Jupiter – Saturn – The Moon

Jupiter, Saturn and the Moon seen through the Celestron NexStar 130 SLT and using the logitech quickcam 3000 pro.

Tutorial on how to make a cheap astrophotography camera for your NexStar 130

This is a tutorial on how to make a cheap astrophotography camera for your NexStar 130 SLT out of an old webcam – in this case the logitech quickcam pro 3000 that I wasn’t using anymore anyway.  At the end of the tutorial I show the  results of my initial attempts to record AVIs of Jupiter, Saturn and the Moon and a final image of each after a bit of image processing with this fairly cheap way of doing astrophotography.

As mentioned in the video you need the following

When you have set up your telescope with your camera and a notebook you can experiment with the camera settings through the software that goes along with the camera.

Registax link

http://www.astronomie.be/registax/

How to use registax

http://www.youtube.com/watch?v=ALqQfExMRBA

Hope you liked it. Clear skies.

Advice on how to secure proper GoTo alignment of the NexStar 130 slt

Having had a bit of trouble getting my NexStar 130 slt aligned properly (it does almost always say aligned correctly) and where it afterwards goes correctly to new stars, planets or other deep sky objects I got some great advice on how to secure the best alignment and goto experience on the AstronomyForum. Here is the advice I got:

  • Do not extend the tripod legs more than about 25%
  • Take the time to ensure the mount is level, I discovered the bubble in my tripod wasn’t true and now use a proper spirit level. Can’t emphasise this one enough
  • Tighten the bolts that are used to attach the upper tripod leg sockets to the tripod head, to minimise tripod flexure. From the factory this was not done properly
  • Always have the accessory tray locked into place
  • Use 2 star alignment and do not use a planet as an alignment star
  • Centre the alignment stars first with a low power eyepiece (e.g. 25mm) and then again with a high power one (e.g. 9mm). Defocus the alignment stars into a big donut shaped blob that almost fills the entire FOV when centering.
  • Never use any stars higher then 75 degrees NOR lower then 30 degrees for your first 2 alignment stars no matter what method of alignment you are using.. And seperate them by close to 90 degrees. The 3rd star (it is NOT an alignment star it is only a conformation star) when doing a SkyAlign alignment can be placed anywhere between the first two to form a triangle
  • Most users use one of the 2 TWO star alignments and always use Polaris as the first star
  • Make sure that GPS coordinates and the time is set correctly

It has helped me getting better alignment than before. But it is also my experience that the GoTo functionality after an hour or two gets worse eventhough the above actions have been taken. But I also think that this is acceptable price vs. quality of this scope considered.

 

Collimator for your NexStar 130 slt

 

Collimation of your reflector telescope is very important as this will secure crisp images of what you are looking at. The NexStar 130 slt is collimated from the factory when you get it. But this does not mean that it doesn’t need collimation straight away – mine did. This was due to the transport I am sure. But it was not like I couldn’t use it straight away. So generally I would say that you need a collimator over time.

Basically what collimation does is securing that the secondary and primary mirrors are correctly aligned against eachother and the focuser in which you have your eyepiece. This will secure good images.

In order to do the collimation you need a collimator. You can get collimators from everything from 20£ and up. My collimator is from Seben and is one of the cheapest ones out there. It did the job perfectly.

I made a youtube tutorial on collimating the NexStar 130 slt. The procedure is quite easy and doesn’t take more than 10 minutes with the right tools.

Powersupply for the NexStar 130 slt

Eventhough the possibility to use batteries is a big plus I found that I had to buy a power supply. If you can use your scope in your garden or somewhere else, where you can drag a cable I think it is a very good idea to have an external power supply. Nothing is more anoying if you finally have clear skies and you have no batteries left. Many electronic devices need AA batteries and suddenly you are out of stock :-(

The second reason is of course the cost of batteries. It can get rather expensive to change these batteries or buying the good rechargeable ones.

The third reason is the fact that if you want to experiment with astrophotography – as I am – you need more power to drive the motor.

Universal power supply

I went out and bought a universal power supply with 8 different DC tips. For the scope it needs a 12 volts, at least 2.5 amps and a DC tip of 2.5/5.5 mm (inner/outer measurement). That one cost me around 44 $/27 £. It works nicely.

Now for some bitter experiences of a newbie. I thought I was clever and used some plastic strips to firmly secure the power supply and cord to the tripod of the NexStar 130 slt. Well it looked very nicely. When I used it the first time and I used the GoTo and motor to find a particular star, it of course ripped out the powercord of the power supply as it turned around in the motor. So make sure that you fasten the power supply to fork arm instead of a tripod leg :-) And also keep your batteries in the battery compartment eventhough you use a power supply – you might get your power cord ript out of the extender that you use as you slew around with your NexStar 130 slt. If that happens and you loose power you have to do all the alignment once more :-( Also a bitter experience :-)

Batteries for the NexStar 130 slt

Batteries

You will need 8 AA batteries for the scope to function. I have read several posts on the internet whether the batteries can be rearchageable or not. The notion is that non-rechargeable are better but if you use rechargeable batteries they must be 2500 mAH or above. I use normal Duracel batteries which I find good and longer lasting in general.

duracellAA

That the NexStar 130 slt can use batteries to drive its motor and handcontrol is a big plus. The light weight and not too big a size of this scope means that you can take the scope anywhere to find a particular dark place to look at the stars. And you can just bring extra batteries, so you do not run out of power.

