Zoom EP questions

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Ylem United States of America
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Zoom EP questions

#1

Post by Ylem »


I have been thinking about snagging one for both solar and vacation use.
What I don't really like about them is it seems FOV Increases with higher magnifications.

Does anyone make one that the FOV Increases with Lower magnifications?
Clear Skies,
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Don Pensack United States of America
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Re: Zoom EP questions

#2

Post by Don Pensack »


No, because that is physically impossible.
However, APM (7.7-15.4mm)--approx 66°, and TeleVue (3-6mm)--approx 50°, make zooms with constant apparent fields from one end to the other.
And Leica (8.9-17.8mm) may be wide enough for you (57° at low power, 78° at high).
But I agree with you--zooms work pretty much the opposite of what you'd like to see.
Though, I could deal with a zoom that went from 21mm to 7mm and 80° to 100°, but that won't ever be made.
Astronomer since 1963
Currently using a 12.5" dob and a 4" apo refractor
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Re: Zoom EP questions

#3

Post by Ylem »


Don Pensack wrote: Tue Feb 28, 2023 11:09 pm No, because that is physically impossible.
However, APM (7.7-15.4mm)--approx 66°, and TeleVue (3-6mm)--approx 50°, make zooms with constant apparent fields from one end to the other.
And Leica (8.9-17.8mm) may be wide enough for you (57° at low power, 78° at high).
But I agree with you--zooms work pretty much the opposite of what you'd like to see.
Though, I could deal with a zoom that went from 21mm to 7mm and 80° to 100°, but that won't ever be made.
Thanks Don.

That APM looks nice, something to consider.

Thanks!
Clear Skies,
-Jeff :telescopewink:


Member; ASTRA-NJ



Orion 80ED
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Vixen Porta Mount ll
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Bigzmey United States of America
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Re: Zoom EP questions

#4

Post by Bigzmey »


Budget zooms tend to be too narrow (40 or even 30 deg at the lower power) and too dark for my liking. But I do enjoy using Baader Mark IV zoom. It is a part of my vacation/ultra light grab and go package. In my 80ED scope it delivers 2.3deg TFV at 24mm (21x), wide enough not to bother with RACI finder.
Scopes: Stellarvue: SV102ED; Celestron: 9.25" EdgeHD, 8" SCT, 150ST, Onyx 80ED; iOptron: Hankmeister 6" Mak; SW: 7" Mak; Meade: 80ST.
Mounts: SW: SkyTee2, AzGTi; iOptron: AZMP; ES: Twilight I; Bresser: EXOS2; UA: MicroStar.
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EPs: Pentax: XWs & XFs; TeleVue: Delites, Panoptic & Plossls; ES: 68, 62; Vixen: SLVs; Baader: BCOs, Aspherics, Mark IV.
Diagonals: Baader: BBHS mirror, Zeiss Spec T2 prism, Clicklock dielectric; TeleVue: Evebrite dielectric; AltairAstro: 2" prism.
Filters: Lumicon: DeepSky, UHC, OIII, H-beta; Baader: Moon & SkyGlow, Contrast Booster, UHC-S, 6-color set; Astronomik: UHC.

Observing: DSOs: 3106 (Completed: Messier, Herschel 1, 2, 3. In progress: H2,500: 2180, S110: 77). Doubles: 2382, Comets: 34, Asteroids: 255
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messier 111 Canada
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Re: Zoom EP questions

#5

Post by messier 111 »


hi jeff ,
here is the one I use with my televue 85 .

I like the eye relief and the field of view.
for the price it is very good.
I use it to see the sun and when traveling.

https://telescopescanada.ca/products/sv ... iece-sv135
I LOVE REFRACTORS , :Astronomer1: :sprefac:

REFRACTOR , TS-Optics Doublet SD-APO 125 mm f/7.8 . Lunt 80mm MT Ha Doublet Refractor .

EYEPIECES, Delos , Delite and 26mm Nagler t5 , 2 zoom Svbony 7-21 , Orion Premium Linear BinoViewer .

FILTER , Nebustar 2 tele vue . Apm solar wedge . contrast booster 2 inches .

Mounts , berno mack 3 with telepod , cg-4 motorized , eq6 pro belt drive .

“Your assumptions are your windows on the world. Scrub them off every once in a while, or the light won't come in.”
― Isaac Asimov

Jean-Yves :flags-canada:
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Re: Zoom EP questions

#6

Post by Don Pensack »


messier 111 wrote: Wed Mar 01, 2023 12:59 am hi jeff ,
here is the one I use with my televue 85 .

I like the eye relief and the field of view.
for the price it is very good.
I use it to see the sun and when traveling.

https://telescopescanada.ca/products/sv ... iece-sv135
But only 40° at the long end and 57° at the short.
That's a pretty narrowfield eyepiece.
Astronomer since 1963
Currently using a 12.5" dob and a 4" apo refractor
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Re: Zoom EP questions

#7

Post by messier 111 »


Don Pensack wrote: Wed Mar 01, 2023 1:03 am
messier 111 wrote: Wed Mar 01, 2023 12:59 am hi jeff ,
here is the one I use with my televue 85 .

I like the eye relief and the field of view.
for the price it is very good.
I use it to see the sun and when traveling.

https://telescopescanada.ca/products/sv ... iece-sv135
But only 40° at the long end and 57° at the short.
That's a pretty narrowfield eyepiece.
you are right Don, but I find that for the sun and planets when I travel especially it does the job.
I LOVE REFRACTORS , :Astronomer1: :sprefac:

REFRACTOR , TS-Optics Doublet SD-APO 125 mm f/7.8 . Lunt 80mm MT Ha Doublet Refractor .

EYEPIECES, Delos , Delite and 26mm Nagler t5 , 2 zoom Svbony 7-21 , Orion Premium Linear BinoViewer .

FILTER , Nebustar 2 tele vue . Apm solar wedge . contrast booster 2 inches .

Mounts , berno mack 3 with telepod , cg-4 motorized , eq6 pro belt drive .

“Your assumptions are your windows on the world. Scrub them off every once in a while, or the light won't come in.”
― Isaac Asimov

Jean-Yves :flags-canada:
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