Just being a bit lazy - TV Nagler zoom or fixed focal?

[Moonshane]

Hi all

It's a bit slack at work at the minute (not dangerously so thankfully!) and this as usual means that I start thinking about shiny eyepieces.

Stupidly I have created a spreadsheet which when I put in a focal length and FOV for an eyepiece, it gives me the magnification and true field for the eyepieces in my two scopes (I have even set up a section for a scope I don't own yet - a wide field short refractor - I think I am losing it).

Anyway, my point. I have the following (all Televue and the 'Powermated' eyepieces are in brackets) :

14mm Radian (5.2mm)

18mm Radian (7.2mm)

24mm Panoptic (9.6mm)

35mm Panoptic

2.5x 1.25" Powermate

This is a nice range but I am hankering after just buying perhaps three further eyepieces that will provide me with the higher magnifications on their own for Lunar and Planetary / doubles 'work'.

I am thinking that I should (eventually) sell the Powermate and loving my TVs I have concluded that the following (all used) could be got for maybe £500 - £100 for the Powermate so £400 net. I could buy them over the next 6-12 months and then sell the Powermate.

3-6mm Nagler zoom

7mm Nagler T6

9mm Nagler T6

The only one I am 'concerned' about is the Nagler zoom given the tighter eye relief and narrower field. I'll be using my eyepieces with the scopes below and although I wear glasses, I don't to observe (and am considering contacts as I'm ready for a new pair of specs anyway). I don't generally have any issues tracking with the dob.

The main advantage of the zoom as I see it is that you can fine-tune to the seeing and that it covers a good range of higher mags which can be used when the seeing permits. Also, the difference in magnification between a 3-4-5-6mm individual eyepiece is large and I like the idea of infinite magnification range between these focal lengths.

I have some time for my decision and would welcome comments from those that have had them all. Apologies in advance as I am sure this subject has been well covered. I thought I'd try and prompt some refreshed responses.

Thanks in advance to all

[Moonshane]

Can anyone advise please?

[johninderby]

I used to have the 3-6 zoom and was very pleased with it. Optically it's just as good as the Naglers, the only compromise being the FOV of course. However I replaced the zoom with the 2.5mm,3.5mm and 5mm Naglers as my high power eyepiece set. The 82 degree FOV is just that much better with an undriven mount. I think there's a few SGL members that have gone the zoom first then the separate Nagler route.

Financially the zoom makes good sense compared to the price of three Naglers, and it would be easy to sell later on if you did go the separate Nagler route.

With the Ethos 3.7mm SX coming out in a couple of months time though I can see my 3.5mm and probably my 2.5mm Naglers going.

John

[Moonshane]

cheers John

I reckon you are right that the Nagler fixed are the way to go eventually. I'll try and find someone with a 3-6mm zoom and get over to them to use it. maybe then I'll make my mind up. as I say, I have lots of time as I need to save up first!

thanks again

Shane

[JamesC]

I've got the 3-6 zoom and use it with my starblast. I have to say it is a real gem of an eyepiece. I've also got 3mm and 6mm radians, which I use with my large scope - not that I would especially recommend these focal lengths - I often wish I had something inbetween. On the small scope the zoom couldn't be better. Top quality eyepieces are usually so chunky and yet this thing is really small, light, and yet works brilliantly. I have to refocus after zooming, but I think that's probably because I'm extremely short-sighted. I don't mind the short eye relief and narrower field of view on the small scope, probably because the high magnification isn't actually that high. With my big scope I really appreciate the extra bit of field that comes with the radians, and the eye relief too. I see you've also got a 12" dob, so I kind of suspect you might be happier with something with a wider field, but then once you've got that small apo...

[Helen]

I've got one and its great as you say to be able to tune to the conditions. It is clickstop though, so you'll get 3,4,5,6 not really the in between values.

Helen

[Moonshane]

cheers James and Helen

This is great feedback and I think it's going to be worth a try although I'll see if I can get out to someone with one to try it if possible before I buy one.

Helen, reading the various reviews etc I was under the impression that the zoom was although having click stops at the mm positions, it was continuous throughout the range and therefore you could use the inbetween zones as well? maybe I misunderstood the reviews. what happens to the view between eg 3-4mm?

[johninderby]

Although there are click stops it can also be used at any position in-between.

John

[Moonshane]

cheers John

that makes a big difference to my decision. I am still favouring the zoom for now I reckon.

[johninderby]

Buy the zoom second hand for £200.00 and then if you sell it later on you'd still get £200.00 for it so you wouldn't loose out even if you decided not to keep the zoom.

John

[Moonshane]

I reckon you are spot on mate.

the benefits definitely outweigh the negatives for me at the minute.

I will start saving