Astronomy

CCD CookBook CB245

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First of all my electronics knowledge is little or none. Sure I’ve had to learn a bit in the process of putting this thing together but I still consider myself a complete newbie when it comes to reading a wiring diagram or even figuring out how to wire 2 transformers together. If you fit this description this is not exactly an easy project but if you are patient and are willing to learn, adapt, and implement modifications to suit your needs it is an immensely enjoyable and ‘doable’ project.

Berry, Kanto, and Munger have put together an incredibly simplified and unbelievably robust project. My list of boo-boo’s in building this have been long and severe but somehow its kept on ticking and is finally ready to take some pics. This thing surviving my building it is an achievement in itself! ;o)

Also keep in mind that it is not an elegant solution. There are wires running everywhere, water cooling is a pain, and every once in a while something will probably stop working, forcing you to drag out the Cookbook, multimeter, and the soldering iron and do some detective work. If you want something you can bang on the back of your scope to take pictures and not have to worry about anything else get an ST4 or a Starlight or something. But if you’re a tinkerer, and if you want to learn not only about how to take pictures but also about how a CCD works, and especially if you’re on a budget this project is a whole lot more fun…

Besides, the finished product is yours. By that I mean, (good or bad), there’s not another one out there exactly like it.

And never forget help is always available on the mailing list. The people on this list have been incredibly patient and completely indispensable in helping me put this thing together. (Thanks guys and gals!) You can subscribe to the mailing list on the AstroArchive web page and its called the “Homebuilt CCD” list.

Well now that I’ve gotten off of my soapbox let me tell you about how I’ve built this thing.

The power supply and interface are housed in an old external SCSI drive bay. There was plenty of space for everything and I decided to leave the SCSI power supply in (board at the top) to feed the Peltier off of the 5v it provides. I wired everything to the same AC input and switch and also used the SCSI power supply to power a fan, led’s, etc.

Next down you can see a couple of 12v/500ma transformers. I had to opt for this solution because I simply could not track down a 15v/500ma supply here in Portugal. Silly huh? Anyway this setup gives me about 17v which is within spec and so far has been working great.

The bridge and 4700uF capacitors have been glued with a glue gun to the back of the box.At the bottom you can see the interface board and the heat sinks which barely fit.

Here is the closed box. From the left is the connection for the Peltier from the SCSI supply, then the fuse, power led, the signal shield jack, and 2 female DB25 connectors for the camera head and computer… (have to label those!)

Surprisingly I’m getting a very clean image even with everything stuffed into the same box. From what I read on the CB list I was expecting to get of lot of interference from the power supplies sitting next to the interface board. On the first night out I did 2 min integration’s and got very clean images none the less. Lucky me?

For the camera head I didn’t deviate at all from what’s in the CookBook. I tried some wacky ideas that went very badly and quickly decided to stop trying to be a smart ass and follow the instructions provided. For the newbies: Boy are you going to have fun with this part! Little tip: look for 16 pin ribbon cable connectors like the ones used for connecting IDE drives. Long ago the 16 pin ones were used to connect joysticks but I’m sure they’re still pretty easy to find. The plastic connector can be easily trimmed down to fit in the opening on the camera head and epoxied into place. Worked for me!

“First light” was on the 3rd of October, 2000 at 00:56UT with the camera head on the table and a 50mm Canon lens on top of it. I taped a Kodak film box top to the ceiling and hoped for the best…

Check out my CB245 gallery for images taken with this camera:
http://astroturtle.com/imaging/

I’d like to end this by leaving some links for would be CB245’ers:

Richard Berry’s CookBook Home Page
http://www.wvi.com/~rberry/cookbook/cookbook.htm


Win245 CookBook control software by Tybee Evans
http://www.intricate-ms.com


Lunar Eclipse – Portugal January, 2000

If you’ve enjoyed these tips and are in the market for electronics or photo gear, using these links to buy from TigerDirect or Amazon.com or alternatively using the PayPal Donate button to make a small contribution helps me keep this site going. Thanks!

I seriously started to doubt my sanity when the alarm clock went off at 2:45am. I found myself pulling on layer after layer of clothing before dragging my tired carcass outside to join the telescope in the crystal clear 4ΒΊC January weather. The moon looks like countless other full moons I’ve seen before. Maybe a little brighter than usual, but maybe that’s just my imagination.

I was seriously starting to doubt that I’d got the right day, when the show finally started. “Looks like somebody’s taken a bite out of the moon”, I said and smiled to myself. Time to get to those pictures! In between pictures I took occasional looks through my binoculars, but what really fascinated me was the environment.The crisp shadows were slowly dissolving, and the stars were beginning to show! A few times I couldn’t help removing the camera and looking at M42, or a cluster or two. Don’t get much chance for that during a full moon!

