Domain: celestron.com
Stories and comments across the archive that link to celestron.com.
Comments · 17
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Re:Sony makes the best camera modules?
No, vignetting is fairly major with Hyperstar and f/2.1. Hyperstar and Fastar are really the same thing, Celestron sold the technology to Starizona. However the later incarnations of Hyperstar (I have the latest version 3), add things like easy to use rotator and collimation bolts
However, taking flat field images cancels it out very nicely. You would want to do this to deal with blemishes since the corrector is a dust-magnet anyhow. I haven't found an easy way to use a flat field box, but doing twilight flats is pretty easy. I have been thinking of using a box that fits all the way over the hyperstar+camera attachment. Early on I have had success without flats, and with the Sony sensor I don't ever bother with dark frames. Even with a 10 minute dark exposure, usually not a single pixel is illuminated.
I also bought specifically designed f/2 Baader narrowband filters, since I hear that regular narrowband filters do poorly on hyperstar. So far the results on Ha have been fantastic. It did end up being such a pile of money that I wonder if I was better off with a different setup. Not being able to use a filter wheel is a serious pain in the rear. At least hyperstar lets you use the much cheaper 1.25" filters.
Early on I did not know how to take or process flats, and had good results anyhow. Pixinsight has some very good tools for dealing with background gradients, either vignetting or light pollution. But the flats do a better job easier on vignetting.
If I was not going to ever use the scope for visual, I probably would have saved myself a hundred or two dollars and gotten a regular C8. However the thing is a dream for visual as well. I think C8 scopes are the best bang for your buck on aperture for a mixed imaging/visual scope. Eventually I plan on getting the
.7x reducer, and if I ever get a really nice mount, maybe image at f/10. Having looked through both Edge and regular C8s before purchasing, I think the Edge falttener makes a big difference for visual. Especially if you like those fancy 82 degree fov eyepeices. Eventually I will be getting a 2" diagonal. (sadly it only ships with a 1.25", which wastes some of the scope's potential.)Though if you really want a Hyperstar-only scope, there is the Rowe-Ackermann. It was out of my budget anyhow, since it requires a beefier mount. Its about the same price as the Edge11, but you don't have to buy the $800 or so Hyperstar lens.
The only complaint I would have is that dew control is a serious pain in the rear if you live someplace cold. But that is the case for every SCT. At least a C8 is small enough that the dew heaters are pretty effective.
I actually just got home from a trip to a dark site and have a pile of data from hyperstar to process. Was my first time with a focus motor, which makes a pretty big difference, since as you know the focus with fastar/hyperstar is really really touchy.
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Re:Telescope
Or if you're not sure, an inexpensive but quite usable one like the Celestron dobsonian FirstScope:
http://www.celestron.com/c3/product.php?ProdID=568
It's cheap enough for me to get one for my nephew for xmas and I don't have to worry that he might not use it.
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Re:Better than they need to be?
On its closest approach, Saturn is about 7 AU away. The diameter of its rings are about 360,000 km. Doing the math, this means that best case scenario, the angular size of Saturn including its rings is around 1 arcminute. The 2-inch diameter Galileoscope has a diffraction limited angular resolution of 0.05 arcminutes. The gap between the rings and the planet (around 6000 km) is going to be about 0.02 arcminutes. This is all large enough we can safely ignore atmospheric seeing.
So basically this scope is going to be capable of seeing the rings of Saturn quite easily, although they won't be clearly distinguishable from the planet. This is exactly what early astronomers saw, and while it confused them at the time, any kid who has seen a picture is going to know immediately what it is. While the picture in a book or the view from a big expensive telescope is obviously going to be more impressive, there is something to be said for being able to see it at all with your own equipment in your own backyard. Personally, I bought myself a 5" newtonian for personal use even though my current work involves setting up and operating two 16" SCTs, for that very reason.
And I'm not sure what it being a refractor has to do with it. Tripod is definitely an issue though. I personally like the Celestron FirstScope http://www.celestron.com/c3/category.php?CatID=92 better for that reason, plus it has an extra inch of aperture - it is $50 vs. $20 though. -
Re:Lovely
No problem.
