Carsten A. Arnholm, October 2005.
Here, you will find some of my facts and experiences in trying to put this camera to good use. If you came here to find highly technical information about dark currents, "shot noise" and such low level technical issues you may be disappointed, but maybe my general impressions and imaging results will give you an idea of what the potential of this camera is, as seen through the eyes of a user, not a camera builder. If you want to comment on this review, please use the contact information found via the link on the top of this page.
Perhaps it is also worth noting that I am a Norwegian, the language mistakes in this text is not due to the camera :-)
The Artemis camera is the much talked about and long anticipated follow up to the modified webcams, but unlike the SC webcams, the Artemis has been designed "ground up" for astronomical use and can therefore be considered an alternative also to other "professional" CCD cameras.
All the cameras in the Artemis series look the same (except for colour), they have a very unique shape. The housing is made
of solid aluminium which also serves as a big heat sink. The camera uses a USB1 connection to transfer images
to the computer.
The only difference between the Artemis models are the CCDs. On the left is the largest option, the ICX285AL. This black and white 2/3 inch Sony CCD has 1392x1040 pixels and 6.45x6.45 micron pixel size. It also features "vertical anti blooming" and a very low dark noise. There are several other CCDs options. These vary in size, resolution, colour vs. monochrome, and of course, price.
At the time of writing, the Artemis is supplied from Artemis Astronomical only as a kit for the buyer to assemble himself, but
a ready made version is available under the name ATK-16 from sources such as
One of the biggest advantages of the Artemis over webcams is the 16 bit analog to digital converter. In theory it means you have 65536 levels of grey. However, such things as pre-charge and so forth reduce the actually number of levels of grey left for your image. Still, compared with the maximum of 256 levels of grey in 8bit webcams, it means that a much wider range of brightness values can be captured, which is very important for most deep sky objects.
The camera arrived assembled for review in a box containing the following parts
The power is supplied via the DIN socket on the back side, and the USB cable attaches to the "narrow" end of the camera house. At left you can see the fan at the far left and the special Artemis guideport above the USB port.
I have not used the Artemis guideport, but I am told that it can be used to control the shutter on a long exposure webcam - support for this is expected to come soon in webcam autoguiding software such as Guidedog. With such a feature it will then be possible to image with the Artemis and autoguide with a long exposure modified webcam without needing a printer port on the laptop.
The 1.25" nose-piece adapter can be unscrewed and reveals standard M42 threads to which old style SLR lenses can be attached for wide field imaging. This is quite attractive as I have several such lenses. Also, by removing the nose-piece and replacing it with a telescope adapter ring, the big 285 CCD is less susceptible to vignetting, i.e. image darkening towards the edges of the CCD.
The female M42 threads are found on the inside of a ring that is held in place using 4 set screws. This ring also serves to hold an optical window in front of the CCD. By removing the ring, it is possible to get access directly to the CCD should it become necessary.
The Artemis is always used with a computer. This is not a stand alone camera like a digicam or a DSLR. The camera is always remote controlled from a PC using an image capture application. Drivers for capturing images via applications like AstroArt or MaximDL exist, but for users who don't own any of these, the "Artemis Capture" program can be used, and that is what I have done.
The image at left shows a screenshot of Artemis Capture. For illustration purposes I have overlayed the program screenshot with one of my IC1805 images, but notice the IC1805 image is not a 'live' screenshot. To see an actual live screenshot, click here.
Image download can take up to 11 seconds when imaging with the large ICX285AL CCD, shorter with the smaller CCDs. When binning is used, download times are reduced dramatically. Also, when imaging in sub-frame mode download times are reduced with the size of thesub frame. One might think 11 seconds is prohibitively long, but with exposure times of 5 minutes or so, 11 seconds is really not a big issue. In focus mode, the update is almost real time.
Imaging with the Artemis is in many ways dead simple. There are no gain settings or anything like we are used to with the modified webcams. Other than varying the exposure length, you can however use binning to combine 2x2 or 3x3 pixels before analog to digital conversion to achieve higher sensitivity. To put it simply, the Artemis just counts the incoming photons during the exposure and saves the result as 16 bit FITS files to be processed and tweaked later. The fact that no image processing is going on at capture time is one of the secrets to achieving good results.
