TO EXPLORE THE UNKNOWN UNIVERSE
Telescope: Askar FRA600
Mount: iOptron CEM40
QHY offers a very comprehensive and flexible adapter system that allows our cameras to achieve focus to meet mainstream needs of most users (e.g., Multi-Purpose Coma Corrector, Canon lens adapter, Nikon lens adapter, etc.). Users can choose the corresponding adapter set according to their needs to ensure focus.
QHY offers a very comprehensive and flexible adapter system that allows our cameras to achieve focus with a variety of accessories, including camera lens adapters, off-axis guiders, filter wheels and numerous optical systems. The many potential combinations of these items produce an equal variety of back-focus distances that must be considered to make it all work together. This variety and flexibility, however, also can be confusing particularly for new users. Therefore, based on users’ feedback we have decided to include a fixed combination of adapter kits to meet mainstream needs of most users (e.g., Multi-Purpose Coma Corrector, Canon lens adapter, Nikon lens adapter, etc.). Users can choose the corresponding adapter set according to their needs to ensure focus. There is no need to measure and calculate the back focal length, choose adapters, and customize screws as before. We will directly provide the calculated results and corresponding adapters.
If you have no special requirements for the back focal length, you can use a standard T-Mount. If you need a specific back focal length, you can select one of the specific adapter sets to meet your requirements or use QHYCCD’s All-In-One adapter kit to combine your own set of spacer rings to meet your particular requirements (See below).
Back Focal Length (BFL), in the commercial camera field, refers to the design distance from the center of the rear lens element to the surface of the sensor. Generally, the lens will only focus correctly at infinity if the camera’s back focal length meets the standard requirements provided by the lens manufacturer. This is also true for many Multi-Purpose Coma Correctors designed to be used on telescopes before the camera.
| Optical system | Back focal length required |
| Typical Multi-Purpose Coma Corrector | 55mm – 57.5mm |
| Canon 35mm lens | 44.1mm |
| Nikon 35mm lens | 46.5mm |
Note: Not all astrophotography gears have specific BFL requests, for example, some refrector scopes with internal flat correctors. In such cases, you needn’t use the following adapter kits. Instead, you can use a T ring or any adapter that can help connect your camera and scope.
When an optical system requires the sensor of the camera to be located at a specific distance from the last optical element, mechanical spacer adapters are used to position the camera at the right location. If the camera system also includes a filter wheel and an OAG, for example, between the camera and the telescope, the space required for these items must be taken into account. As a simplified explanation, for example, if a telescope’s field flattener requires the camera focal plane to be 55mm behind the last optical element, and the filter wheel is 20mm thick, and the OAG is 10mm thick and the sensor is set 10mm inside the camera then these items all take up 20+10+10=40mm of the back focal distance. Still, the camera needs to be 55mm away so we need to add spacers that take up this remaining 15mm. This also means that if you have an optical system that requires 55mm of backfocus distance and your filter wheel is 25mm thick and the OAG is 20mm thick and the sensor in the camera is 17mm from the front plate, then these items take up 25+20+17=62mm of backfocus. Too much! In this case something has to go to reduce the total back focus distance of the camera to 55mm or a different optical configuration must be found.
For the convenience of calculation, all the data displayed are the increase in the back focal length taken up by using the adapter, which is not necessarily equal to the thickness of the component itself. All the adapter data provided by QHYCCD are based on the focal length increment.
At present, our adapter combinations for monochrome cameras are based on the focal length of the following combinations, which are also our recommended combinations. If you use combinations other than those recommended, the adapter set may not achieve its purpose.
Please refer to: https://www.qhyccd.com/product/astrophotography-combos/
Note: if you do not want to use an OAG in the above combinations, we provide an additional 10mm spacer adapter in some kits to replace it.
The New Combo B1 is designed to be more flexible to achieve multiple output specifications. Since June 2023, we are adding a 5mm spacer with M54 threads into Adapter kit B1. This addition gives the user a choice of terminating the output in either M48 or M54 threads. You can get 55/56mm BFL with M48/M54 threads according to your needs. Since are standard accessories included with the camera, this addition has no affect on the price.