By all accounts your NexStar should be an excellent scope for viewing. You should however be aware that there are limitations when it comes to long exposure astrophography on an alt-az mount, even with a field de-rotator. The Celestron C8-SGT 8" Go-To XLT shouldn't be much different in price, has goto, and is on an EQ mount. Bear in mind that I've not used either scope. I just know if I was going to want to do any photography I'd pick an EQ mount. It's your choice, of course.
http://www.celestron.com/c2/product.php?CatID=11&ProdID=60
I haven't had much experience with GOTO, bascially because I'm too cheap and you can pretty much double the price for buying astro gear in Australia. (I have considered buying one of the baby NexStar gotos and using it as a spotting scope with green laser pointer attached, but I don't imagine that would be anywhere near as worthwhile as true GOTO). The sad truth is I don't use the gear I do have because I don't have much time to observe these days. -
Simpler version from celestron
Celestron seems to be doing a simpler version of this with their SkyScout unit: http://www.celestron.com/skyscout/new/index.php which uses GPS and inertial sensors (coupled I assume with a digital compass) to identify the object that you are pointing at, or direct you to a specific object. Actually this sounds like a better learning tool and is available off the shelf for $400.
On the other hand, an augmented scope which is slaved to a remotely operated scope is of some interest for those of us stuck in light polluted areas. -
Skyscout by celestron
http://www.celestron.com/skyscout/new/index.php
Celestron has been there and done it allready. This a great device if you have the means and a desire to learn about the heavens its highly recomended. And yes this is real its here and you can buy one instead of reading about it in slashdot and saying wouldnt that be cool. -
Nifty product out of CES
Looks like this might be a nice device for starting out if you want to get into astronomy.
Might be a good product to get kids interested as well.
http://www.celestron.com/skyscout/no_flash.php?Fla sh=N/
It has some pretty neat features such as:
"Tonight's Must-See List"
"Constellation Lessons"
etc
Cheers,
TimeForGuinness -
Tiananmen Square massacre
Nothing has changed. The Chinese gvt knew who the leaders of the rebellion were because they had photos courtesy of equipment released to them by the US gvt. (http://www.celestron.com/telescopes.htm) These compact Cassegrain optics were (and may still be) controlled items under the restriction of transfer of technology. It was a felony to export them The green light came from the highest authority. So the students who thought they were far enough away to not worry about photographs were wrong. Dead wrong in some cases. So to kvetch about Yahoo is just misplaced. It shows a lack of appreciation of the real dynamics of global politics. FK
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Re:HAHAHAHAWe had a telescope setup outside with a solar filter and were doing observations of sunspots 6 months ago for astronomy. We did not have a solar filter so we put an inverted bevarage cup upside down on the finder scope that we drew a skull and cross bones on to warn people.
Enter: A business student who took off the cup placed it on the ground and than looked momentarily through the finder scope was instantly screaming and shouting and cursing and talking of sueing us the school and the sun; hilarious only in the fact that she did not have permament damage to her eye.
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Not all scopes exhibit diffraction spikes.
Something I've wondered for a while... what's up with the points coming off the stars?
As was mentioned in another post, those are diffraction spikes from the supports for the secondary mirror.
Newtonian reflectors and classical Cassegrain telescopes support their secondary mirror with "spiders" that produce diffraction spikes. There have been various efforts over the years to eliminate these from that type of telescope. One method is to seal the tube with an optical flat (a flat piece of optical glass) which supports the mirror. The trade-offs include longer times for the scopes to reach temperature equilibrium, distortion from imperfections in the optical figure of the flat, and slight light loss. Other attempts have included the use of spiders with curved support arms, which reduce or eliminates spikes at the cost of slightly degraded overall image contrast.
