Am I using my new scope wrong?

[AdamR87]

Hi all,

I'm brand new to astronomy (a little lie, I got the astronomy badge with Cubs when I was tiny but have forgotten everything since!). I'm hoping to view the Jupiter/Saturn conjunction, so trying to get all set up and practiced over the next week or so.

 

I've just got a starter scope, a Sky-watcher SKYHAWK-1145PS 114mm. Chosen mainly due to cost and what seems to be a global shortage of telescopes at the moment severely limiting choice! But it seemed alright for the price.

I've got it set up and aligned but not sure I'm using it right. I'm looking at Mars (I think!) but can only see a very bright point of light using either the supplied 10mm or 20mm eyepiece.

 

When I try to adjust the zoom/focus on the eyepiece controls, instead of the object (in this case, mars) being enlarged, it just goes out of focus and what I end up seeing is a perfectly focused impression of the spider vane, which just gets bigger and bigger as I adjust the focus more.

 

Is that normal?  Do I just need to get some different eyepieces in order to achieve a better magnification, or is there something obvious I'm doing completely wrong?

 

Thank you all! 

 

 

 

 

[DaveL59]

Hi Adam and welcome aboard.

For focus, you need to adjust until you get the smallest/sharpest image of your target. Going outside of focus you will get a fuzzy ball/disc and racking back you will start to see the black dot in the centre of the disc (the secondary) and the spider vanes. 

Unfortunately at 500mm focal length, your scope with the eyepieces will only give you, if I'm not mistaken:
25mm x20
10mm x50

Did you get a barlow lens supplied with it? That would increase the magnification by whatever factor it has printed on it. x2 or x3 usually. 

If you do a search for the thread "what can I expect to see" on here it'll give you some guidance of what to expect. A 114mm scope will be limited in max magnification, according to specs it says x228 but in reality probably closer to x150 before you lose detail. You'd need shorter FL eyepieces to get up to that and being an F5 scope probably not cheap ones as it is a fast scope. 

[Moonshed]

Hi Adam,

If you can only see Mars as a bright point of light this could be just a problem getting sufficient magnification. With the eyepieces you have you are getting  x20 and x50  not enough really, you need to add a 3 x Barlow lens, you can get them for around £20-25. Even so don’t expect too much.

Keith

https://www.amazon.co.uk/s?k=3x+barlow+lens&adgrpid=56953970767&gclid=Cj0KCQiAzsz-BRCCARIsANotFgMzeJoBcO5ixAV0W2lanTor3l-FEL0Oyq9kgeimlcYWVi520MzK6zoaAkJzEALw_wcB&hvadid=259046965144&hvdev=c&hvlocphy=9045098&hvnetw=g&hvqmt=e&hvrand=14680539150393234506&hvtargid=kwd-366585573997&hydadcr=3955_1711755&tag=googhydr-21&ref=pd_sl_2zhgqsvd8o_e

Edited December 11, 2020 by Moonshed

[Ricochet]

1 hour ago, AdamR87 said:

When I try to adjust the zoom/focus on the eyepiece controls, instead of the object (in this case, mars) being enlarged, it just goes out of focus and what I end up seeing is a perfectly focused impression of the spider vane, which just gets bigger and bigger as I adjust the focus more.

The focuser is just that, a focuser. It is not for zooming in and out. Standard eyepieces give a single magnification when used with a particular telescope. To calculate the magnification that a telescope-eyepiece combination gives use the equation: 

Magnification = Telescope focal length / Eyepiece focal length 

Rather than buying a whole selection of eyepieces of different focal lengths some people prefer to use a zoom eyepiece. A relatively cheap and well thought of zoom is the Hyperflex 7.2-21.5mm, one of which FLO currently have on their offers page. This eyepiece should be noticeably better than the eyepieces supplied with your scope, but you would still need to pair it with a 2-3x barlow of your choice. 

[AdamR87]

Thank you all for your helpful replies! Sounds like a Barlow lens is the answer (and maybe down the line a zoom eyepiece; that looks useful).

 

Hopefully this will give me something more like what I was hoping for. I didn't have huge expectations, maybe something the size of a lentil for Mars! But certainly more than just a pinpoint.

Thanks again!

[DaveL59]

I think there may be a 2x barlow in the kit? Perhaps not the best quality if it's an all plastic body but worth a try.

A decent quality x2 barlow would be worthwhile depending on what is supplied with the scope and a better short-FL eyepiece as the 10mm's supplied are pretty poor. The 20/25 is generally usable even if not the best but a zoom eyepiece will cover the range and be better than the supplied ones. With a good barlow you'll be able to adjust the magnification to suit the target and conditions and also be able to use them on a future scope if you eventually upgrade. Another option in the zoom range is SVbony 7-21mm which isn't expensive and performs pretty well as does their 8-24mm but that is rather large and heavy.

[Jasonb]

Welcome Adam,

I'm a newbie too (I didn't even do it in the Cubs!) and my Telescope has a focal length of 650mm, which means my 25mm and 10mm Eyepieces give me 25x and 65x magnification respectively. With the 65mm eyepiece Mars is basically a very small disk, though it it visually a disk, not a pinpoint of light. Jupiter and Saturn (if you can catch them early in the evening as they're low) are much more impressive, at 65x Jupiter is a bigger disk and you can see its four largest moons as pinpoints of light, and Saturn is a noticeable disk with a ring around it. Still not crazy impressive, but clearly something other than the pin points of light we're used to. Seeing them for the first time just brought it home to me that I was looking at a planet. If you get a chance, check out Jupiter/Saturn with your 10mm and see what they're like. Conditions make a huge difference too, while I was looking at Saturn, without me changing anything on the scope, it could change from what almost looked like a slightly out of focus bump around a dot, to a clear distinct ring with black areas between it and the planet, all down to conditions in the atmosphere changing for a second or two. I'm learning that it definitely helps to just observe and watch for a while.

