Help me choose my next eyepiece

[Matthew.Blake]

The eye piece is for a 1000mm f/5 Newt. It will complement a 30mm Aero and 21mm Hyperion (which I don't use nearly as much as I thought I would as I prefer the Aero with a barlow).

I want it to oogle at Jupiter mostly to replace the 6.3mm Meade plossl I use at the moment and get a bit extra power.

My dilema is thus: I was looking at the 4mm Nirvana, but had been thinking "well the WO 4mm megaWAN is not much more". Trouble is, that line of thinking keeps going doesn't it. So now I'm wondering do I shell out the extra £50 and just get a Nagler and go for the 3.5mm or 2.5mm for the extra magnification.

What do you think?

[John]

I currently use Nagler Type 6's for high power viewing. I love them but I've also owned UWAN's and Nirvana's (which are pretty much identical as far as I can see) and they offer 90% of the Nagler performance at a lot less £'s.

I could see that a 3.5mm would be useful on good nights but I doubt the 2.5mm would see much use.

An alternative might be a 7mm plus a decent 2x barlow (eg: Celestron Ultima).

[Moonshane]

consider the used Radian. they are about £100 used and they are excellent in all scopes. you could try an 8mm barlowed to 4mm and bet you'd be delighted OR just get maybe a 4mm Radian. you'd be very happy with it I am sure. decent 20mm eye relief, 60 degree field of view and instadjust which means you can set the rubber cup height to suit your preferences. some people find the eye relief on the Nagler T6s a little tight although as John says they are excellent.

[Capricorn]

Suspect that 2.5mm will show little detail, too much magnification 400x, would almost think similar for a 3.5mm, 285x.

Suspect a 6mm would be much more use, 166x.

[Matthew.Blake]

The radian suggestion prompts another question: with its smaller field of view, what is the advantage over getting the 82 degree Nagler?

As for Barlows, I use the Skywatcher ED one. I'm happy with the Aero's performance with it, the Hyperion is OK, but I don't like the results at higher powers when I've tried to get a better view of Jove. I get a very soft image even when "focussed".

[Moonshane]

there's no advantage as such to either, they just have different characteristics which suit the observer more or less depending on their circumstances.

Radian

About £100 used

ER 20mm (good for glasses wearers) on all

Adjustable ER in the eye cup

60 degree field

some say a bit flatter view giving a more aesthetically pleasing image

Nagler T6

About £150 used

ER about 12mm on the higher mags

Fixed eye cup (except T4)

82 degree field

some say tone a bit warmer (I think) and field not as flat as Radian

As you can see the main thing you pay for is the increased field. I am of the view that they are both as sharp as each other etc, although I have used 3 Radians (8mm, 14mm and 18mm) and only one T6 (7mm). They are all excellent.

Capricorn makes a very good point though. In my 6" f11 dob, I have recently been getting the best views of Jupiter with my 13Ethos (about 125x). It OK in the 8mm Radian (200x) but I think that a 10mm Radian (160x which I am now hunting for) would have been ideal.

There is the odd night when you get really good seeing to 200x or even 250x but these are not common (although the moon can usually take a lot more - with this I can even regularly use my 6-3mm Nagler zoom and still get a reasonable image at 3mm (500x +) although it's better at 4.5-6mm (250x-350x).

hope this helps a bit!

[Nick P]

The radian suggestion prompts another question: with its smaller field of view, what is the advantage over getting the 82 degree Nagler?.

As Moonshane says there is very little difference in image quality, however if you are using an undriven mount the extra FOV of the Nagler's and not having to constantly 'nudge' the scope to keep the object in view can be a godsend especially at higher powers.

I also found eyeplacement incredibly fussy on the 4mm and 6mm Radians that I used to have - correct eye location is crucial with these to avoid black outs.

HTH

Nick

[Ben Ritchie]

I don't believe there is a significant difference between the SW Nirvana and WO UWAN. The 4mm is a nice eyepiece, but possibly a touch too high powered for regular use - 250x is pushing the seeing a bit in this country, and you'd probably get more regular use from a 5mm focal length.

I also found eyeplacement incredibly fussy on the 4mm and 6mm Radians that I used to have - correct eye location is crucial with these to avoid black outs.

That's odd, as I find them very easy to use!

[Nick P]

That's odd, as I find them very easy to use!

The experience I had put me right off them, its probably because I like to get close to the eyepiece to view, but I found the slightest movement of my head would have the view disappear! very frustrating!

[catburglar]

I have 7mm & 4mm Skywatcher Nirvana's. Tried them in dobs and refractors- they're great for DSO's, but I get a lot of light scatter when used on planets.