55mm M48/M54 are suitable for standard flatteners and multiple purpose coma correctors (MPCC), while 56mm M54 threads are common for Takahashi reflectors.
The QHY600M-PH SBFL and QHY268M with CFW3L filter wheel can fit an optional Canon EF or Nikon F Lens Adapter without additional spacers. Smaller filter wheels may require additional spacers.
Since June 2023, we are adding a 5mm spacer with M54 threads into Adapter kit C1. This addition gives the user a choice of terminating the output in either M48 or M54 threads. Since C1 are standard accessories included with the camera, this addition has no affect on the price list.
Note:
Combo C1 is the solution without OAG. The QHY600M-PH or QHY600M-L with CFW3L and OAG result in a backfocus greater than 55mm. Therefore, if you must limit this BF distance to 55mm due to a corrector lens or DSLR lens, we recommend the QHY600M-PH SBFL.
If you need more than 7 x 50mm filter positions for the QHY600, you can use the CFW3XL filter wheel with 9 x 50mm filter carousel.
E1 is designed for QHY533C, 294C, 163C, 183C, 174C. Of course, if you use 163M/294M/183M/174M while a filter wheel or OAG is not needed, you can use E1 as well.
A1: Connecting MPCC that requires 55mm BFL and M48 interface to Camera with Filter Wheel and OAG.
Note:
A2: Connect Canon lens with filter Wheel. You need to remove the filter wheel and the original connection interface of the camera and replace it with a new adapter.
A3: Connect Nikon F Lens to Camera with Filter Wheel
Generally speaking, there’s no need for an OSC (one shot colored) camera to match filter wheel. If there’s any special needs, please refer to mono cam combos and choose the corresponding filter wheel. All OSC cams use OAG M if needed.
| Model | BFL Consumed |
| QHY600C/410C/367C/128C/247C/168C | 17.5mm+6mm (CAA) |
| QHY268C (Version before 2022) | 17.5mm+6mm (CAA) |
| OAGM | 10mm |
*About IR-Cut filter：
The sealing glass of QHY OSC cameras whose format are above APS-C is AR glass instead of IR/Cut filter. That’s because when the sensor size is bigger, if IR/Cut is closed to sensor, it’s easy to cause haloing effect on image. We use IR/Cut filter as sealing glass on 4/3 format cameras or below, like 163C, 183C; as for big sensor OSC cams, such as 268C, 367C, we provide a special adapter for fixing 2-inch IR/Cut filter at a farther position from the sensor, or users can fix the filter inside the default T mount.
D1: Connecting MPCC with 55mm BFL and M48 interface
If you don’t use an OAG, please use 10mm adapter in the adapter kits to fill the original position of OAG.
D2: Connecting Canon EF Lens
Connecting Nikon F Lens
0.5mm/1mm Spacer is designed for those who have vary strict requirments of back focal length of the optical system, or the default 55/56mm solutions are not suitable (for example, some correctors require 57.5mm BFL). Combined with our Adapter Kits, the spacer can be used for precise adjustment.
First please confirm whether there are specific requirements of BFL on your equipment. If not, just use a standard T-ring to connect the telescope.
If you do have strict requirements of BFL, since 7/23 we provide 0.5mm and 1mm spacers as purchasable items for a precise adjustment.
If all the existing combo kits cannot meet your demand, such as special back focus requirements, we also offer M42 and M54 all-in-one adapter packages that contains nearly all of the adapters we provide in the kits: 0.5, 1, 2, 3, 7 and 14mm spacers can be combined to make any back focus needed from 0.5mm to 27.5mm.
