Planetary imaging with a webcam.


I use a Philips ToUcam 740K because it contains a CCD chip which is more sensitive than webcams with a CMOS chip although I have been told these CMOS webcams do perform very well.

The following are the programs that I use on a laptop running XP Home. All are freeware except K3CCDTools which you pay for after your trial period ends.


K3CCDTools from Peter Katreniak for capturing images/AVI's.

Registax from the Aberrator for aligning the images/AVI's

The Gimp for the final tweaking of the images.

WcCRTL By Martin Burri for controlling a webcam without continuously opening Video Capture\Video Source etc.

Hints

On

Stopping

The

Frame


Dropping

21st January,  2006

For the first time I had frames dropping while using K3CCDTools. This was quiet serious as it was dropping a frame every second,  sometimes 2 frames a second were dropped. It took me a while to find the solution but here is what I did to stop all the frames being dropped.

Checked in the BIOS and turned of the S.M.A.R.T technology.
Open the Device Manager and make sure Enable Write Caching on the Disk is ticked.
Shut down the Anit Virus software (I was not on the internet so this did not matter too much)
Shut down the Firewall (again this was not a problem as I was not on the internet.
Opened the Device Manager and made sure the DMA was checked to make sure the saving to disk was running at top speed.  Then Reboot the Laptop.
I have also found that Defraging the partition helps here too !

After doing all this I was able to capture like I normally do without the frame dropping.  I still don't understand why I had to go through all this as frame dropping had never been an issue before.


The sequence of events that I use for a nights capturing the planets are as follows.

Set up my 222mm f/7.2 telescope on the EQ5 mount at least an hour or two before usage to allow the mirrors to cool down to ambient temperature.
Polar align using the polar scope. This gets quite accurate with practice.
Plug in the handset and turn it on making sure that I have it set to North for northern hemisphere.


I don't use the C Cell batteries as I find they will only run for a couple of nights then die on you when you least want them too and it turns out to be very expensive. I now use a 240VAC to 6VDC converter plugged into the EQ5 handset. Be sure to check its polarity and that it is set to 6 VDC before plugging it into the handset and switching it on. I have made the fatal mistake of catching the voltage switch unknown to me and put 12 VDC through the handset. Believe me the handset doesn't like it at all. New motors and handset had to be ordered. Now I have put electrical tape over the slider switch to stop accidentally moving it.


Next step is to check the collimation of the primary and tweak it as necessary. I have found that when collimation looks good for visual use is not good enough for planetary imaging because of the high magnification used. Typically in the range of f/28 to f/40. I have used my Laser collimator which gets it very close to collimation, but if you move the focusing knob you will find that the laser beam will also move and not sit on the primaries centre any more. Here I note which one, either racking in or racking out gets me closest to the centre point of the primary so that when out under the stars I will go past focus and rack to focus remembering from earlier which one of the two got me closest to central primary position.


Time to get the laptop up and running. Start a star atlas program and turn on night vision mode. Then I lower the laptops screen brightness. Plug in the webcams USB plug and the parallel port plug even if I am not going to use it that session. Its amazing how many times I have gone to use the long exposure modification only to find I can't do long exposures. Then the penny drops ........ The parallel port is not plugged in.


Connect a cam


Now I start the capture software. In my case its K3CCDTools and WcCTRL. Tell WcCTRL to connect a cam and choose which camera your going to use.  Once started I tell K3CCDTools it to use the WDM driver in the Video Capture drop down menu and make sure the Preview is also ticked. It also pays to turn up the Gain to help in finding that star to help in focusing.

Fit the X4 Barlow lens into the eyepiece holder and then insert the webcam into the Barlow lens. This gives me an effective focal ratio of f/28.8 I some times pull the webcam out a little bit more there by increasing the focal ratio even more. By how much I am not sure but lets say around the f/36 mark.


Star spikes


Find a very bright star and defocus it so that you can see the shadow of the secondary mirror on screen. Notice where it is and how close it is to the centre of the primary. The closer to central point it is the sharper and more detail your images will have. Collimate as best you can. Now realign that star and focus until I have the 4 needle sharp spikes associated with the secondary mirrors spider vanes. If the spikes are single and needle sharp you know you are in focus. On the other hand if all you see is twin spikes associated with each of the spider vanes then you are not in focus.

When I have the focus just "so" I now check that the finder scope is set up to look at the same object. When the telescope and the finder scope are not matched perfectly its almost impossible to put the planet on the small CCD chip.



settings

Now to find that planet.

Which ever planet I plan on capturing I now place on the webcams CCD chip. Believe me this is easier said than done as the webcams chip is very small.
When the planet is being tracked by the telescope I turn my attention to the capturing software again. Using WcCTRL in the Primary Tab I set Gama 0, Gain 50%, Shutter 1/25 and FPS (frames per second) to 5 and I click the Freeze Colour Balance. If Freeze Colour Balance was ticked to start with I tick Auto colour for a few seconds until the software catches up then click Freeze colour Balance again. This stops the software from constantly changing the colours.



WcCTRL


On the Secondary Tab of WcCTRL make sure Colour Mode is ticked. Saturation is 100% and Cont is 0%. Next in K3CCDTools either click the tools icon at the top or click Options then come down to settings. Frame Rate is set to 5.00 fps. Enable capture time limit: here I tell the software how long to capture for. If its Jupiter I capture for around 90 seconds and no more because the Planet rotates very quickly (10 hours) and it will blur the final image. Saturn and Mars you can go longer because on Saturn there is not much detail that will blur and Mars rotates in just over 24 hours.


setting and WcCTRL



Directory is where I store the captured Avis. Finally I give the AVI a name and make sure the Incremental is ticked so that the name will have consecutive numbers after the name. Then click the Camera tab and make sure the SC Long Exposure Modified Camera is not ticked.

