Why I Bought the Canon EOS Ra

In early May 2020, I decided to purchase a Canon EOS Ra camera from B&H photo. This is Canon’s latest astrophotography camera, and it has some seriously impressive specs (like a  full-frame 30.3 MP astro-modified sensor).

For a complete rundown of the Canon EOS Ra, you can read my full review from January of this year. Essentially, it is a clone of the popular Canon EOS R mirrorless camera, with a specialized IR cut filter optimized for astrophotography.

In this article, I want to discuss why I purchased the EOS Ra, and share my results from the backyard. 

Is the Canon EOS Ra Worth it?

With a price tag of $2500 USD, you’ll want to think long and hard before taking the plunge on a niche camera like the EOS Ra. 

After all, there are plenty of affordable options available in the DSLR line-up, although these are not sensitive to hydrogen-alpha like the Ra is. 

You could modify your DSLR for astrophotography, but unless you’re comfortable dissembling your camera, that task is better left to the professionals.

I considered purchasing a professionally modified Canon EOS 6D Mark II as an upgrade to my Canon EOS Rebel T3i (and Canon EOS 60Da), but the price was not substantially less than a brand new EOS Ra. 

I also wanted to “future-proof” myself to a degree, and be able to utilize Canon’s new RF lens mount lineup in the future. 

The EOS R (and RP) were attractive options, but ultimately the ability to record deep-sky images (nebulae regions) sold me on the Ra version.

Another consideration was the ability to utilize the 4K video mode of the EOS Ra. The EOS R version will capture “normal” looking colors in the daytime, while the EOS Ra will have a red cast to them due to the modified IR cut filter.

The EOS R would be a better choice if the camera was primarily to be used for filming my YouTube videos, but this camera is destined for the stars.

The Milky Way. Canon EOS Ra with a Sigma 24mm F/1.4 lens attached. 

I can still use the EOS Ra during the day for photography and filming, but I will need to correct the white balance in post-production.

To be totally honest, I didn’t want to be left behind like I was with the EOS 60Da. This camera quickly sold out and was no longer available unless you could find one used.

I don’t think there will be any new Canon EOS Ra’s left by the end of the year, but we will see. As an example, finding a used Canon EOS 60Da is nearly impossible.

The Heart and Soul Nebula captured using the Canon EOS Ra and Radian Raptor 61 APO.

Compared to a Dedicated Astronomy Camera

Many of you may be in a situation where you are deciding whether to invest in the Canon EOS Ra or a dedicated astronomy camera. I currently shoot with all types of astrophotography cameras from a CMOS one-shot-color, to a monochrome CCD.

Each camera will have its own strengths and weaknesses, and much of the decision comes down to the user experience you are looking for.

For example, a nightscape photographer that is used to shooting with a DSLR or Mirrorless camera on the road will have a hard time justifying the purchase of a dedicated CMOS camera that requires a slew of new software and hardware to run.

Dedicated astronomy cameras have their place, and for many projects, I wouldn’t dream of using the Ra over my Starlight Xpress SX-42 or ZWO ASI533MC Pro.

Rather than a long list of strengths and weaknesses, I’ve highlighted the aspects of each camera (good and bad) that are unique to each one:

Canon EOS Ra 

• Full-Frame Sensor
• Battery Powered
• Portable and Lightweight
• Native Lens Mount (RF and/or EF with adapter)
• No External Hardware Required to Take Pictures
• Produces RAW/Jpeg files Instantly
• Live View Display Screen
• Framing/Focusing Can Be Done On-Camera
• All Camera Settings Can Be Adjusted On-Camera
• No On-Board Cooling

Dedicated Astronomy Camera

• On-Board Cooling (TEC)
• Back-Illuminated Sensor
• Low Noise Images
• Designed for Long Exposure Imaging
• Calibration Frames Easier to Replicate/Produce
• Full-Frame Models (Eg. ZWO ASI 6200) Are Expensive
• Requires Additional Hardware/Software to Run (eg. PC, ASIair)
• No On-Camera Control (Live View, Camera Settings)
• Requires External Power Source
• Produces FIT files that Must be Converted to Edit

In the end, I would recommend a DSLR or Mirrorless camera to a nightscape photographer who uses lenses, and a dedicated astronomy camera to someone that primarily shoots through a telescope at home.

There is a third category of imager (that I am a part of), that enjoys the DSLR/Mirrorless experience too much to stop using them for all types of astrophotography. 

Compared to the EOS 60Da?

