OPTOLONG L-eNhance FILTER

A very handy, well made filter for emission targets

I've been using this filter for around 6 months, now, and have found that it is a very useful tool in my a.p. armoury. It is well made: the filter is solidly clamped in its holder, the holder ring is nicely narrow so that it is unlikely to be a problem mounting it in a filter wheel, and the loss of light transmission is not too much to concern most people. What I have found useful, though, is that it cuts the effects of Moon-glow by a good amount, helping to increase image contrast on those times when clear skies and target availability without Moon are limited. In addition, emission targets appear nicely sharp - sharper than unfiltered images of the same target. As I live in a Bortle 3-4 area, artificial light pollution is not a serious issue for me, so I cannot offer comments on its efficacy in this regard. This is a filter for emission targets, not for general targets like star clusters and galaxies. And finally, is it a dual-band or a tri-band filter? It passes two bands of light, one for H-alpha, but the other is broader and passes both H-beta and O-III emissions. I'll leave it for those more knowledgeable than me to argue whether the definition should describe the bands of the filter, or the bands passed by the filter!

Best filter for my situation

Was advised to look into purchasing this filter by a friend who has been involved with Astrophotography for a number of years, best advice I’ve been given as a newbie to this art form. Living in an urban area of Townsville Qld has me in a very light polluted suburb, but the filter takes away a lot of the pain shouting the night sky from my backyard! It’s a must have part of your kit to have available to you to achieve good results!

Just 8.5 hours of data

Well have had the OPTOLONG L-eNhance FILTER for 35 days and only managed to get 8.5 hours of data. seeing was only 3 at a bortal 5 site. Tarantula Nebula was 4 hour, Helix Nebula was 4 and the Horses Head just 30 minutes. Scope is the SHARPSTAR 94EDPH APO TRIPLET F/5.5+Flattener reducer, ASI 183 MC Pro camera. Mount is a HEQ5 pro, ZWO Focuser and ASI120mm guid camera. Exposures where all 180 second Gain 120 and offset 15. From the results so far the filter does pull out the extra detail in a pollute sky, I cant wait for the skies to improve so that I can retry all my old targets and see the improvement. I love the results obtained to date