
ZWO ASI294MM Pro Cooled Monochrome Astronomy Camera
The ZWO ASI294MM Pro Monochrome Camera features a 4/3" Sony sensor, 11.7MP resolution, 4.63µm pixels, 14-bit ADC, and two-stage cooling for detailed, noise-free astrophotography.
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Large well depth capacity, low read-out noise and high dynamic range!
*Contrary to the image extracted from ZWO above, the sensor is a Sony IMX294.
The ZWO ASI294MM Pro is a monochrome astronomy camera equipped with a 4/3" Sony IMX492 CMOS sensor, featuring a 23.2mm diagonal and 11.7-megapixel resolution (4144 x 2822). It offers 4.63µm pixel size and operates with a rolling shutter, providing an exposure range from 32 microseconds to 2000 seconds.It is the mono version of ASI294MC Pro, one of the top selling cameras from ZWO.
Camera Performance
The full well capacity of 66387e of ASI294MM Pro is near the top of all ASI DSO cameras. It ensures a very high dynamic range up to 13stops that will greatly reduce overexposure probability and help gain richer color gradation.
High Quantum Efficiency
The ZWO ASI294MM Pro has a very high QE value with a peak at about 90%, but feature an ultra-low readout noise of 1.2e. If you are seeking for a small-format mono camera for astrophotography, that makes the ASI294MM Pro an ideal choice.
Cooling
The ZWO ASI294MM Pro incorporates two-stage TEC cooling, capable of reducing the sensor's temperature by 35°C to 40°C below ambient, significantly reducing dark current and noise for long-exposure astrophotography. It includes a USB 3.0 interface for fast data transfer and features a 256MB DDR3 memory buffer to ensure stable operation.
The ASI294MM Pro is a versatile and high-performing option for deep-sky and planetary imaging.
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About ZWO Optical
Astrophotography has never been easier.
Established in 2011, ZWO Optical is a fast-growing global astroimaging camera powerhouse based in Suzhou China. They focus on building and innovating ground-breaking CMOS cameras such as the iconic ZWO ASI120MM Monochrome CMOS camera (the first-ever planetary CMOS camera to beat a CCD in the early 2010s). ZWO continues to pioneer new astrophotography technology with revolutionary features to capture exceptional quality images of space that will last you a lifetime. Today, ZWO cameras are recognised by every passionate astrophotographer and are available in over 25 countries internationally.
Product Code: ASI294MM-P
Colour / Monochrome | Monochrome |
---|---|
Sensor Type | IMX294 |
Sensor Size | 4/3" |
Resolution | 11.7MP (4144*2822) |
Pixel Size | 4.63µm |
ADC | 14bit |
Read Noise | 1.26-8e |
USB | USB3.0/USB2.2 |
FPS | 19FPS |
Shutter | Rolling Shutter |
QE Peak | 90% |
Full Well | 66000e |
Back Focus | 6.5mm |
Power | 12V 5A DC |
Operating System Compatibility | Windows, Mac OSX, Linux |
Cooling Temperature | -30C |
Cooled? | Yes |
Working Temperature | -5°C—45°C |
Usage | Deep Sky Imaging |
Camera Weight | 410g |
Warranty Information | 2 Years |
Image | Item | Qty |
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ZWO ASI294MM Pro Astronomy Camera - Body | 1 |
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ZWO Cover | 1 |
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1.25" Nosepiece | 1 |
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M42-M48 Adapter | 1 |
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T2-1.25" Adapter | 1 |
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T2-M48 Extender (16.5mm) | 1 |
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T2 Extender (21mm) | 1 |
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Spacer | 4 |
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USB2.0 Cable (0.5m) | 2 |
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USB3.0 Cable (2m) | 1 |
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Soft carry bag for camera | 1 |
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ASI Quick guide | 1 |
Q1. What is the standard backfocus distance for ZWO cameras?
All ZWO cameras have a standard backfocus of 55mm. This matches the optical design of most flatteners and reducers. Always check your reducer/flattener manual to confirm the required distance.
