Zoom EP's

[ianB (Ian)]

Being new to EP's can you give me a brief overview of both the pros and cons of zoom ep's
over standard ep's as i am thinking about saving towards getting one as the thought of using just one ep without having to find other ep's in the dark is appealing, earlier ton7ght i was going from 25 to 9 to 6 mm back and forth.
( also why are Televue ep's so expensive ? )

Thanks,

Ian

[pw (Peter)]

Optics are a series of compromises (lets say five factors), juggle the variables to achieve the outcome you need.
Optimise one or two optical factors and the price is low.
Optimise three or four of the factors and price is medium.
Optimise all five of the optical factors and price blows out.

That is a simplistic but pretty accurate way to understand the broad price range you see in most types of lenses including eyepieces.

TV have optimised many factors and the price reflects that.

[ianB (Ian)]

Rather than start a new thread i'll ask here.

When out in the field observing should you re cap the ep when you remove it, even if you will use it again soon, or is it better to leave the cap off ?

And, now this may sound silly but i am new, when you take the scope out to cool down should you also take the ep's out and let them stand in the open as well, or keep them in their sealed containers?

TIA

ian

[pw (Peter)]

When my scope is in use I just put the eyepieces in the little rack on the side of the mount, I put their caps on when I pack it away at the end of the night.

[barx1963 (Malcolm)]

I keep all my eps in a case with their caps on until needed. When I am not actually using the scope I have a cap on the eyepiece in the focuser, not for dew just to minimise any dust or pollutants that may get on it.

My old scope had a rack but even when I had EPs on it they were always capped.

Malcolm

[Varangian (John)]

Originally Posted by ianB

Rather than start a new thread i'll ask here.

When out in the field observing should you re cap the ep when you remove it, even if you will use it again soon, or is it better to leave the cap off ?

And, now this may sound silly but i am new, when you take the scope out to cool down should you also take the ep's out and let them stand in the open as well, or keep them in their sealed containers?

TIA

ian

My EPs are capped whenever they are not in the focuser. I've had a few near misses leaving the lenses exposed in the dark.

Also, the Baader Planetarium click zoom was one of my favorite EPs and IMO the best of the mid-range zooms. I spent more time at the eyepiece when I owned it rather than fumbling about for the right focal length.

[ianB (Ian)]

Thank you.

[Micah-Jon (Micah)]

Originally Posted by Varangian

My EPs are capped whenever they are not in the focuser. I've had a few near misses leaving the lenses exposed in the dark.

Also, the Baader Planetarium click zoom was one of my favorite EPs and IMO the best of the mid-range zooms. I spent more time at the eyepiece when I owned it rather than fumbling about for the right focal length.

Can I ask why you no longer have it?

[WynneP (Peter)]

In my experience, zoom eyepieces can be excellent, if they are high quality. I have a Baader Hyperion Mk3 zoom and rarely use anything else with my 12" Dob. The views it gives are as good as any of the Plossls and Orthoscopics I have in my collection. Not sure how it would compare with a Televue or other expensive eyepiece, but I am very satisfied. Some time ago I had a (cheap) Bushnell zoom, which was certainly inferior and hence little used.

[dannat (Daniel)]

the cons of zoom ep is the small fov at the wide end (usually 40-50deg)
pro's are you can usually leave one ep in the focuser -& usually get good fields of view when using high magnification

i have recently bought a nikon spotting scope -the zoom ep is excellent (i am trying to get an adapter made for it)
if you are going to get one & use it a lot get either the badder zoom or WO premium zoom (also sold by orion)

[MortonH]

The Orion 7.2mm-21.5mm is very sharp. I bought mine at Bintel.

You're right about it being narrow at the long end. I sometimes use a wider angle 21mm eyepiece to help find the object I want, then switch to the zoom and adjust the magnification to suit.

[GUS.K (Ivan)]

I have three zoom eyepieces, Baader Hyperion, Orion premium (AKA WOs) and the Lunt solar zoom and they are all good eyepieces.I mainly use them on my H alpha and white light solar scopes, as they allow me to adjust magnification according to the constantly changing daytime weather conditions, and the narrow AFOV doesn't matter so much for solar.
If you are after an all purpose eyepiece with a wide range of magnifications,then a zoom is a great choice.