Totality finally arrived about 4:30am. Dark red, beautiful. So dark at one point that I had some trouble framing the moon in the camera. Time for a blanket, some coffee and to pop in another roll of film! 10 minuets later, bundled up and sipping from a thermos I crashed on a deck chair to enjoy the show.

I was lucky enough to catch 2 “shooting stars” while I tried to stay awake for the second half. Suddenly, there it was. A sliver of light so bright it made the moon look oval. 5:20am and I know I’m not going to be worth a damn tomorrow, but right now that really doesn’t matter. Back to the camera. I gotta get some pictures for the sleepy heads!

Turtle! 22/01/2000

Click on an image to see a larger version.
Some info on the pics: 2 rolls of 24 exposure Kodak Gold 400ASA film shot with a Canon AE-1. Exposures during partial were between 125th/s and 15th/s. 4 to 10 second exposures during totality. All were taken at prime focus on my LX50 with Meade’s Variable Tele-Extender. 21 descent pictures out of 48 exposures. Better than I expected! πŸ™‚
Animated GIF:
From the images above I was able to put together this rather jumpy animated gif of the eclipse using an aincient copy of MS GIF Animator… (Now there’s a piece of software that never in my life thought I was going to use!)
Added 24/03/00: Just got the Kodak PhotoCD back from the photo lab, and wow what a difference!!! Click on the thumbnails below for 640×480 at 256 colour versions. They are all taken from the same negative.
Scanned with and Epson FilmScan 200 and edited in PhotoShop. I sharpened the image, and darkened the background.
Original Kodak PhotoCD image.
Kodak PhotoCD edited in PhotoShop. Specks and scratches removed, light unsharp filter applied and I fiddled with the colour and contrast mainly to darken the sky.

Tuthill Polar Alignment Calculator by Ray Porter

If you’ve enjoyed these tips and are in the market for electronics or photo gear, using these links to buy from TigerDirect or Amazon.com or alternatively using the PayPal Donate button to make a small contribution helps me keep this site going. Thanks!

If you own a Tuthill Polar Alignment finderscope then this free little utility written by Ray Porter is something you need. Thanks to this handy utility I have never even had to look at the Tuthill Polar Alignment scope’s rather complicated instructions.

This is a more modern version of an an old QuickBasic program also available as freeware on the internet.

Some important modifications have been made such as adjustment for longitude, daylight savings time, and time zone, but is still fast, light weight and very easy to use.

The program asks you for your date, earliest setup time, latest setup time, your longitude and time zone and does all the calculations for you. The results can be read and discarded or the report can be copied to the clipboard.

If you want a copy of TPACalc just send an e-mail to Ray Porter and he will e-mail you the program.

Click image for larger version


MouseCam – Conectix QuickCam Mods

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I finally managed to track down a used Conectix black and white wecam on E-bay and after a few weeks I was testing and tweaking to my hearts content.

I quickly realized I was going to need some sort of box to put this thing in so it would
attach to the scope more easily.

After rummaging around some old computer equipment at the office I came across an old IBM PS/2 mouse. Hey, the dimensions were right… Its really light, the hole at the bottom seemed the right size… Well why the heck not??

As it turns out the hole on the bottom where the mouse ball goes in is the exact size of a 35mm film canister. I had to break off and sand down the plastic that held the ball cover in place. Not too much as I was going for a tight fit. If fact the fit turned out to be so good that I didn’t even bother to glue the canister in place.

I had a laugh when I discovered that the IBM mouse’s guts were made by Logitech. How ironic… (Conectix was bought by Logitech.)

On the inside of the mouse the Conecix PCB fits perfectly and the cable is about the same size as the old mouse cable so I could use the plastic guider and retainer that was already part of the mouse housing.

To hold the wecam board in place first I made an outline with an permanent marker of where I wanted it to stay, and eyeballed more or less the best places for the screws to go and marked them as well. Then I took one of the thicker type paper clips and heated up with a lighter and melted guide holes through the marks I had made.

For the bolts, I ransacked a couple of old serial cables. The type that go from the mother board and end in a 9 or 25 pin D connector on the computer box where you plug in your mouse or modem or whatever usually have a hex-nut that is the perfect size for this job.

I removed the hex nut with the screw and the little bolt on the inner side of the 9 pin connector and used the hex nut on the inside of the mouse and the bolt on the under side to tighten it in place.

The Conecix board is held in place by a strip of plastic I cut out of an old QIC-80 tape
box. It was easy enough to cut with scissors without breaking. I made melted a whole on either end with a paper clip and threaded two more hex nuts. This was then screwed on top of the circuit board into the hex nuts already in the mouse body. (as seen in the picture below) Nice tight fit. and all ready to close up and pop it on the scope.

And here’s a bottom view of the finished product. It is very easy to align the CCD to
center as the fit is tight enough to hold the board in place from an occasional bump, but not tight enough to keep you from putting it back into place with your fingers if the alignment goes off.

