Author Topic: Difference between Lumicon UHC and Deep Sky filters?  (Read 223 times)

ruesonecrai

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Difference between Lumicon UHC and Deep Sky filters?
« on: December 30, 2017, 11:01:30 AM »
I am unable to determine the difference between the Lumicon UHC and Lumicon Deep Sky filters. The product description of the Lumicon Deep Sky filter says its Lumicon's "most popular nebula filter" and claims the same stuff as the UHC. So what is the difference then between the UHC and Deep Sky filters? From my reading on CN, it looks like no one is using the Deep Sky filter but everyone has the UHC filter.

Thanks



ingaslobull

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #1 on: January 10, 2018, 02:43:02 AM »
I usually find that my deep sky filter gives better views when I'm close to home and the UHC is better when I'm away from the city lights.
But it also depends on the particular object sometimes the OIII blows them both out of the water.

wordpuzzlesubc

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #2 on: January 11, 2018, 03:07:42 AM »
I have owned the Deep Sky, OIII and UHC. I have never really found a good use for the Deep Sky. It just darkens everything too much. If I had to have just one, it would be the OIII, but the UHC does have its uses too.

Guy Cleveland

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #3 on: January 12, 2018, 06:47:54 AM »
Manufacturers should not make claims like that. They are significantly different filters for different purposes. Two important criteria are passband and bandwidth. The passbands of the 2 may be fairly similar. The bandwidths are not. A UHC filter, to be most useful to most users on most nebular objects, will be a narrowband filter as the Lumicon is. The Deep Sky filter is a classic broadband filter. Several years ago I tested a range of broadband filters, UHC and UHC-type filters against each other on a range of nebulae in several different aperture scopes from both my very light polluted driveway and the rural dark site the club maintains. The results caused me to try and sell and then try and give away the broadband filters. I think they're still in a back closet. I know I got no takers. Nothing is going to make the objects I like to observe, galaxies and nebulae mostly, visible from my driveway. So I drive up to the dark site and see them very well.
The Lumicon UHC filter is an excellent choice if you want to increase the apparent contrast of many nebular objects against the surrounding field.
An O-III filter has an entirely different passband than a UHC or UHC-type and to work well should certainly be a narrowband filter. They too are very useful, but on a different set of objects than a UHC though there are overlaps in the applicability of the two.

opalytun

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #4 on: January 16, 2018, 10:59:25 PM »
Lumicon Deep Sky:
https://www.optcorp....sky_chart_4.jpg

Lumicon UHC:
http://www.owlastron...images/UHC2.jpg

Look at the wavelengths that are passed vs blocked.

larterpchaka

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #5 on: January 17, 2018, 12:56:36 AM »
Somewhere I have an old Deep Sky filter that's gathering dust too. As mentioned, the Deep Sky is only (slightly) better from highly light-polluted areas. If you're in a decently dark sky, the UHC is a much better choice. The O-III is fantastic but only a much smaller number of select objects. If you only get one filter, make it one of the high-quality UHC-type filters (those include Lumicon's UHC filter, DGM's NPB filter and Astronomik's UHC). Mainstream scope manufacturers' lower-cost nebular filters typically don't measure up performance-wise in field tests.

Randy Wiggins

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #6 on: January 31, 2018, 12:46:17 PM »
That DeepSky filter comment was on the Lumicon website forever. Maybe it was true once but has probably not been the case for a long time now. I like having a broader band filter but have somewhat retired my DeepSky in favor of an Optolong 'UHC' that has an ideal bandpass for these filters IMO and passes H-alpha. The DeepSky passes the main Swan bands of comets that is good for comets and mostly bad for everything else.

You'll want to be careful buying Lumicon filters for now. They no longer make the high quality O-III and it's still unknown what exactly the UHC is. Also careful with eBay, the SVOTek scammers are back.

kentifilitt

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #7 on: January 31, 2018, 01:27:24 PM »
As an aside, I was lucky enough to travel to a dark sky site in Australia in 2005 and 2007. I remember looking at the Tarantula Nebula in the Large Magellanic Cloud. It was an amazing object. It looked very different using naked eye, OIII filter and UHC filter. I can't remember anything that had that effect. And then to realize that not only was it bigger and brighter than the Orion Nebula, it was in another galaxy! Mind Blown!

ingeblomes

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #8 on: February 02, 2018, 04:15:29 PM »
There is an additional factor worth considering in the use of filters with differing bandwidth: exit pupil size.

I use filters of different bandwidths for different exit pupil ranges with some variation based upon individual target. These are the filters I use:

Farpoint UHC (28nm bandwidth)
Optolong UHC (~50nm bandwidth)
Astronomik B-band deep sky imaging filter (~92nm bandwidth)

I find each of these filters useful depending upon the exit pupil and target object.

As a general rule:

Farpoint UHC is used at exit pupils of 2.0mm and larger
Optolong UHC is used at exit pupils from 2mm to 1mm
Astronomik B-band is used at exit pupils from 1.7mm to 0.7mm

So based upon my experiences the Lumicon deep sky filter (~70nm bandwidth) should be useful at exit pupils smaller than 2mm. Last time I was out I found beneficial gains in contrast using the Astronomik B filter at exit pupils as large as 1.7mm.

Ray Gibas

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #9 on: February 03, 2018, 05:25:55 AM »
Difference between UHC and Deep Sky is rather simple.UHC is 2-3 times more effective in nebulae observing (in any conditions).Deep Sky can help a bit in observing wide range objects in conditions of light pollution.

ciouloconwai

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #10 on: February 08, 2018, 09:01:25 PM »
No offense guys, but this thread has just confused me more. I just purchased a 1.25" Lumicon UHC filter and a 1.25" Lumicon O-III filter. Now i'm doubting what i'm actually receiving... am I going to be getting the excellent reputation version of the Lumicon filters or am I getting these new Lumicon filters that apparently are lower quality?? I am not experienced enough to tell the difference but want absolute certainty i'm getting the actual "worlds best" Lumicon filters and not the new lesser quality ones. How can I tell? They are arriving by FedEx tomorrow and based on the responses in this post, there is a 50/50 chance i'm returning them.

thesaroha

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Re: Difference between Lumicon UHC and Deep Sky filters?
« Reply #11 on: February 09, 2018, 10:34:05 AM »
Do Lumicons ship with a transmission curve?