[Chris H]

The radian suggestion prompts another question: with its smaller field of view, what is the advantage over getting the 82 degree Nagler?

As for Barlows, I use the Skywatcher ED one. I'm happy with the Aero's performance with it, the Hyperion is OK, but I don't like the results at higher powers when I've tried to get a better view of Jove. I get a very soft image even when "focussed".

The 'soft image' is probably due to the atmosphere not being steady enough to give you a clear view at that level of magnification. Buying a Nagler ep will not solve this. As Moonshane said sometimes less is more I've been getting my best views of Jupiter at x100 and x150. I have an ep which delivers x240 but it's not often steady enough to use it.

[John]

The experience I had put me right off them, its probably because I like to get close to the eyepiece to view, but I found the slightest movement of my head would have the view disappear! very frustrating!

Isn't that why Tele Vue supply the round plastic pupil guides with the Radian's and T4 Naglers ? - they are designed to get you used to the correct eye positioning.

[Moonshane]

your comments really encourage me too Chris as I was beginning to think my collimation was not going well.

I was getting (seriously!!) photographic images with my 13mm Ethos at 123x the other night. it took my breath away when the seeing cleaned up. I have ordered an 11mm Televue Plossl now (used at £40 - bargain!) as a cheaper option to a 10mm Radian to see if a 10mm Ethos might get more use in my scopes (both 1600mm focal length so 160x) than an 8mm E. Once I have used this and the 8mm Radian for a bit, I'll make a decision. the 10mm E is looking fave for now.

[Moonshane]

Isn't that why Tele Vue supply the round plastic pupil guides with the Radian's and T4 Naglers ? - they are designed to get you used to the correct eye positioning.

true John and apparently they also stop or reduce fogging according to the leaflet in the box.

[John]

The 'soft image' is probably due to the atmosphere not being steady enough to give you a clear view at that level of magnification. Buying a Nagler ep will not solve this. As Moonshane said sometimes less is more I've been getting my best views of Jupiter at x100 and x150. I have an ep which delivers x240 but it's not often steady enough to use it.

I agree with Chris - Jupiter has delivered more satisfying views for me at 133x with my 4" refractor and 180x with my 6" mak-newt.

[RikM]

The best views of Jupiter I have had recently have been with 2x Barlowed 10 mm (150x) and 15 mm (100x) Plossls.

Rik

[Chris H]

your comments really encourage me too Chris as I was beginning to think my collimation was not going well.

I was getting (seriously!!) photographic images with my 13mm Ethos at 123x the other night. it took my breath away when the seeing cleaned up. I have ordered an 11mm Televue Plossl now (used at £40 - bargain!) as a cheaper option to a 10mm Radian to see if a 10mm Ethos might get more use in my scopes (both 1600mm focal length so 160x) than an 8mm E. Once I have used this and the 8mm Radian for a bit, I'll make a decision. the 10mm E is looking fave for now.

I was stressing about collimation too, did star tests to check and all was well with scope it had to be the atmosphere. Can't remember which night it was last week but with the Ethos 8mm Jupiter was popping into focus for fractions of a second and the views were totally crisp, to say photographic is bang on.

For 1600mm focul length 10mm is the way to go IMO.

Did you see S@N when they put the camera into the 16" dob and showed the image on a screen it don't know what mag it was or whether it was blown up on the screen but the image was far from being sharp, it gave me hope.

[Nick P]

Isn't that why Tele Vue supply the round plastic pupil guides with the Radian's and T4 Naglers ? - they are designed to get you used to the correct eye positioning.

Don't remember having any eye guides in the boxes for the ones I had, how do they work? might explain why I had problems!

[Moonshane]

they are like a big washer that sits under the rubber eye cup. the theory is that you can only look through the right spot. I must admit, I never used mine.

http://www.televue.com/pdf/literature/Pupil%20Guide%20Instructions.pdf

[Ben Ritchie]

Never used mine either. Main thing I found is to get the click-up eyeguard positioned correctly, once you've done that then I find eye positioning natural (the Pentax XW is similar in this respect, as it also suffers from blackout unless the eyeguard is adjusted)

[Matthew.Blake]

I have 7mm & 4mm Skywatcher Nirvana's. Tried them in dobs and refractors- they're great for DSO's, but I get a lot of light scatter when used on planets.

Anyone know if this is particular to the Nirvanas or would I get it with the WO equivalent as well? My primary use for the EP will be planetary.

[Ben Ritchie]

Anyone know if this is particular to the Nirvanas or would I get it with the WO equivalent as well? My primary use for the EP will be planetary.

My understanding (based on comments from a dealer when I inquired) is that the two series are functionally identical.