Why does Canon just have to make EOS R3 and R1 so big, and compromise portability?

[Zalkonian]

EOS R3 and R1 are only camera among the few Canon cameras that use latest stacked BSI type CMOS (I asume it's BSI since it's latest, am I right?) with low resolution for good low light performance what got me interested in considering it as an alternative Sony A7sIII. But sadly there always seem to be design problems and in the case of EOS R3 it is it's huge size.

I want to take a camera for bikepacking trips and mountain hiking so size and weight are important factors. There are camera clips to attachs camera's to backpacks such as Peak Design V3 but big Canon camera will just stick out a lot unlike say R6.

Why is it so big, due to battery capacity or some other important components that improve photo/video quality? I owned a Sony A7sI and it was amazingly compact for a full frame sensor camera. I had actually modified it to full spectrum for infrared and UV photography so I seen that there is very little space wasted inside the magnesium alloy/plastic chassis.

Some people do need larger battery capacity but it can be expanded by separate battery grip attachment to keep the camera as compact as possible and more travel friendly. New battery technology such as silicon nanowire batteries can help reduce battery size and weight.

Why do professional camera manufacturers just have to compromise quality and not design cameras as good as possible using for example front lit sensors despite charging many thousands of euros for them?? It would be easier to find the best fitting camera if they just learned from previous designs and used the latest technology.

[johnrmoyer]

Canon does not tell me why they do things.

But, I find a larger, heavier camera easier to hold steady. Better lenses are usually heavier and larger.

You may find an example of "why?" questions answered at: https://asia.canon/en/campaign/rf-lens-world/the-world-of-L-series-lenses/developer-interview 

[Tronhard]

I think you need to consider that Canon, like all manufacturers, make specific cameras for specific markets.   The R1 and R3 are specifically designed for professional sports photographers, along with those who shoot news events.  If you look at such events, they are dominated by those cameras because they are a specific tool for that profession.  

They canvas those professionals to find out what features they want or don't need. Then they build the camera to deliver those benefits via a feature suite.   In the case of the R1 and R3, those photographers wanted:
1. Extremely sturdy cameras with serious weather sealing, massive batteries, and fast dual memory cards for reliability and endurance.  That contributed to the large body size.
2. They wanted large, high-performance BSI/Stacked sensors but of modest MP count to rapidly capture images of action in a wide range of lighting conditions.  Those sensors needed to be backed by high-speed processors, large buffers and fast cards to process and store the images.
3.  They needed super high-speed internet connectivity, both via Wi-Fi and Ethernet to send said images to their agencies in as close to real time as possible for publication on web-pages, social media and magazines.  Also, they wanted to be able to remotely control cameras to capture action from various angles where they might not normally be able to be themselves.
4.  They desired duplicate controls for portrait work, and high levels of customization of controls.
5.  They needed to manage the heat that all that tech produced, so the cameras had to incorporate heat sinks and, in the case of the R1, a venting system.

All of that required a lot of technology to be squeezed into the bodies they did produce, and they are miracles of design and functionality - for the purposes for which they were intended. They never specifically intended that you would go backpacking with such gear: there are other models far better suited to that.  

I might also add that bodies are often not the heaviest component of a camera system.  The optics often weigh at least as much as the body and the better the optic the larger and heavier it is.

Those cameras were not designed for you.  They are designed for the purposes clearly stated in the documentation and as I have explained. If you want to go backpacking then consider a camera designed for that purpose.   Maybe a Sony might be better for your purposes, if you really want.  But these cameras is not the issue. It's your process for choosing gear.   
So, I would suggest you come back with some details about what you need:
1.  Budget -  There is no point in us suggesting gear you can't afford - that should include the cost of optics.
2.  What subjects you photograph under what conditions - light, environment.  The optics required for photographing macro predators are going to be seriously different from shooting wide scenic vistas.
3. What do you produce?  For social media, digital display, small-medium prints or extremely large prints for sale?
4  What are you prepared to carry?  Sure, you are backpacking over multiple days, but do you want something that will sit in a holster, hang from your backpack harness or what?  If you are considering multiple optics what would they be, and how will you manage them?

I have been backpacking for decades as a wildlife photographer, and I would not choose the R1 or R3 for that purpose.  I would choose (depending on conditions, my purpose and what I expected to shoot) either one of the R5 or R6 models with something like a RF 24-240 lens, or a Sony RX-10IV if bulk and weight were really an issue and I needed a massive focal range.

So, if you really want help to choose a Canon camera, then come back with the answers to my points, and we can help you.  Otherwise, get the Sony you seem to prefer.

[shadowsports]

@Zalkonian,

We understand size is important to you.  You've been told which Canon models have a BSI sensor.  The R5mkII is currently the "smallest" model with a BSI sensor.

Comparatively the R5mkII is 5mm thicker and 3mm taller than the R6mkII.  Roughly 3/16 of an inch, and barely 1/8 of an in. taller. This is what's available in a BSI sensor.  It will likely change, but no one but Canon knows when.  (Taken from another one of your posts).  All of the "scientifically objectifiable" reasons why BSI sensors are better is fine.  If you want Canon and BSI, you know what's available.  I previously provided a means for you to make product feature request and a way to leave suggestions and feedback.  Have you done that?  This is the way to let Canon know what you'd like to see in future products.   The Canon sales team are an excellent resource for making comparisons and identifying key differentiators between products.  I hope you will take advantage of these resources as well. 

Canon Sales / Support
1-800-652-2666

**Edit +1 to Trevor's reply above.  👍

[Tronhard]

Like my colleague Rick, I too noticed that in previous posts you had made the point about BSI/Staked sensors.  These sensors are specifically beneficial for fast moving wildlife, action sports and some news events where being able to capture fast action is necessary.  That is not something that in my experience is mission-critical for the kinds of subjects one is going to encounter backpacking, so again I ask what are your functional priorities and subjects.  

However, such sensors come with a cost, and that cost is inherent in the design, and (as one who shoots Nikon and Sony too) not limited to Canon cameras. Such a sensor will deliver about 1EV less dynamic range and ISO performance compared to a conventional sensor, so like all things, it is a compromise - at least for the time being.

The R1, and R3 mitigate this issue by having very low MP counts, while the R5II, with its higher photosite density, will be a bit more prone to this.   So, if you want to stay with Canon, for the time being you need to consider the pro's and con's.  Technology itself will not get you better photos, your skill as a photographer is far more critical.

There is one suggestion I will make.  Wait.  It is projected that Canon will release an R6III body in Q1 of next year, and it is suggested that this will have a BSI/Stacked sensor based on that in the R3 giving you 24MP in a much smaller body, with great focusing and tracking, good weather sealing and at a much lower price point.   The current R6II is a fabulous body in its own right.