TELESCOPE FAQ PART 5 - Accessories! Accessories!
by adminIn Part 4 we covered your telescope’s mount and how to choose one. In this part we will discuss all of those things that come with, or are added to your telescope to make it function, make it function better, or just do something nifty!
The sign of a lower quality telescope: If you buy a cheap department store telescope odds are they are going to give you a lot of accessories in the box. This is for several reasons: 1) It looks like you are getting more for your dollar 2) It lets them brag on the box copy about impossible magnifications (i.e. 50mm telescopes claiming they can get 800x) and c) means that the company doesn’t need to bother with a support parts infrastructure.
Trouble is, all of these accessories are likely junk or very close to it. They will function, but just barely. It is a shame as some of these accessories are important parts of the telescope’s optics.
Let’s cover the accessories category by category:
EYEPIECES: These are often overlooked, but they are more than half of your telescopes optics! Most telescopes usually come with 2 eyepieces, cheap models often come with 3, and a few rare models come with just 1 (but a good one!). Look closely at the eyepieces that come with your telescope - if they have ‘H6′ or some other number then they are not good quality. That ‘H’ stands for ‘Huygenian’ and it is a eyepiece design that goes back to the 17th century! This was acceptable in the infancy of telescope but there is no excuse for using it today beyond making things as cheaply as possible. Try to get a telescope that comes with Kellner or Plossl eyepieces bot are more modern designs but are still at a reasonable cost for beginner telescopes.
Related to eyepieces are barlow lenses. These are optics that you insert your regular eyepieces into and get double the power. The main trade-off is that you are adding optical glass to the system (which reduces light) and the barlow will not be part of the original eyepieces optical system (which can reduce image quality a bit). Like eyepieces, barlow vary dramatically in quality from junk to superb. Few good quality telescopes will have barlows included but many cheap telescopes will have 1 or 2 (usually one is called an ‘image erector’)in the box. That way they can advertise ludicrously high magnifications that can be obtained (sorta) by using the high power eyepiece and the barlows. The images you would get with these combinations are simply not worthy of any serious discussion.
FILTERS Better designed telescopes usually do not come with filters, but one should consider getting some for their special purposes (filtering moonlight, colored filters for planetary viewing, and light pollution filters). Some low end telescopes might have a moon filter of some sort (usually just a piece of green glass). Some models might have a ‘Sun Filter’ included that threads onto the included eyepiece and let us give you some advice about these:
If you have one throw it away. NOW! Never EVER use it!
These ’sun filters’ are not in any way safe and you can permanently damage your eye using one and it fails for some reason (usually overheating and cracking). They are dangerous enough that even the cheap telescope makers have mostly stopped packing them with their telescopes and instead add some kind of solar projection system - which while not perfectly safe is miles above the ‘filters’.
FINDERS These are the little telescopes that go on top of your telescope to help you aim it. At the low end there is a split between using cheap 5x finder scopes and ‘red dot finders’ that give magnification but are much easier to set up and use. At the low end, the red dot finders usually win out. The low power finders just don’t work so well as you might think and are a case of trying to do a low-cost version of what the bigger telescopes do. Starting with intermediate level telescopes you should get a finder scope more worthy of the name, and perhaps more importantly a bracket that allows you to change a different finder model if you prefer.
OTHER STUFF There are plenty of other things out there to help your viewing experience: accessory cases, telescope bags, motors, fans, flashlights, tools and so forth. Most telescopes, even good ones, probably won’t come with these in most cases (some telescopes that double as spotting scopes will often come with a carrying case). Consider getting these if you think your needs might make them useful. One accessory we always recommend is a Planisphere. Be sure to leave some money in your telescope budget for some accessories - they really will enhance your viewing experience.
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