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matt
02-10-2006, 09:01 AM
Just having a bit of trouble deciding between 2 excellent UHC filters - the Lumicon UHC and Astronomik PROFI UHC filter.

I guess the good news is I can't lose, whichever I decide to go with.

Their performance characteristics are pretty much the same.

Anyone able to find any major performance difference/s between these 2 and happy to give a highly subjective opinion which one to choose?

Thanks

ausastronomer
02-10-2006, 12:36 PM
Matt,

As you say, you won't go wrong with either. Having used both on many occasions, my preference is the Astronomiks by a very small margin. It doesn't dim the background stars quite as much as the Lumicon which is an advantage when using smaller aperture scopes (under 12")

CS-John B

CoombellKid
02-10-2006, 01:41 PM
Is the coatings on the Lumicon sealed in like the coatings on
the Astronomiks. I have an Astronomiks UHC brought on the
advice of JB here. Have tried several other brands but not
enough to give you a well informed impression, mostly because
it was a while ago and I wouldn't want to quote from my memory.
But it could be a deciding factor... the durability of the coatings.

regards,CS

Rob

PS: I have to admit I only really use my UHC filter on maybe 2-3
objects. The Swan & Eta Carina Neb's and maybe M42 when there's
a bit of moon about. Apart from it's mainly used to locate tiny
planetaries with in a field of stars... like in M46 but smaller

matt
02-10-2006, 01:41 PM
Hey... that's freakish timing John.

I just went back through some old posts through this filter forum and some of yours reminded me to think about the DGM NPB.

Guess what? I've decided to go with one of these instead!:lol:

Placed the order only an hour ago.

I hope the Mars poster's still part of the deal (lol)

But seriously, I hope I've made the right choice? Have people been happy with their DGM purchases since the NPB discussions of about a year ago?

You still got one, John?

Thanks for your comments too, Rob

wavelandscott
02-10-2006, 02:48 PM
I have an Astronomiks UHS and it seems to work as advertised...

Over on Cloudy Nights the DGM seems to get some good support too.

ausastronomer
02-10-2006, 03:43 PM
Hi Matt,

I have Astronomiks UHC and OIII filters in 1.25" format and the DGM Optics NPB in 2" format.

The DGM NPB is a bit of a hybrid between a UHC and OIII. It has basically the same bandpass as an OIII filter extended a bit more than a normal OIII in both directions around the OIII lines. A normal UHC filter extends this same bandpass a good bit more either side of the OIII lines. In addition the Astronomiks UHC has an additional bandpass in H-Alpha.

What does all this mean, that on some types of targets one filter will outperform the other a little.

I dooubt that on an overall basis, it's quite as good as the Astronomiks filters but it is a very good Narrowband filter and you will be very happy with it. At less than 50% of the cost of the Astronomiks filters it represents easily the best value for money and a great buy.

If I was buying my first DSO filter, it is certainly the one I would be buying.

CS-John B

matt
02-10-2006, 04:20 PM
Thanks John

I've actually ordered it in the 1.25" format and it works out about the same price as the Astronomik and Lumicon UHC filters in the same format.

I was encouraged and motivated to make the purchase by the glowing praise of a few of your American "friends" like Phil Harrington (Star Wares), and Optical Consultant Mike Palermiti, who had given it very high marks in comparisons with other narrowband filters

According to those knowledgeable gents it actually outperformed a few of the UHC filters from some of the more well-established manufacturers?

ausastronomer
02-10-2006, 06:36 PM
Matt,

Phil Harrington's review was on a few selected targets only as he had a dozen filters to compare on the same targets.

On a large sample of targets it ISN'T a better filter than either of the Astronomiks filters, but it is certainly very good and right up there. That of course is a very subjective call and based entirely on my own personal observing preferences. Not everyone is looking for the filter to enhance exactly the same thing on a given target.

The prices have gone up dramatically. It cost me $AUS 150 for the 2" DGM NPB landed in Australia, at that price it was great deal.

You will be very happy with it, you can take that to the Bank :).

CS-John B

Don Pensack
04-10-2006, 01:14 AM
It's all about bandwidth. A wider bandwidth won't dim the stars as much,but will provide somewhat less contrast enhancement for the nebula. In terms of bandwidth, the 3 filters mentioned can be ranked from wider to narrower:
Astronomik, Lumicon, DGM.
Any of the 3 would be better than no filter at all. Users of small scopes might find the Astronomik more pleasant to use, and I appreciate the H-Alpha transmission, but the other two filters do enhance the nebular visibility a little more.
Whichever one you get, you'll find the contrast enhancement incredible. The Lagoon nebula (M8), for example, seems to quadruple in size in my scopes when using a UHC filter.
I don't recommend UHC filters with too-wide bandwidths (such as Celestron/Baader/TeleVue/UHC-E) unless you are looking for a replacement for a broadband filter that does more than a simple broadband can do.
Don

matt
04-10-2006, 04:34 AM
Thanks Don

I'm looking forward to the DGMs arrival, hopefully in time for the weekend:D

Although the moon will probably spoil the party for the next few weeks.

Will let you all know my first impressions.:thumbsup:

matt
11-10-2006, 04:06 PM
Well.

