The Astronomik UHC-E comes complete with its own protective plastic case, there are the usual male and female threads and there is a slight ‘crown’ on one side of the filter housing. Astronomik claim a 94% transmission with a range of 480nm to 525nm and 645nm plus. First impressions are that it is indeed less aggressive and has a better transmission percentage than the similar Baader UHC-S. Both filters supposedly work well with smaller apertures up to and around 125mm. Looking through it by hand held up to a light source it has a very nice turquoise/blue tint. It looks very well made and I assumed the filter thread would be M28.5x0.6 as it seemed to suggest this on their site.

http://www.astronomik.com/en/visual-filters/uhc-e-filter.html



However, I soon discovered that it doesn't thread properly into a lot of my eyepieces, which is a bit of a disappointment. I think this is important as I don't want anything falling off into the OTA and causing any damage. It fits well on anything Meade, GSO and Bresser, but not my 14mm Baader Morpheus, any of my Japanese made Abbe orthoscopics or anything Vixen. It threads into all of the TeleVue 1.25" Plossls, 2x and 3x TeleVue Barlows, 2.5x TeleVue Powermate, but not my 16mm T5 Nagler or 19mm and 24mm Panoptics.



I used the UHC-E at 164x with a 130mm f/6.9 Newtonian on Jupiter around transit and then, after a break, several hours later as it was setting. I was impressed with the overall brightness and view. It really manages to display certain features well on Jupiter with good clarity and distinction. I could easily see the GRS slowly disappearing near the south western limb, and later still a fair amount of detail in the equatorial belts and north temperate zone. It seemed equally as good, if not better than, Wratten #80A Blue and 82A Light Blue filters.


Astronomik UHC-E compared to the Baader UHC-S (the UHC-E is on the left).

However it doesn't fare so well on Saturn. It does make the rings appear very bright and contrasted though. It improves the Cassini Division slightly but doesn't really do much for surface detail. Titan was easy to see with it. I got a hint of the Lagoon Nebula at 64x with a 14mm Bresser 60° 'Plossl' and the UHC-E. I couldn't see the nearby Trifid Nebula at all. I doubt this is a light pollution issue as I live over 180 metres above mean sea level in the greenbelt. Although this was probably as it was starting to get light and the overall transparency wasn't too good to start with anyway. I inevitably compared it with a Baader UHC-S threaded onto a 19mm TeleVue Panoptic for 47x. The Lagoon seemed a bit more pronounced with the UHC-S but that could have been because of the lower magnification with the Panoptic. The Astronomik certainly seems to have a better transmission than the Baader, and is easier to locate targets with. Basically as it gives a more natural view than the Baader UHC-S, especially of star fields, in my opinion. All in all, I like the Astronomik UHC-E, it wasn’t overly expensive and is adequately designed for use with smaller apertures. However, the lack of M28.5x0.6 filter threads does limit its use for me.