- Baader FCCT I for RASA 8" – suitable for Ø 77 mm QHY-Cameras (e.g. QHY 174 / 163 / 183)
- Baader FCCT II for RASA 8" – suitable for Ø 90 mm QHY-Cameras (e.g. QHY 268 / 294)
- FCCT I to FCCT II Expansion Kit for QHY 268 / 294
- Filter changer and Tilter (mechanical image-plane corrector), specially designed for Celestron RASA 8" Astrograph and QHY cameras
- The Baader FCCT (Filter Changer Camera Tilter) allows the use of filters as well as the image position correction / fine adjustment of camera and filters.
- Depending on the camera model, you will need one of the following FCCT versions:
- FCCT I for RASA 8" – suitable for QHY cameras with 77 mm diameter (e.g. QHY 174 / 163 / 183)
- FCCT II for RASA 8" – suitable for QHY cameras with 90 mm diameter (e.g. QHY 268 / 294)
- The Baader FCCT (Filter Changer Camera Tilter) allows the use of filters as well as the adjustment of camera plus filter to the optical path
- With the FCCT, a very fast adjustment or finest readjustments are possible - without having to unscrew the camera each time. This makes working with the RASA 8 a pleasure
- 3D-printed filter sliders are available for the FCCT, which exclusively accommodate unmounted filters with diameters of 31 mm / 36 mm and 2" (w/o cell)
- Baader offer selected 2" filters specifically for the FCCT in an unmounted variant, but basically all Baader 2" filters will work when removed from the filter cell
Scope of supply of FCCT-I and FCCT-II:
- FCCT I or FCCT II with inserted dark slider and two 0.5mm spacer rings for focus finetuning
- Extra long 2mm hexagon screwdriver as torque wrench (28cm long), as well as short 0.9mm, 1.3mm and 1.5mm hex keys
- Three M2 hexagon socket screws for camera adaption
- Filter-Extractor-Tool for inserting/extracting the filter drawer
- 1 Pair Cotton Cloves for mounting sensitive accessories (#2905050)
FCCT I to FCCT II Expansion Kit for QHY 268 / 294
- Set consisting of telescope-sided extra-short RASA 8 adapter, three additional screws as well as camera-sided adapter plate for Ø 90 mm QHY cameras (e.g. QHY 268 / 294), which is screwed onto the standard FCCT QHY flange for Ø 77 mm QHY cameras
- Allows to convert an existing Baader FCCT I for RASA 8" – suitable for Ø 77 mm QHY-Cameras (e.g. QHY 174 / 163 / 183) (#2459070) into a Baader FCCT II for RASA 8" – suitable for Ø 90 mm QHY-Cameras (e.g. QHY 268 / 294) (#2459071), if you purchase a new/additional camera
- Information about the conversion can be found in excerpts in the FCCT instruction manual
Baader FCCT (Filter Changer Camera Tilter)
The Baader FCCT was designed exclusively for Celestron's RASA 8 Astrograph and QHY cameras. It is a filter changer with camera adjustment mechanism for covering the largest possible field size that the RASA8 can suppply, enabling sharp image corners and ultimately fast fine corrections to the optical plane. The Baader FCCT (Filter Changer Camera Tilter) allows quick filter exchange as well as very easy correction of field any existing tilt – without having to remove the camera from the RASA 8" each time.
Celestron's most transportable astrograph, the RASA 8" – Rowe-Ackermann Schmidt Astrograph, ccan capture spectacular deep-sky wide-angle images in seconds. This incredibly fast f/2.0 system is the perfect telescope for modern astronomical CMOS color cameras, smaller CCD cameras and mirrorless cameras. What would otherwise require several nights of exposure time can be accomplished with the RASA in a single night – in principle. Until now, the most severe obstacle was to get the stars in each corner of the chip really round and minimized in size. To do this, the camera had to be removed in order to reach the adjustment screws in the front of the Schmidt plate. But whenever the camera is put back in place, unavoidably this will result in a small lateral offset of the mechanical image train, which causes another corner of the image to show slightly distorted stars. This problem is solved by using the FCCT since nothing needs to be disassembled anymore.
Only the RASA 8 has the image plane is so close to the Schmidt plate that the original front adjustment screws cannot be reached as soon as a camera is connected. To remedy this shortcoming, the FCCT can accommodate specially designed, 3D-printed thin filter drawers and, in addition, precisely align the chip plane within fractions of a millimeter by means of easily accessible adjustment screws positioned 120° apart at the side of the filter chamber. This makes working with the RASA 8 a pleasure, without having to fight for a perfect image position for a long time.
For the FCCT, we offer three sizes of 3D-printed filter drawers that exclusively accommodate unmounted filters with diameters of 31 mm / 36 mm and 2" (unmounted diameter = 47.4 mm). Smaller filters than 31mm very often lead to vignetting in the image corners even with small chip sizes and force cropping of the image content – leading to correspondingly unhappy customers. For this reason we do not offer the smallest possible filter size of (unmounted) 1¼" filters for the RASA 8". The large angle of view of 14 degrees forces to choose filters as large as possible to avoid image deterioration at the corners as well as vignetting and reflections. A filter should at minimum be 20% larger in diameter than the chip diagonal
The design of the Baader FCCT is of revolutionary importance for the successful use of the RASA 8. The performance of this RASA 8 optics is praised everywhere in the highest tones - only the difficult (better impossible) adjustment of the stars in the chip corners was a nuisance from the beginning. Many users have to work on the move and often did settle for a somewhat blurred image corner in order not to lose precious exposure time.