Other telescope types, such as refractors, Maksutovs, Schmidt-Cassegrains, and Yolo reflectors have no diffraction spikes, but they are all more optically complex (Yolos, for instance, require toroidal mirrors) and are more difficult to produce as a result. Refractors have the added problem of chromatic abberation, which is the fringing of color on the edge of bright objects. Various complex, multi-element objectives have been developed to reduce, or even practically eliminate, this problem. The problems are optical complexity, cost, and light loss. Figuring a 3-element objective lens for a refractor means grinding six optical surfaces with precise curves. Compare that to a Newtonian which has a single parabolic primary mirror and a flat optical secondary.
There are many other telescope types than the few popular types I mentioned here and each have their proponents. Most designs that have survived the test of time can be made to perform well, but each has trade-offs. -
Lessons learned from my $1000 telscope...(1) If you want a point and click telescope for 1000 bucks you will end up spending 3/4 of the money on point and click hardware and 1/4 on apperture. I went for apperture.
(2) There are 7 objects that take little to no effort to find with your telescope manualy:
Sun (ALWAYS use a filter here!!!)
Moon
Venus
Jupiter
Saturn
Mars
Mercury
With my 135 mm opening telescope I can see sunspots, Moon craters, the phases of Venus, the cloud bands of Jupiter and his 4 biggest moons, and the rings of Saturn. Mars will be back later this year and I have not seen it through my telescope yet.
(3) To find anything with your telescope that you can not see with your naked eye you will need 3 things:
Dark sky (The light of 1/4 Moon is enough to make observation pointless, zero ambient light, and transparent sky)
Star charts
patience, patience, patience
I own my telescope for 6 months now and have been out a couple of times, the only thing I managed to spot that I could not see with my naked eye was the Orion nebular and the Andromeda Galaxy. Trust me - this is a perfect time sink. Prepare to be disappointed.
(4) Prepare to be amazed and exited. This is a wonderfull hobby.
Please do not forget that with age, sight deminishes. This basically rules out deep sky (galaxies, nebular) observation. This means you will want moderate aperature and more focal length instead because this will be better for observing the objects that your father can enjoy: the planets, the moon and the sun. And since you wont need a computer to locate these you can dump more money on the telescope and mounting and less in computer stuff.
I own a Vixen - GP E R135S and love it. Next I will probably go for the Celestron Nexstar 11 GPS.
PS: The link to the pictures in an earlier post are wonderfull but do not expect to see this with your telescope and your naked eye. Under excellent conditions Jupiter will be more like a small white ball with very faint beige bands.
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Go for aperature
Get the largest aperature you can afford. Both Meade & Celestron make models with an 8" apperature with auto goto in the price range you suggest. You can easily hook either of them up to a laptop by using a webcam. Sample photos from a webcam of Jupiter can be found here.
Use a Philips webcam (Forget the name of it, but it is mentioned on the web page listed above) because it has the most sensitive CCD of the webcams, and takes the best photos. You can also get an adapter for around $20 to hook up the webcam to your computer, or you can easily make one.
Also, if you don't absolutely need the auto goto, you can get a good Dobsonian mounted telescope pretty cheap. Check out Orion Telescopes for some good Dobsonian mounted scopes, and some good Newtonian reflectors in the price range you wanted.
And oh yeah... $1,500 is by no means an ultra expensive telescope! A high quality mirror alone can cost several thousand dollars. -
Re:Another question about the shower...There are a few different things going on.
The reason they are called the Leonids is that the main orbital path the meteroids are on before they strike the earth is such that it points back in the general direction of the constellation Leo at the point where the earth crosses the comet's orbit each year (meteor showers come from debris broken off a comet).
If you make a black-on-white copy of a starchart, and draw a line on it for each meteor you see when it happens, with an arrowhead in the direction of travel, at the end of the night you will see the most of the paths generally radiating away from Leo, like spokes radiating from the hub of a bicycle wheel. This is like what you'd see if you stood in the middle of a multilane highway as cars sped past you, facing where they come from - you'd see the cars angling to the right and left, but "radiating" from one spot in the distance.
