Focusing in on planet

[Tomjayes]

Hi I have bought a celestron 130 I am getting on ok with it I have managed to find Saturn but it's really tiny in the scope and if I try to zoom in it goes out of focus I only have the 10 mm eye peice it came with as I got it from e bay is this as good as I can get it or do I need another eye peice any help would be great thanks tom

[Ally8446]

There is no zoom. What you are doing is putting the object out of focus by turning the knob on the focuser. The only way to make the object larger is by using a shorter focal length eyepiece.

[CodnorPaul]

You can't zoom on a fixed length EP, you can focus and that's it - for more magnification you need to change EP length

[Garethr]

Tom

I have a Celestron 130 as well.  The image will be small and I don't think when you try to "zoom in" it will work as all your doing is changing the focus. maybe a smaller eyepiece such as 6mm will help but the image will still be quite small but a bit more detailed,  good quality eyepieces will also help bring out the features.

[LukeSkywatcher]

Saturn in a 130mm scope with a 10mm EP will be small. If the focus is spot on, it will still be small but pleasing. A popular size of eyepieces for observing the inner planets is 8mm.

[bruno]

can you not use a barlow EP to enlarge it

[John]

To get Saturn (or any other object) to look larger, you either need an eyepiece with a shorter focal length (eg: 5mm) or a barlow lens to make your 10mm eyepiece into a 5mm one.

I think the Celestron 130 has a focal length of 650mm so the 10mm eyepiece will give you 65x magnification (mag = scope focal length divided by eyepiece focal length). A 5mm eyepiece (or a 10mm eyepiece in a 2x barlow lens) will give you 130x magnification so Saturn will look twice as large through the scope.

What you are seeing as you adjust the focus wheel (zooming as you call it) is the planet going out of focus and, as it does so, it appears to get larger, but all that is happening is that the out of focus disk of light is expanding as it gets more and more out of focus. When an object is at it's smallest in the eyepiece is when it is at sharp focus. 

[stevend]

I would also recommend reading this thread: http://stargazerslounge.com/topic/196278-what-can-i-expect-to-see/

[OscarTheGrouch]

I have a Celestron 130 and Saturn is small using the 10mm eyepiece.  As mentioned before, the focal length of the scope is 650mm and if you divide this by the size of the eyepiece you're using it tells you the magnification - 650/10 = 65 x magnification.  In theory, you can get a maximum useable magnification of 307 x according to the manufacturer, so you're right at the bottom end of where you want to be!!

When you attach a Barlow lens to your eyepiece, this increases the magnification.  The multiplier on the Barlow tells you by what factor it will increase, so a 2x Barlow attached to your 10mm eyepiece increases your magnification to [650/10 = 65 x 2] 130 times.  a 3x Barlow gives you [650/10 = 65 x 3] 195 times and so on. 

I also have a 6mm eyepiece.  This gives me a magnification of [650/6] 108 times.  I use my 2x Barlow with it to get 216.  This gives you a MUCH better view.

My suggestion would be that rather than going off and buying more lenses now, join your local astronomy group and see if there is anyone who wants to sell off some of their old kit.  That way you should get good quality eyepieces for less