ZWO ASI294MM Pro Cooled Monochrome Astronomy Camera

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ASI294MM Pro

All Pro cameras (with cooler) need to be connected to an external 11-14v power supply to image.  You can also use ASIAIR to power the cameras.

Even when the cooler is not being used the power supply must be used for the camera to be recognized.

By popular demand, we now introduce the ASI294MM Pro. This is the monochrome version of the ASI294MC Pro – one of the top selling cameras from ZWO. Some of the highlights include:

• Back-illuminated sensor – improving sensitivity and reducing noise
• 4/3” format with 4.64 um pixel size – ideal for many types of telescopes
• 14-bit ADC – giving a high dynamic range
• An impressive 66ke- full well capacity- helping to reduce the issue of for example saturated stars
• 4144*2822 high resolution – with the Bin1-mode the camera can operate at a resolution of 8288*5644 and pixel size of 2.3 um.

On top of this, not only does it have a very high QE-value with a peak at about 90%, but also features an ultra-low readout noise of 1.2e. If you are looking for a small-format monochrome camera for astrophotography, you can’t go wrong with the ASI294MM Pro.

▶IMX294CJK

Sony 10.71M-Effective Pixel Color CMOS Image Sensor (official description from Sony site), with a diagonal of 21.63mm (4/3 format). ZWO has refined the sensor and remolded it to increase the diagonal to 23.2mm with approximately 11.71M-Effective pixels (4/3 format).

▶High-Sensitivity Type 4/3 CMOS Image Sensor that Supports 4K for Astronomic Cameras and Industrial Applications

The IMX294CJK sensor is the first in-house image sensor for astronomic cameras to adopt the 4/3 format and provides the necessary number of pixels for true 4k output at 120 frames per second (w/ ADC 10-bit output mode, the ASI294MC can run up to 25fps at 4k format when used with USB 3.0). In addition, the use of larger-sized pixels achieves SNR1s of 0.14 lx* which is very close to the value of the ASI224 (0.13 lx*).

▶Exceptional low-illumination performance

Exceptional low-illumination performance of SNR1s :0.14lx is realized by use of a large-size optical system and by expanding the area per pixel to 4.63µm. This makes the IMX294CJK ideal for astronomic camera market applications that require low-illumination performance.

14-bit ADC and 13stops dynamic range

ASI294 Pro has very similar parameters as its color version. Both have the 14bit ADC and a high dynamic range of 13 stops, which is even higher than that of the well-known and celebrated ASI1600MM Pro camera.

Backlit Sensor

Sony’s back-illuminated CMOS image sensor improves the sensitivity and noise reduction – the key factors to enhancing image quality. It does this by radically realigning the fundamental pixel structure from front-illumination to back-illumination, while still retaining the advantages of CMOS image sensors such as low power consumption and high-speed operation.

With a conventional front-illumination structure, the metal wiring and transistors on the surface of the silicon substrate that form the sensor’s light-sensitive area (photo-diode), impede photon-gathering carried out by the on-chip lens. A back-illuminated structure minimizes the degradation of sensitivity to the optical angle response, while also increasing the amount of light that enters each pixel due to the lack of obstacles such as metal wiring and transistors. These components have been moved to the back-side of the silicon substrate.

Camera Performance

Large well depth capacity, low read-out noise and high dynamic range.

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 of up to 13 stops that will greatly reduce the issue of overexposed images and also help to collect richer color information.

When the gain value is set to 120, the HCG high gain mode is turned on. We’re not saying it’s magic…but we’d like to think it is pretty close. With the HCG-mode turned on, the readout noise is greatly reduced, and the dynamic range is basically unchanged.

HCG Mode

HCG (high conversion gain) mode, which reduces read noise to even lower levels at higher gain without loss to dynamic range, is automatically enabled when the gain setting is 120 or higher. Read noise will drop under 2e-, while dynamic range will remain at 13 stops.

Unlocked Bin1 Mode

Yet another perk of the ASI294MM Pro is that the pixel size is switchable – you can switch between unlocked Bin1 mode and Bin2 mode anytime in your astrophotography software. The unlocked Bin1 mode changes the pixel size into 2.3um and increases resolution to 8288×5644. The ability to unlock bin1-mode was a popular request from our customers. Of course we listened to you and worked quickly to make it possible.

Remember that using Bin1-mode will decrease the full well capacity compared to the standard bin2-mode.

