Skywatcher 130 advice please

A place to hang out and chat about astronomy

Skywatcher 130 advice please

Postby qu54856bo » Thu Feb 02, 2006 1:20 pm

Hello fellow travellers. I hope to acquire my first scope in the next month or so. The Skywatcher 130 seems to have a good press here and elsewhere. The 130 comes in 2 versions, 130M Newtonian with motor (f900) and 130P Newtonian Parabolic, no motor or barlow (f650), £10 more. Both EQ2 mount.

Can anybody tell me if the 130P will perform visibly better? they have different f no's and lengths so the P is poss more deep sky oriented?

Am new to this level of interest - Sky at Night mag brill and website and forum also v useful.

best wishes
Auray
qu54856bo
 
Posts: 115
Joined: Sun Mar 13, 2011 2:22 am

RE: Skywatcher 130 advice please

Postby Chanctonbury » Thu Feb 02, 2006 1:36 pm

IMHO the 130P will perform better as it does not have a built in 'relay' lens. This means that it's focal length is shorter which will give lovely wide fields of view (relatively) but if you need to 'zoom in' then a good Barlow lens will allow you to do this.
Chanctonbury
 
Posts: 4457
Joined: Thu Feb 03, 2011 5:57 pm

RE: Skywatcher 130 advice please

Postby qu54856bo » Thu Feb 02, 2006 1:53 pm

Thanks Steve. Excuse my ignorance but what relay lens? Does the 130M have an extra lens that the 130P doesn't?
best wishes
Auray

PS Found your excellent website and observatory very interesting indeed.
qu54856bo
 
Posts: 115
Joined: Sun Mar 13, 2011 2:22 am

RE: Skywatcher 130 advice please

Postby cumbrianwolf » Thu Feb 02, 2006 2:26 pm

I would advise you to decide what realms of the universe you want to see as otherwise you may limit your choice let me try to explain.
I own a F4 reflector and this is primarily for deep sky work as the wide field views is what i want, but when i use it for planetary work it is at a loss as i need to crank up the power to well within the 200X and at this magnification the scope can wobble too much for detail to be shown.
Thats where the High F number prevails it reduces the field of View down so that such a high magnification is not needed, you can see just as much as mine on say 75X and that reduces vibration showing through the eyepiece.
Hope this helps.[;)]
cumbrianwolf
 
Posts: 103
Joined: Mon Feb 13, 2012 6:23 pm

RE: Skywatcher 130 advice please

Postby Chanctonbury » Thu Feb 02, 2006 3:16 pm

The 130M has an extra lens built into the focusser ( called a relay lens ) this lens is always in place and extends the apparent focal length so that you can have an apparently long lens in a shorter tube.

Cumbrianwolf, you are quite right to suggest that Auray considers his main use carefully as this will dictate the type of instrument that he buys, however, I am not sure that I agree with your logic over the change in 'wobble' as magnification is 'magnification' no matter how it is achieved. [size=2]To calculate the magnifying power of any telescope you simply divide the focal length of the objective lens or mirror by the focal length of the eyepiece so to achieve the [b]same[/b] size image, no matter what telescope you have, the actual magnification will have to be the same which means the same risk of wobble will also be the same if you see what I mean![/size]
Chanctonbury
 
Posts: 4457
Joined: Thu Feb 03, 2011 5:57 pm

RE: Skywatcher 130 advice please

Postby qu54856bo » Thu Feb 02, 2006 5:46 pm

Steve and Wolfie - thanks for your comments guys - I'm learning a lot very quickly with the help of experienced people like yourselves. I want my scope to do everything including making coffee. However, deep space will be first priority though I certainly hope to see some good planetary images too.

cheers
Auray
qu54856bo
 
Posts: 115
Joined: Sun Mar 13, 2011 2:22 am

RE: Skywatcher 130 advice please

Postby cumbrianwolf » Thu Feb 02, 2006 6:03 pm

When i say wobble i meant it in a basic sort of sense in that the higher the X the more movement becomes apparent.
I can get a very small image of saturn using my SN 10" F4 at a round 150X but my fellow freind can use 75X to gain the same view with his high F ratio scope so there must be some optical reason behind it.
But i wont confuse matters by a debate as it will get to technical and i am not one for that method i prefer to look and see.

cumbrianwolf
 
Posts: 103
Joined: Mon Feb 13, 2012 6:23 pm

RE: Skywatcher 130 advice please

Postby g4aqb » Thu Feb 02, 2006 11:36 pm

I've just checked my Skywatcher 130m and it does not have a relay lens in the focuser...could this be because the older 130m's did not have a parabolic mirror and had the relay lens fitted at the time?

Can't go wrong with the 130m, mines brill!! Have a look at the results on my website see what you think [url=http://www.g4aqb.org.uk]www.g4aqb.org.uk[/url]

Steve
g4aqb
 
Posts: 123
Joined: Mon Feb 13, 2012 6:20 pm

RE: Skywatcher 130 advice please

Postby Chanctonbury » Fri Feb 03, 2006 12:43 am

Steve,

It is probably an earlier one I am thinking of then because a relay lens could also be used to correct for a spherical mirror. It was some time ago that I first saw one and that was not a new one even then!
Chanctonbury
 
Posts: 4457
Joined: Thu Feb 03, 2011 5:57 pm

RE: Skywatcher 130 advice please

Postby qu54856bo » Fri Feb 03, 2006 2:36 pm

Hi g4

Had a look at your website and was very impressed at what you have achieved. I have taken on board what people have been saying though whether I have understood it all is another matter! I think the 130M, having a longer tube than the 130P (sorry to be technical) and a bigger f no, is marginally going to give a longer view (slightly less wide field) and so perhaps a bit easier on the occasions I want to view a planet (+barlow which I note the 130P isn't shipped with). I might have got this totally wrong.

Skywatcher 130 this birthday (March but maybe earlier!). Next year perhaps a long refractor just for the planets.

Once again thanks to all for help and advice.

Auray
qu54856bo
 
Posts: 115
Joined: Sun Mar 13, 2011 2:22 am


Return to General

Who is online

Users browsing this forum: No registered users and 1 guest