I am using Quadband filter for EAA with Celestron RASA 8 and APO 130mm a its providing excellent results. Now I can do astrophoto even from backyard in big town with extreme light polution.
This filter is expensive, but worth every penny. I only wish I would have purchased it sooner.
I don't know what to write that other 5 star reviews haven't written. I heard about the filter on the podcast, but the reviews sold me. I live in the Northeast USA so light pollution and more cloudy nights than clear nights equals limited time to gather data. Four filters saves time and (in the long run) money. I've had this filter less than a week, but some how the astronomy gods have looked favorably on me and I've gotten 4 cloudless nights already. The difference in the raw images and some quick stacks/edits is staggering. Thank you!
This is the best filter I have ever purchased. I use it with a wide field telescope (51 x 250 mm) and Canon EOS Ra DSLR. The images of various nebula's are sharp with great detail even on nights with a fairly bright moon.
I have to type fast before my wife sees the debit. The filter is excellent! I shoot from Long Island, close to NYC. The lights come out clear and sharper then with other light pollution filters. I hope I can use it more before my wife murders me. She can, she’s a nurse!
I wasn't sure what to expect from this filter, I had been using a much cheaper Triband filter so was thinking 'how much better can it be?' The answer very quickly become, incredibly! For me this filter has 2 important advantages over triband filters available from many other brands, also available from radian. 1) Having 4 discrete narrowband passes allows for the create of genuine narrowband images, this is basically 3-4 high quality 5nm bandpass filters built in to one, the nebula isolation is incredible. Triband filters tend to have a decent Ha pass in the 7-12nm range but the O3 and Hb pass is usually 1 big pass in the range of 35nm or so. For me this causes a couple of issues. a) You get big stars, especially in your blue and green channels due to the larger pass, this makes post processing difficult as you get less contrast in blue and green as star light floods in. b) The broader bandpass in green and blue allows light pollution in which can also cause you greater issues in post. Also the red channel being a smaller pass lags behind significantly in exposure which again can make gauging exposure times and flat exposure times tricky. 2) Halo's, cheaper filters will give you filters, regardless of anti reflection coatings being claimed, browse Astrobin you'll see many a halo. The fact this filter gave me very few halo's was brilliant it just leaves you with a far cleaner final image and, for me, is the hallmark of a true top quality filter. For the reasons above I've found this filter a genuine pleasure to use, post processing is easier as the data produced by it is clean and naturally more balanced due to the narrow band passes that flow in to red green and blue channels of the sensor. OPT were kind enough to use some image that I took with the filter in the images above and I can say that they are some of the best images I've ever taken. I shoot in Bortle 7 so far from extremes of city centre 9's but still strong enough to struggle with RGB. This filter allows me to shoot any day of the week regardless of moon phase and generate excellent results. For these reasons I think this makes the filter good value for money as it actually increases the number of days that you can image.