thank you very much for replying.
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Originally Posted by mental4astro
what do you want to achieve with the filter?
You say you "need to buy a filter"- why?
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i need the filter to clear the details of the planets and moon. i observed before some planets with a small telescope and they appeared just as a white/brown disks.
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How big is you scope to say you can't see DSOs from the big smoke?
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this may seems strange, but i don`t have a telescope yet. i was joining an astronomical competition, and i hoped to get a telescope in it. so i started to search for the telescope accessories (because i need to buy a telescope soon even if i will not get it in the competition). anyway, the most likely is that i will not buy a telescope more than 3 or 4 inches, so i don`t expect that i would observe DSOs with it and i live in the city.
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Filters are tricky things. They can "help", but they don't solve all your problem. Remember, filters will reduce the amount of precious light that your telescope is gathering for you.
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i know, but the planets and moon is a bright object, and lossing a bit of brightness would not make a big different. on the other hand, the brightness will not be useful if the details is unclear.
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The advertisment doesn't convince me that it is nothing more than a glorified colour filter, around the one known as #80A Blue. Maybe with a little added violet. It really will only help you with some Lunar and planetary observations. It can't help you with deep sky objects as it is actually reducing the very spectrum at which nebulae glow at, other than a little blue- but our eyes are not very sensitive to this part of the spectrum, especially at low light levels, so it is of no real help. The ad does mention that this filter cannot take the place of a dedicated nebula filter, but it doesn't mention that you won't see more with it either.
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how much it will be useful with the planets? i don`t know actually, it is not likely that i will observe a DSOs, at least not very much, and i think that a good filter for them will be much expensive.
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You say that you can't see deep sky objects from where you are. If you describe where you are city wise and site wise, we might be able to give you some tips on how to improve your situation (other than knocking out the power grid, ).
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"tips"? like what? i live in the middle of Jeddah city.
thank you for the link. but i can`t buy any good filter, i can`t pay a big price, so i need to know how much is that filter useful than other cheap filters? if you know a better filter under 40$ i will buy it.
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What I'm getting at is I mainly just use my own eyes to do the majority of my observing. I'll give you an example. On one occassion at a star party here in Sydney, with poor seeing conditions, we tried some galaxy hunting using my 17.5" scope. My 40 year old eyes could see a really faint smudge of a galaxy where a 17 year old couldn't. That was only due to experience- not filters. See what I mean?
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it is not my problem if you have a sharp eyesight and i don`t
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