If a meteor's path is very short, it is headed in your general direction. If it just a bright spot, then it is headed straight for you, so you know when to duck. If it is very long, it is headed away from you.
I don't know if it is still practiced, but there used to be organized efforts among amateur astronomers to map meteor paths during showers so their orbits could be calculated. Now I guess it would be more practical and accurate to do it with radar. To do make such a calculation, the observers also need to write down the time they saw each meteor.
Even so, the meteors won't all be radiating from a single point. There will be a lot of randomness. Part of this will be because the meteoroids are spread out in space, to either side of the comets orbit, each on its own slightly different orbit.
Also, as it approaches the earth, the earth's gravity will disturb the orbit of the meteoroid. If the meteoroid is heading straight to the center of the earth just before it hits, then it will just go faster. If it's heading a ways to one side of the earth, then its path will be deflected in towards the earth, and when it hits it will be at a highly deflected path. If it's even farther to the side, it won't hit the earth but it's orbit will be disturbed, and many orbits of a planet through a comet's path will introduce a lot of scatter in future showers.
Now let me shill for amateur astronomy. I'm grinding my own telescope mirror. You can join the Amateur Telescope Maker's mailing list and they'll tell you how - read the FAQ. Dan Cassaro can sell you a mirror grinding kit. You can get books with instructions (you need a whole book, it's pretty involved) from Willman-Bell. You can find lots of tips on the Telescope Making WebRing.
Or you can buy telescopes from Meade and Celestron or shop at the shop at the astronomy mall. Finally, there's a new ATM portal at www.telescopemaking.com.
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Amateur Astronomy and Telescope MakingLet me use this opportunity to plug a fascinating and intriguing hobby, Amateur Astronomy and Telescope Making.
I made several telescopes when I was a teenager, and have recently taken up grinding glass again after a long hiatus. I was also pleased to find the Central Maine Astronomical Society is in my area and joined last night while visiting their new observatory.
Telescope mirrors can be made by hand with suprisingly simple equipment. An eight-inch diameter telescope will run you about $250, maybe less if you're creative, for the mirror kit, eyepiece, aluminizing, and mounting.
There may be a telescope making or astronomy club in your area. A good way to find out is to subscribe to the ATM mailing list. Another way is to follow some of these links:
- Chabot Telescope Maker's Workshop (Oakland, California)
- Sidewalk Astronomers (Los Angeles and San Francisco)
- Amateur Telescope Makers of Boston
- Stellafane - Springfield Vermont, where the hobby was started in the USA
If you don't want to build a telescope, you can buy one. The telescopes made by Meade and Celestron are well known. You can find ads for dealers in the pages of Sky and Telescope Magazine, which you'll find in many bookstores.
A large number of astronomy products may be found through the Astronomy Mall.
Although the price differential for small telescopes like 6 or 8 inches is not that great between making it oneself and purchasing, the cost of purchasing really large instruments is really prohibitive, while large ones are actually affordable to make, comparable to purchasing a computer. If you start off making an 8 inch mirror, your next mirror can be much larger, say 16 inches, and amateurs commonly make mirrors from 20 to 30 inches, and I think there is a 72 inch mirror nearly complete made by some amateurs. My goal is to have a 40 inch observatory in my backyard.
Although I've listed U.S. organizations and companies, telescope making is practiced world-wide. A while back someone from Iraq subscribed to the ATM list and asked for help obtaining a kit. There are lots of subscribers from Europe and a number from Asia and Africa. Follow the links, and maybe you'll find a club in your home town, or at least within a reasonable distance!
I cannot describe the awe that comes from beholding the wonders of the heavens through a telescope made with one's own hands.
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Here's how you grind a telescope mirrorHere are the basics of how you grind a telescope mirror. There are many variations. You definitely want to get a book. I used:
- Amateur Telescope Making by Albert Ingalls
- How to Make a Telescope by Jean Texerau
The stubby Celestron and Meade telescopes that are popular with amateur astronomers who prefer to purchase their instruments are of a type called a "schmidt-cassegrain". This has a nearly flat corrector plate in the front, that actually has a shallow fourth-order curve ground into it to correct spherical aberration, a deep prolate spheroidal primary mirror, and a convex secondary mirror mounted on the back of the center of the corrector plate.