Now check to see what the image looks like on screen and adjust the settings until the image is just nice but slightly on the dark side. The reason for this is when you stack the images it will gain a little in brightness as well as detail. If the image is bright to start with as it is being captured then when stacked the image will be far too bright and all the detail will be washed out and you won't be able to do much with the image.


When I am happy with what I see on screen I tell the K3CCDTools to capture the AVI. After each AVI I alter the Gain settings a little on either side of the original settings and capture more Avis. The reason for this is bracketing either side of your original settings and then you stand more of a chance of hitting the right settings.


At the end of the nights captures you could end up with many Gigs of Avis. What I then do before I do anything else is Zip them up with WinZip. Astronomy Avis Zip up quite well. I have seen 15 Gigs Zip up into under 700 Megs. I then store these on a USB2 external harddrive. Also I write them to CDs and DVDs just incase the harddrive crashes.


When the weather plays up and stargazing is not happening because of rain or cloud (more than likely here in the UK) then I turn to processing the captured Avis. For this I turn to Registax.


I click select. Browse to the directory were I store the Avis and choose the first one. If you can't see the Avis then choose AVI file type from the drop down menu. When I have loaded the first AVI I normally go through it by hand to throw away the bad frames. This is done by clicking the Framelist on the bottom right. Use the up and down arrows and Space Bar to tick or untick the individual frames. When I have done this I then choose a box size from the list at the top that completely covers the planet then click in the centre of the planet. Here there are 2 choices. Either work Manually or Automatic. I choose to work manually as it gives you that
little bit more control over what is being done.


To start with you could go through the tutorial on Registax to help you get started. There is no right way or wrong way to capture and process images. Each amateur astrophotographer has their own technique.


Choose the Method of quality. For the planets I use Gradient and the Lowest quality I set at 70%. Next click Align then fetch a cup of tea. Next click Limit. You can click several options here including resizing using either of the Resampling or Drizzling and the Factor. Otherwise click Optimise then sit back and drink the tea you just fetched. When the program has optimised all the frames its time to stack them. Click the Stack tab again here you can make use of any and all the options but here I normally click stack. After the images have been stacked its time to adjust the image with the Wavelets. Move the sliders to the right and watch the image. With careful use you will be able to bring out the faint detail in the image. Move the sliders a little too much and you can add processing artifacts which is not what is wanted. Down the right hand side of the screen there are more tabs that can be used to enhance your image. The art of adjusting the image is to make the final image look as though it has not been processed at all.


The final stage is to save the image out. Once this has been done you can now load the image into your favourite graphics image package. Here I use The Gimp on my desktop PC because I have found that the LCD screen on my laptop makes all the images very bright. One other thing I have noticed is that CRT screens tend to be better for graphics work as they tend to show more detail. This last point is a personal choice.


Getting your ToUcam to work under Windows 7

Having had my laptop break down and the insurance company tell me that because the laptop was too old I had to have another laptop for astronomy.   So instead of a single core I opted for a dual core laptop.  Try as I might to get hold of a laptop that would have XP on it I could not find one.  So Vista it had to be,  only to find out that a few weeks later most of the laptops had the newer Windows 7 on them and this was supposed to be the next best thing to sliced bread.    
I downloaded the trial copy of Windows 7 64 bit but this gave me a lot of problems for my astronomy cameras so I then downloaded the 32 bit version and installed it on my new EMachines G720 and it found every part of my hard ware without any prompting from me.  Its quicker than Vista too.

Well try and get your ToUCam to work under Vista was bad enough but you could do it.  I used this webpage to get my ToUcam 740K to work under Vista.
http://www.azcendant.com/VistaToUcamInstall.htm
Try the same thing under Windows 7 and it will give you a lot of heart ache.   I have been trying to get it to work for the past 5 days when I found the answer.
Using the information for Vista and getting the Toucam to work I tried this method and it worked.   Here is what I did.

Put all the files for getting the ToUCam to work under Vista in a directory.

Now plug in the webcam and let Windows 7 do its thing and load the drivers.  After a while it comes back and tells you that there was a problem.
Now open the Control Manager/System and Security/System/Device Manager   Under the Universal Serial Bus controller you should see your Philips webcam as a Philips Composite USB Device,   but look above and you should see an unkown device with the yellow warning icon.  

Double click this and then go to the update driver.  This opened a dialog box and I chose the Driver tab.  Then Update Driver,   this opened another dialog box from which I chose "Let me pick from the list of device drivers on my computer".   Another dialog box opened up and I clicked the Have Disk.  Another dialog box opened and here I chose Browse then found the directory where I had stored all the XP/Vista/Windows 7 ToUCam files and clicked on  several of the .inf files there and the only one that worked was the Camcom20.inf.   After a short while Windows 7 complains that the driver is not signed,  I clicked install anyway.

After  a little while the computer said the drivers were installed.  I closed all the boxs and started up xwAstroCapture and found that my ToUcam was working just fine.
Again I looked in the Device Manager and now I have 3 Philips entries.  The Philips Composite USB Device under the USB,  I have the Philip ToUcam Pro Camera; Audio(Microphone) and under Imaging devices I have the Philips ToUcam Pro Camera; Video.

After a reboot I found that the camera worked just fine.   I make no gaurantees that this will work for you but this worked for me.

Hope you find this page helpful.