Category : How To

Control Your Observatory PC Remotely

Since the weather has been very cold lately I thought about putting in a warm type of partition in the observatory to keep me warm whilst imaging, but I knew there was a way to remotely control your PC, as a lot of people do it, now I know how and it did not cost me a penny.

There are services on the web who will charge you a fee so you can access your PC from anywhere – such as GoToMyPC etc. But there are other ways as well.

The first thing I looked at was using the program “LogMeIn Free” which is a free program you install on both machines, there is also the free VNC servers, such as TightVNC or UltraVNC.

But I found that Microsoft Windows has ‘Remote Desktop Connection’ and it’s really easy to set up.

The only downside is that ‘Remote Desktop Connection’ on the host computer (the one you are trying to connect to) must be a XP Professional, Vista Business, Vista Ultimate, Windows 7 Professional or Windows 7 Ultimate edition.

You can use any Windows version on the client machine (the remote one that you are using). I even connect to my observatory PC via my Samsung Netbook which runs Windows 7 Starter edition!

If you have the correct version of Windows on both the remote PC and the local control PC or laptop. All you need to do is (this is what I did on XP Pro):

1. Create a user account on the remote PC and give it a password
2. On the remote PC right click on My Computer on the desktop and go to ‘Properties’ and then choose the ‘Remote’ tab. Then make sure the ‘Allow users to remotely connect to this PC’ is checked.
3. Now go to your other PC and go to ‘Programs -> Accessories -> Remote Desktop Connection’, now enter your IP address in the computer field and enter the username you set up on your remote PC.
4. If you now click ‘Connect’ and everything is setup properly the remote PC desktop will appear on your screen.

I know there is nothing like being next to the telescope to sort things out, but in the future if it’s doing a long imaging run, I may leave the observatory and just check up on the imaging run via my laptop in the more comfortable and warmer house.

How To Make a Digital Camera Solar Filter

After buying my A4 sheet of Baader solar filter paper I have been making all sorts of filters.

The last of which has been a solar filter for my Canon 450D digital SLR camera, but my method of construction will work for any SLR camera, as its really simple.

I started with a flower shaped lens hood. I bought the lens hood a while back cheaply from someone in China on eBay, I think it only cost a few pounds.

DSLR Flower Shaped Lens Hood

I then cut out two circular pieces of cardboard to put either side of the circular solar filter paper. I cut them to fit just inside the lens hood. I then cut out the circular solar paper.

Cutting the solar paper can be a pain, it is best to cut the filter paper between two other sheets of paper and then remember that there is a really thin piece of transparent film on the solar paper which needs to be removed once the shape has been cut out.

I previously used scissors to cut out the solar paper, but for this attempt I used a very sharp scalpel.

I then placed squares of double sided sellotape around the cardboard circles, in order to hold the cardboard onto the solar paper, be careful not to get fingerprints on the solar paper.

Then place the filter into the lens hood and I just used standard sellotape to tape the cardboard part of the filter to the plastic sides of the lens hood.

Homemade SLR Digital Camera Solar Filter

I then screwed on my new solar filter and took an image, usually I would take video of the sun with a CCD camera and then stack the results to get a final image. This time I took the sun image below with my DSLR at a setting of 1/4000th second at ISO100 with my 300mm lens.

I then played about a little with the brightness and contrast and colour levels with a photo editor program.

Sun with homemade solar filter on a DSLR camera

You can just make out two sunspots (1080) on the top right handside.

How To Make a Diffraction Spike Mask

I have seen these pleasing images where the stars have spikes coming out of them, most notably on the pleiades (seven sisters) images.

I want to be able to get these in my images as well, and now I have found out how to get them by using a diffraction mask on my LX200.

Today I decided to make some by using some plywood left over from my observatory build.

Here is a list of the raw materials I used:

  1. Plywood
  2. 8x Screws
  3. Spare length of wood (24″)
  4. 2ft Washing Line
  5. Black Wood Paint (optional)

Cutting out the wrong size maskCutting the right size maskI began by taking the LX200 telescope metal cover and drawing a circle around that thinking that would be just right, although after then cutting it out with a jigsaw I found out that it was far too big.

So I went back and just measured the diameter of the telescope and then found an old style school compass to draw the circle on the wood.

I then cut out the circle using my electric jigsaw.

I then cut down the piece of plywood into one manageable piece, with about 1.5 inches to spare around the sides of the hole.

Adding all side woodNext I cut four lengths of some rough timber I had spare which was used on a previous gardening job. You don’t have to add this part, but I did because I wanted the mask to sit back from the front of the telescope, plus these pieces of wood at every side allowed me to make the mask fit snugly around the scope.