In most cases, we recommend the M54 All-in-one Kit. The M42 All-in-one Kit is only suitable for use with the QHY183M and QHYCFW3S.
| Model | Product No. | Compatible with | To Connect | Kit Includes | Note |
| Combo A1 | 020100 | QHY294M/163M + CFW3M-US + (OAGM)* |
55mm BFL M48 Threads | 5mm M54-M48 Threads Adapter*13mm Spacer*1
0.5mm Spacer*1 10mm Spacer*1 22mm M3 Screws*8 |
This Combo A1 is included as a standard accessory with the QHY294M |
| Combo A2 | 020101 | QHY294M/163M +CFW3M-US |
Canon EF Lens | 10mm M54 Canon EF Adapter*14mm M54 Screwed Adapter*1
3mm Spacer*1 1mm Spacer*1 Cam Top Adapter (originally 020063) 10mm M3 Screws*8 |
_ |
| Combo A3
(Nik Adapter1) |
020102 | QHY294M/163M +CFW3M-US |
Nikon F Lens | 10mm M54 Nikon F Adapter*1 | _ |
| Combo B1 | 020103 | QHY268M+CFW3L/CFW3M-US + (OAGM)orQHY600M-PH SBFL +CFW3L + (OAGM) |
55mm/56mm BFL M48 Threads
55mm/56mm BFL M54 Threads |
5mm M54-M48 Threads Adapter*15mm M54-M54 Threads Adapter*1
3mm Spacer*3 1mm Spacer*1 10mm Spacer*1 24mm M3 Screws*8 28mm M3 Screws*8 |
This Combo B1 is included as a standard accessory with (a) QHY268M and (b) QHY600M-PH SBFL version |
| Model | Product No. | Compatible with | To Connect | Kit Includes | Note |
| Combo C1 | 020106 | QHY600M-PH+CFW3L |
55mm/56mm BFL M48 Threads
55mm/56mm BFL M54 Threads
|
5mm M54-M48 Threads Adapter*1
5mm M54-M54 Threads Adapter*1 1mm Spacer*1 7mm Spacer*1 14mm M3 Screws*8 |
C1 is supplied as a standard accessory with QHY600M-PH |
| Combo D1 | 020107 | QHY268C (Version before 2023)/ QHY600C-PH/QHY168C/ QHY247C/QHY128C/QHY410C/ QHY367C | 55mm M48 Threads | 5mm M54 to M48 Adapter*12.5mm 2inch Filter Fixer
(Original Name 020055) 10mm Spacer*1 14mm Spacer*1 36mm M3 Screws*8 |
D1 is supplied as a standard accessory with QHY600CQHY268C (Version Before 2023) |
| Combo D2 | 020108 | QHY268C (Version before 2023)/ QHY600C-PH/QHY168C/ QHY247C/QHY128C/QHY410C/ QHY367C | Canon EF Lens | 10mm M54 Canon EF Adapter*14mm M54 Screwed Adapter*1
2.5mm 2inch Filter Fixer (Original Name 020055) 3mm Spacer*1 1mm Spacer*1 14mm M3 Screws*8 |
_ |
| Combo D3 | 020109 | QHY268C (Version before 2023)/ QHY600C-PH/QHY168C/ QHY247C/QHY128C/QHY410C/ QHY367C | Nikon F Lens | 12mm M54 Nikon F Adapter*14mm M54 Screwed Adapter*1
2.5mm 2inch Filter Fixer (Original Name 020055) 3mm Spacer*1 1mm Spacer*1 0.5mm Spacer*1 14mm M3 Screws*8 |
_ |
| Combo E1 | 020110 | QHY294C / QHY163C QHY183C/ QHY533C |
55mm M48 Threads | Three Customized adapters and a 0.5mm spacer | This Combo E1 is included as a standard accessory with the QHY533C |
| Combo F1 | 020120 | QHY533M | 55mm M48 Threads | 8mm M42-M48 Threads Adapter*1
3mm Spacer*3 10mm Spacer*1 23mm M3 Screws*8 |
This Combo F1 is included as a standard accessory with the QHY533M |
If you need an adapter not listed on this page we closely work with our partner PreciseParts: All types of custom adapter can be designed online to assemble custom image trains using QHY cameras.
Click the logo or the link: https://www.preciseparts.com for more information!