My new DGM NPB filter arrived yesterday and so far I'm delighted.

It arrived very nicely packaged and included all the relevant paperwork:D

I had a very brief opportunity to test it last night around 7pm on 2 obvious candidates: M8 and M17.

Wow:scared: Very impressive. I've not looked through many other UHC-style filters but I can say this compares very favourably. IMO, it easily outpunches the Baader equivalent. I'd also be inclined to say it's not very far behind (if at all) the Astronomik filter I've looked through. Although I don't remember which specific "flavour" of UHC that was, other than it was a UHC:)

The lagoon was simply stunning. It looked almost as bright through my 9.25 as M42 without a filter:eyepop:

The major dark channels, the grey nebulosity, the bright central core and curving "sandbar" to the east were impressively clear.

I was so excited I quickly slewed the scope over to the Swan. Ditto. Nebulosity jumping out all over the place on an inky black background!

I'd never seen the looping black channels so clearly on the body of the Swan and the neck and head were very easily seen.

And then of course? Well, it's a familiar story: inexplicably for a Tuesday night, neighbours on both sides turned all the backyard lights on:mad2:

On one side they are a household of three very full-on smokers and all decided to step outside to "light up" at the same time, just as I was attempting to hunt down The Triffid.

I kid you not when I say it was like being at a Benson and Hedges convention. The smoke issuing from that backyard resembled something very closely akin to the view of The Great Fire of London:P

I'm not a smoker. That was me done. Inside by 7.15pm... stinking like I'd just spent 4 hours down the pub without a rosy glow to show for it!

But ........

as far as the NPB goes? It looks very promising:thumbsup:

Tamtarn
11-10-2006, 08:02 PM
Hi Matt

We have a Astronomik UHC Filter 1.25 & a DGM NPB Filter 2" and we find that we use the DGM filter much more. To the extent that we have also ordered a DGM NPB 1.25" as well to be used on our two Pentax EP'S.

As John B has said you will be more than happy with your purchase. :thumbsup:

David

JohnH
27-10-2006, 10:04 AM
Thanks to all who contributed to this tread - I now have a new 2" DGM - a birthday gift :) . Of course it is cloudy now so my apologies to you all for that.

BTW Is it normal that these filters look like they are dusty on delivery, I tried a blower to remove but to no effect - I imagine the mirror-like coatings are quite likely to emphasise the dirt but I thought it should be pristine out of the box - anyone out there care to share?

Tamtarn
28-10-2006, 10:43 AM
Hi JohnH

Both our filters arrived in pristine condition.

You could try removing the dust very carefully with a cotton bud tip (Q Tip ) Don't wipe it, try to remove each speck of dust with a twist action. Don't use any solution with the tip at all.

Once all dust is clear wipe very carefully with an Optical Cloth available from an Optometrist.

TidaLpHasE
28-10-2006, 11:38 AM
:)Hi JohnH, i would have thought it would be pristine out of the box too.

I would be maybe if it is that bad/dirty, gently rinsing it under luke warm water with maybe some diluted dishwashing stuff,let it air out to dry completely,or hit it at a distance with the hair dryer.

This link http://www.samirkharusi.net/filters.html shows testing of various filters on M42.

I have the Astronomik UHC, that hardly gets used, so i can't really comment on its quality and performance.

matt
28-10-2006, 11:40 AM
Maybe DGM has some advice on their website on cleaning their filters?:shrug:

Tamtarn
28-10-2006, 01:13 PM
Found this link on the Omega Website re Filter Cleaning.

https://www.omegafilters.com/index.php?page=tech_cleaning

I would take special notice of paragraph 6 which suggests that any cleaning may degrade the surface and create a bigger problem than you already had.

Our method in our previous post above has worked fine for us.

matt
28-10-2006, 01:22 PM
Yep. Knew it had to be there somewhere on the website.

Just too lazy to go looking :lol:

And yes... like all optical surfaces, the advice is don't touch unless it's absolutely necessary.

You could try aiming a very low jet of distilled water at the surface/s showing dust. You could perhaps soak a few pure cotton balls in distilled water and gently swirl those around the filter and then rinse under distilled water or gentle running tap???

CoombellKid
29-10-2006, 07:26 AM
The great thing about astronomiks filters is the coatings are sealed in the
glass where most other brands are coated on the surface where it can
become scratched, this is one of the main reasons I went with astronomiks.
You can clean them with a scara-dish pad. I haven't tried any of the
DGM range so I'm not sure how they compare with astronomiks but I
prefer my UHC over most that I have tried and maybe one or 2 may of
come close. But for the extra durability and no hassles cleaning I go for
astronomiks

regards,CS sunny days

Rob

PS: get yourself a hurricane puffer, or do what I do grab an onion bag
or if ya misses has fishnet stockings. throw ya filter in there and hit it
with the vacum cleaner dust free in mms ;)

matt
30-10-2006, 03:51 AM
:whistle:

Dobman
30-10-2006, 06:18 PM
I bought my DGM NPB about a year ago & have been very pleased with it (& the cost) so far but have never tried anyothers. Works great on orion, Eta Carina & tarantula.