Saving Money at the Telescope: The Real Story
Posted by Alan Holmes
An amateur interested in astrophotography has many options these days, such as modified webcams, high end digital SLR cameras, and cooled CCD cameras like ours. It does not surprise us that the amateur is often perplexed about what to buy, since good pictures taken by all of these choices can be found on the web. I hope the user can consider a few of the following points in making his purchase.
When pricing our astrophotography camera options, most of us forget to price in our most precious resource: Our time.
How much time do you want to waste each viewing night wrestling with cheaper equipment that may need more fiddling, more coddling? How many useless images do you want to struggle with as a percentage of good or even great images? How much frustration do you want to pack into your equipment bag to lug out to the viewing spot with you? How much (or little) support do you want from the manufacturer in getting the most out of your investment?
At SBIG, we never forget that your time is valuable. We work very hard to eliminate the frustrations and maximize the value you get out of each hour you spend imaging the night sky. We value your time as much as we value our own, because we are amateur astronomers like you, from the CEO on down. We understand what you seek to accomplish, and make our products to get you there more enjoyably and with better results.
Unpack the frustrations that come with cheaper cameras by packing in an SBIG camera instead.
OK. I will get off my soapbox and discuss some options in more detail!
High-end digital cameras: I have personally used a Canon 10D and was quite impressed with the images I obtained. There is an incredible amount of engineering in these products. It’s great that one can use them for general photography as well. However, they have no guiding capability, so one needs to acquire a guider to go with it. The filters are optimized for general photography, but several websites discuss how to remove the infrared blocking filter in the camera. Of course, after removing the infrared blocker, the color balance is bizzare on daylight scenes, so filter removal wrecks the camera for general photography. My opinion based on my limited experience is that these cameras are a great alternative to film astrophotography, but do not have a lot of the features that our cameras have incorporated to simplify the amateur’s task. In general, they have no focus mode, no guiding, no cooling, no shutter for taking dark frames, and, in the case of the 10D, required timing long exposures with a remote shutter release and a stopwatch. Most of the available software is not really optimized for astronomy, either. However, I don’t want to sound too negative – they are really a different type of product from ours that has substantial utility for astrophotography – just like a film camera.
Modified WebCams: Here I have stronger feelings. Most of these cameras have no cooling and were optimized for short exposures, but have been modified for longer exposures. They work, and the price is really attractive, but one is forced to sum a lot of short exposures to get a usable result on deep sky objects. They produce interesting results when used at fast F/numbers like F/3.3, where the sky background can overwhelm the read noise in exposures of 30 seconds or so, but will be disappointing at the slower F-ratios typically used when imaging the smaller objects in the sky. The results posted on the web for planets have been particularly impressive, where read noise is not such an issue. I have used these and found that I had to work pretty hard to capture what was, at the end of a half hour at the telescope and an hour of image processing, a mediocre deep sky image. If I had never taken an image before, I might have been impressed. However, an ST-402 image of similar exposure under the same conditions was dramatically better. Of course, ST-402s with color filters are more expensive, costing around $1495. I would like to point out, though, that for exposures under 5 minutes, the ST-402 will take an image the equal in sensitivity of our highly regarded STL-6303 and ST-10XME cameras – the quantum efficiency is the same, the filters are the same, the dark current is comparably suppressed, and one has a shutter for darks. Our CCDOPS software is highly optimized for astronomy, which REALLY helps. So, for $1495 you do not get a poorer camera, you get a smaller camera, with less pixels, but sensitivity as good as anything we sell.

Just for fun – an unguided ST-402 image of M42, the Orion Nebula, captured with an Orion Star Blast (4 inch aperture, 16 inch focal length - $169), mounted on a Losmandy G11 mount. This required a 30 second red, 30 second green, and 60 second blue exposure. CCD imaging is amazing!
Another point to consider is that the digital cameras and webcams are severely limited in what they can do – they are virtually all single shot color, with ambiguous digitization bit depths and unknown linearity. Our cameras all produce photometrically accurate data with careful use, and can be used by an amateur interested in participating in monitoring and search programs that are often described in the popular magazines. Lets face it – a modified webcam will never take a deep sky image to rival what can already be found all over the net, and after one realizes this after a few sessions at the telescope, discouragment will cause many to abandon the hobby. With our products you don’t have this ceiling – you can help professionals with many research opportunities, investigate spectroscopy, or use them as a highly sensitive guider. And, as I mentioned before, our larger cameras will not take better pictures of the smaller objects – you just get more sky around them.
But HEY – it’s your life! I am being a little facetious here, but the bottom line is it takes the same amount of time at the telescope regardless of which camera you use. Imaging can be a chore – dragging out the telescope and a table for the laptop, polar aligning, finding and focusing the object, taking a sequence of images while your fingers freeze, or the mosquitos feast, or something sneaks up on you from a nearby bush, and then tearing it all down in the early morning when you are tired, and spending considerable time processing the image to its limit the next day. Do you really want to save a few dollars on the camera, or do you want to know that you achieved the best image possible with your telescope and mount? Would you buy a car that would only go 55 miles an hour even if the price is very, very good?
The camera you buy today will last for years. Make the most of the precious hours you spend under a night sky by getting the right equipment the first time. As I noted above, we think your time has great value, and we value it like no other astrophotography camera manufacturer. That is why SBIG camera solutions give you superior images while simultaneously saving you time and minimizing frustrations. Folks say “you get what you pay for.” That goes in spades for astrophotography cameras!
SBIG cameras: Simply the Best Value for Serious Astronomers!
Looking Back: SBIG Interviewed at NEAF 2011
As we look forward to sharing all the news SBIG released at last week’s AIC, here is a quick look back at Sky & Telescope’s inverview with SBIG’ Ron Bissinger and Alan Holmes at this year’s NEAF. Ron talked about his plans for SBIG as its new CEO, and Alan shared details about products we had released over the previous 12 months, including the all-sky camera, the ST-i autoguider and new accessories for the ST-8300.
More than You Ever Wanted to Know about Autoguiding!
By Alan Holmes, President of SBIG
SBIG has been in the autoguiding business for 22 years and has learned a lot over that time. A lot of that learning went into our newly released ST-i guider. Indeed, we make a strong claim that, coupled with a 100 mm F/2.8 lens, it will perform quite well as a guider. There is good science behind this claim. Get the details in a paper I wrote here.
When we started with autoguiding with our ST-4 back in 1989, we stated, with only anecdotal proof, that a focal length half that of the imaging scope’s focal length was a good choice. It was an educated guess that seemed to work based on our experience, but using our new ST-i autoguider, I now have a new answer to this question with some data to back it up!
Click here to open the full paper.
It always feels great to be able to make a definitive statement! There are urban legends in CCD astrophotography that came from me that are still circulating, and I need to correct them.
I look forward to your reactions to all of this. You may comment here, send us a note to sbig@sbig.com, or place a message in the SBIG Yahoo User Group.
