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Starting Astronomy..

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Putaendo Patrick

Putaendo Patrick

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Unless you buy a special zoom eyepiece, eyepieces used in telescopes are fixed magnifications. So you change the eyepiece to change the magnification. Start with the lowest magnification and gradually increase.

You probably have two eyepieces in the box with your telescope, 20mm which will give x33 magnification and 10mm which will give x65. You will probably find the 20mm quite adequate for the moment, but you may not be so lucky with the 10mm.

To look at the Moon in detail and the planets at higher magnification, you might consider getting a 5 or 6mm eyepiece in the future. However I would use what you have for the moment. In the UK a decent 5mm Plossl eyepiece will cost from around 25 pounds new up to several hundred pounds for really top optics. Plossls are good - but have short eye relief so can be quite uncomfortable to use, the BST Explorer series (also branded as Starguider and Paradigm) are well considered and are more comfortable but cost about 50 pounds each.

If you enjoy observing the Moon but find its brightness uncomfortable, you can buy an inexpensive basic Moon filter - or you can use sunglasses! Personally I would not buy any other filters for the moment - to start with, there is plenty to see without them and often their effects are really quite minimal.

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ronin

ronin

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You do not really need a filter of any sort, I have managed happily for the last 16 years without any, and feel no great desire to rush out and buy one of any sort. A big problem of any filter is understanding what they do. For example a blue filter does not make the image "bluer", what it does is remove the Red and the Green and it leaves only blue. The filter has removed wavelengths. When people talk of making it "bluer" they are really talking of making it less red and green. Substitute any other colour for "blue". For now and in my view jsut about forever just get as much light down to your eye as you can.

Use the eypieces that yopu have, the long one will give the widest field of view and the least magnification of the object. The shorter one will therefore deliver the narrowest field of view and the greater magnification of the object.

Do not head off to buy the smallest focal length eyepiece you can track down. You likely have a 10mm and a 25mm. Generally the 10mm is not good, so that means you are likely going to want another shortish one. An 8mm plossl will likely be about the best for high magnification. Guess the scope is 50mm focal length - may be more - so an 8mm will give just over 80x magnification. That is fine for just about 95% of things. Saturn next year (July ish) may need more but that is 8 months away.

Eventually I guess 8mm, 12mm and 20/25/30mm and for high power a 6mm of some variety.

A plossl eyepiece is reasonable but the eye  relief is a function of the focal length, about 2/3 or 70% use which ever is easier for the mental arithmatic. So for shorter foval lengths you have to get your eye closer to the eyepiece. 8mm plossls are about the comfortable limit, hence the comment of a 6mm of some variety - it may not be a plossl.

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Stu

Stu

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22 minutes ago, ronin said:

You do not really need a filter of any sort, I have managed happily for the last 16 years without any, and feel no great desire to rush out and buy one of any sort. A big problem of any filter is understanding what they do. For example a blue filter does not make the image "bluer", what it does is remove the Red and the Green and it leaves only blue. The filter has removed wavelengths. When people talk of making it "bluer" they are really talking of making it less red and green. Substitute any other colour for "blue". For now and in my view jsut about forever just get as much light down to your eye as you can.

Use the eypieces that yopu have, the long one will give the widest field of view and the least magnification of the object. The shorter one will therefore deliver the narrowest field of view and the greater magnification of the object.

Do not head off to buy the smallest focal length eyepiece you can track down. You likely have a 10mm and a 25mm. Generally the 10mm is not good, so that means you are likely going to want another shortish one. An 8mm plossl will likely be about the best for high magnification. Guess the scope is 50mm focal length - may be more - so an 8mm will give just over 80x magnification. That is fine for just about 95% of things. Saturn next year (July ish) may need more but that is 8 months away.

Eventually I guess 8mm, 12mm and 20/25/30mm and for high power a 6mm of some variety.

A plossl eyepiece is reasonable but the eye  relief is a function of the focal length, about 2/3 or 70% use which ever is easier for the mental arithmatic. So for shorter foval lengths you have to get your eye closer to the eyepiece. 8mm plossls are about the comfortable limit, hence the comment of a 6mm of some variety - it may not be a plossl.

Whilst I agree with Ronin that there is no need to buy any filters at the moment, the comments about their usefulness are not something I agree with.

Specifically filters like a good UHC or OIII can greatly enhance an object, in a few cases turning it from invisible to visible. This is achieved, as said, by cutting out all the unwanted frequencies of light including that from street lights and light pollution generally.

So, my advice is to crack on using the kit you have and learn about what you like and dislike before spending any more cash. Ask questions on here and over a period of time, decide which eyepieces or filters may suit you.

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