Optec

The two outer holes are clearance holes with a diameter of 9 mm. The one in the middle is a 1/4 - 20 UNC thread hole. This is the standard thread used on camera tripods.

Because of the > 3x focal lenght extention of the FFC, you will most likely see just some rest of coma at the edges of the field. But if you place an coma corrector and an FFC in a row, the image quality will degrade in the whole field. Therefore its better to use only the FFC without coma corrector

The Baader BCF is more open in the red part of the spectrum, means all other colours pass the filter plus some more red. This gives "normal" (daylight) photos a pink touch that you can correct in image processing

Yes, this latest addition of the UFC-family - the new RASA 8 / S70 UFC-Adapter (#2459136) which will launch on our website very soon - is compatible with 17 mm back-focus cameras such as ATIK Horizon. The UFC allows to change any kind of filter from 1 1/4" up to 50x50 mm square in front of the RASA 8.

The only function, that still might be left to desire, is an easier way to reach the front adjustment hex-screws of the RASA 8. Due to the very short backfocus available, it is somewhat difficult to reach these screws and to "tweak" the star sizes in each corner of the image to absolute perfectness.

So - in order to even reach this goal (exchange filters AND effortlessly adjust the camera tilt), in February latest we will launch a separate product - only produced for the RASA 8: the FCCT (Filter Changer & Camera Tilter). This unit will feature 3D-printed filter sliders and be only able to accept filters in diameters of 31 mm / 36 mm / and 2"(47.4 mm) w/o cell mount. This is a revolution for the RASA 8 since it makes perfect adjustment of all stars in the field a joy. Already now the first imagers are using this solution as prototypes and the results are outstanding, see here: https://www.baader-planetarium.com/en/blog/rasa-8-extreme-images-michael-jaeger-with-ccd-camera-f2-highspeed-filter/

Bresser is selling this optic with different versions like essential line or proffessional line etc. To be sure please unscrew your 2" clamp and
take a ruler - it must be 54mm or 63mm diameter. And please take a look at this picture where you can find all data:
https://d3gqwrfrlgdnxc.cloudfront.net/media/extendware/ewimageopt/media/inline/72/3/baader-2-clicklock-eyepiece-clamps-from-t-2-to-41-2df.jpg
The M54 clamp is #2956263 the M68 is #2956269