TO EXPLORE THE UNKNOWN UNIVERSE
Telescope: Askar FRA600
Mount: iOptron CEM40
Filters: Chroma 36mm LRGB Ha
Here are the combo we recommend for the QHYCCD Astronomy Camera QHY268. Compared with purchasing them seperately, you can get a discount about 5% off for the combo.
First there’s no doubt that 2-inch filters are large enough to cover the whole sensor area, but they’re not cheap enough for everyone. With a rough estimate, we think 36mm filter can be matched with scopes whose focal ratio are smaller than f/5 (f/4 worths a try, too). However, if your scope has a large focal ratio like f/2.8, we suggest you think carefully before using 36mm filters.
| Model | BFL Consumed | Filters Supported |
| QHY268M | 12.5mm | |
| CFW3M-US | 17.5mm | 7 position
36mm unmounted |
| CFW3L | 21.5mm | 7 position
2inch mounted/50mm unmounted |
| OAGM | 10mm |
Note: Adapter Kits B1 is provided FOR FREE with each QHY268M model.
B1: Connecting MPCC that requires 55mm BFL and M48 interface to Camera with CFWL and OAG. B1 is standard accessories of QHY600M SBFL and QHY268M, so you needn’t purchase it if you’ve had the cams. If you own a CFW3M-US (which is 17.5mm) rather than CFW3L (21.5mm), you need to add another 4mm adapter and longer screws, which are also included in B1. Below shows two examples:
Note:
B2: Connect Canon EF lens to Camera with filter wheel
B3: Connect Nikon F Lens to Camera with Filter Wheel.
Note: The current Nikon adapter used here is different from the 10mm adapter we used to provide. Now it has a back focal length increment of 12mm.
From 2023, the top part of QHY268C will change to the shorter one just like that of 268M. In fact, you can get the “SBFL(shorter back focal length” version of 268C right now.
The previous 268c has a back focal length of 17.5mm, and since it cannot connect to the scope without CAA, so it’s actual BFL is 17.5mm+6mm=23.5mm. Now after the change, 268C’s BFL will be shorten to 14.5mm, which provides more spaces for a filter wheel drawer, or an eletric CAA, or DSLR Lens, etc.
The new 268C adapts a new kit B4 which can best make use of the standard accessories. B4-2 and B4-3 share common parts from the necessary B4-1(for MPCC) .When you need to connect Canon or Nikon lens, you only need to get one Canon/Nikon adapter, not a “kit” like D2 or D3 anymore.
