What Our Customers Have to Say

This user shared image of NGC 1805 taken with a 120mm Refractor, in very light polluted skies, and near full moon shows the NPB's qualities for cutting through light pollution and teasing out details, even in poor conditions, and the unexpected value the NPB possesses as an imaging filter. Stats: 52 x 180 sec lights 10 darks.

Hi Mr. McShane,

I just wanted to let you know how pleased I am with the NPB filter that I purchased from you last November – I have since used it many times in conjunction with my 10” SCT and 8x56 binoculars. Even though it’s my only filter currently, I’ve found its performance to be excellent on most every diffuse nebula I’ve tried it on so far. I wanted to get a narrowband filter (instead of an O-III) because I read that they’re forte was enhancing emission nebulae – the ones that tend to be the harder of the two types for me to see. I will admit that in my research of your NPB filter, I bought it based solely on the Philip Harrington review that you had on your website and a review and many mentions of it by David Knisley (of CloudyNights and The Prairie Astronomy Club). Here are just a few of the nebulae that I have found it enhances quite well:

NGC 6960, 6992, 6995, etc. – Veil
IC 5146 – Cocoon
NGC 281 – Pacman
NGC 1499 – California
NGC 2359 – Thor’s Helmet
Sharpless 2-296 – Seagull
Sharpless 2-276 – Barnard’s Loop
IC 443 – Jellyfish
IC 434 –Horsehead

Plus, I enjoyed the fast shipping! It allowed me to be able to get out and start using the filter the day after I got it.
Scott N. Harrington


I just wanted to let you know that the NPB is doing a fantastic job in every situation possible. I could never be happier with the performance of any filter like the NPB.

Pastor Greg,
Baton Rouge, LA

I was a bit skeptical when a good friend of mine suggested that I pick up this filter. I have had some filters in the past and got rid of them because I generally dislike the green coloring that they provide to stars and nebulas. After a bit of nagging by my friend I went ahead and pulled the trigger. So on a Saturday night at my clubs public outreach I put the filter into the Ethos 13 and then inserted it into the focuser of the clubs 18" F4.5 Starmaster in the middle of light polluted Miami, Florida. WHOA NELLY!!! What a view!!! I had never seen M42 pop out like it did, I was instantly a happy customer. I decided to remove the filter to compare the views and I just had to put it right back on. Without the filter the nebula was there but there was a large amount of skyglow and lack of detail. With the filter the sky goes black and the contrast on the nebula is raised quite a bit providing the most pleasing image. Unfortunately this was back in March 2010 and the rainy season in Miami was about to start so I have not been able to use it since. I can't wait to get this out to a dark site and try it on a lot more objects. My advice, GO GET ONE!!!

In a medium/large scope the DGM NPB works very well on a few targets which "some" narrowband or OIII filters don't do all that much with. The Crab Nebula (M1) which is a supernova remnant, is one of these for instance. It also does a tremendous job on the Orion Nebula (M42), the Tarantula Nebula (NGC 2070), Eta Carina (NGC 3372) and a host of other planeteries and emission nebula. If I could only own 1 filter (I own > 30), the one filter I would pick each and every time would be the DGM NPB.

In regard to the packaging, my DGM NPB filter, which I purchased over 5 years ago, came direct from DGM optics, not Omega who are the manufacturer. My filter was very nicely packaged in a hard but slightly flexible plastic case and was clearly machine laser inscribed on the side as to its origin, size and type. Couldn't fault how it arrived.

John B

I recently purchased a used NPB filter, and I have to say that my first look at M42 through this filter knocked my socks off! I have previously used an Orion Ultrablock filter, and still use a Lumicon OIII filter, but the view of the Great Orion Nebula through the NPB was the best that I have ever had. Thanks for a fine product!

Doug Midway, FL

Tonight I was at a fairly light polluted site. It was hard to tell just how polluted with the Moon just short of full. Orion's belt was visible, to the naked eye, the sword was not. I was out because the weather was unseasonably warm and I wanted to align my new Telrad finder.

On a lark, I told my GOTO mount to find M42. Of course the Telrad showed nothing but the gray glow of the moon light.  My conventional finder showed little more. The main scope, an 8 inch Meade SCT showed a few stars. I put your NPB (what does that stand for ?) Nebula filter on a 32mm Celestron Plössl eyepiece and told the scope to execute a spiral search.

There it was! NGC 1973! I've never seen a nebula before and here under the worst conditions imaginable with a modest telescope I'm looking at one.

I took a look without the filter and I could imagine that I saw something, sort of. But the DGM filter really made a difference.

