Astro 6D (Cooling modified eos 6D)

Astro6D is a cooling modified Canon EOS 6D.
Up until now we have used two methods to modify Canon DSLR’s to a cooled configuration.
The first is to insert a cooling module into the camera body, whilst the other is a reconfiguration of the camera system, as in the case of CDS-5D.
The inner space of the 6D and A7s is so tight that we have introduced a new modification concept for these cameras.


A. Removal & relocation of image sensor.

We took out the sensor and moved it towards the lens and made a cooling module. We considered this the right solution for the 6D camera which has such tight inner space.

We had questions about the reliability of the extended CMOS connection cable and decided to test it.

Before we performed the tests, we strengthened the ground circuit and made a heat sink and cold block to unite to the camera’s ground circuit and made shield covers.

With the extended cable the camera worked well without any errors in still shot photography and in movie mode.

I guess that the CMOS cable delivers only digital signals. The lines are composed with pairs and the additional ground and shield has helped the stability of the circuit.

The relocation of the image sensor out of the body has merits and demerits.


First the mechanical shutter is made redundant because the CMOS has been moved in front of the shutter.
Canon DSLR’s control the amount of light to the sensor by a combination of the mechanical and the electronic shutters.
The modified 6d’s exposure time will be controlled only by the electronic shutter which means exposure control of sub second exposures is not reliable.
Second is the fact that you are no longer able to use the optical viewfinder. However you can focus using the Live View mode.


1. Drop in Filter System: The back focus distance between the image sensor and lens mount allowed room for the drop in filter holder. This system makes it possible to install filters without removing the lens. This is very useful including for narrowband imaging.

Astro 6D’s is maintained at 44mm, the same as the Canon EF mount.

2. The cylindrical heat sink and cooling module is similar in shape to that of a normal DSLR and makes for a good user experience.

3. The mirror holder of a full frame DSLR can cast a shadow onto the image sensor when it is lifted to take a shot. The amount of light is not too serious but can effect the regularity of the background brightness. This can be troublesome when constructing mosaic images, however the modified Astro6D has no obstacles in front of the sensor.


B. New cooling system

1. Passive cooling

A7s is a very good camera for movie recording. But when it’s recording of shooting shots the temperature of the image sensor rises to ambient +7C. This rising temperature adds noise to the output image. In low light photography this internal heat is a major obstacle to overcome.

We designed a cylindrical heat sink by 3D modelling and manufactured it by MCT machine. This heat sink has sufficient radiation areas to allow a cooling of the image sensor to -6-7C when the TEC is powered by 4v DC without the cooling fan.

Because the sensor temperature of the unmodified 6D is Ambient +7-+8C, the passive cooling of the Astro 6D is having a 14-15C cooling effect over the unmodified 6D. This substantially assists in producing good quality movies and low light images.

Passive cooling is fan less and is silent. The current consumption is only about 0.8 amps and a 12v 12Ah lead sealed battery would allow about 15 hours of continuous use.

2. Active cooling

Attach the EXcooler to the bottom side of the heatsink and operate the cooling fans. In this case 8.5v DC is supplied the TEC and through this “active cooling”, the temperature of the image sensor will now drop -18C (+2C – 2C)

3.Detachable EXcooler

This uses the products of the Austrian “Noctua” company, renowned for their silent and high performance cooling fans.

We installed two 40mm notch fans to the EXcooler and a 8.5v power circuit for the TEC. The EXcooler easily attaches to the underside of the heat sink using a single 1/4” screw bolt.


4.Digital Thermometer:

For monitoring the temperature of the image sensor we offer a digital thermometer as an accessory to the 6D.


C. Dark Fram Comparison of Cooled 6D

1. Indoor temperature, ASA1600, 450sec, RAW, 500x500pixels center Crop (Original)

2. Indoor temperature, ASA1600, 450sec, RAW,  500x500pixels center Crop (Photoshop Level  255 -> 30)


D. Adapters for Astro A7s


Information of the product :
*Cool down the temperature of CMOS sensor about 18 Celsius degree(±2℃) from that of ambient air.
*Absolutely high-Quality image in B-shutter use compared with usual DSLR
*Realtime Monitoring of the cooling temperature by digital thermometer
*Drop-in filter system
*Use of high efficiency Thermo electric cooler module.
*Power: 12V, 3.0A DC
*Low Pass Filter Removed.
*Optimal design by 3D CAD modelling
*Precision manufacturing by CNC machine
*Perfect tuning of optical axis of CMOS sensor by 3 point alignment

*Permanent Anti-dew system applied.
*Detachable Excooler (40mm cooling fan 2pcs & Power supply) included.
*Live-view Focus function alive.
*Mechanical Shutter and Sensor Cleaning function are disabled.

Various Adapters for Astro 6D