Astrochannels: Blog

A few years ago, when relatively inexpensive digital security cameras began to be adapted for astronomy use, a whole new vista was opened to the amateur astronomy world and as the quality increased the whole concept really changed everything. It took a few years for the technology to see eye to eye with the always discerning senses and sensibilities of the average amateur astronomer, but those of us who are realists and are willing to adapt took to it without so much as a hitch in stride. And of course there remain die hards out there who decry “But it’s not live!” Well, it’s live enough, as the view is only 2 to 28 seconds behind live.

The point is that you’ll never be able to see through glass optics what you can see with a video camera, and due to optical physics it’s not open to debate. The reason for that is the camera collects and “stacks” image data in a way the eye and brain are not equipped to do. The camera we use stacks 128 frames in a given increment of time, 2, 7, 14 and 28 seconds. Each of these increments refers to the length of time the CCD (charged-couple device) “shutter” is open, and so what is seen on a display is refreshed, or redrawn, upon the expiration of those increments, meaning that if the camera is set on 14 seconds (our most often used setting) the view is refreshed every (you guessed it) 14 seconds. The CCD is the light-gathering unit in any digital camera and is what captures the image.

To us it doesn’t matter that it’s something like 14 seconds behind live, as the camera collects as much as 4000 percent more light. This makes a 14” telescope show images similarly to the way a 56” telescope in an observatory at the top of a mountain does, quadrupling the aperture, which is a fancy way of saying “the scope’s diameter.” This avails amateurs with views formerly reserved for government and university level specialists.

There are so many additional advantages to using astrovideo cameras, but we’ll touch on just a few here.

First, in amateur astronomy one of the grails is to maintain what in astronomy is known as “dark adapted eye” (which I personally believe would make a great name for a rock band). This refers to the need to have your eyes remain adapted to the dark so that when you step up to look through an eyepiece your eye (or eyes, if using binoviewers) stays ready to gather as much of the light coming through the view as possible. In this state, a cigarette lighter can be blinding, and if one of your buddies comes driving up through the area with the truck lights on, which is blasphemy, he’ll soon know the full measure of amateur astronomer punishment.

But not so with a videocamera. You’re seeing the view on a television or projector screen, which is already adapting your eye to greater light. Your buddy’s truck lights only interfere if they’re pointing at the television or if you defiantly (and foolishly) decide to look straight at them. However, that being said, it’s still rude! And there are still punitive measures, a legacy from times past.

Secondly, at starparties you’ll see lines forming at the eyepieces of the telescopes, as only one viewer at a time is able to enjoy the view. Not so when a 27” TV is in use, or even a projected 60” view. Not only does everybody get to view at the same time in this way, but when tracking objects that are, say, 20 million light years distant, telescopes have very little margin for error, and so if it gets bumped, for instance by a child whose dad hoisted her or him up to the view, it’s time to drop everything and realign the scope.

Those viewing, as well, can on the screen point object features out they’re particularly enjoying, verses having to give clock face coordinates with detailed (and often maddening) descriptions of what it is they’re seeing through an eyepiece and can’t, with frustration, figure out why you don’t know what they’re referring to.

When we project a 60” to 70” screen size, 150 people can gather around, have a party, listen to music, enjoy the fire, and watch the beauty on the screen. That all by itself is enough of an advantage to drop eyepiece traditionalism and get with the times. Well, unless you’re a lone wolf who hangs out in the pitch black, grumbling about things beyond our ken.

Thirdly, it’s all digital and therefore can be captured on a DVD-R for later viewing, and at the same time can be uploaded to the Web via a video encoder, which renders the “feed” as a streaming media file. In case you don’t know, streaming, explained simply, is the ability to receive and view (or listen to) media files simultaneously. For example, all Web radio stations use streaming media. All Web news channels (Fox, ABC, CBS, etc.) use streaming media files.

What this means for the average person is that they can simply click a link, which automatically launches a media player, and anybody anywhere in the world sitting comfortably in their home or office can view what ten years ago only a handful of people in all the world were able to see on a regular basis.

Soon, we’ll see Google, NASA, and others doing round-the-clock astrovideography. There’ll be channels on satellite TV and cable carrying such programming. There’ll be “street-corner” impromptu parties, where people gather just because there’s something to see when they’re passing by, and the beauty of that is the telescope is located somewhere in a dark sky location beaming the feed to the Web, and the street corner party-thrower is just using a laptop, a Starbucks Wi-Fi and a projector to show the view.

The possibilities are endless, but if it ever comes up, just let them know that you saw it first on Astrochannels.

J Davis