My Advice for Beginners
Before entering a hobby that can be demanding, time consuming, sometimes frustrating, and usually expensive, it makes sense to ask yourself what you want from the hobby. Do you like to work with and build equipment? What do you want to take images of? Are you looking for public recognition or just private satisfaction? Are you interested in near perfection or just taking a few images where quality is less important? What will your images be used for? Knowing the answers to some of these questions can help to point you in the right direction when it comes time to start buying equipment.
You will need a camera designed for astronomy. Although some have had success with using consumer digital cameras for very bright objects like the moon, most sky objects are too dim for the short exposures these cameras are capable of. The camera should be cooled, usually by what is called a Peltier cooler, and should be capable of long (up to an hour or more maximum) exposures.
You should have a camera that is somewhat matched to the optics it will be used with. First, you should consider the field of view that the camera/optics will give you (for making sure the ojects you want to image will fit). Second, you should make sure the pixel size of the camera will yield a decent sampling with the optics you plan to use. If the pixels are too big for the optics, you will get blocky, poorly-sampled stars and objects. If the pixels are too small, you will waste sensitivity. Fortunately, there is a fairly wide range over which things will work just fine.
There are a few one-shot color cameras out there. Although these are OK for quick color work, they lack the resolution and the versatility of color images taken by swapping filters in front of a regular greyscale camera. It is probably best to start with greyscale imaging and work up to color. This is also a somewhat cheaper way to start.
To guide or not to guide?
That IS an important question! For me, the short answer has been yes. Although there has been some very nice work done with unguided systems, most of the higher quality work done by amateurs has been done with guided systems. The magnifications present at all but short focal lengths tend to show any drift very quickly.
How to guide?
- Manually with a guidescope or off axis - this has been done successfully, but is not very common, takes a lot of skill, and is difficult to acheive good results with.
- Autoguide with separate autoguider - this can also be done and a few of my older images were done this way with good results. It takes a bit of patience to work well, however, so it can be a bit of a pain to set up each shot.
- Guide with an autoguiding camera - Right now the only cameras to do this are the several of the SBIG cameras which have a built-in separate guider chip. Although a bit more expensive, most imagers that have used these units would agree that their ease of use and guiding ability make these cameras worth the cost. Many of my images were taken with an ST7, ST8E, or ST10E.
The answer to the question "What is the most important piece of equipment?". Since the early days of astrophotography, there has been clear agreement that the mount is the most important part of the system. In my opinion it is even more important than the camera itself. This is where you should put you money. It should be heavy duty, stable, and track precisely. It should not be overloaded. Bells and whistles like GOTO are great, but they only help you get to the object and are of no use in producing a clear image. If you have a choice between a good non-GOTO system and a fair GOTO system, get the good non-GOTO system. Of course, if you can afford both, systems like the AstroPhysics GTO mounts (my choice) or the Bisque Paramount are great! If you have a choice between buying a mount that is heavier than you need or one that "just makes it", get the heavier one. If nothing else, you may decide to get a bigger scope later!
As mentioned above, the optics should be matched to the chip size and pixel size. They should be of reasonable quality and of a design that makes sense from a camera mounting and use point of view. Commercial SCTs have been used with great success as have medium sized refractors and even camera lenses. Newtonians can work well, although camera mounting can be a bit of a challenge. Excellent optics are great if you can afford them. I currently use an RC Optical Systems Ritchie Cassegrain.
For collecting images, nearly any computer, even the older, slower ones will work fine. Most cameras work via the parallel port, so even a laptop should be OK. There are a few systems that require an ISA or PCI slot for a proprietary card and these systems require a desktop computer. For processing images, the speed and memory requirements are dependent on the number of pixels that your imaging camera has. Sub-megapixel chips like that used in the cookbook camera or the ST7 can get by with less power. Larger, megapixel cameras such as the ST8, ST10, or similar need more computing power to process images.
Location, Location, Location!
One of the reasons CCD has become popular is the idea that images can be made from light polluted locations within populated areas. This is true to a degree, but it is also true that to get really good results, it is still better to get away from light pollution. It all depends on how serious the user is about quality!
I hesitate to make specific recommendations on the advice page since there are too many user-related variables to consider. If you have any questions I would be happy to try and answer them. Recognize that like most users, I have experience only with the equipment I have used, so may be hard-pressed to give totally accurate comparisons.
Listed below are those manufacturers that have web pages:
General Equipment (Note: You can buy most of the listed manufacturers from Anacortes)
These pages created and maintained by William McLaughlin
All images copyright William McLaughlin