What's the best UHC filter ?

[spaceboy]

Really did'nt get on with the Celestron LP filter I bought a few years ago, in fact its the only bit of kit I have ever damaged, dropped the sod and it cracked the glass, is still in the accessories case taking up space!

I think this is another one of those incorrect labeling thing. The celestron LPR is actually a UHC and so is far more aggressive so ideally needs to be in a larger scope with a good exit pupil EP.

[Moonshane]

TBH tho Shane I think the problem I am then going to have is fitting the extension into the focuser

you might be right but worth a try for sure!

[Nexus 6]

I think this is another one of those incorrect labeling thing. The celestron LPR is actually a UHC and so is far more aggressive so ideally needs to be in a larger scope with a good exit pupil EP.

Ye, I did buy it for use with the 6se I had and found it darkened the sky sooo much! I had no decent ep's at the time so maybe was a bit hasty in my appraisal of it.

As we tend to do, I was buying a lot of kit I thought was pretty much essential soon after buying the scope, if only we knew what is reallly important.

[bish]

I have found LPR's a total waste of time. OIII IMO is the best filter going and all of the nebs I've used them on POP! The UHC dose bring out some detail but not as well. The only reason why I insist on having both is because it costs me time and money to journey to my dark site so I want to make sure I get my monies worth.

Think I will go for the Oiii first then. If these castell are decent enough as seems to be the opinion then it only means spending £40 or so.

[spaceboy]

you might be right but worth a try for sure!

Already attacked it with the lathe. The stop is now 10mm further down the adapter touched up with black paint and the EP & filter now fit a dream. Hoping it stays clear tonight so I can give the vail another go

[Lowenbrau]

I use Lumicon UHC, some extensive reading and comparing 2-3 years ago made me choose that one. I like the narrowest bands as I use relatively larger instrument. Castells are common here, at almost 3 times lower price you'll surely be satisfied. It's wider though.

Consider 2" UHC, which is double the price, but double the usability as well. I have other filters in 1.25", but I've chosen 2" UHC for general purpose, before zooming in to smaller EPs.

[euphony]

Interesting read this thread, and a lot to digest.

I bought this:

http://www.firstlightoptics.com/light-pollution-reduction/skywatcher-light-pollution-filter.html

It was the cheaper one on offer and I'm not convinced so far that it makes any difference to what I am able to see. It may be that I have not had the best skies to view through properly yet though, so I'm going to hold fire until I make a definitive conclusion. I was thinking of going for a more expensive one when I have the cash, but want to be absolutely certain that this one isn't making much difference first.

Chris

[Lowenbrau]

Again, that's not the narrowband UHC filter. Big differences on dark sky, yet that one might be a bit better "general purpose" filter for all skies and smaller scopes.

Just to update, I was bothered by a big scratch on my Lumicon UHC and I ordered a pair of UHC filters from DGM Optics(both sizes). They call is NPB (Narrow Pass Band) They're available directly from the manufacturer from ebay.

Reading direct comparison I realized they're quite similar to Lumicon in bandwidth (not too narrow but definitely not wide) but a bit sharper and superior in coatings. Lumicon UHC is hardy available anywhere anymore for decent prices. Here in Europe is 200 euros which is too much I reckon.

[TheLookingGlass]

http://www.prairieastronomyclub.org/resources/by-dave-knisely/filter-performance-comparisons-for-some-common-nebulae/

Certain filters should be used on certain targets for the best views like what is in the list in this link!

Cleat skies

[TheLookingGlass]

Some come close, some are tied, but the one filter that got the highest ranking was the UHC filter.

Bandpass is the importand aspect of a filter, along with the exit pupil used.

it is not true that the O-III is best suited for a smaller aperture scope. You just need the right size exit pupil and the right target.

[TheLookingGlass]

important*

[BGazing]

I know this is an old thread, but exit pupils aside, OIII works better in a dark site, UHC better in pollution, and UHC-S is a better versioon of UHC for small aperture. Also, Castell is good...did I miss anything?

