Yes it's expensive but the difference more than makes up for the price of these top quality filters, Fitted to a sky-watcher star travel 120 ota and it does make a real big difference when viewing.

Thank you for a great product and the delivery service to me in Australia was excellent. DHL courier service excelled.

A simple must have filter for any telescope user. Cuts chromatic aberration to zero with excellent light transmission. Purchased it for my Startravel 120 and made tons of difference to the image. Also says it can be used with my 200p reflector. Sadly, I now need to wait until later in the year for Jupiter and Saturn to be visible and in a favourable position. It will probably be cloudy when they are.

I bought this to see if it would reduce the colour fringing on my SW 120 Startravel refractor - it does! and has proven to be such a good addition to the telescope that I have left it permanently in place.
I should say that I am very happy with my SW achromatic refractor, it's only real drawback being the inevitable yellow/violet fringing present when viewing bright objects like the Moon, something which this (admittedly expensive) filter pretty-well eliminates altogether.
FLO's usual outstanding service means they are always my first choice for astronomy.

Peter

Nice filter! Brings out detail in Jupiter and Saturn's surface. Also has some IR/UV cut so works well with planetary cameras. Very happy with extra detail i am able to achieve. Superb service from FLO as always!

Bought this for the planets. Basically Mars, Jupiter and Saturn. I was pleased with the benefits i got, especially on Jupiter. Definitely a worthwhile addition to my filter collection. First class service from FLO

Wished I'd purchased this filter months ago. A beginner for nearly a year with a refractor telescope and what an amazing difference with the images that now have the chromatic aberration removed. The images are amazing especially with the Orion Nebula. Thanks FLO for the swift delivery and well packed as usual.

I've only managed one observing session since the Baader Contrast Booster filter arrived so my impression may change in time. But, I'm impressed with this filter. I live in a Bortle 6 area which has recently taken out the sodium street lights and replaced with LED and this filter reduces considerably that white glow glow in the night sky. My targets have shown against a darker sky than normal. When viewing the moon I fancy the maria are more contrasty however the moon was near full at the time so this may change at other phases. So far I'd say it's a worthwhile purchase.

Most useful filter..EVER ..IMHO..
MARS filter..
Testing the Baader Contrast Booster on my Apo and 6 sct brings out the Red Spot and Belts ESP FESTOONS clearer than the moon and skyglow..def helps contrast and bad seeing perfect for Mak and SCT uses who dont want too feel they've been robbed of some contrast due to central obstructions ..much better than that cheap green / yellow filter thats not as sharp, plus a much more NATURAL view!
PS:Also works a treat on bright doubles like Rigel helping to mitigate scatter, light flares up the lens and intensity of the Primary star so close faint companions can be seen ..I recommend this and maybe a yellow to help split some others like Antares even ...was marvelous on a mates achro (NO BLUE HAZE) and an ED on Mars..NO RED SPILLOVER That can happen with Mars!.