Make an AstroCam (out of an old webcam Trust SpaceC@m 100/200 or other simular CCD webcam)
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					What's Astrophotography What is an astrocam Modify webcam Prime Focus	M E N U

What is astrophotography?

Astrophotography is a specialized type of photography that entails making photographs of astronomical objects in the sky such as the Moon, Sun, planets, stars, and deep sky objects such as star clusters and galaxies.
Before the development of photography, observations were gathered in the form of sketches made at the telescope. Modern-day electronic innovations, notably charge-coupled devices (CCDs), provide a more efficient light-gathering capability than photographic film as well as enabling information to be transferred to a computer for analysis and modification. However, CCD images are expensive and very small in size compared to photographic plates. CCDs are often used for individual objects, which may be very faint, within a narrow field of sky.
Astrophotography ranges from simple images of bright objects to very complex exposures designed to reveal objects that are too faint to observe with the naked eye. With only a few exceptions, almost all astrophotography employs time exposures since both film and digital cameras can accumulate and sum light photons over long periods of time. This is just one of many distinct aspects of astrophotography that sets it apart from conventional photography.

Astrophotography poses challenges that are distinct from normal photography, because most subjects are usually quite faint, and are often small in angular size. Effective astrophotography requires the use of many of the following techniques:

• Mounting the camera at the focal point of a large telescope
• Film emulsions with low light sensitivity or specialized CCD cameras
• Very long exposure times and/or multiple exposures (often more than 20 per image).
• Accurate tracking of the subject to compensate for the rotation of the Earth during the exposure
• Use of filters to reduce background fogging due to light pollution of the night sky. (wikipedia)

There are of course other ways to take astronomical photographs. One is simply to use your digital photocamera. Even with a basic model you can shoot your own impressive images. I use a simple Kodak EasyShare C330 (see here) mounted with a Universal Camera Adapter that is available for cameras with or without thread.
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What is a astrocam?

The CCD cameras was more a revolution than an simple evolution in the small world of amateur astronomy. CCD sensors (Charge Coupled Device) are very sensitive, and they reduce the time exposition in a dramatic way. By using long time exposures like only few minutes to see plenty of very faint luminous objects in deep sky observation. There are more advantages: one can see immediatly the image on the computer screen, numerical image processing is very easy and powerful often improving the image immensly.
You can build/modify your own webcam or you can buy them. There are several astrcams out there, like the StarShoot Solar System Color Imager II which has a four times greater resolution than its most older webcams - 1.3 megapixels to be exact. Or a ATK-16IC CCD-camera which allows changeble exposure times! All these can be used for prime focus photography with your telescope.

Prime Focus:

Camera lens must be removed. Telescope used like telephoto lens Field Angle = (Image Diameter ÷ Telescope Focal Length) x 57.3° For Dobsonian/Newtonian, use Paracorr to correct coma. Telescope focal length increases 15%. Optimum back focus distance (T-Ring shoulder to focal plane) is 56mm.

Let's go modify the webcam

This webcam/Astrocam is a homemade DIY Telescope Camera (astrocam) that could be built quite cheaply. Transforming a Trust SpaceCam is very simple to realize, and no knowledge in electronics is required. The main step in the Trust SpaceC@m modification consists in removing the integrated optical device.

Here’s one of the many ways a webcam can be converted to a camera for a telescope. This is kind of an old mod but it shows pretty well the kind of things you would need to do. There is no limit on the design on these cameras, everybody pretty much goes their own way. You can check the web for all kinds of links for designs and free software, but I have made a special kind of software just for this purpose called "SpaceSnap".

You must keep in mind that this modification will erase the company guarantee (if any is left, because these oldies do not) and is done at your own risk.

1. Get empty photo film boxes of 24x36 mm film. Those black ones with a gray top cover are very well adapted for this application, because they ideally fits in the web cam's flange, and the diameter of the box is 31,7 mm, so it fits perfectly in a 31,75 mm size's eyepiece mounting.
   
2. Cut off the bottom.
   One important thing and often forgotten: flock or paint the inside mat black!! Yes, you'll notice the inside of the canister shining big time! If you have some flocking paper...use it please. Else, roughen the inside with heavy grain sandpaper and then paint it with flat mat black paint.
   To make the astrocam holder (= film canister) I enforced it by using a 4cm piece of alu/iron tube the fits snugly inside the canister (or another plastic tube the has a slightly smaller diameter) and glued it. This isn't necessary but it does make the whole thing sturdier. If you do use a second tube to make it stronger then please do not forget to sand it down too and paint it flat mat black (or flock it). I painted the top/cover of the film canister too.
   
3. Do not throw away the top, instead drill/cut a hole large enough to allow the CCD opening to have an unlimitted view.
   
4. Open the webcam and remove the lens. Be careful around the CCD area. The black cover over the CCD-element is a IR (Infrared) blocker. If you are planning to shoot IR photo's only you need to remove it. The moon, and some planets can be usefully imaged using infra-red light. Webcams (with their built-in filter removed) are very sensitive to IR, and the narrower bandwidth (when compared with "normal" visible light) makes a sharp image easier to obtain.
   
5. Method A) We keep the Trust Webcam body:
   Because the Trust Spacecam 100/200 is somewhat rounded where the lens opening is we need to file down some of the plastic (around the opening) to get a flattened surface. This flattened surface will allow a larger area to firmly glue the top on (cover of the film canister).
   
   Method B) We use a new box to hold the webcam electronics. I have removed the blue lens holder to be able to use the webcam as a normal cam or to shoot images in non prime focus.
   
6. Use some sandpaper and roughen the top. Glue the top of the film box to the webcam (first use a strong glue and afterwards 'fill' the gaps up with to use of a glue-gun ). This will hold the canister that will function as an eyepiece holder.
   
7. Mount and close everything up and click the film canister on the top holder.
   
8. Your newly recovered astrocam is ready for use
   
9. The astrocam mounted on the SkyWatcher Newtonian telescope
10. 
    

Here is one and my very first photo took with my modified Trust webcam without ANY filtering, NO digital processing and NO other filters on the telescope, painfully as raw as could be, meaning it can not get any worse then this very first quick as-is shoot! Too much light for sure! It was mounted on my SkyWatcher SKP13065EQ2 (D130mm/F650mm) pointed at the moon in the middle of my city (and those darn city lights). Oh yes, at that time my Skywatcher telescope was not flocked nor did I use a dewcap.

Looks better now doesn't it? You need to experiment with the software, your telescope and with the settings of your webcam to get the best images. Practice makes art.

Much more can be found here:

look at my personal astronomical photographs on this site that I took with this modified webcam and with my Kodak EasyShare C330.

I also would like to recommend my freeware program SpaceSnap which can be used with any webcam/astrocam and has several imaging processing tools.

More about astrophotography here

Astrophotography, info about telescopes, tips & tricks, homemade scopes and lenses etc.
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