Q2. How do I achieve 55mm backfocus with a ZWO cooled camera?
Start with the camera sensor to flange distance, typically 17.5mm, then add spacers and accessories to reach 55mm total. For example: 17.5mm (camera), 21mm (M42 extension ring) or filter drawer, 16.5mm (M42-M48 adapter or OAG). This gives a total of 55mm.
Q3. How do I calculate backfocus when using a ZWO filter wheel?
ZWO’s 5 Position 1.25"/31mm/36mm filter wheels and filter drawers add 20mm-21mm of backfocus.
For a typical setup: 17.5mm (camera), 20mm (filter wheel), 16.5mm (M42 extension or adapter) for a Total = 54–55mm.
Q4. How do I set backfocus when using a ZWO OAG (Off-Axis Guider)?
The ZWO OAG adds about 16.5mm of backfocus. A sample setup might look like: 17.5mm (camera) + 16.5mm (OAG) +21mm (extension ring) Total = 55mm.
Note: The OAG prism needs to be aligned with the sensor for proper guiding.
Q5. How do filters affect backfocus with ZWO cameras?
Filters, especially in a filter drawer or wheel, shift focus slightly—typically 1/3 the thickness of the filter. For a 2mm thick filter, this means reducing the backfocus by about 0.66mm. ZWO already accounts for this in their 55mm recommendation, assuming standard filters are used.
Q6. What if my stars look distorted at the edges—could it be a backfocus issue?
Yes, coma, elongated stars, or blurry edges are common signs of incorrect backfocus. Double-check each spacer’s thickness, make sure components are properly threaded, and measure the total optical path to ensure it equals the required backfocus.
Q7. Do ZWO planetary and guide cameras require a backfocus setup?
No, uncooled ZWO planetary or guide cameras (e.g. ASI178MM, ASI662MC, ASI174MM Mini) are usually connected directly via 1.25" nosepiece and don’t require backfocus spacing unless used with optics (e.g. OAG or Barlow). They are focused by adjusting position in the focuser or OAG helical focuser.
Q8. What software can I use with my ASI camera?
The ASI Caemra range is compatible with a wide range of astrophotography software. You can use:
ZWO ASIAIR for a mobile-friendly, all-in-one imaging solution (requires ASIAIR Plus sold separtely), ZWO’s native Windows/Mac drivers with ASIStudio, third-party software such as NINA, SharpCap, APT, Sequence Generator Pro, and FireCapture, using ZWO’s ASCOM and native SDK drivers.
Make sure your software is updated to the latest version to ensure full support for this full-frame camera.
Q9. Does the ZWO ASI Cameras work with ASIAIR?
Yes, ASI cameras is fully supported by ASIAIR. You can control cooling (for cooled cameras), gain, offset, exposures, filters (if connected via EFW), and guiding through the ASIAIR mobile app. Be sure to keep ASIAIR firmware and the app itself updated for best compatibility.
Q10. What is the recommended gain and offset setting for the ASI cooled cameras?
This varies by target and sky conditions, but ZWO recommends:
Gain 100 for optimal dynamic range and low read noise
Gain 0 for maximum dynamic range in bright targets or longer exposures
Offset typically ranges from 30–50 but should be adjusted depending on your software and histogram.
Q11. Can I use my ASI Camera with a DSLR lens?
Yes, you may be able to use your ASI Camera with DSLR lenses using appropriate ZWO lens adapters (e.g. M54 to Canon EF/Nikon F). You will need to ensure proper backfocus and may need a manual or electronic lens controller for aperture/focus adjustments.
Q12. My software doesn't recognise my camera – what should I do?
Try the following:
- Install the latest ZWO native and ASCOM drivers.
- Check your USB 3.0 cable and port; use a powered hub if needed.
- Test connectivity with an alternative app like ASIStudio.
- Update your software or firmware (e.g. ASIAIR, NINA).