found zoom EPs not very appealing when compared to fixed focal lengths. The contrast is usually distinctly lower than that of fixed focal length EPs. I typically have better views than a mag 3 limit over here, so I cannot tell how much you would notice the difference in your case.

[brantuk]

The Hyperion is great for a zoom lens - better than most out there - I use mine all the time unless observing very specific details of very specific objects. It's a great all rounder - but fixed focal length will be better at any given magnification. The WO Uwans are probably the best around before venturing into TV country lol

[michael.h.f.wilkinson]

The Hyperion is great for a zoom lens - better than most out there - I use mine all the time unless observing very specific details of very specific objects. It's a great all rounder - but fixed focal length will be better at any given magnification. The WO Uwans are probably the best around before venturing into TV country lol

and Meade UWA country is almost just as expensive as TV . TMB Paragon is worth a try for about the same price range as the WO UWAN as I understand it (the SWANs are way cheaper). I have the 40mm and absolutely love it ("only" 69 deg AFOV, but still great).

[omega3]

Thank you all for your comments. If I go for WO UWAN, would the 16mm be the one I get first, as it is in the middle of the 8-24mm range of the Hyperion zoom, and I can get 8mm with my Orion Shorty plus barlow. Or should I be getting the 7mm to see details of fuzzies.

Regards,

Alan

[John]

If you get the 16mm and use it with the Shorty plus barlow you probably won't need to use the zoom at all - at the longer end of the scale the 16mm UWAN will show you more sky than the zoom can at 24mm.

[brantuk]

"I have the 40mm and absolutely love it ("only" 69 deg AFOV, but still great). "

Michaels right about this e/p. The WO Swans are superb and the 40mm a real treat. You can get them for a very respectable s/h price on the for sale section. If you get the Uwan 16mm then get a 40mm swan as well to extend your range - you won't be dissapointed.

[michael.h.f.wilkinson]

I was actually referring to the TMB Paragon 40mm (I do not doubt the WO SWAN is great as well).

[omega3]

Thank you all for your comments. Will I benefit from these recommended eyepieces (UWAN, SWAN) in my very light polluted situation, limiting magnitude around 3.

Alan

[russ]

Thank you all for your comments. Will I benefit from these recommended eyepieces (UWAN, SWAN) in my very light polluted situation, limiting magnitude around 3.

Alan

Hi Alan,

Do you mind me asking what you are mainly observing?

From my heavily light polluted area i find absolutely nothing (more aperture, filters, new eyepieces) helps with improving the view of galaxies. The LP drowns them out and nothing will help to a great degree. Only a dark sky sorts it out.

Where i find my UWAN 16mm really helps is providing a large FOV, which is pin sharp across the field with my f5 scope and all this at a good medium power (which helps spot the smaller objects and also improves contrast compared to a lower power eyepiece with the same FOV).

[michael.h.f.wilkinson]

Nothing beats dark skies. Good EPs are indeed no cure for LP (this must be confusing to people thinking in terms of record players). For deep sky I should really get out of the city more often than I currently do. Plonking the telescope in the back of the car and driving just 10 km makes all the difference.

[omega3]

Russ,

Basically I look at everything. I have not seen a galaxy (apart from Andromeda) yet, though I have tried many times. I have sort of given up looking for galaxies. I have not tried my SW LPF with my dob yet, but it was no help with my 3" refractor. So now I look at the moon, look for clusters and doubles.

From your comments my thoughts for future eyepieces are first 16mm UWAN, then 40mm SWAN or similar. Then I am thinking whether to have a higher power eyepiece either a 7mm UWAN or the Pentax XF 8.5mm.

Alan

[John]

From your comments my thoughts for future eyepieces are first 16mm UWAN, then 40mm SWAN or similar. Then I am thinking whether to have a higher power eyepiece either a 7mm UWAN or the Pentax XF 8.5mm.

Alan

All good choices Alan although personally I'd stick to 32mm as a maximum focal length eyepiece for the dobsonian. 40mm creates an 8mm exit pupil which is a bit on the large side IMHO.