I then screwed the pieces of wood with 2 screws on each of the 4 pieces of wood, although I only used 1 screw on 2 pieces of wood so that I could still move the pieces of wood once the mask was on the telescope to fit them even more snugly against the scope.

Now go back to the telescope and place the mask on the front and mark on the blocks of wood you have just attached to the mask where the screws are on the LX200. You should have a screw in each of the four corners of the cover that holds the main front glass in place on the front of the telescope.

Doing this will mean that your washing line crosshairs will be exactly in the centre on the mask.

Adding washing line crosshairsI then cut 2 feet of washing line from our main home washing line, although you could go out and buy this. I then cut the 2 foot piece into 2 x 1ft pieces.  I tied a knot at one end of each pieces of the washing line.

Now drill holes with an electric drill all the way through the blocks of woods at the location you previously placed your telescope screw marks.

Thread the washing line through one of the holes. To hold the other end of the washing line in place I could have used wing nuts or bolts, but I did not have any, so I used a piece of dowelling, and hammered this into the holes to hold the washing line in place.

Diffraction spike mask completed unpaintedDiffraction spike mask on lx200I then tried the mask on the LX200 to make sure the washing line crosshairs were exactly centered.

On my first attempt they were not so I had to re-drill some more holes and re-thread the washing line, then they were perfect.

Here is the unpainted mask on my 10″ LX200 telescope.

I then painted the mask by using some black wood paint from Wilkinsons.

Hopefully I will now get the chance to try the diffraction spike mask out and see what images I get.

Find Comet Lulin in Stellarium

I am starting to get quite excited about having Comet Lulin to image, so if your like me and want to know how to plan your observing or astrophotography then you’ll need to know how to find Comet Lullin in the sky.

I began using an old version of Starry Night Pro, but that would not show me the comet. So I decided to install Stellarium again on my laptop. By default Comet Lulin is also not in Steallarium, but I did find a way to map it into Stellarium.

Install Stellarium, if you have not already

Located the ssystem.ini file in the data folder where you installed Stellarium

Edit the file and place the following text at the end of the file:

[Lulin]
name = Lulin
parent = Sun
radius = 1000
oblateness = 0.0
halo = true
color = 1.0,1.0,1.0
tex_halo = star16x16.png
tex_map = nomap.png
coord_func = comet_orbit
orbit_TimeAtPericenter = 2454842.1414
orbit_PericenterDistance = 1.212289
orbit_Eccentricity = 0.999987
orbit_ArgOfPericenter = 136.8614
orbit_AscendingNode = 338.5353
orbit_Inclination = 178.3730
lighting = false
albedo = 1
sidereal_period =

Then save the file and re-start Stellarium

Use the search facility in Stellarium to locate the Comet Lulin

Lulin is also in the Meade Autostar database as C/2007 N3 Lulin, so if you are outside already it should GoTo it, otherwise just connect your telescope to a computer and do an update within the Autostar program.

How to attach a Camcorder to a Telescope

After buying my Panasonic SD9 HD camcorder I was thinking if it could be used for astronomy. I wondered if I would have to take a trip to my local astronomy store to see if they had anything in stock to allow me to connect my camcorder to my LX200 telescope.

In the same way you use a Ring on an SLR camera with a T mount I thought there may be the same thing for my camcorder, I definitely did not want one of the metal contraptions that are used to attach compact digital cameras to telescopes (more commonly known as an Ultra Afocal Digital Camera Support).

37mm T-mount adaptor to attach camcorder to telescopeThe Panasonic SD9 camcorder has a 37mm thread. Luckily I took a chance and ordered an adaptor, and I am so happy to say it worked. It is a 37mm adaptor to a T-mount. Which means that you can connect it to the Meade T-adaptor or any other connections such as a focal reducer and then onto the telescope.

Camcorder with T-mount 37mm adaptor attachedThe SD9 camcorder allows you to screw in the 37mm adaptor directly to the front of the camcorder, as shown in this accompanying image, although there is only space for the adaptor to be threaded on for about two turns.

Although there is another way to connect the adaptor to the camcorder.

Camcorder Lens Cover Removed and Tmount adaptor attached directlyIf you unscrew the silver lens cover there is a deeper 37mm thread depth available underneath it, and the adaptor can be attached to this, as shown in the image. 

The only downside to doing this is that you must be careful to not damage the camcorder lens as there is no protection for it. 

With there being a chance of scratching the lens whilst out in the dark fumbling about, I have ordered an UV 37mm screw-in lens for the camcorder in order to protect the camcorders lens.

Now I just need to try and do some videoing with the camcorder attached to the telescope to see what I get.

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