The Canon EOS 60Da is a fantastic astrophotography camera. I’ve taken countless images through my telescope with the 60Da, and it is currently my best DSLR camera for astrophotography.

The Canon EOS 60Da DSLR.

Until the Ra came along in November 2019, the 60Da was Canon’s latest official camera for night sky imaging.

However, the features and specifications of this 2012 camera have become outdated, although many of them are largely ignored for long-exposure deep-sky imaging.

For astrophotography purposes, the biggest differences between the two cameras are the size of the sensor, and the lens mounting system.

• Canon EOS 60Da Sensor: 18 MP CMOS (APS-C)
• Canon EOS Ra Sensor: 30.2 MP CMOS (Full-Frame)

In the end, chances are that many owners of modified DSLR cameras will not feel the need to upgrade to the Canon EOS Ra.

Make no mistake, a talented amateur astrophotographer will be able to produce results as impressive as ones taken with the Ra using an affordable, astro-modified DSLR.

My wide-field deep-sky astrophotography setup.

Results Through a Telescope

I recently attached the Canon EOS Ra to my William Optics RedCat 51 refractor in the backyard. A wide-field instrument like this really utilizes the full-frame sensor of the camera.

I chose to photograph a “fool-proof” area of the night sky, the Sadr region. At a focal length of 250mm, several deep-sky nebulae objects are available. 

The image below includes 15 x 5-minute exposures at ISO 3200. The images were stacked and registered in DeepSkyStacker, and processed in Adobe Photoshop 2020.

Nebulae in Cygnus. Triad Ultra Filter and Canon EOS Ra (Click for larger image).

The Radian Telescopes Triad Ultra filter is a superb match for the EOS Ra, and I plan I using it extensively with this camera this summer. It possesses the qualities of a narrowband filter, with the added ability to create “almost” natural-looking colors (with some color correcting in post). 

When reviewing the data shot using the EOS Ra and Triad Ultra filter, the colors focus at the same point. I regularly process my images on a per-channel basis, and often have to control the star size in certain channels (usually blue). 

That is not the case when shooting with this filter as each channel looks sharp in a single RGB image. 

Photo Details:

• Total Exposure: 1 Hour, 15 Minutes
• Integration: 15 x 5-minutes @ ISO 3200
• Calibration Frames: 15 Darks, 15 Flats, 15 Bias
• Image Acquisition: Astro Photography Tool
• Pre-Processing: DeepSkyStacker
• Final Editing: Adobe Photoshop 2020

Equipment List:

• Camera: Canon EOS Ra
• Telescope: William Optics RedCat 51
• Filter: OPT Triad Ultra
• Filter Drawer: Starizona RedCat Filter Drawer
• Guide Scope: William Optics 50mm
• Guide Camera: ZWO ASI290mm 
• Mount: Sky-Watcher HEQ5
• Dew Heater: Starfield USB

Tips for EOS Ra Owners

Astro Photography Tool really shines when you’re using a DSLR or mirrorless camera. The latest version recognizes the EOS Ra, and I can do important tasks like framing and focusing on my laptop.

Alternatively, you can use the beautiful articulating LCD screen on the Ra.

You may just choose to focus and frame your target directly on the camera rather than through software on your computer. Use the helpful 30x live view to really nail your focus.

I use a Canon EF to EOS R adapter (picture below) to connect my camera to the telescope. You will also need this to pair the EOS R with any existing Canon EF-mount lenses.

The Canon EF – EOS R lens mount adapter.

An important camera setting you’ll need to use when the Canon EOS Ra is attached to a telescope is to enable the “Release Shutter W/O Lens“. The camera doesn’t recognize your telescope as a lens, so you’ll need to set this to take a picture.

Another tip I should mention is that the camera comes with a USB Type-C to Type-C cable, so if you plan on connecting the camera to your laptop, you’ll need a USB Type-C to USB 2.0 cable or an adapter.

Lastly, you’ll want to use the Adobe DNG converter to create RAW files that your pre-processing software will recognize. At the time of writing, the RAW CR3 files the camera produces are not recognized by pre-processing software such as DeepSkyStacker.

The Adobe DNG Converter software.

Final Thoughts

A lot of people seem to think that the EOS Ra is an odd choice considering the price tag and the fact that it’s not a dedicated Astro camera.

I totally get it, and I don’t think it is for everyone. Not even close. I think this camera was designed to meet the needs of a very specific type of amateur astrophotographer.

One that has progressed through this hobby using DSLR’S, lenses, and wide-field refractors.  

With about 10 images using the Ra under my belt now, I can confidently tell you that this camera feels like it was designed just for me.