[michael.h.f.wilkinson]

All good choices Alan although personally I'd stick to 32mm as a maximum focal length eyepiece for the dobsonian. 40mm creates an 8mm exit pupil which is a bit on the large side IMHO.

I agree, remember a 40 mm SWAN has about the same true field of view as a 31 mm Nagler, but the Nagler gets you a tighter exit pupil (even that is some 6.5 mm on a F/4.7 dob). I am fine with my Paragon 40mm (similar to SWAN) but then I have an F/10 scope, so that gives me an exit pupil of 4mm.

If you are over (roughly) 35, do not stretch the exit pupil beyond about 5-6mm, or the most expensive part of the light from your scope (i.e. from the outer inches of the aperture) will not reach you retina.

[russ]

From your comments my thoughts for future eyepieces are first 16mm UWAN, then 40mm SWAN or similar. Then I am thinking whether to have a higher power eyepiece either a 7mm UWAN or the Pentax XF 8.5mm.

Alan

Great selection of eyepieces. I can personally give both UWANs and the XF a double thumbs up. The SWAN is nice too but as John says, look to a 30-32mm focal length. I had a 32mm SWAN clone and it gave a whopping 1.87deg true field in the 250PX. Edge correction is poor in an f4.7 scope but it doesn't seem to matter too much at low power. I have replaced my 32mm with a Skywatcher Aero ED 30mm. It's better corrected for faster scopes but still not in the league of the 28mm UWAN or 31mm Nagler. But it's a lot cheaper, especially when bought secondhand.

[irishbloke]

I changed my 8mm hyperion for a 7mm Nirvana and now love that eyepeice. I love looking at the Andromeda galaxy and it's partners through it as there's so much to see. I've also just changed to a 28mm UWAN but haven't got out with it yet.

[michael.h.f.wilkinson]

Great selection of eyepieces. I can personally give both UWANs and the XF a double thumbs up. The SWAN is nice too but as John says, look to a 30-32mm focal length. I had a 32mm SWAN clone and it gave a whopping 1.87deg true field in the 250PX. Edge correction is poor in an f4.7 scope but it doesn't seem to matter too much at low power. I have replaced my 32mm with a Skywatcher Aero ED 30mm. It's better corrected for faster scopes but still not in the league of the 28mm UWAN or 31mm Nagler. But it's a lot cheaper, especially when bought secondhand.

Remember, poor edge correction in a fast Newtonian can be caused by coma, not the EP. With a good coma corrector is really needed when using a wide true FOV.

[russ]

Remember, poor edge correction in a fast Newtonian can be caused by coma, not the EP. With a good coma corrector is really needed when using a wide true FOV.

An f4.7 will cause coma but it's not the biggest problem with the SWAN. It suffers with astigmatism, with only the inner 60% of the field truly sharp. Compared to the Nagler which is sharp across 95% of the field and the last 5% is due to coma inherent from the telescope design, not the eyepiece. A Coma corrector would give the Nagler a perfect fov but would only remove the minor abberation from the swan. But all that said, i find the SWAN (and clones) a very pleasing eyepiece to use. The abberrations just dont seem that distracting.

[omega3]

Thank you all for your wisdom. Any comments about the higher power eyepiece 7mm UWAN vs Pentax XF 8.5

Alan

[Darren B]

The Pentax maybe a bit sharper than the Uwan, but it will not have the wide FOV that you would want in a Dob. You'll be pushing it more often and please note, I did say maybe as the Uwans are very good eyepieces.

[russ]

I went with the 12mm XF with my 200P and 250PX because the 8.5 just didn't quite fit in with the focal length of the 250. It gave a magnification (141x) that for me wasn't high enough by itself but too high if barlowed. But the 12mm gave 100x, which was perfect for globs/small planetaries and some lunar work. But could be barlowed to a perfect 200x.

The downside to the 12mm was the edge correction, which is inferior to the 8.5mm.

The 7mm UWAN gives a nice 171x in the 250 but i did wonder if i would want a little more than that. As it turns out, the 7mm UWAN would have been perfect now with the 12" dob.