SKY-WATCHER Skyliner 200P User manual

Planet Astrophotography with a Dobsonian Manual
Telescope
Thanks for downloading my guide to planet astrophotography with a Dobsonian manual telescope.
With this guide I hope to explain, how to end up with an image you will be proud of. However,
please don t expect to end up with a super image the first time, it will take a lot of practice, patience
and clear skies.
Why am I doing this tutorial? Basically help fellow Dobsonian users with the techniques I have
perfected in my quest to end up with a worthy image.
Contents
1. Equipment
2. Software
3. Setting Up
4. Sharpcap Capturing
5. VirtualDub Editing
6. Castrator Editing
7. AutoStakkert Editing
8. RegiStax Editing
9. Gimp/Photoshop Editing
10. End Result
1. Equipment
Dobsonian Telescope with Finderscope
This my Skywatcher Skyliner 200P. You can use
any Dobsonian you like as long as it good
quality. For this tutorial I will be using the
finderscope, however if you have a Telrad or
similar finder you can use that.

Barlow Lens
You will need a barlow of reasonable
quality, as this will affect the results.
It is best to start with a barlow of 2x
magnification, as it will be easier to locate the
planet on the laptop.
Converted Web Camera
This is a Philips SPC900NC web camera. It has
been modified by removing the original lens and
been replaced with 1.25” nozzle adapter with an
IR filter screwed on. This particular webcam has
been discontinued and is fetching high prices on
online auction sites. However, there are
alternatives available for a reasonable price;
such as the Xbox and the Microsoft Cinema HD
the latter being a bit more tricky to modify.
You can find tutorials online, that explain how
to modify these three webcams.
Laptop
Not much to say about this, as long as you have
plenty of memory, it is not too slow and a
power source if the battery is poor. Make sure
all the drivers for the webcam are installed.

2. Software
All the software required, is available online for FREE. So click on the links provided and
download the latest versions. Even though they are free, some of the websites do accept donations,
if you wish to give them a few silvers for all their hard work in producing these excellent programs
– go ahead.
There are other programs out there which are similar to the ones listed below. So if you are happy
using others that you use already, then feel free to. I use these as I m most comfortable with and
happy with the results I achieve from them.
Sharpcap http://www.sharpcap.co.uk/
VirtualDub http://www.virtualdub.org/
Castrator http://www.astrokraai.nl/castrator.php
AutoStakkert!2 http://www.autostakkert.com/
RegiStax 6 http://www.astronomie.be/registax/
Gimp http://www.gimp.org/ or Adobe Photoshop CS (not free)
3. Setting Up
Before you can start capturing videos of your chosen planet, you will need to go through a few
checks. Firstly, make sure the finderscope is aligned with the main scope and secondly that the
scope is collimated. If you are unsure how to do these, you can refer to your telescope user manual,
or there is plenty of instructions around online.
On your chosen night for capturing our solar system neighbours, you will need to take the telescope
outside an hour before you intend to use it. This so the whole thing can reach ambient temperature,
thus avoiding any distorted images.
Whilst the telescope is cooling down, you can gather everything you need for the night. You will
need a stable stand or table to place the laptop on, which will need to be positioned next to the
telescope. Whilst still inside, turn on the laptop, so that if it needs to do any virus scans or Windows
updates etc. they will be finished by the time you want to start capturing. Have the webcam and
barlow ready to hand. Dig out some gloves, hat, jumpers and coat especially if it s a particularly
cold evening.

On your laptop, go to wherever the video documents are kept and create a new file, for example,
this tutorial so I shall be capturing Jupiter, so I will rename the file - Jupiter 2Feb13
When the hour has passed you can then, take the laptop, barlow and webcam outside. Attach the
barlow lens into the focuser tube and the webcam into that and plug into the laptop. Now you can
begin to capture.
4. Sharpcap Capturing
There are tutorials on how to use Sharpcap on Youtube so I will not be going into a great detail
regarding settings for this program. These guides can explain in a lot more detail then I can in
this written tutorial, I suggest checking these out before progressing further.
1. Open Sharpcap and select the camera from the cameras menu.
2. Select the set capture file from the file menu, this the folder you created earlier, mine was -
Jupiter 2Feb13. This is where all the saved videos will be kept.

3. Select your capturing settings from the drop down menu and load this.
4. We want to find the planet easily on the Sharpcap screen so we need to slide the exposure setting
to the lowest figure. This will make the planet a white blob, that will make it easier to find and to
focus too.
5. Providing your finderscope is aligned to the scope as perfect as you could earlier, the following
should cause not too much trouble. Find the planet in the finderscope and centre it in the cross-
hairs.

6. With one hand on the telescope focuser, the other on the scope and your eyes on the laptop,
move the scope very, very slightly left, right, up, down etc. till you see what resembles a white disc.
Once you found it adjust the focus till its nice and sharp on the screen.
Did you see which direction the planet was drifting across the laptop screen? We want the planet to
drift from left-to-right on the screen.

7. To do this, loosen the webcam in the barlow lens and get the planet visible on the screen again,
let go of the scope and turn the webcam until the planet drifts left-to-right and re-tighten the
webcam in the barlow lens.
8. Get the planet onto the laptop screen and look through the finderscope and make a mental note of
where the planet is positioned. This is the critical point you want for the arc of the planet to drift
into. For example as detailed below.

9. The next bit is really trial and error until you find the correct path. Looking through the
finderscope, point the planet at the critical point then move the telescope so the planet is slightly
right and up from the critical point. Let go of the telescope and look through the finderscope and
watch the planet drift towards the critical point, once it reaches the critical point, take a look at the
laptop screen. Does the planet appear? If not, you will have adjust the drift path so it hits the critical
point dead on. This will take a long time to master, it took me many evenings just to get the hang of
it – some evenings even now, it just doesn t happen.
10. Set the planet drifting across your screen, and quickly adjust the Sharpcap settings. Reduce the
exposure so you can see planet details and adjust the other settings if need be, till you are happy
with the on screen image. You may need to drift a few more times till the settings are complete.
11. Click on the start capture button and use these settings when the window pops up. Don t press
start just yet.
12. Set your drift path and once the planet appears on the screen, hit start. MAKE SURE THE
PLANET IS 100% VISIBLE, EXCEPT WHEN IT IS ENTERING AND EXITING THE SCREEN.
Once the planet leaves the screen on the right hand side, click stop capture. Repeat this process and
aim to capture at least 15 good videos. Don t touch the telescope whilst you are capturing.
When this is done, bring all the kit back inside.

5. VirtualDub Editing
1. Open up the VirtualDub software and click file, then click open ideo file and find the video
folder that you created earlier, where all the Sharpcap videos are stored and click on that.
2. Double click the first video - that will open up in the VirtualDub screen.

3. Next, you need to add on the second video to the back end of the first. To do this, click on file
and click Append AVI Segment.
4. This will bring up the video folder again, so double click on the next video and this will be added
to VirtualDub. Repeat this for all the remaining Sharpcap videos.
Once you have added all the Sharpcap videos to VirtualDub, you can now begin to edit them. This
is so you can remove frames where the planet is not 100% visible on the screen and any bad ones,
from poor seeing, cloud etc.
At the bottom of the screen you will see a line stretching right across, this is all the frames from the
videos you have loaded up. Underneath, are the function keys.