A decent Barlow is also on my list, along with a decent eyepiece to replace the 10mm one I got - from what I've read, the eyepieces shipped with scopes tend to be basic, and while the longer one (20mm in your case, 25mm in mine) can be ok, and shorter one (10mm) tends to be poor, and is recommended to be the first one to replace. Once Christmas is done, I'll be looking at getting a Barlow and hopefully a 8mm BST Starguider, as they're recommended on here as a good/not too expensive eyepiece.

What I'd really like though is a chance to use the thing, the weather has not been helpful. I've had one good night for viewing, last Tuesday, and I couldn't do anything as I was busy! Any time I've been free it's been partially cloudy at best.

[John]

46 minutes ago, AdamR87 said:

Thank you all for your helpful replies! Sounds like a Barlow lens is the answer (and maybe down the line a zoom eyepiece; that looks useful).

 

Hopefully this will give me something more like what I was hoping for. I didn't have huge expectations, maybe something the size of a lentil for Mars! But certainly more than just a pinpoint.

Thanks again!

It should look something like this at around 150x with a small scope. The darker areas can be difficult to discern depending on conditions. Smaller than a lentil probably !:

[AdamR87]

On 11/12/2020 at 22:50, John said:

It should look something like this at around 150x with a small scope. The darker areas can be difficult to discern depending on conditions. Smaller than a lentil probably !:

That's what I'm hoping for! The Barlow is coming today so will see what difference it makes. Let's call it a lentil that's really far away (I couldn't think of any better comparator >.<)

 

@JasonB I caught Jupiter and Saturn yesterday with some lucky clear skies. Unfortunately I'm in the city and they were right over a street lamp! But still I managed to get them in view and were discernablely bigger than Mars has been and could make out rings and some moons which was really nice. Hope to get out to come dark sky weather permitting soon.

 

Once last question for everyone - collimating my scope. All the online guides show 3 pairs of screws. I only have 3x screws at the bottom and their job seems to be to hold the primary mirror in place, they don't seem to be for adjustment. Is this right or do they actually work for adjustment as well?  The instruction manual has nothing to guide on this. 

[Pixies]

34 minutes ago, AdamR87 said:

I only have 3x screws at the bottom

Can you send a pic?

[John]

25 minutes ago, Pixies said:

Can you send a pic?

That would help.

Some scopes don't have collimation adjustment on the primary now so those 3 screws could just be holding the primary mirror cell into the scope. Sometimes the 3 screws hold a cover on which needs to be removed to get to the collimation screws. Most collimation screws come in 3 pairs - an adjusting screw and a locking screw x 3. A photo of the back end of your scope would help a lot.

 

[Ricochet]

1 hour ago, AdamR87 said:

Once last question for everyone - collimating my scope. All the online guides show 3 pairs of screws. I only have 3x screws at the bottom and their job seems to be to hold the primary mirror in place, they don't seem to be for adjustment. Is this right or do they actually work for adjustment as well?  The instruction manual has nothing to guide on this. 

The new, lightweight, "ps" scopes have fixed primary mirrors that in theory do not require user recollimation. If you find this is not the case the three screws would have to be loosened and you would have to manhandle the whole mirror cell/backplate to alter the angle of the primary.

[AdamR87]

On 13/12/2020 at 10:45, Pixies said:

Can you send a pic?

Here we go (hope this upload works...)

[Cornelius Varley]

That looks correct. The three screws attach the mirror cell to the tube, collimating and locking screws would be at the rear of the cell. This telescope doesn't having a primary mirror that can be collimated.

[AstroMuni]

On 13/12/2020 at 10:10, AdamR87 said:

Once last question for everyone - collimating my scope.

It is good to learn about this subject, but remember its not something that is needed in a lot of the new scopes. They come fairly well collimated.

[AstroMuni]

On 11/12/2020 at 18:27, AdamR87 said:

I'm looking at Mars (I think!) but can only see a very bright point of light using either the supplied 10mm or 20mm eyepiece.

You can use this tool https://astronomy.tools/calculators/field_of_view/  to get an idea of what size you could see with various eyepieces. The quality of image will depend of light pollution etc.

Good luck.

[AdamR87]

One last question... Thanks for answers about collimating the primary. I was looking at the secondary and am I right that this can't be collimated either? It looks like it should have three adjustment screws but they aren't present by the looks of it? 

Cheers

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[faulksy]

is there grub screws in the thread inserts ?

or have you removed any screws

[Ricochet]

8 hours ago, AdamR87 said:

One last question... Thanks for answers about collimating the primary. I was looking at the secondary and am I right that this can't be collimated either? It looks like it should have three adjustment screws but they aren't present by the looks of it? 

Cheers

 

These three holes must have screws inside that you can adjust using an allen key. The big phillips screw in the centre pulls the secondary to the spider, the three outer screws push against it. 

[jacobingonzo]

FLO's blurb on this scope suggests its primary is non collimatable and the second shouldn't require collimation as it hold it so well!!- it may be that they did not intend you to mess with the collimation of the secondary-it looks like you will need three screws to collimate the secondary- I replaced mine with M4 6-30mm screws from eBay they work a treat - would suggest you star test the scope to see if it needs any collimation first https://garyseronik.com/no-tools-telescope-collimation/

 

J