Why are there so many Naglers?

[erick (Eric)]

As in eyepieces made by Televue.

If I have read correctly, the range in mm of focal length is:- 2.5, 3.5, 5, 7, 9, 11, 12, 13, 16, 17, 20, 22, 26, 31.

Surely the differences between, say, 11mm, 12mm and 13mm are so small I cannot see why there needs to be all three? Why a 16mm and a 17mm?

Am I missing something here?

Eric

[Ian Robinson]

http://www.televue.com/engine/page.asp?cat=2

Maybe they have difficulty getting the focal lengths right and so a lot of extra sizes , with so many elements it would be very tedious and time consuming getting the focal lengths accurate to an acceptable tolerance.

[mick pinner]

look at their prices, would'nt you get as many out there as you could?

[wavelandscott (Scott)]

Originally Posted by erick

As in eyepieces made by Televue.

If I have read correctly, the range in mm of focal length is:- 2.5, 3.5, 5, 7, 9, 11, 12, 13, 16, 17, 20, 22, 26, 31.

Surely the differences between, say, 11mm, 12mm and 13mm are so small I cannot see why there needs to be all three? Why a 16mm and a 17mm?

Am I missing something here?

Eric

Yes, I think that you are...

Within the "Nagler" line are also different configurations of lenses that share/aspire to other criteria....the Nagler brand is known for the 82 degree FOV...within that are the T6, T5 and T4 series. Each of these series has different characteristics such as eye relief...the 16 T5 and 17 T4 are very different animals indeed as are the 11 or 13 T6 versus the 12 T4.

Each of them have different aspects which are maximized/targeted/scope type...while I am not saying that you need them all, I would say that after you get a chance to try the different types you will have a better understanding of the virtues of each type and why there appears to be so many.
Clear Skies and Happy Holidays!

[ausastronomer (John Bambury)]

Hi Eric,

Scott is 100% correct. The T4 as distinct from the T5's and T6 series, aspire to meet specific but different design objectives. The T5 and T6 Naglers have shorter eye relief and their focal lengths do not overlap. The T4 Naglers aspire to provide long eye relief and eliminate Angular Magnification Distortion.

Cheers,
John B

[mozzie (Peter)]

love my naglers as good as it gets bring on the ethoes im saving my money
peter

[erick (Eric)]

Thanks guys, now I'm better educated!

Yes, just checked the Bintel website, I should have thought of the significance of the different Types.

[Craig.a.c (Craig)]

2.5! You wouldn't see much with that would ya?

[wavelandscott (Scott)]

Originally Posted by Craig.a.c

2.5! You wouldn't see much with that would ya?

Depends on the scope...remember the formula for magnification...

Magnification = Telescope focal length divided by eyepiece focal length...

I suspect for some scopes it would be brilliant!

Clear Skies...