Review: Canon EOS RP (with an MSM Star Tracker)

It seems like forever since I did a proper camera review, but here we are. In the past I have mainly concentrated on camcorders and video cameras and so-called “action cams” or looked more at the video capabilities of mirrorless and 4/3rds models, but over the “COVID Break” and due to popular request (and responses from surveys), I have decided to branch out and look at cameras such as the Canon RP we have here.

But rather than just as a still camera, in this case (and another camera I’ll be reviewing very soon), I am putting it through its paces in special circumstances; using it with a wide and fast lens to capture images of deep space.

The Camera

Let’s look at the physical aspects of the camera first.

The Canon EOS RP is a lightweight (440g body only), full frame mirrorless unit that shoots up to 26 megapixels. It supports 4K video and natively has a RF lens mount.

In my case, I requested and got and EF-EOSR mount adaptor in order to run the 16mm – 35mm f/2.8 lens I wanted for the star shoots.

On the rear is a swing out, rotating 3 inch monitor with 1.04 million dots, and this is supplemented by a 0.39 inch EVF with 2.36 million dots.

The RP sports a combination stabilisation system and the auto focussing has over 4500 possible positions. Wi-fi and Bluetooth are both supported.

The ergonomic layout is pretty much Canon standard with a rotary dial on the left along with the shutter release, lock, movie shoot button, main dial thumb wheel, mode wheel, and multi-function button. On the left is the on/off switch next to the hot shoe.

The rear of the body has a menu button at top left, and the right hand side an AF and AE lock button, a multi-purpose magnify/ reduce/ AF point button, info button and a navigation button / arrow combination. Beneath that are playback and delete buttons.

Access to the battery is via the bottom of the body of the Canon EOS RP and this also holds the single SD card slot.

On the left-hand side underneath rubberised flaps are a 3.5mm mic port, a remote terminal plus mini HDMI and USB ports.

As I said, pretty much standard fare.

By the way, for the star shooting, a remote terminal and controller is almost mandatory due to the long shutter times used.

The lens I am using is, as mentioned, a 15-35mm f/28 USM which required an EF to EOSR mount adaptor. Once this was installed and the lens attached to the camera, all that was needed was to attach it to the MSM mount setup on my Manfrotto tripod.

MSM Mount

I have had the MSM mount kit for a few weeks now and still coming to grips with the best way to set it up as there are a number of possibnilities. The major problem is we are in the Southern Hemisphere, and the mount has to be calibrated to a pole star to work properly ie: to follow the rotation of the Earth at the correct speed and inclination.

In the Northern Hemisphere they have the Pole Star, but here we don’t have such a thing. This is where the PhotoPills app comes in. This shows a “virtual” sky on your smartphone or tablet letting you align the camera to the south pole. This then allows the mount to track successfully and stop getting any star trails (unless that’s what you want of course).

The second part of the problem is that due to our location and the direction of the rotation of the Earth, the mount and camera can have a nasty habit of unscrewing themselves over time. Subsequently, whilst in the Northern Hemisphere taking long duration shots over a 10 or more hour period is not unheard of, I have no intention of trying that here and having a loan EOS RP end up on the ground (or my Canon 5DS for that matter!)

So I am waiting for a clear night when I can get a series of 1 minute shots – about 30 of them, maybe more – I can stack and then with the magic of the stacking software, Deep Sky Stacker to start with, hopefully get images similar to this.

The MSM mount itself is made up of a series of components as you can see. The main rotator has two points where it can be mounted. One on the large side (which I am using here) but it can also be tipped at 90 degrees.

This is sitting on a Wedge mount attached to the tripod letting you change the inclination of the camera when attached.

On top of the MSM rotator is a ball mount and the camera is attached to this.

On the rear is a bracket to mount a smartphone so you can use the PhotoPills app in situ to set the orientation to the south pole correctly. You also get in the MSM kit a green laser, but here that is pretty useless for the reasons mentioned. In the Northern Hemisphere you would use this to align to the Pole Star.


Due to the nature of the MSM Rotator and its accessories, there are a number of ways you can mount your gear. Some people use an optional Z mount as against the wedge, but after much chopping and changing over the weeks, this method seems to be the best for what I want.

The Canon EOS RP and 16-35mm lens sit perfectly and are well balanced for the task at hand. Now we wait for some clear night(s).

Thankfully here in the West (I am 200km south of Perth) we have mainly had these so I am hopeful over the next 24 – 36 hours we can put the Canon EOS RP to work.

Stay tuned!