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Post by Deleted on Oct 2, 2014 21:24:28 GMT
ok i have a ir/uv filter.
do you use it all the time ? or as needed ?
Ha filter are they worth it ?? needed ?
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Post by Dragon Man on Oct 3, 2014 9:01:46 GMT
Phil, IR/UV filters help in certain situations, like when using an Achromat Refractor. But I use an ED80 99% of the time and find I don't need it, and without it makes faint arms in Galaxies show up better. That is because the IR/UV filter does block a very small percentage of light, but enough to make very faint objects almost undetectable. Without the filter I do get a very small amount of Star Bloat but it is hardly noticable. I know some people using ED80's still use their IR/UV filters. I have tried several times "with and without" tests and I find only a small difference in star quality but do notice that faint galaxies and faint extremities of Nebulae do show up better 'without' the filter. But if you use an Achromat you need the filter to help prevent bad Star Bloat and Chromatic Abberation. It doesn't stop the problem entirely but helps reduce it. I can't answer for SCT's or Reflectors as I haven't tested them 'with and without'. There are also different grades and quality of IR/UV filters. Each manufacturer has a slightly different cut-off point in the spectrum, and some are atrocious and make the view even worse. So far, the best I have used is the Astronomiks UV/IR 'L' filter: www.astronomik.com/en/photographic-filters/l-filter.htmlSecond best I have used is Hutech's IDAS: www.sciencecenter.net/hutech/idas/uibar.htmThird best I have used is Baader: www.company7.com/baader/options/ir-uv.htmlThe worst one I have is the cheap GSO type IR/UV, and IR Filters. These cheap ones send the whole image yellow! I've never used a HA filter so I can't help with that.
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Post by Deleted on Oct 3, 2014 14:54:10 GMT
awsome info ... yeah i did notice a difference wwith without ir filter.. iam sort of thinking what a waste of money it was.. lol
off to read up on them links..
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Post by Dragon Man on Oct 3, 2014 15:13:18 GMT
Another thing I forgot to mention is that another good reason that faint galaxies show up slightly better without an IR/UV filter is because there are a lot of IR and UV objects in galaxies and the filter cuts them out! The stuff we don't want to see in our own galaxy while trying to look at an object in our galaxy is desirable when we see it in a distant galaxy because it makes up the whole galaxy. If you know what I mean
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Post by Deleted on Oct 3, 2014 18:22:10 GMT
as you lookin in my window ? lol
yep yep. i get what your saying. like we in the fog. but dont want to see it. yet we want to see the fog from far away in other galaxys. so we use fog lights.
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Post by Dragon Man on Oct 4, 2014 11:47:24 GMT
Yep, excellent analogy
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