It's the convex secondary that makes the telescope a cassegrain. The 200 inch on Palomar is a cassegrain. I don't have a schmidt-cassegrain to show you but here's how an ordinary cassegrain is laid out.
The use of the schmidt corrector plate allows one to make the telescope very short, with a small ratio of focal length of the primary to its diameter, without making images away from the center of the field blurry.
This is an advanced kind of design for an amateur to make oneself, although many amateurs have. Here's how one guy made a schmidt corrector plate.
The typical amateur starter scope is the "newtonian reflector". This has a concave parabolic mirror at the back end of the tube, and a few inches inside its focus is an optically flat mirror at 45 degrees. The optical path shown in the diagram is for the light from a single star, an image is formed from light sources spread across a small angle, and a small image is formed at the focal plane where it's examined by the eyepiece (a high-power magnifier) or photographed with film, a CCD or I guess even a webcam.
If you make a parabolic mirror with too short a ratio of focal length to diameter (the f-number, like the f ratio on a camera lens), then the images away from the center are blurred. This is called "coma". A parabola only focuses light perfectly if it's parallel to its axis and tilting the beam introduces coma. A ratio of 1 to 4 is about the shortest you can make it - f/4. My 6 inch is f/8, my 10 inch is f/3.5, and my 8 inch is f/6.
Having a longer focal length gives you greater magnification. Having a shorter one gives you a wider field of view, within the limits of the coma. Having a shorter focal ratio also makes it easier to fit in a car, an important consideration for making the scope enjoyable. Those Celestrons are nice because they'll easy fit in the trunk of a car or even in airline luggage (with a hard case) but it comes at the expense of a fancier design.
For the first homebuilt scope one usually grinds the primary and buys the flat diagonal mirror from a vendor. More advanced amateurs make their flats too but again optically flat surfaces are hard to make.
Making a primary that doesn't have too short a focal ratio is not too bad because the grinding process naturally makes a sphere. You grind a sphere of the right radius of curvature, fine grind through successively finer grits, then polish. You then use an optical test to get the mirror perfectly spherical, then deepen the center to move from a sphere to a parabola of revolution, testing carefully as you go.
The way I ground my mirrors was with pyrex mirror blanks on plate glass tools. Initially each is flat. They are both pretty thick, my 8 inch is about 1.25 inches thick, to stiffen them so they don't lose their figure. You have to have a figure that is perfect to about 1/8 of a wavelength of visible light in variation across the whole face of the glass, so any bending is disastrous. The 1/8 wave limit is the same for mirrors of all sizes so it's much harder to figure larger ones - best to start small. I would recommend an 8 inch for a first mirror. I have heard of people doing much larger first telescopes though.
What you do is sprinkle some granulated silicon carbide and water on the tool, place the mirror blank face down on it and push it back and forth until the silicon carbide ("carborundum") breaks down. (This is the same abrasive as you find on black wet-or-dry sandpaper, only in free-flowing powdered form). Then you add more abrasive and water and repeat. When too much mud builds up you wash it off and add more abrasive again.
To grind a concave curve into the mirror blank you place it on top, face down, grind with long strokes and have it hanging mostly off the side. Also you put pressure on it, either pushing hard or putting weights on it. This concentrates the grinding action in the middle and a shallow sphere develops.
Every few strokes you rotate the mirror a little, and once a minute or so you rotate the tool a little, with the idea that every part of the mirror gets ground over every part of the tool in every direction.
These days it has become popular to "hog out" a mirror with a metal ring tool, like a pipe cap as I'm about to try, then after rough grinding you make a fine-grinding tool out of small bathroom tiles mounted in dental stone or portland cement. This is in part because it's getting harder to get telescope making kits, unfortunately because it's so easy to buy a Celestron people don't make their own as much anymore. So people conserve the glass just for the mirrors and make the tile tools instead.