Eventually I’m going to try to setup a computer fan on the other side of the mouse so I can cool my… MouseCam!

One great thing I discovered is that since the ccd chip is much closer to the eyepiece
than in the regular ball housing the camera is now very close to par-focal with my Meade 9mm illuminated reticule eyepiece.

Hey! Whats that on your OTA?!? If nothing else a mouse hanging off the back of your telescope does attract a lot of attention. My father and I had a laugh at how ridiculous the thing looks on the LX50. But, hey… Its works!

Check my astro gallery for images taken with modified webams like this one: http://astroturtle.com/imaging/


Converting a WebCam for Astrophotography

If you’ve enjoyed these tips and are in the market for electronics or photo gear, using these links to buy from TigerDirect or Amazon.com or alternatively using the PayPal Donate button to make a small contribution helps me keep this site going. Thanks!

The method described here works for most “ball” cameras. Mainly for the old Connectix (now Logitech), and QuickCam VC type.

Don’t forget that this sort of fun and games will pretty much void your warranty, and if you kill your webcam by mistake in the process, then that’s it. Get a new one…

The Logitech and Connectix webcams all have a small hole on the bottom. Sometimes it is hidden under a sticker, but its there. If you stick a small screwdriver or even a paper clip into this and twist to on side the the 2 plastic shells that house the circuitry should pop open into 2 halves.

Remember not to force it, if you do this right, the plastic shells will click back together like new. Even if you break the plastic tabs inside, (like me!), don’t worry. Usually the whole thing will stay together anyway. If not a loop of tape around the ball will do the trick.

Once you’ve got the webcam open take a look and try to remember where everything fits, as some of these little buggers can be a bit of a puzzle to put back together. Pull out the guts of your webcam an take a look at the circuit board.

On the lens side you’ll have the lens and the lens housing attached. On the back side you will see the 2 screws that hold the housing in place (2nd image on right, circled in red). You will need to unscrew these with one of those really small screwdrivers the Swiss usually reserve for watches. πŸ™‚

Once you have the lens housing off, unthread the lens from the holder and look inside. You’ll see a small piece of blueish glass. This is an infrared filter. If you want to see something neat, point a TV remote at the webcam and press a button when its completely assembled (i.e.: before you did all this crap to it!) You’ll see the LED’s light up on the capture application. When you remove this filter the webcam becomes even more sensitive to the IR range of the spectrum.

If you’re using a refractor this might not be a great idea as IR light tends to be slightly out of focus in achromatic refractors. On the other hand it is one less piece of glass in the way and makes the camera slightly more light sensitive.

Experimentation and judgment are the best policy here.

Tip: I like to keep those 2 screws in the housing. I drop them in there and thread the lens back on. Its a nice, safe place to keep from loosing them!

Now you reassemble the webcam. 

Looking down the front you should see the exposed CCD as in the first image below. If the housing is having some trouble sticking together (very rare) just wrap some tape around it. Be careful of the series of small holes in the plastic on either side of the webcam. Try not to cover these with tape, as the let some air into the CCD and the circuitry.

Next you’ll need a 35mm film canister. The black Kodak type are best. It turns out that the film tube is about 1.24″ in diameter, and fits perfectly into standard 1.25″ eyepiece holder. You’ll need a descent x-acto knife to cut off the sealed end of the tube and trim it so its as flat as possible. I like to keep the end with the “bump” around the rim, (the end the cap fits on), turned towards the webcam as otherwise it would bump against the lock screw on eyepiece holder.

The easiest way to tape the tube onto the webcam is to wrap some tape all around the bottom of tube so its half on, half off, and then make slits in the tape so you’re left with 4 equal parts. Then you fold them out so your film tube looks like the 3rd image below.

Now comes one of the tricky parts: Do your best to get the tube as in line as possible with the CCD. This is a trial and error thing. No way around it. But once its lined up to your satisfaction press the tape down onto the camera body to hold it in place.

Now you’re going to want to wrap a LOAD of tape around the ex-film tube / webcam body. The whole weight of the webcam, plus any accidental pulls and tugs on the cable are going to be resting on this tape so, take it from me: Don’t be stingy!

Tip: Over whatever tape you use, place some black electrical tape. This cuts down on stray light entering the tube. I don’t like to use just electrical tape as it doesn’t seem to do a good a job at holding things together. Maybe its the tape I use… πŸ˜‰

Tip: Paint the inside of the film tube with some matte black model airplane paint or use some black construction paper to line it. The inside of these film tubes are usually very shiny. This causes some wild reflections when doing lunar photography.

 

Completely assembled your webcam should now look something like the one pictured here inserted into the standard Meade 1.25″ Star Diagonal. Although I have seen better methods listed at QCUIAG and other websites, I especially liked this one as it is a completely reversible process.

Check my astro gallery for images taken with modified webams like this one:

http://astroturtle.com/imaging/


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