The batteries will last everything from a few hours up to 8 (so I hear).

Must have accessories for the NexStar 130 slt

Soon after buying my NexStar 130 slt I found out that certain accessories are necessary or must haves. Certainly for me that is. When I write “must haves” this is of course subjectivily but I think the reasons are well thought through. And I will try to explain why below – and I am going to prioritize the different items.

So money wise if you believe that the money spent on the 130 slt itself was that…think again :-) I think you should set aside another 200 $/125 £/1100 DKK. Having looked at different accessories and pricelevels I have to admit that I am a newbie/beginner, who is not going to spend a fortune on the different accessories, but I am paying enough to get products that are not completely waste of money (I hope). It is of course up to you how much you want to spend and which individual accessories you find the best. What I tend to do is to read customer reviews or reviews done by more professional guys – as I did with the NexStar 130 slt.

So here a few things that could be a good idea/you need:

If you plan to do a bit of astro imaging you will need other accessories as well. I will do a separate post on that later.

 

Assembly of the Celestron NexStar 130 slt

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In November I bought myself my beginner scope after intense reading on the big world wide web. And trust me …. I didn’t know anything from the start. So I am a true beginner.

The choice fell on the Celestron NexStar 130 slt reflector scope. Bought it on amazon.co.uk. Fast and secure delivery, can be recommended – only bad thing is that the prize is somewhat higher than in the united states, well must be down to taxes…hmmm.

Specs

Well back to the scope. The NexStar 130 slt’s most important specs are in my opinion mentioned below. Remember that this is a reflector scope – this will mean that what you will see through your eyepiece will be upside down. Looking at stars, planets and deep space objects thats not a problem, but if you plan to use it looking at things on earth, you should buy another scope :-)

Aperture:130 mm (5.12 in)
Focal Length:650 mm (25.59 in)
Focal Ratio:5
Finderscope:StarPointer
Mount:Motorized Altazimuth
Eyepiece 1:25 mm (0.98 in)
Magnification 1:26 x
Eyepiece 2:9 mm (0.35 in)
Magnification 2:72 x
Computer Hand Control:Fully Computerized / Flash Upgradeable
Alignment Procedures:SkyAlign, Auto 2-Star Align, 1-Star Align, 2-Star Align, Solar System Align

The NexStar 130 slt is with its focal length of 650 mm not the largest scope available and therefore you will probably be able to find a spot for it in the home with having your spouse on your back :-)

Setup

My first impression was that it was a very easy setup. Celestron has made it easy for us newbies, and I like that. 20-30 minutes and it was ready. You don’t really need any tools to put it together, but I would recommend you to tighten some of the screws. It can be recommended to have a look at the official assemply video from Celestron. What you have to note that you do not need to assemble the motor with the tripod as it is shown on the video. Clearly Celestron has used the same videobits on several scope – you will notice that there is another scope on the floor when the tripod is assembled :-) You do need to tighten the screw below the motor to secure proper alignment – I didn’t figure out straight away.

Collimation

The NexStar 130 slt is collimated from the factory (means that the mirrors are aligned correctly when looking through the scopes focuser) but after a little while I could see that it seemed a bit out of collimation. The scope did need to travel a distance to my home and I guess it is easy for the scope and mirrors to get thrown “a bit around” in the I will go into collimation of this scope in this post.

Handcontrol

Setting up the handcontrol is easy. I suggest that you find your longitude and latitude of the place where you are. You can find the nearest large city – but in my case thats over 300 km away and that will not give the best alignment. If you have a smartphone there are many apps that will tell you your correct longitude and latitude. For some Europeans you have to note that the date is set for Month/Date/Year. But that is a minor issue. You have to set your timezone from standard GMT – if you don’t know your timezone you can have a look in the manual – but also find it on the web.

Starpointer finderscope

The starpointer finderscope I find very useful. First you have to align it. Remember to take off the small piece of plastic in order to get the battery connected. Turn on the small red light in the pointer scope. Find a small spot to look at maybe 200 metres away – both through the finderscope and the eyepiece – use the 25 mm eyepiece. Align the finderscope so you a looking at the exact same spot. When you think it is centered reduce the finderscopes red dots light level and change to the 9 mm eyepiece and again make sure both are pointing at the same spot. And then it is aligned.

SkyAlign and GoTo

The SkyAlign and GoTo functionalities will help me getting started quickly, which is good. But I have to say that after owning the NexStar 130 slt for little over a month now, I have had my trouble with the goto functionality. Even with an alignment – skyalign or auto two star – my scope does not get the stars into the field of view – even with the lowest power eyepieces. I have to slew a bit before finding the star/planet and use the starpointer finderscope to do it. Thats why I find the star pointer very useful – not only under initial alignment. Will also go into that problem in a later post and I need to figure out if I can succeed doing anything about it myself or I need to send it back. Generally from reading in forums and on the internet in general you can do a number of things to secure a better alignment.

The cons of this NexStar 130 slt is clearly its tripod. Since the NexStar 130 slt is quite light in itself and also the tripod – the scopes steadiness is not as good as you could have wished for when there is a bit of wind and if you touch the scope too much during star gazing. But the weight is also its advantage, it is easy to carry around, so when you know this it is okay. And I have yet to go out to use the scope when it is very windy, so…

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