UHC FILTERS

[Dave In Vermont]

I've thought about Mr. Knisely's lack of high-marks for the Astronomik filters. I've come up with one possibility: He's never actually had the chance to use them. Or not much at any rate. They can be difficult to find in the USA. As to Lumicon - the 'filter-world' has taken a serious 'hit' with the passing of Lumicon. I won't say what I think about the new ones. But the old one's were/are exceptionally great! They rather set the bar way high.

Later -

Dave

[25585]

I remember seeing M42 & Ring Nebula through the OIII using my 13mm Nagler for the first time. That was a real high!

The Astromik CCD OIII is darker than its visual version (sold by The Widescreen Centre). Perhaps why it's theoretically better? 

[Paul73]

Glad that I invested in Limicons when I did. Missed out on the two inch UHC though!

The OIII is the only 'golden bullet' though. I find that messing about with differing magnifications digs out as much detail as most UHC's under normal uk rural sky.

Paul

 

[John]

12 minutes ago, 25585 said:

I remember seeing M42 & Ring Nebula through the OIII using my 13mm Nagler for the first time. That was a real high!

The Astromik CCD OIII is darker than its visual version (sold by The Widescreen Centre). Perhaps why it's theoretically better? 

What I liked about the visual Astronomik O-III was that it was not too "severe" with regard to it's band pass width, not as narrow as the Baader O-III for example. The Astronomik worked well in all my scopes from 4" to 12" in aperture I felt and there were still some stars to be seen to set the target nebula in context. I think David Knisely prefers filters that stay within what you might call "established" band pass widths for their class. The Astronomik O-III might be considered a little too generous by that standard. Personally, I liked it a lot, enough that for a couple of years it served as my only deep sky filter. 

Like many other things in this hobby, personal preferences will come into filter selection. The band pass width charts do give some indications of where a particular filter might fit into the scheme of things so at least you have some indication of what to expect.

 

[alan potts]

I am really taken by how much these filters differ from each other but still hold the same massive price tag, not sure exactly what mine are as they are in the obsey but my Astronomik I believe are high 95's and low 96's. All of mine are about 4-5 years old and were secondhand then.

 

[Dave In Vermont]

Yes that's true. But it's that way over here as well - if there's any truth to the adage about "misery loving company." Usually what I see is people wanting to know if the price jump is really worth it - while citing they've found a no-name brand UHC somewhere in Amazon. I try to explain how these things work - often losing my audience on such stumbling blocks as 'transmission' and 'graph.' Ah well.

I have learned to explain a filter should be a 'lifetime-purchase' and expect to need to save up for the best and thereby only buy once. Rather like the 'cheap Barlow vs. TeleVue® Barlow' example.

Last Analysis: Astronomik Filters are expensive.

Dave

[25585]

Well I will only buy an OIII in 2 inch I think. If the Astromik is lighter, sort of part UHC too, perhaps that is the ideal all-purpose galaxy/nebula filter so might be worth its cost. My Lumicon is excellent for nebula but filters out stars almost too much, even most in M42. 

[GavStar]

I had a bit of a surprise this evening. Previously I've always viewed m42 filterless. In my garden in SW London it was nice but not as stunning as turn left at Orion makes out. 

Tonight I tried my Astronomik UHC which did extend the nebula a bit but still not that impressive. I then thought I'd give my lumicon oiii a go just for a laugh. I got a shock - it transformed the nebula into a monster with arms extending either side - I've never seen the arms like this before. Very impressive.

After the Veil this summer and now m42 tonight, this lumicon oiii is a definite keeper!

[Dave In Vermont]

Hi GavStar - thanks for asking!

Would you know approx. how old your Lumicon OIII-Filter is? Lumicon recently closed, due to retirement, and the company-name was sold. The new 'Lumicon's' are now an unknown quality, which is why I ask you how old your's is - around?

If you have an older OIII - for goodness sake - hang onto it! They are eagerly sought after and far & few between.

Best Wishes -

Dave

[John]

I think it depends on how dark your skies are.

Here, while not LP free by any means, from my location I find that the O-III filter causes the central regions of M42 to appear a little "burned out" when observing. The DGM NBP filter (a UHC type) has a more pleasant effect by extending the outer whirls of nebulosity while maintaining contrast and detail within the central regions, so I prefer that to the O-III. When the sky is really dark I prefer no filtration.

