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UHC-S filter worth buying for 90mm MAK?


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Last night I spotted the Ring Nebula for the first time. As expected it was a very very faint dark gray circle but nevertheless I was thrilled! I live in a horribly light polluted city as well as have some of the worse air quality regarding particulates (Rubbish in the air) in the country and also deal with weeks of +100F temps which is currently happening. I'm pretty sure all this makes veiwing conditions atrocious and I'm taking the scope to the pitch black mountains soon and was wondering if a UHC-S filter is worth buying to bring along.

What can I reasonably expect using this filter on my scope? Will I see any color to the Ring Nebula?

Is this filter usable on a small scope like mine with the unfavorable sky quality where I live? Any advice is appreciated.

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Colour in deep sky objects is notoriously elusive even in large scopes so I don't think the filter will show it. It will increase the contrast in nebulae such as the Dumbell, M42 etc and in some cases, such as the Veil and Owl nebulae may enable you to see something rather than nothing !

You may find a standard Skywatcher UHC slightly more effective than the UHC-S, even with a 90mm.

I you buy your filter used then you will probably be able to recoup your investment if you find it's not to your liking.

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Great idea taking your scope far away from city lights this will help immeasurably.

As John said colour is tricky and from what I can tell is often down to aperture, focal ratio and the individual observer themselves. I have seen colour in the ring nebula through large fast scopes at low power. But I would think it would be pretty much a no - no with a small Mak.

Have fun up there in the mountains. :)

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I confirm John's comment that the SW UHC filter will be better for you and your scope aperture, the Ring will look like a small grey smoke ring, and the Dumbell will look stunning, albeit grey like all DSO's.

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Thanks to all. It looks as though they don't sell the Skywatcher UHC in the states :( All in all I'm thinking it's pretty much not worth investing in this type of filter for this scope. Off topic, what kind of scope works best for DSO's?

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What works best for DSO ?, basically the largest aperture reflector you can afford, as in the Dob range for example. With regard to Nebula filters, it is quoted by the authors of the of The Illustrated Guide to Astronomical Wonders, that although it is heard that these filters are only good for scopes above 6", they were able to observe the North America Nebula with an O111 through an 80mm refractor from a dark site in the States, if you are going to a dark mountain site it could be worth your while if you could pick up a s/h filter before you go, from somewhere like the Cloudy Nights forum. If you are anticipating going on the DSO trail in the future, it would be helpful to have one in your kit anyway. just a thought before you shelve the idea entirely :)

John.

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There are other good UHC filters out there. Have a look at reviews on Cloudy Nights for ones available in the US. No all objects respond well to a filter. A UHC filter will help with DSOs, even in your Mak, but be aware that the light lost to the filter means that your highest useful magnification goes down to about 7x per inch (give or take). So don't expect the filter to provide a better view of small DSOs, like the Ring. Just use higher power for those. The filter will help with larger ones, which can be viewed at low power. e.g. M8 and NGC7000. However, to really go after DSOs you should hang up the Mak and go with a Dob. 8" to 12" would make a fine DSO observing platform.

The reason you don't see colour in DSOs is because there isn't enough light available to activate the cones in your retina. The only way to see colour in DSOs is in photographs or if you are lucky enough to get a look through a giant, observatory class, telescope. Filtering is only going to decrease available light and so can't possibly create a situation where a DSO becomes coloured.

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Hi Veegs23, the light pollution really does create problems for faint nebulae, filters are fine, but as said previously the more "specific" filters offer very narrow spectral lines - so narrow band filters such as OIII really do darken the field of view, give false colour stars.

I've tried the UHC - S in my small Mak and they do improve the "appearance" of certain nebulae, but as you increase aperture these nebulae become brighter and brighter - visible in the 127mm Mak, but in the 11" Celestron they become absolutely breathtaking - nothing like the photos and images produced in the press and on here - but really amazing, the other night I was looking at M27, M57 with my OIII Lumicon filter. Since owning the larger Celestron I've only had limited use due to weather here in the UK - but from very light polluted skies where I observe from, very impressive on the brighter nebulae with the OIII, the increased WOW factor with the filtered view as opposed to the non filtered view will stay with me for a long time.

Remember, these objects are very faint and the light from them has travelled vast distances to reach our back gardens - so just to see them against a sky when , due to light pollution, only the very bright stars in each constellation are visible is a triumph in its own right. I have never travelled to a dark site to observe - so I only have my polluted sky to comment on, we all seem to observe from different sky conditions from very light polluted to pitch black skies, we all understand that certain objects are never going to be seen but this is only due to the conditions we have to put up with, so just finding them is a milestone.

Sounds like you have the best of the both sites - it would be nice if you could give us all a report/comparison from the 2 sites. Hope that helps a little - sound like "aperture" fever is due to set in shortly. Paul.

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I use a UHC-S with my 150 newt under pretty bad LP. It does help lots with nebulae but you do lose a lot of light and the dimmer stars just vanish hindering star hoping. Your scope has less light grasp and so will suffer more from light loss with a UHC-S. A wider band width filter will work better for you :smiley:

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