Very newbie questions

[Blaze]

Sorry for such simple questions, it must make me sound so dumb. My parents bought me a telescope and I have never used one before and I don't know anyone else who has so it is just me. 

1. What does the large plastic cap do on the end of the telescope ? It has what looks like holes in it that undo. When taken off I look down it and see my face at the end. I haven't yet been successful with night time viewing, I have only managed to focus clearly on trees during the daytime. Is that cap on the end meant to be totally removed, or just one of the smaller caps attached to it ? Also I need a replacement as a plastic clip has broken, what are they called ?

2. I have a moon filter but it only seems to attach directly to the built in telescope lens, not any of the extra lens I bought. Is that right ? When I try and focus on the moon all I see is a blurred blob of white no matter how much I try and focus.

3. When I managed to view some stars they seemed to shoot off to the right within seconds, are they actually moving fast or was it just a trick of the light ? I am presuming stars don't move that fast, even distant ones ? 

Thanks all !!

[jambouk]

Hi.

1. I suspect you are referring to something like this: http://www.grelf.net/im/equip/s8295_10lid_200x200.jpgIf not, I've got the wrong end of the stick. For most observing remove the whole black thing, which is the cap which protects what is inside; the whole big black circle should pull off the scope, and can be the size of a dinner plate or bigger depending on the size of your telescope. Don't worry for now about the smaller ones, but keep them attached to the main cap and don't lose them. Can you take a picture of the clips you talk about?

2. Again, I think a picture would help here. You don't need to use a moon filter when looking at the moon. Never ever look at the sun or anywhere near the sun if you are using it in the day time; it really will cause damage to your eyes.

3. Yes, the stars can appear to move quickly. Again a picture of your actual telescope and the various eye pieces you have will help us. Most eye pieces have a number written on them, like 20mm, 10mm etc. This is the focal length of the eye piece. The lower the number, the more magnification they will provide when looking through them. The more magnification you use, the quicker the stars will appear to whiz to the right. Someone "clever" will come along and tell us that the stars aren't actually move, it is us, on a rotating planet which is moving, but we both know that don't we Again if you can get a picture of how your telescope is mounted (the stand which holds the telescope) it will help people work out how to help you track the stars. Fancy mounts have a power supply and can track the stars so they don'#t appear to whiz away. But a picture will help.

So, great news that you have got it out and started to fiddle with it. Get some pictures of the telescope and its mount, and the eyepieces and other bits you have with it. If there is any writing on the telescope about its make and model, tell us that, and we can probably find a manual online for its use. Have you got the manual?

Look forward to seeing what happens.

James

[Paul73]

Hi

Don't wory. It is confusing.

Yes, the whole cap comes off. This lets the maximum amount of light hit the big mirror at the bottom. The curvature of the mirror bounces the light back up the tube onto the little flat mirror high turns the light through 90° and out through the eye piece.

The fact that you can focus in the day would suggest that there isn't anything too wrong. You will need to columate (check/adjust the alignment of the mirrors at some stage. There are loads of threads on this topic.

are you other questions. Some pictures of your scope would be helpfull in explaining how the different parts should be set up.

Paul

[VikkiFord]

I tend to use the moon filter when observing the moon, even then I'm half blind in my right eye for a minute or two when I walk away from it. That critter is bright without a moon filter. 

Vikki.

[Dave Lloyd]

These are all valid questions Blaze, you're on the right site to have the answers. As your knowledge and experience grows YOU'LL be the one giving advice to beginners. Happy gazing.

[laudropb]

Hi Blaze. Don't worry, we all had to start out at some time and faced the problems you are now encountering. It would help us to give advice if we knew the model of telescope you have. There are some very helpful videos on you tube which deal with setting up your telescope for the first time

[Tzitzis]

Hi dude. I'm new here too. Don't worry, I had the same questions as well.

I can answer to one of your questions and maybe be useful; as mentioned before the plastic cap (called a dust cap) prevents your mirror from getting dust on it and it comes off as a whole. 

The little whole in the cap is to help you observe the moon without any filter. If you want to observe the moon and not get half blinded you take the little cap off and leave the big cap on: This reduces the amount of light that comes through the scope's mirror so you won't be blinded. I don't need a filter (although I have one) cause I do this "trick". 

Again some pictures would be helpful.

Have a great time stargazing!

[Tums]

Hey Blaze, some good advice in the previous posts, I remember when I started, I found some videos on YouTube from these guys, there very good at explaining things, definitely worth you having a look through there posts.

[VikkiFord]

Tzitzis: I wondered what the little hole was for in the cap. Thanks   I will try that.

[Tzitzis]

It's great believe me!!!

[-Aldebaran-]

Tzitzis: I wondered what the little hole was for in the cap. Thanks   I will try that.

I only discovered that little "trick" a couple of months ago on here! Who would have thought.

[Blaze]

Wow guys. this is fantastic, thank you ALL for the answers. I am going to take some photos and will post them here within the next 2 days. 

THANKS AGAIN !!  

[RichieP]

I only discovered that little "trick" a couple of months ago on here! Who would have thought.

I would avoid using the little cap to reduce the brightness of the moon. Yes it will do that, but it also reduces the aperture of your scope, effectively turning it into a smaller scope.

There is a huge amount of detail to be seen on the moon but, with a smaller aperture, you will miss out on a lot of it. Use a moon filter instead.

[jambouk]

Some people advocate using the smaller aperture to increase the focal ratio of the scope to give better "contrast" on solar system targets...

James

[Tzitzis]

It's great. I saw the moon and it was better than it would be with full aperture and the filter.