[BGazing]

Bump...sorry...a question.

Does every UHC filter have the same color shift? My Castell UHC, which, it appears, is on a very soft side for a UHC (basically between the more narrow UHCs and the LPfilters), tints everything green. Shouldn't it be more of a green-blue tint with a bit of red as well (if passband diagrams are to be believed)?

[YKSE]

There are color shift among diffferent UHC filters if you look at some filter graphs. If an UHC filter is perfect, if should only let through light in about 485nm to about 501nm, which we can see here that it should be only blue and green lights. Rd tin means it has "red leak" - some (bright)stars will show red color. Many UHC filter do have "red leak".

Another missconcept about these DSO filters (UHC, OIII and H-beta) is that you need aperture  to get it work better (8" is an often mentioned number), while Lumicon's recommendation here(page 4 and 5) is ONLY exit pupil size, nothing about aperture. I've used all 3 filters with my scopes from 80mm to 200mm with good results. They work in light-polluted backyard, but they really shine under dark sky.

[BGazing]

1 hour ago, YKSE said:

There are color shift among diffferent UHC filters if you look at some filter graphs. If an UHC filter is perfect, if should only let through light in about 485nm to about 501nm, which we can see here that it should be only blue and green lights. Rd tin means it has "red leak" - some (bright)stars will show red color. Many UHC filter do have "red leak".

Another missconcept about these DSO filters (UHC, OIII and H-beta) is that you need aperture  to get it work better (8" is an often mentioned number), while Lumicon's recommendation here(page 4 and 5) is ONLY exit pupil size, nothing about aperture. I've used all 3 filters with my scopes from 80mm to 200mm with good results. They work in light-polluted backyard, but they really shine under dark sky.

thanks, a very useful page. it seems, though, that it confirms that the small scopes (such as mine) would struggle with the oIII filter with anything but the longest ep focal lengths (as the exit pupil would be lower than 2mm.

[YKSE]

I'd like to think that it's your scope's slow focal ratio combined with 1.25" focuser is the limiting factor for using(or even finding) eyepieces with larger exit pupil. Scopes with moderate speed (f6-f8) are among easiest to find very good range of suitable eyepieces without much cost.

[JOC]

No sense in starting another thread, but thanks to SGL classifieds (the downfall of my bank balance) I am now the proud owner of:

1.  A 2 part polarising filter of unknown parentage marked Variable Polarizing Filter #3 (if anyone has any ideas on parentage I'd be interested - I note English spelling of Polarizing)

2.  A Skywatcher UHC filter - a lovely purple, greeny reflective surfaced object 

3.  A Skywatcher Light Pollution filter - a transparent violet/purple colour

It is my intention to use the polarising filter on the moon (assuming we ever see it again with all this cloud).  The light pollution filter when I look North over my adjacent factory lights and West when I look out over the glow of towns and villages and the UHC filter when I look at M42 and when I try to find other Nebulas.

So as a novice why did I buy so soon?  Well, I was always interested in having a polarising filter - I have always used them in photography and an quite familiar with their effect, and the UHC is often mentioned for nebulas, both those came up usefully in the classifieds.  The LP filter just happened to come along at the right time and seemed a useful gain.  I think these feel like a potentially useful set of filters for a novice.  A couple of questions if I may please:

A.  If I look for nebulae in my light polluted areas is there anything to be gained in stacking the LP and UHC if not will one be more use than the other?  If so which please

B.  Do my perceived uses seem reasonable and given what I have are there other subjects which I might notice a benefit to using any of them on please

 

[John]

On the stacking question, there is no harm in experimenting but as far as I know there is nothing to be gained from stacking the LP and UHC filters.

I did try a couple of broadband LP type filters in the distant past but they did little or nothing for me. The breakthrough came when I got a UHC and then an O-III. Those seem to deliver much more tangible results, especially the latter.

 

 

[LukeSkywatcher]

I use the Skywatcher UHC and OIII filters. Cheap enough but they work very well in my opinion. The Castell also gets very good reviews by people who use them.