Unlocked Bin1: 12bit ADC,2.3um pixel size,47megapixels,8288*5644 resolution, 14k full well capacity.

Bin2: 14bit ADC,4.6um pixel size,11.7megapixels,4144*2822 resolution, 66k full well capacity.

You can learn more differences between unlocked Bin1 and Bin2 modes by comparing the performance charts.

If the sampling accuracy you get with the 2.3um pixel size falls within a reasonable range, then the unlocked Bin1 mode will help you get more object details. However, you will lose dynamic range and ADC bit depth. Also the image files you get at Bin1 will probably be around 4 times bigger than Bin2.

So in the end the unlocked Bin1 mode is double-edged, you may choose to use it or not depending on the specific circumstances during your imaging sessions.

Reliable Mechanics

There are four screws on the camera that seal the sensor chamber. This kind of design has been extensively tested and is very stable and secure. Even when used in higher humidity environments, ASI294MM Pro will still work fine without dew problems.

ASI294MC Pro has the same mechanics as ASI1600 Pro. There are four screws that seal the sensor chamber. Our camera design has been extensively tested and is very stable. Even when used in higher humidity environments, ASI294MC Pro will still work well without dew problems.

QE Value

As ZWO’s latest BSI (backside illuminated type) monochrome camera, ASI294MM Pro has a very high QE performance, not only higher than its color version, but even than that of ASI1600MM Pro. It is estimated that the QE peak value is about 90%.

The IMX294 sensor is a BSI (backside illuminated type) sensor, which has very high QE (quantum efficiency, which we estimate is over 75% peak).

ASI294MM Pro vs ASI1600MM Pro

Dark Current

The dark current of the ASI294 is a bit lower than the ASI1600 at same temperature, based on our test results. Dark frame sample @ Highest dynamic range settings, 300s, -10°C, bin1. Please check the dark frame to make sure you fully know the performance.

Thanks to the two stage TEC cooling, ASI294MM Pro can lower the CMOS sensor temperature to more than 35 degrees Celsius below ambient temperature, which can greatly reduce dark current generation and sensor noise even during extended exposure times.

*The Delta T 35℃ is tested at 30℃ ambient temperature. It might get down when the cooling system is working for a long time. Also, as the ambient temperature falls, the Delta T would also decrease.

The unique dark current suppression technology can further reduce dark current noise. When it’s cooled to -20℃, the current noise can be as low as 0.0022e/s/pix, which is completely negligible!

Please notice that the camera needs to be connected to an external 11-15v power supply to implement the cooling function. We recommend you use 12V@3A DC adapter (5.5*2.1mm, center pole positive) or lithium battery with 11-15V to power the camera. If you don’t have one, please click this link to buy a 12V power adapter. There are 4 different standards for different countries, please make sure you selected the correct adapter when placing the order.

DDR Memory Buffer

The ASI294MM Pro is equipped with a USB 3.0 transmission interface and a built-in DDR3 cache to ensure stable and secure data transmission. Under long exposure, it effectively avoids frame dropping and greatly reduces the glow effect caused by slow reading speed.

DDR memory buffer is the main difference between ASI “Cool” and “Pro” cameras.

USB 3.0 Port & USB2.0 HUB

USB 3.0 Port: Provide 5Gb bandwidth to make it possible for ASI294 Pro to run at 16 fps (14bit, normal mode) or 19 fps (12bit, high speed mode)  at full resolution(11.7Mega).

USB 2.0 HUB: can connect with various accessories, such as filter wheel, guide camera and electronic focuser, so you can better manage your cables. The ASI294 Pro includes two short 0.5m USB 2.0 cables. The integrated USB 2.0 hub is powered by the external power source if you connect one.

Cooling System

Thanks to the two-stage TEC cooling, ASI294MC Pro can lower the CMOS sensor temperature to 35-40 degrees Celsius below ambient temperature, which can greatly reduce dark current generation and sensor noise even during extended exposure times.

*The Delta T 35-40℃ is tested at 30℃ ambient temperature. It might get down when the cooling system is working for a long time. Also, as the ambient temperature falls, the Delta T would also decrease.

Please notice that the camera needs to be connected to an external 11-15v power supply to implement the cooling function. We recommend you use 12V@3A DC adapter (5.5*2.1mm, center pole positive) or lithium battery with 11-15V to power the camera.

Connecting Diagram

Mechanical Diagram

What’s in the box?