Be aware, before you say "well it's easier to buy a Celestron", that the price of a telescope goes up astronomically with increasing diameter - my 8 inch kit was $78 including shipping, I'll probably spend a few hundred to make a nice clock-driven mount, but the 10 meter telescope on Mauna Kea cost $90 million! If you know how to make your own, it is within your reach to grind your own 20 inch, which will have astounding views, but few of us could hope to afford to purchase a twenty inch commercial scope.
I know people who have ground 30 inch scopes and I know of some amateurs who are now figuring a 67 inch mirror!
Anyway it takes several hours of work to rough grind your mirror, more if you're doing a short f/number, less if you have a higher one, also less for smaller mirrors and more for larger ones. My 6" f/8 was about as deep as the thickness of an american dime, I don't know a little more than a millimeter.
Then you fine grind, grinding for a few hours with successively finer grades of abrasive. Usually you rough grind with 80 mesh silicon carbide - it is graded by sieving it through a mesh with 80 wires in it (same as the sandpaper sizes). Then you grind with #120, #220, #320, #400 and then several very fine grades of aluminum oxide whose sizes are given in microns.
The idea is that each finer grade erases the pits left by the previous grade. Between each grade you must scrupulously clean yourself, the mirror and tool and your work environment lest a coarse particle get into a finer stage and cause a scratch.
With each grade the mirror and tool surfaces will become more and more accurately spheres, within the limits of the sizes of the grits. This is because a sphere is the only shape that allows two surfaces to be placed anywhere against each other in any position or rotation (a flat surface is the limit of this as the radius goes to infinity). If there are any high spots, they will get more pressure and grind off quickly; any low spots will miss out on grinding and the surrounding surface will come down to match.
Then you polish. You make a "pitch lap", using either another dental stone base or the glass grinding tool, covered with refined, thickened pine pitch. You cut channels in the pitch with a knife or mold them in with a silicone mold. Then you cover the pitch lap with a suspension of cerium oxide in water, or else ferrous oxide (same as rust but finely powdered - "jeweler's rouge"). Then again you stroke the mirror on the pitch lap.
During fine grinding and polishing you use shorter strokes, and alternate which is on top, the mirror or the tool, to keep the depth constant. You also stroke a little side-to-side, in a W pattern. This evens everything out.
To test the mirror you use the Foucault test or the Ronchi Test. The foucault test appatatus I link to is much fancier than you need, although nicer to use - you can do it all with your naked eye and the tester, you don't need a camera.
In each test you use a light emanating from a pinhole or narror slit just to the side of the center of curvature of the mirror. The image of the pinhole or slit will form an equal distance to the other side, where you can place a knife edge (Foucault) or screen (Ronchi) across it and hold your eye there and look at the mirror.
It's kind of hard to explain but each of these has the effect of dramatically magnifying deviations from spherical surfaces in the mirror. A dramatic demonstration is to have someone hold their hand in the beam - you can see the distortion in the beam caused by the warm air rising from their hand.
You can easily make out a bump or hollow that's a fraction of a wavelength high on the glass.
Then you make your mirror perfectly spherical by preferentially polishing off the high spots. If you did the fine grinding and polishing well you won't have to work hard to do this.
Unfortunately what we want is a parabola, not a sphere. This must have a precisely controlled error in each test. This is a little more than I want to get into, but basically your preferentially polish out the center of the mirror so it's deeper in the middle than appropriate for a sphere by a little bit. Get it just right and you have a parabola, and your mirror will focus perfectly.
Then you package it securely and send it off to one of the people who does vacuum aluminization. They clean the mirror extremely well, place it in a high vacuum, and evaporate aluminum off of tungsten wires. The aluminum vapor sticks to your glass and you have a telescope mirror.