FCCT Alternatives and recommended accessories
Baader UFC-System (Universal-Filter-Changer) and Baader/Zeiss M68-System with Tilter.
For all RASA optics, especially for the RASA 11 and RASA 36 models, the UFC (Universal Filter Changer) always remains the first choice to take full advantage of the excellent contrast performance of this most modern of all Schmidt cameras together with CMOS-optimized Baader f/2 (Ultra) high-speed filters. The combination of UFC filter drawer and UFC filter has long enabled comfortable work on the two large RASA models.
Due to the short backfocus of the RASA 8, only the use of the UFC filter drawer was possible on the smallest Celestron astrograph for a long time. With the help of the Baader UFC S70 RASA 8" Telescope-Adapter (optical height: 1.4 mm) (#2459136), cameras with 13mm backfocus and T-2 female thread - like the ATIK Horizon - could also be used on the RASA 8, together with all regular filters. To do this, the original Celestron coupling nut and adapter plate must be removed and the UFC adapter screwed directly onto the RASA 8 primary thread. Only the adjustment of the optics is complicated, because due to the design the UFC body overhangs the adjustment screws in the Schmidt plate plane. The only thing that this design lacks (only in the case of the RASA 8 optics) is easy access to the pull and push screws of the field alignment lenses in the RASA 8 Schmidt plate plane – hence the resulting development of the FCCT.
With the larger RASA 11 and 36 optics, more backfocus is available, so for this we recommend only using the UFC filter changer system, in conjunction with a Baader UFC-Tilter (#2459146) (mechanical image-plane corrector), where these components in combination perform the same function as the FCCT for the RASA 8. However, the UFC filter changer does not require ultra-thin filter drawers, but makes the full range of standard filters usable. The UFC-tilter also makes it possible not to have to remove the camera when you need to correct the image position of the chip.
Another choice is the Baader M68-Tilter (#2458170) whenever the UFC is not required and a filter wheel is attached to the camera or no filters are needed when imaging for example with a DSLR or CMOS/CCD color camera.
Baader FCCT - Filter Changer Camera Tilter
The FFCT (made for RASA 8) UFC and M68 tilters provide a solution to very easily and quickly alter tilt in an imaging system. To understand how to correctly adjust the tilter, please see the following FAQ.
Q. How do I adjust tilt and achieve micron adjustment with the FCCT, the UFC and M68 Tilter?
A. Each tilter essentially consists of 3 pairs of opposing set screws which independently move the inner tilt mechanics and are easily accessed from the side using the included hex key (Allen wrench). These screws have tapered and hardened points that bear against a precision hardened ‘zero-clearance’ steel-counterpart. The direction that each set screw moves the tilter is shown with an etched arrow next to the individual screw. On the FCCT the extra-long hex-key with handle also serves as torque-control against overtightening. As soon as the handle starts to rotate (to "flex") without continuing to turning the screw then the maximum torque allowed is reached and instead of continuing to increase pressure on that screw, the other screw in that pair first must be unlocked by a very small amount.
CAUTION: Never tighten a screw all too firmly, only light to medium tension is required to hold the tilter with zero play. Tightening the screws too hard could cause damage to the hardened screw tips.
- Check each set screw to make sure it is lightly tightened down (seated). The screws only need to bear against the internal mechanism with light pressure.
- To move the tilter in a particular direction, first loosen the opposite direction screw a very small amount, then lightly tighten the screw that moves the tilter in the direction you want it to go. Only very small adjustments are needed to square the mechanical axis, so only move the screws a small amount.
- Final small tweaks may be made by very slightly increasing the pressure of just a single screw, or very slightly decreasing the pressure of the opposing screw.
- It is recommend that you start with the tilter set at its nominal position with both parts flush. The tilt allowed is approx 0.4 mm to either side.
- The amount of loosening and tightening controls the amount of tilt movement. Always put the image center into perfect focus first and then work out the edges.
- A simple way to check if overtightening occurs is to closely inspect each single image frame taken during the adjustment procedure to see if some upper or lower-side movement (that is: lateral movement) is visible when trying to move one screw in the system to adjust for more angular tilt. Even slightest lateral movement would indicate that at least one of the three pairs of screws is severely overtightened, as each tilter-system is mechanically matched to zero-play.
- In case lateral movement is visible at all in the image frame, then loosen the opposing screw by the same amount and it will cause a tilt action immediately. You will need some time to "get the right feel" just how finely each these three pairs of screws work as a team, to increase pressure and reduce pressure in order to do the adjustment in very minute increments. In this way, micron movements are possible.
- The FCCT is designed to carry up to 2 Kg of camera equipment, the larger M68 and UFC-tilter can take up to 5 Kg of camera total weight.
- The tilter should be positioned close to the camera, to reduce additional loads from having the camera cantilevered far from the tilter.
How to achieve micron tilt adjustment with the Baader FCCT, UFC and M68 Tilter
RASA 8 - WITH QHY CAMERAS AND BAADER FCCT
WITH THE BAADER M68-TILTER TO PERFECT ALIGNMENT
THE BAADER UFC TILTER ADAPTER (PART 10)