ASI294 Pro Series box includes all necessary cables, adapters, and manuals.

Spacer thickness:0.1mm *1+0.2mm *2+0.5mm *1

The best solution of 55mm back focus length

Q & A

1. I noticed an amp glow present on the corners of my dark frames,  how should I remove it?

Please don’t worry about that. The amp glow is pretty normal actually.

2.  I’ve heard there might be strange patterns on some ASI294MC Pro stretched images, does this mean the camera is defective?

No, it is not a defect, and it is just a characteristic of the sensor. The pattern calibrates out of the light image with proper flat frames. A proper flat frame is a capture using an evenly illuminated light source, dimmed down to achieve an average ADU value of 24,000 (this is up to the user and their setup – recommended the histogram peak at 1/3 to 1/2 from the left, as shown in the figure below), a 5-second exposure, captured with the same gain and focus point as the light frames.

Tax
The price list on our website is USD without tax
Please note that buyers are liable to pay tax involved, such as Import tax, VAT , customs handling fee, etc. The additional fees may be collected at time of delivery by courier.

Warranty and Return Policy
We provide 2-year warranty for our products, we will offer the repair service for free within warranty period. After the warranty period, we will continue to provide repair support and service on a charged basis. We do not provide any replacement unless ZWO confirmed the product is DOA (Dead On Arrival).
This warranty does not apply to damage that occurred as a result of abuse or misuse, or caused by a fall or any other transportation failures after purchase.
Customer must pay for shipping when shipping the camera back for repair or replacement. If we confirm you can get a replacement, goods must be returned with all accessories, instructions, etc and must be suitably packed.
If you get a faulty camera, Please contact us as soon as possible. Please describe the problem in detail and we will do our best to help you solve the problem. Most instances perceived problems are simply bad driver install or software configuration.

1.1 How can I check the shipping cost for my order?
You can add the items you want to your shopping cart, enter your country/state/city/postal code, and then view the shipping options and costs on the cart page. Before checkout, you can choose your preferred shipping speed/method/carrier.

You can also contact us and send us the item model, quantity, and shipping requirements. We will calculate the accurate shipping cost for you and inform you accordingly.

1.2 How are free shipping items delivered?
Items marked as "Free Shipping" on the product page mean you do not need to pay any shipping fees. This usually applies to buyers from any country (except for certain special countries or regions).

For free shipping items, buyers cannot choose the shipping method. We will select the shipping method based on the destination country.
Typically, we use standard surface shipping methods such as 4PX, EMS, or local postal services.
We may also use UPS, FedEx, DHL, Aramex, etc., depending on the specific order and country. The final choice is at our discretion. Regardless of the shipping method used, we will notify you upon dispatch and provide a tracking number and tracking website.

• Standard tracking website: https://www.17track.net/en
• UPS: https://www.ups.com/
• FedEx: https://www.fedex.com/
• DHL: https://www.dhl.com/

Please note: If you return an item (excluding quality issues or incorrect items), you will be charged for all shipping costs incurred, including delivery, return, and customs fees.

1.3 What if I want to specify a shipping method for a free shipping item?
If you want to specify a particular shipping method (e.g., UPS or DHL) for a free shipping item, please contact us before placing your order. You will need to pay additional shipping fees, and we will ship via your preferred method.

1.4 What if I buy multiple items, some with free shipping and some that require shipping fees?
You can place your order as usual. You only need to pay shipping fees for the non-free shipping items.
If you want to specify a shipping method or have other special requests, please contact us.

1.5 How long does it take to ship my order?
After receiving your order, we need some time to process it.
Orders received before 5:00 PM China time will be shipped within 3 days.
Orders received after 5:00 PM China time will be shipped within 4 days.
Orders placed during Chinese public holidays may be delayed by 1–2 days (due to courier holidays).

1.6 When will I receive my package?
Delivery time varies depending on the shipping method used:

• 4PX, Postal Services, EMS, etc.: about 15–25 days
• UPS: about 7–15 days
• FedEx: about 7–10 days
• DHL: about 5–9 days

These are estimated times. Actual delivery is subject to the carrier's schedule.

If your package tracking has not been updated for a long time, please contact us.
If you haven't received your package after a long period, please contact us.
If there are any other irregularities, please contact us.

Please note:
After we ship your package, it may take 2–3 days for tracking information to become available.
Based on our experience, packages shipped to South America and Central Asia typically take longer.
Shipping around public holidays may result in delays due to carrier workload.