After using Artemis 2.08 and 2.09 Capture for a while, I can say it is a stable and fairly intuitive program to use. I prefer "to-the-point" programs without too many "bells and whistles" and this program fits the bill quite nicely. I really don't see a need for much else, but there are some minor things that perhaps could be improved:
My experience with the Artemis software so far is limited to Artemis Capture, but I am looking forward to using it much more.
Coming from a background of using modified webcams, I think it is fair to say that this camera is more demanding of its user, it is more difficult to use than webcams, and autoguiding is a must unless very short focal lengths are employed. This is due to the fact that the camera is a 16bit camera that can take exposures for many minutes (certainly longer than 5 minutes) without saturating. To exploit the camera potential you therefore end up taking much fewer, much longer single exposures than you do with a modified webcam. You should plan for taking at least 3-5 minute exposures and that requires better tracking than most amateur equipment can deliver, hence the need for autoguiding. I found that using my trusted SC3 webcam as autoguider was an ideal solution, and it made me work on my guiding capabilities, with good results. This way, the Artemis pushed me to become a better imager!
The "cable with DIN socket" turned out to be a power cable Arthur Edwards had prepared so I could supply power to the camera from my 7Ah PowerCube battery. This was very nice for portable use. The cigarette plug draws 12V for the camera and fan while the smaller plug draws 5V (but 6V is also ok for the peltier cooler). I could use the camera for about 3 hours before the battery ran out, but more practical is to replace the battery cable and use the 240V AC power supply, which will provide all the needed power. This is of course preferable in a permanent setup like mine.
One thing that struck me immediately when I saw this camera and held it in my hand, was that it was bigger and heavier than I had thought it would be. The camera dimensions are approximately 145x78mm (x50mm thick), not counting protruding cables or telescope adapter. The camera without cables weighed approximately 600g on a simple kitchen scale. So using the camera will have an effect on the weight distribution of a small to medium size telescope. You could say that in this regard it is quite similar to a digital SLR camera body.
The 240v power cable works just fine, but the cable itself is quite stiff (especially under cold conditions), and the cable between the camera and the AC/DC converter box is quite short, so it could end up hanging from the camera as it did from one of the scopes I used (C14+Paramount). A longer, more flexible cable would be a good thing.
Another area of slight concern for small telescopes is the asymmetric body shape of the camera housing. This introduces torsional bending into the telescope adapter. If a nose-piece is used, there might be some torsional slippage over time if you don't take care to avoid it. The short power cable can add to this issue as it connects to the part of the camera that is furthest from the optical (and mechanical) axis. But given that you are aware of and understand this issue it is not a big problem to handle it.
Click images for large versions
NGC 6992 (Veil nebula)At August 19 2005, Heggedal, Norway.
I put the Artemis 285 to test under the full moon, but for once my high latitude came to my benefit (very low moon).
Exposure: 3x180s + 7x240s (Astronomik H-alpha)
IC1805 in CassiopeiaAugust 31, 2005, Heggedal, Norway.
Exposure: 9x300sec H-alpha
NGC 7635 (Bubble nebula)September 4, 2005, Persbuhaugen (~850m above sea level), Norway.
Exposure: 10x300s unguided (PEC only), H-alpha, 2x2 binning
IC 5070 (Pelican nebula)September 6, 2005, Heggedal, Norway.
Exposure: 7x300 sec, Astronomik H-alpha
The Sun with active region 10808 in H-alphaSeptember 10, 2005, Harestua, Norway.
Scope: Takahashi Sky-90IISV
The Sun with active region 10808 in H-alphaSeptember 10, 2005, Harestua, Norway.
Scope: Takahashi Sky-90IISV, 2x Powermate
Update 29. Oct 2005: There is now an Artemis image gallery with images taken by different imagers using different Artemis models.
On September 20, 2005 I arranged a experimental live deep sky webcast, where I used the Artemis to show images of various deep sky objects live over the internet.
The solar eclipse October 3, 2005 managed to get some Artemis webcast images into the Norwegian national news:
But the upside of all this is that if you invest some time in it, it pays back with interest in the form of much better images than what you can produce with webcams. If you want, you can build the camera from a kit and save lots of money while also learning to know the camera intimately. Or alternatively, you can buy the camera ready made if this suits you best.
The final words are that I liked this camera so much that I bought it :-) What more is there to say?