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Webcam: Yes, but not yet; Astrophoto: Not well
I can sympathize with what you are trying to do, as I've tried both uses with my Nikon Coolpix 950. The short answer is both are possible, but it isn't likely to be easy to get what you want out of the setup. Once drivers are available, you should be able to use your digital camera as a webcam fairly effectively, though you may have issues with autofocus, flash, and other camera-only adjustments. For astrophotography, it isn't likely you'll be able to get worthwhile images with the Elph, but I've included a few links on how to get started.
Digial Camera Webcams
Digital cameras defintely produce a much more compelling image than a typical webcam. I have a 3Com HomeConnect (a pretty good quality webcam) and it looks just awful compared to my Nikon N950 (not just resolution, but also trueness of color, CCD noise, and sensitivity). The main limitations are that you can't usually take mini-movies or fast sequences, some key functions are often only controllable on camera (for instance auto-focus and flash), and you'll need a power cord for the camera if you don't want to drain the batteries very quickly.
The easiest way to control the camera from a linux box is with Scott Fritzinger's GPL'd gphoto program. gphoto allows basic control of a variety of cameras through serial or USB connection (and supports both interactive and commmand line modes - add a bit of perl and cron and you can do all sorts of fun things). Its still under development, however, and unfortunately doesn't currently support the Digital Elph (PowerShot S100) to my knowledge. I'm not sure how involved it would be to write a USB Elph driver for it, but you can check out the site if you feel up to it.
Digital Cameras and CCD Astrophotography
With astrophotography, you are getting into a rather specialized and involved use of CCD devices and generally speaking, it takes a good bit of expertise and dollars to get good results. You don't mention what you are looking to capture or what existing equipment you have, so I'll point out some of the basics and you can research further from these. FWIW, I'm not by any means an expert here, but I've been looking to jump in, so I'm seeing the same issues.
While there are limited exceptions, CCD astrophotography generally requires the use of specialized equipment. Your Canon Digital Elph doesn't have the required sensitivity (its equivalent to ISO 100 film), ability to take long exposures, long and fast enough lenses, or adapters for telescope mounting. While its possible to use a barn door tracker or equitorial tracking camera mount with the Elph, the results aren't likely to be worth the effort.
If you really get interested in astrophotography, you'll probably want to pony up for a specialized system like those built by Celestron and SBIG. These are highly sensitive, small array CCD cameras with specialized cooling and software for high gain operation. Add a high quality telescope, equitorial tracking mount, and related accessories, and you are talking about no small dollar commitment. Also, you'll need a lot of time and patience to find and capture accurately really good photos. I'd like to try CCD astrophotography out, but will be playing with 35mm (add a T mount and a Meade ETX and you can get started for under $1000) until I decide I'm really committed and move to a less light polluted neighborhood.
Sky & Telescope has a pretty good guide on where to start. Some good introductions to astrophotgraphy are:
- Sky and Telescope Imaging Resources
- Amateur Astrophotography links
- CCD Astrophotgraphy (annoying sounds)
- Santa Barbara Imaging Group (SBIG), a leading astro CCD maker
- Pin's Astronomy Page
Have fun, RJS
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Computers are cool, but....
Have you ever looked through a real telescope? No, you don't see what the Hubble sees. Things are not in color (usually).
For the price of a brand new all-the-bells-and-whistles-included Linux box, you can get a top of the line amateur telescope. Yet you don't have to spend that much if you don't want to. But do get a good one and not some department store piece of crap. Celestron makes some of the best ones out there I think.
What you will see is so astounding you will never ever forget it. You are seeing it with your own eyes - not some camera. I still remember the first time I saw Saturn 22 years ago. It was and still is something to sit and stare at for hours.
Yeah, I take pictures with my scope, and I stick em up on the web, but well, they don't compare to really seeing something for yourself. I guess when it comes to this I am a Luddite.
I guess a good way to put it are the porno webcams. Sure, it is fun to watch, but nothing beats being there.
I do like the idea, don't get me wrong. But seriously, if you are the least bit interested in astronomy, do yourself a favor and buy a real telescope. The experience is worth it.