One thing we really liked about the Atik 314L is its low readout noise, but what exactly does this mean? Well, imagine a CCD sensor kept in the dark and given a really short exposure.
You’d probably expect it to capture nothing. A reasonable assumption, you’d think, because if a pixel doesn’t get any light it surely shouldn’t record anything.
In practice, it doesn’t quite work like this. The CCD reads each pixel off the chip through an amplifier, introducing what’s called readout noise.
The amount of this noise is calculated statistically, giving a value for the typical number of noise electrons generated during the readout process.
Whereas the readout noise of a typical CCD camera is generally in the 15-40 electrons range, the 314L’s readout noise is quoted as being 4 electrons, which is impressively low.
When the camera is put to use on a target, this means that shorter CCD exposures should show a better signal-to-noise ratio, making faint detail such as delicate nebulosity appear cleaner and more define
The 314L has a few tricks up its sleeve to combat noise.
It’s actively cooled with a Peltier cooling circuit that can drop the sensor’s temperature to an impressive 25°C below ambient temperature.
This combats thermal noise, one of the main protagonists that can ruin your images.
The cooling circuit does a good job too, and in a number of dark-frame tests the results were very clean.
While thermal noise really goes for the throat, readout noise is a much gentler affair; it typically interferes with faint detail in shorter exposures.
The 314L’s design minimises readout noise very capably (see ‘Keep the noise down’, right), which means that this camera is a good choice if you’re not yet set up for long autoguided exposures.
You’ll need a 12V power supply to power up the 314L and it comes with a 1.8m lead fitted with a car plug to get you started.
With a USB 2.0-compatible computer and a telescope or lens to deliver an image, you’re all set.
The USB cable that connects the camera to a computer was a decent 3m in length, which allowed for lots of movement.
The camera attaches to your scope using a supplied 1.25-inch adaptor screwed into a T-threaded aperture on the camera body.
You also get a program called ArtemisCapture to get you imaging straight out of the box, and if you’re a Maxim-DL or Astroart user, plug-ins for these are provided too.
It took moments to install the software, connect up the camera and start imaging.
We really liked the simplicity of ArtemisCapture, but it does have one quirk: it just won’t run if the camera isn’t connected.
Not a problem if you know about it, but an on-screen ‘camera not detected’ message would have saved some hair pulling.
A caged fan on the back of the 314L’s body expels heat generated as a by-product of the main Peltier cooling process.
The whirring it makes when the camera’s powered up is noticeable but it’s not an unpleasant sound.
Our results from the 314L were impressive from the start.
A quick five-minute test shot of the Dumbbell Nebula through a 3-inch refractor revealed the nebula in all its glory.
It even did a good job of picking out the faint outer halo which is less commonly seen; this camera relishes imaging faint detail.
And it didn’t take long to see the images on screen: a full-frame download takes about 1.8s, while in preview mode it’s just 0.9s.
We imaged using an Astronomik RGB type-2 filter set and an Astronomik deep-sky hydrogen-alpha filter.
All of the filters were mounted in a T-threaded manual Atik filter wheel, which is not part of the basic package.
It’s worth keeping an eye out for one though, because there are a number of online bundled deals currently available that include both a wheel and filters with the camera.
The 314L delivered good, rich h-alpha results, excellent for faint emission nebulae and H-II star-forming regions in galaxies.
This camera is an excellent proposition, whether you’re an established deep-sky imager or just starting out.
Apart from the minor issue with the software not running unless the camera was attached, the device was very stable running on a Windows XP computer.
If you’ve been contemplating getting into deep-sky imaging, then you’re not going to go far wrong with this excellent camera.
What’s more, it can do all this at a price that isn’t going to give your wallet reason to make any unwanted noise of its own.
This review appeared in the September 2008 issue of Sky at Night Magazine