Zoom lens with sky watcher SkyMax 127 AZ-GTI WiFI

[Knighter]

Hi, I am new to star gazing and just bought myself a  sky watcher SkyMax 127 AZ-GTI WiFI. I am considering buying a Celestron zoom eye piece. But can see mixed reviews of whether to use them on a telescope. They look a good idea as you don’t have to swap out eye pieces etc but I know you sacrifice a little clarity but some some it’s hardly noticeable. Any advice would be appreciated.

Regards
Matt

[Bobby1970]

Welcome to SGL

I have the same scope as you and an AZGTi. I have a zoom eyepiece its a Seben 8-24mm. For what it cost I think its pretty good tbh. Do a search on here for some owners reviews of it.

Zooms tend to have a smaller FOV as far as im aware so have this in mind. What I tend to do is use something like a 32mm Eyepiece as my initial "finder" as it gives about the widest views in your 127mm Mak as far as I know. Once on a target I swap it for the 8-24mm zoom. I paid around £20 used for my zoom. Not sure what they are new but it seemed worth a punt at the time and its pretty good on the moon also I have found.

 

 

 

 

 

Edited May 11, 2020 by Bobby1970
link added

[John]

Hi Matt,

These days, zooms work pretty well and their optical quality is almost as good as fixed focal length eyepieces.

The downside with them (most of them anyway) is that at the longer focal lengths, the field of view is quite narrow. This widens out at the shorter focal lengths though.

The Celestron and Skywatcher (and Seben) 8-24 zooms are quite good quality and all the same item as far as I can see. The cheaper 7-21mm ones are not so good though.  The Baader 8-24 is very nice but a lot more expensive. The Skywatcher Hyperflex zooms are pretty good as well.

With your scope I can see the attraction. I might want to compliment the zoom with something like a 30mm fixed focal length eyepiece for low power wider views than the zoom can provide.

Cheers,

John

[Ricochet]

If I was looking for a zoom I would look around for the cheapest available clone of the Lunt/OVL/Skywatcher/etc 7.2-21.5mm zoom, as it is well reviewed by people whose opinions I would trust. I looked through one of the 8-24mm zoom clones and the most accurate description I could give it is "blurry". Perhaps it was a poor example, but it wasn't something that I would choose to use.

[johninderby]

I find the Lunt / TS / OVL / Skywatcher  1.25" Zoom Eyepiece 7.2mm-21.5mm are very good indeed. Price varies enormously though for what is the same eyepiece under different brands.

Edited May 11, 2020 by johninderby

[John]

I should have mentioned that 7.2mm-21.5mm - it's the one that I currently have as well !

 

[Knighter]

That’s brilliant guys Thankyou I have also bought the skywatcher deluxe  Barlow lens x 2. Looking at YouTube videos to get the max out of the scope a Barlow lens with a 6.2 lens Max’s out the scopes capabilities. So thinking about a zoom lens so tats great. Would this set up give me good close up views of the moon surface etc. 

Matt

[John]

The 6.2mm eyepiece will max out the scopes capabilities on it's own most of the time  - that's 242x !

Much observing is done at the low to medium magnifications.

 

 

[johninderby]

Using the Televue eyepiece calculator and the Skymax 127 specs (actual aperture of this scope is abpit 119mm) gives these results.

[ScouseSpaceCadet]

The same MZT8-24 zoom eyepiece is sold under several different brand names for wildly varying prices.

Celestron, Skywatcher, Seben, Zhumell,  Omegon, BST and probably several more..

Shop around for the cheapest. Which at the moment might be:

https://www.ebay.co.uk/itm/Starguider-8-24mm-1-25-Zoom-Telescope-Eyepiece/382821209392?hash=item5921ec1530:g:2IYAAOSw5LZcfWSE

 

Edited May 11, 2020 by ScouseSpaceCadet

[Knighter]

Thanks for the info. I’ve just tried to have a look tonight but with the Barlow lens and 25mm eye piece it was a little disappointing but I am limited to nw viewing vega I could use for 2 star alignment but like I said a little disappointing 

[John]

Wait for Vega to rise higher in the sky - it will look nicer.

The famous "double double" Epsilon Lyrae is close to it - well worth a peek !

[Knighter]

Ok will take a look maybe in my mind I was expecting it to be a larger image it doesn’t seem to be much bigger than looking with the naked eye apart from it’s much brighter 

Edited May 11, 2020 by Knighter

[Ricochet]

7 hours ago, Knighter said:

Ok will take a look maybe in my mind I was expecting it to be a larger image it doesn’t seem to be much bigger than looking with the naked eye apart from it’s much brighter 

Stars are so far away that they will always be point sources through a telescope. What you will see is more stars in any given area of the sky than with the naked eye. The only star that is an exception and can be seen in any detail is the Sun, but this requires specialist solar filters or solar telescopes. 

The moon, planets, nebulae and galaxies will appear larger through a telescope than with the naked eye. 

[Knighter]

Hi yes I have ordered a solar filter today so Looking forward to looking at the sun is some detail. What colour filter would you recommend to use with this?. 

Edited May 12, 2020 by Knighter

[Knighter]

8 hours ago, Ricochet said:

Stars are so far away that they will always be point sources through a telescope. What you will see is more stars in any given area of the sky than with the naked eye. The only star that is an exception and can be seen in any detail is the Sun, but this requires specialist solar filters or solar telescopes. 

The moon, planets, nebulae and galaxies will appear larger through a telescope than with the naked eye. 

Hi yes I think I just need to manage my expectations better. As I said I am completely new to this so still getting to grips with the scope and the GOTO software etc. Any tips though very gratefully received 

[Knighter]

19 hours ago, johninderby said:

Using the Televue eyepiece calculator and the Skymax 127 specs (actual aperture of this scope is abpit 119mm) gives these results.

 

[Knighter]

Thanks for the advice. 
my calculations are as follows

focal length 1500mm

primary mirror 127mm

so 127mm x 2 = 254mm. This is the max scope magnification?

so 1500mm divided by 254 = 5.9 so 5.9mm max eyepiece 

with a x2 Barlow focal length now 3000mm so if I used the 10mm lens this would give me 300x which is overpowered?. 

So if I used the Barlow with a 25mm eyepiece this would give me 120x

and if I use the Barlow with a 15mm eyepiece this would give 200x 
Are my corrections correct?

Edited May 12, 2020 by Knighter

[johninderby]

Close enough although the scopes aperture isn’t actually 127mm but118 to 119mm. The mirror isn’t what determines the aperture but several other factors. You might call 119mm the usable aperture. Many have compained for years about Skywatcher being misleading about not giving the usable aperture but the aperture of the corrector.. It’s a problem that occurs with other scopes.

The Skymax 150 and 180 also used to be smaller aperture but Skywatcher made changes so they are actually the correct size but haven’t done anything about the 127. 

Edited May 12, 2020 by johninderby