I thank you.

Tom R

“Tried out your NPB filter last night. Quite nice. It definitely has an edge over my Lumicon UHC. For instance, it allowed me to see edge detail in M42 beyond the UHC.  I also felt that I could see the Theta-1A -- -1D a bit more cleanly than with the UHC. After a few more nights with it, I'll have a better feel  for whether or not I'll be using it exclusively.”


Mt.Baldy, CA

“Hi Dan

Just a line or two to says thanks for the delivery of the NPB filter which arrived safely (some time back). I did not have a chance to try it out until last night and I had to email and say - WOW!

I have seen the Veil nebula in Cygnus before, but last night I had a chance to use the filter for the first time and was blown away! I was using a Meade 25mm eyepiece and without the filter it appeared as a very  faint streak. With the filter it was an arc right across the eyepiece with detail and shape - all this with a half moon setting in the West and a hazy sky!

Your NPB filter is all the Mag said it was Dan - many thanks to you and your company for a great optical aid -- can't wait to see M42!

All the best and kindest regards”

A Jones


I was recently lent 2 nebula filters made by DGM Optical. They are the VHT, Very High Throughput, and the NPB, Narrow Pass Band filters. Dan McShane, who also makes those great off-axis Newtonians, designed the filters. I believe that these filters to be the very best of their kind.

Both filters offer exceptional performance and there is enough of a difference between the 2 to appreciate the accentuation of different details in different objects in various deep sky objects.

IMO, they both beat Lumicon and Thousand Oaks UHC types. Not just in contrast, but also in optical transparency. They can take the high magnifications of the kind that I prefer planetary nebulae.

That was unanimous amongst 4 experienced of my observing friends as well. We used a TOA 130, my 6" refractor with Chromacor, my 9.75" Dob and an 18" Dob.

I had no trouble adjusting to the transmission differences and others did not mention it having to do so either. The main feature about the filters was that depth and varied gradations were maintained especially in favorite objects like the Lagoon, Trifid, Swan, Cat's Eye, M27 and Veil with the NPB. The comments were that the views of the Veil Nebula were the best ever seen in the various aperture scopes.

For me, the VHT on the Cat's Eye at 318x in my 10" Dob was a revelation. It not only showed its central star and football shaped perimeter, but also that dim "wiggly" feature that crossed its shorter longitude. I've never seen that in any of my scopes.

Old standbys like M27 had more undulations with the VHT, but much more extension with the NPB. This was true also in the larger scopes others had nearby in that many gradations were visible with the VHT. My feeling is the NPB would be more popular. With the VHT, my 9.75" Newtonian showed what I would subjectively call refractor-like contrast.

These filters have got to be amateur astronomy's best-kept secrets.

Great filters and many thanks to Dan.

Sol Robbins


Date: 18 May 2005 07:16:14
From: shneor
Subject: Re: Filter question

Hi David,

One excellent filter you left out is the DGM Optics NPB. It's like a UHC, with less starlight color distortion and a significantly brighter image. I sold my (premium) UHC which I had owned for several years when I purchased the DGM, as the results are noticeably better than the UHC.
Another advantage of the DGM is it's low price - about $105 for a 2".

Clear skies,

Dear Daniel,

I recently purchased your 2" NPB filter and must tell you it is simply incredible!  I compared it to my much beloved Lumicon UHC (purchased 11 years ago) and Orion Ultra-Block (purchased about one year ago) in my 12" SCT with a fairly wide range of 2" Nagler eyepieces.  The Dumbbell Nebula was the chosen target for comparison.  Do you know anybody that would like to purchase a Lumicon UHC and/or Orion Ultra-Block? ;^)

David A. Jessie

President, Astronomy Club of Akron www.acaoh.org

Hi Dan,

Yeah I have a 2 inch Lumicon filter selector. I live under very light polluted skies. I loaded my IDAS and the DGM filter into the selector, I compared views with no filter, then IDAS, then yours. The IDAS filter made the background sky a little darker than having no filter, and then I slid my NPB filter into place. Wow, the sky was pitch black, and I mean totally black. The Dumbbell was still as bright as it was without a filter. Yeah, the NPB was a good buy. I can't wait to image through it.




Used my new DGM Optics NPB (narrow pass band)filter on M16 (Star-Queen nebula) last night. Using my XT10 without the filter it looked like your average small cluster. However, with the filter in place, the nebulosity was striking. I also used it on the Lagoon,Trifid, and Swan nebs and it gave a more contrasty view. I'm sold!!