If delays occur, we kindly ask for your patience and understanding. We share the same desire as our customers—we hope every package is delivered quickly and safely.

If you want a faster and more secure delivery, we strongly recommend choosing UPS, FedEx, or DHL.

1.7 What does it mean when tracking shows "Label Created" but the order hasn't shipped yet?
When we provide a tracking number, your package has already left our warehouse.
However, the tracking status may show "Label Created" or "Awaiting Package" because the package is still en route to the courier's sorting facility.
Due to China's vast geography, transit between cities can span over 1,000 km, so it takes time.
It may also be undergoing export customs clearance. Your package should be delivered soon.

If your tracking status doesn’t update for a long time, please contact us.

1.8 What if my package needs special delivery instructions or other requests?
If your shipment requires an invoice to be attached, special packaging, delayed dispatch, or other requests, please contact us.
We will do our best to accommodate your needs and provide the best service possible.

1.9 About receiving the package
Whether you sign for the package personally or through a representative, it is considered as acceptance of the package, the quantity, and the included items.
To protect your rights, we strongly recommend recording a video while opening the package and verifying it against the order and packing list.

1.10 I don’t live in China. Can I have my order shipped to a Chinese address?
Yes, you can. Just place your order and provide a Chinese recipient address.
For orders shipped within China, we do not charge any shipping fees. If your item shows a shipping fee, please contact us to have the fee waived.

You are responsible for all applicable taxes and fees that may be imposed by your country or region, including but not limited to import duties, value-added tax (VAT), customs handling fees, and other similar charges.

These import duties, VAT, and customs fees are not included in our product prices or shipping charges.
We have no control over, and cannot predict, these charges or how they will be collected—whether they will be charged at the time of delivery or through other means.

Customs policies vary greatly by country. Some countries (such as Brazil, India, etc.) strictly enforce high duties and additional taxes.

It is your responsibility to check with your local customs office before purchase to determine what additional costs may apply.

Customs fees are usually charged by your local courier or postal service, often at the time of delivery or pick-up. The shipping carrier (especially UPS) may also charge brokerage or clearance fees for handling customs on your behalf. These are not unpaid shipping charges and must be fully covered by you.

If the package is returned, held, or destroyed due to the buyer’s refusal or failure to pay customs duties, any resulting costs will be borne entirely by the buyer. These costs will be deducted from your refund.

1.1 What is your return policy?
I ordered the wrong item/size, or I changed my mind—can I return it?
I received the item but decided I don’t like it—can I return it?
I received the item but found it’s not suitable for me, or I found a better option—can I return it?

In the above cases, we accept returns within 30 days of receiving the item, provided that the product is in brand new and unused condition.

• Buyers must apply for a return and send the product back to us within 30 days of receipt.
• You are responsible for all return shipping costs.
• We will deduct the original shipping cost incurred to deliver the item to you.
• We will deduct 4% for credit card or PayPal transaction fees.
• If you choose to receive a store credit instead of a refund, we will waive this 4% fee.
• If the returned item shows signs of use, a handling fee may be charged.

If the returned item is damaged, missing parts, or shows excessive wear, we reserve the right to reject the return and no refund will be issued.

1.2 Where should I send the return?
Please contact us for the correct return shipping address. (The return address may not be located in Mainland China.)
Please ensure the item is properly packaged and that the original product packaging is not damaged.

Important: Do NOT return the product to the sender’s address shown on the parcel. You must contact us first to obtain the correct return address. Unauthorized returns may be lost or undeliverable—any such loss will be fully borne by the buyer.

1.3 Can I return or exchange the item after 30 days?
For any reason, we do not accept returns or exchanges after 30 days.
30 days is considered a very reasonable and standard return period for online purchases.

1.4 What if I received a wrong or defective item?
Please contact us within 3 days of receiving the item and provide photo evidence or a clear description of the issue. We will promptly send a replacement item.

If you return the item to us:

• Please use the least expensive shipping method.
• We will reimburse part of the shipping fee from your original order as compensation.

If you’re unable to return the item or don’t know how to ship it, please contact us—we may provide a free return shipping label.

1.5 How will I receive my refund? How long does it take?
We will process the refund within 7 days of receiving your returned item.
Refunds are usually issued via the original payment method.
Processing the refund involves internal verification and approval by management, so we appreciate your understanding and patience.