 

 

[alan potts]

I got most of my filters new as they rarely seemed to come up secondhand and then if they did they were gone in a flash. Both Lumicon and Astronomik's seem to hold top spot for price and were by far the most talked about on here, the former always seemed more difficult to even buy new, for this reason alone I got the Astronomik's brand. There are I am sure other makes available in the States that are not easy to lay hands on in the Uk or where I am here in Bulgaria. I found the Astronomik's very good indeed though without anything to compare to, at the price one just can't afford to lay out 160 quid on the chance it may be a tiny bit better, even the slightly lesser ones, Baader for example, are not free with Cornflakes. I would one day love to see these top players side by side on a range of targets just to see if indeed there is a difference, but then as we know every filter is slightly different so how do we know we would ever match the result.

Alan 

[Dave In Vermont]

Geeze, Alan - you're say exactly what I've been saying to some friends of mine in the last week - seeing a side-by-side photo-montage of the different filters from different outfits. Like Baader, Lumicon (old and new), Astronomik, etc. Or a chance to do it 'live' at some event. The ideal would be a "lending-library" for filters - like one for books. Anywho - here's a very good, yet unique, type of semi-UHC that Orion-USA has had out for about 20 years (?):

https://www.telescope.com/Orion/Accessories/Telescope-Eyepiece-Filters/Orion-UltraBlock-Narrowband-Filters/rc/2160/pc/-1/c/3/sc/48/e/71.uts

And they have a few other interesting creatures as well:

https://www.telescope.com/Orion/Accessories/Telescope-Eyepiece-Filters/rc/2160/pc/3/48.uts

In as much as everyone's eyes & vison is different, pretty much impossible to get truly accurate results of which & whose filter is "THE" best. Something I'm playing with is a series of colours, utilizing the Munsell Colour-System, for people to choose from to match a given stellar-object they've viewed - stars, nebulae, etc. Then publish the results. Bet that would be quite enlightening!

Dave

 

Munsell Colour-System circa. 1929

 

[GavStar]

4 hours ago, Dave In Vermont said:

Hi GavStar - thanks for asking!

Would you know approx. how old your Lumicon OIII-Filter is? Lumicon recently closed, due to retirement, and the company-name was sold. The new 'Lumicon's' are now an unknown quality, which is why I ask you how old your's is - around?

If you have an older OIII - for goodness sake - hang onto it! They are eagerly sought after and far & few between.

Best Wishes -

Dave

It's the old version Dave, confirmed directly by Lumicon in a cloudynights thread. I purchased it earlier this year - it was the last old stock held by a Dutch Astro shop.

I will definite be hanging on to it.

[Dave In Vermont]

1 minute ago, GavStar said:

It's the old version Dave, confirmed directly by Lumicon in a cloudynights thread. I purchased it earlier this year - it was the last old stock held by a Dutch Astro shop.

I will definite be hanging on to it.

You lucky devil! Glad to hear you'll be hanging onto that gem!

Dave

[GavStar]

3 hours ago, John said:

I think it depends on how dark your skies are.

Here, while not LP free by any means, from my location I find that the O-III filter causes the central regions of M42 to appear a little "burned out" when observing. The DGM NBP filter (a UHC type) has a more pleasant effect by extending the outer whirls of nebulosity while maintaining contrast and detail within the central regions, so I prefer that to the O-III. When the sky is really dark I prefer no filtration.

 

 

Very interesting John. I have a DGM NBP filter as well (which I've not particularly liked in the past) so I will try to compare that with my oiii next time. I think my skies here are just a little bit worse than yours (understatement!) so that might be a factor as well - the darkening effect of the oiii having more impact here. Hoping I will also be able to try this at my dark site as well. Last night was the best views I've had of M42 so I was quite chuffed! Admittedly I did have a larger scope on it than I have had in the past.

[Stu]

1 hour ago, GavStar said:

Very interesting John. I have a DGM NBP filter as well (which I've not particularly liked in the past) so I will try to compare that with my oiii next time. I think my skies here are just a little bit worse than yours (understatement!) so that might be a factor as well - the darkening effect of the oiii having more impact here. Hoping I will also be able to try this at my dark site as well. Last night was the best views I've had of M42 so I was quite chuffed! Admittedly I did have a larger scope on it than I have had in the past.

I'm sure we need heavier filtering here than John given the higher light pollution.