An interesting test of an affordable alternative to the 0.7x Celestron Reducer for the EdgeHd-Series: The TS CCD47 (0.67x)

After the purchase of my new telescope, the Celestron EdgeHd800 (which is an awesome scope for the galaxy-season), I immediately thought about buying the Celestron 0.7x Reducer to reduce the focal length to about 1500mm, which is for me the best compromise between aperture and focal length. The focal ratio with it is then f/7 instead of f/10, which is ok (still slow, but ok ;-) ) for Deep-Sky-Imaging.

The price in Europe is about 530€. A very high price in my opinion, which made me think about buying it. But after an unsatisfactory first light without an reducer (I have struggled with the longer exposures and with finding the correct back focus without the reducer), I decided buying the expensive piece of glass.

Unfortunately I have found out, that the reducer is not available at any German or Europe dealer who delivers to Germany. After an intensive research I read (only) one sentence about the possibility to use the CCD47 (which is designed for Ritchey Chrétien RC-Telescopes), but I couldn't find any tests about this combination nor any picture made with this setup (not even on astrobin).

But, happily, I had one of these reducers from my old RC-Telescope, so I tried it.

It wasn't a problem to get the correct back focus in this combination. I could easily adapt it with the Baader Click-Lock. From the thread of the CCD47 it is an suggested back focus of 85mm. Enough space for other gear like a filter-wheel.

Another advantage of the CCD47 is the opportunity, that you could thread in a 2" Filter in front of it very easily.

The first light shows a lot more light than without the reducer and, of course, a wider field of view. The star-shape was surprisingly good, so I decided to try it out and go for a darker site of the Black Forest to capture M51 - The Whirlpool-Galaxy.

Strong winds are the reason why I took only about 3 hours of clear data under a clear and dark sky (about Bortle 4). I decided to set up my rig after coming home on my city balcony (about Bortle 6 but directly above a bright illuminated parking space) to shoot some Narrowband Data. At least I had 18 Minutes H-Alpha, not much, but the red spots of the H-Alpha regions of M51 came out fine and clearly visible.

So, this is what I've got: An successful test of an cheap alternative. I guess, that I will still use the CCD47 in the future. (I guess this type of reducer is also produced from other brands than TS-optics)

Here is my result:

Celestron EdgeHD 800

CCD47 (0.67X Reducer)

Skywatcher EQ6-R-PRO

ZWO ASIAIR Plus

ZWO ASI 294MC Pro

ZWO ASI 120MC Guidecam, 50mm f/4 Guidescope

83 x 120 sec UV/IR-Cut Filter

18 x 60 sec Duo Narrowband-Filter

3,06 h in total