What is a full spectrum camera
Astrophotography cameras differ slightly from a full spectrum camera. It has filters that pass Ha (Hydrogen Alpha, 656nm), OIII (Oxygen III, 501nm) and SII (Sulfur II, 672nm) light.
Full spectrum camera has all the filters removed from the front of the sensor. It sees all the light that the sensor can see. Usually with auto white balance it shows a reddish image.
Download Our Free Infrared Photography Guide
- How to take infrared pictures with a digital camera
- What are infrared filters available
- How to process infrared images
- How to modify a digital camera for infrared photography
- How to modify a digital camera to a full spectrum
A full spectrum camera may have fitted on the sensor so called Borosilicate glass or Fused Silica glass to protect the sensor. This glass is also necessary to use if we want to retain the sensor’s ultrasonic cleaning function.
When we remove all the filters from the front of a sensor there is still a piece of glass that protects the sensor matrix. We can use this sensor as it is in a full spectrum conversion. Though, we should expect then that all the dust particles would be more visible.
A full spectrum camera is a universal camera that we use for infrared photography by adding filters on the lens. This can be 590nm filters or standard infrared 720nm filters.
We can use it as an astrophotography camera if we attach it to our lens astrophotography filters.
Different cameras will have different conversion difficulties. For example, cameras like Fujifilm S2980 will be easy to convert and will give good results.
Some cameras like Fujifilm X-Pro 1 and Panasonic G2 will be difficult to convert as they require modifications to fix focusing issues.
What is astrophotography camera
Which camera we call an astrophotography camera is probably a matter of taste.
We simply can take a light pollution filter and use it with our regular DSLR or mirror less.
We can also modify our mirror less camera to see more Ha (Hydrogen Alpha). For example, we can make our Canon camera see more Hydrogen Alpha if we remove the second sensor filter.
There are cameras that are used only with a telescope. For example, ZWO Optical ASI120MC Color CMOS camera, ZWO Optical ASI183MC Pro Cooled Color CMOS camera or Altair Hypercam IMX174 USB3 mono imaging camera.
We can use our full spectrum cameras and attach to it a Baader, Astronomik, Astrodon or other astrophotography filter.
There are insanely expensive astrophotography filters. For example, RADIAN TELESCOPES 2″ TRIAD ULTRA QUAD-BAND NARROWBAND FILTER with a price tag of 1000 USD.
And there are more affordable filters like Astronomik CLS-CCD with a price tag around USD $100.
Astronomik (cheaper), Baader (something in the middle) and Astrodon (high-end) are the main astrophotography filter suppliers.
In general, astrophotography cameras should pass Ha (Hydrogen Alpha, 656nm), OIII (Oxygen III, 501nm) and SII (Sulfur II, 672nm) wavelength.
These are the main wavelengths for astrophotography. There are some more wavelengths but not used that often as the main three.
Sensor cooling is important for astrophotography cameras. Heat is a source of noise and we want to have noise levels as low as possible. Dedicated cameras sometimes have big heat sinks and active cooling to transfer the heat from the sensor.
Sometimes modified DSLRs are fitted with bigger heat sinks or have heat sink pipe installed to connect it externally to a cooler.
DSLRs are a bit better for astrophotography because they have bigger sensor assembly with more metal which helps dissipate the heat.
Top of the line Canon 6D has a large sensor assembly and has good sensor characteristics. It is probably the best DSLR for astrophotography.