You don't need that much apperture to see the moon. I see great detail with my little 60mm refractor with the dust cap on. Lots of detail. Great views. I will agree jambouk too.

[Coastliner]

I have found the smaller aperture useful for solar viewing, I gaffer taped a small piece of Baader film over the aperture on the inside of tha cap, this is then protected when the small cap is in place. I used strong gaffer tape because you don't mess around with this stuff, you want to make sure it stays put! As an extra precaution I tape the large cap to the tube when solar viewing to totally ensure it stays in place. You definitely need to do this especially as you suspect one of the clips is broken. See pic, it shows my 200p with the film over the small hole and the main cap taped up.

[Blaze]

Thanks all ! Here are the photos as promised.

 

[pipnina]

Thanks all ! Here are the photos as promised.

-snip-

I have the exact same scope, model and all. It's a shame you/your parents didn't ask here first so I could rant at you about how I regret my purchasing decision. (after further thought, I decided a 200p dob would be a much better first scope.)

I must admit I never had any issues with focus, It seems easy enough to focus with mine (although I took a screwdriver to the primary mirror cell fairly quickly after making a collimating cap from the focuser dust cap (simple GCSE construction lines )

I, personally, don't understand the main dust cap skywatcher put with the telescope. If that second mini-cap wasn't a perminent fixture it would have made a great focussing mask!

Did a moon filter come with yours or was that an extra? I don't remember one coming with mine.

(p.s. Your focussing issue might have something to do with your EPs not being in the focusser properly. that metal bit at the bottom of the EP should not be visible!)

(p.p.s. Don't bother with that barlow lens. It's crummy!)

(p.p.p.s. Stars will shoot off into the distance if the telescope isn't balanced properly, make sure your counter weight isn't over/under compensating and that the tube is balanced front to back)

[Starlight 1]

With the cap my one is allways falling of so I put some black tape round it 2 or 3 time round the lip.  On some telecopes  you can fit the cap over the mirror end to keep stay light out of the mirror. Edit 1 when you take the little cap off fit it on the one next to it save you from lossing it.

[Blaze]

Telescope is : Skywatcher BK 1309 EQ2
 

pipnina, thanks for the info. We got the moon filter from Amazon separate to the scope. What reasons didn't you like the scope ?

Yeah I wondered why the 2nd cap was fixed, doesn't make much sense to have it as a cap but seal it. Any ideas where I can get a replacement ?

[jambouk]

When setting the kit up, make sure the Right Ascension (RA) axis is pointing north - use a compass if you have one, but don't get the compass too near the metal of the kit as it will interfere with it:

[jambouk]

So it looks like your kit is a Skywatcher Explorer-130 on an EQ2 mount. The scope has an aperture of 130mm (just over 5 inches), and a focal length of 900mm.

If using the 10mm eye piece you get a magnification of 90x.......... = 900 (focal length of scope) / 10 (focal length of eyepiece)

Is using the 25mm EP you get a magnification of 36x......... = 900 / 25

If you use that 2x Barlow as well, this effectively double your focal length of the scope so:

Using 10mm EP and 2x Barlow = (900 x 2) / 10 = 180x magnification

Using 25mm EP and 2x Barlow = (900 x 2) / 25 = 72x magnification

Don't be drawn to the maximum magnification possible as you increase the magnification, the clarity of the image you can see will fall. The maximum useful magnification is dependent upon the aperture of your scope (and down to many other factors like the atmospherics and "seeing" and "transparency" which you will come to learn about). In the UK, it is said the maximum useful magnification is at best 30x your aperture in inches; for for you that is 30 x 5(inches) = 150x magnification. So even on the best of night, it looks like the 10mm EP and the 2x Barlow will be pushing things and I suspect whatever you are looking at will be blurry.

In addition to this, the EPs supplied with scopes are generally of the cheaper variety - the company doesn't want to give away good stuff! they will be fine for now, but if you continue to get into the hobby you might want to get some other EPs. It's always best to get to a star party with your kit and try other peoples EPs and see which ones work best for your kit and your eyes before making a purchase. You need to join a local astronomy group - what is your nearest city or large town?

James

[jambouk]

Another reason the stars may be shooting off if that you haven't polar aligned the mount. There is a guide here on how to do this for your mount:

http://www.opticalvision.co.uk/documents/170.pdf

Again, members of your local astronomy group will be able to help with this.

James

[pipnina]

Telescope is : Skywatcher BK 1309 EQ2

pipnina, thanks for the info. We got the moon filter from Amazon separate to the scope. What reasons didn't you like the scope ?

Yeah I wondered why the 2nd cap was fixed, doesn't make much sense to have it as a cap but seal it. Any ideas where I can get a replacement ?

I didn't like the scope for one reason:

It's equatorially mounted, but cheaply.-

I feel that EQ mounts below the EQ3-2 are entirely useless for astrophotography, and if you're not using it for AP, you want it to be as comfortable as possible as well as portable. The EQ2 does not provide this at all. The declination axis sticks at certain points unless the locking screw is completely undone, this means even the slightest nudge throws you 5-10 degrees off and the slow-mo controls don't work. Also, the scope collides with the mount as you approach the azimuth (Not good! you might want to take the R.A. slow mo off btw, the metal gear will suit you fine)

Most importantly, it's heavy. The counterwight itself is probably 5+ kilos plus the rest of the mount+tripod makes it very difficult and awkward to carry to the car/to the back garden. All of these issues are less present in dobs and they might well be cheaper due to lower construction costs.

That's basically it. I enjoy the views the actual scope gives me. But the mount is toxic in my opinion.

I wouldn't be in a huge rush to replace it, though. It will still give you some nice (but modest) views to begin with. It's just not ideal.