The list of cameras dedicated to astrophotography has expanded to include a special variant of the Canon EOS R. It has been equipped with a modified infrared filter to facilitate the observation of effective emission nebulae.
Canon EOS Ra is the first mirrorless camera of this brand dedicated to astrophotography, but not the first camera of such purpose. The Canon EOS 20Da appeared at the beginning of the popularity of digital SLR photography, which then replaced the Canon EOS 60Da. Custom-made cameras from this brand were also available. Also Canon's biggest competitor, Nikon, had its astronomical versions of SLRs.
Digital cameras have made astrophotography affordable for everyone
The introduction of digital sensors has revolutionized observational astronomy in both professional and amateur editions. Scientists began using CCDs for many years before the first consumer digital cameras appeared. Astrophotography enthusiasts reached for dedicated digital circuits back in the days of digital cameras, but it was still a solution for an ambitious user.
There was also astrophotography using classic analog cameras all the time, but again it required skill and patience. But when digital cameras were connected to the telescopes, this very satisfying field of photography, although a niche in spite of everything, became available to everyone. Without exception, because astrophotography can be done even without a telescope or special assembly to track the circadian movement of the sky. However, the telescope gives a lot more scope to show off when we want to reach deeper into space or take a closer look at objects such as planets in the solar system or our moon.
To the telescope through a special adapter ensuring the alignment of the optical axis of the camera optics and telescope, we can even connect a smartphone or a simple compact. The sky, however, is demanding, it does not shine bright light, although this light comes from countless stars. The small amount of light that falls on the sensor intensifies the errors in the form of noise. The larger the sensor, the better the results. Therefore, special versions of astrophotography cameras are based on digital cameras with APS-C or full-frame sensors.
Of course, we can also photograph the sky and related phenomena with a "regular" digital camera. Achieving similar effects as a dedicated camera will require more effort.
Canon EOS Ra – full frame for astrophotography enthusiasts
One of such full-frame cameras that has a dedicated astrophotography version is the Canon EOS R. A special version called Canon EOS Ra is equipped with an IR filter which has changed the light transmission properties in the near infrared band compared to the regular model.
The IR filter in EOS Ra allows you to reach four times more light at a wavelength of about 656 nm or H_alfa. Emission nebulae that contain huge amounts of hydrogen are visible in their corresponding color. The hydrogen contained in them is ionized by the light of nearby stars and when it returns to a lower energy state it emits radiation of the said length.
It is possible to register by an ordinary camera, but due to the strong limitation of its intensity by a traditional IR filter, it gives quite a weak effect in the pictures. More such light is a better image and that's why cameras like Canon EOS Ra are created.
Canon EOS Ra – why this camera?
Canon EOS Ra is a good choice for astrophotography also because it is a mirrorless one. The one by definition has no mirror, and this means that we will not experience the vibrations that raise it. Of course, SLRs have the function of pre-raising the mirror, but in astrophotography it is unnecessary luxury. Live view is also practical thanks to the integrated LCD screen, which can be freely tilted. At a time when SLRs did not have this option, aiming at the right part of the sky was a very thankless task, or it required the use of optical path modifiers that positioned the camera relative to our eye.
Features typical for mirrorless cameras, support for manual focusing (Focus peaking), but also a sensitive AF system in Canon (from -6 EV), are useful for photographing the sky. Because we don't necessarily need to connect an astronomical telescope to the camera (photo above). It can also be a lens (photo below). This is a good solution when you do not want to narrow the field of view too much, and in the case of observing emission nebulae this is not always advisable. I will say that they form a large part of the Galaxy, and the impressive images of the galactic disk are also their merit, not just more densely spaced stars.
The Canon EOS Ra is based on the EOS R and, apart from the features associated with the design of the IR filter, has the same properties as the first full-frame mirrorless camera in the Canon offer. Including the ability to record 4K video and time-lapse movies in this resolution. This can be useful because astrophotography is not always limited to static objects, we may also want to show the dynamics of sky movement by placing the camera on a fixed mount.
Another feature that makes EOS Ra (but also any other camera with built-in wireless connectivity) a convenient tool for astrophotographer is the ability to remotely control. We can leave the camera on a tripod and move a bit away so as not to disturb the image recording with exhaled air or even the light of the camera or smartphone display.
Source: inf. own, Canon
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