As a long-time astrophotography enthusiast, I switched from Canon to Sony a couple years ago and have been extremely impressed with Sony's cameras for this application. The A7S III in particular is phenomenal for astrophotography thanks to its unbelievable low light capability (goes up to 409,600 ISO!) and impressive dynamic range. The large sensor and lack of an optical low pass filter also help maximize detail.

Compared to competing cameras I've used like the Canon 5D Mark IV and Nikon D850, the Sony absolutely blows them out of the water when it comes to high ISO performance and preserving details/colors in deep sky objects. The in-body image stabilization is also a huge plus for astrophotography. Battery life could be better, but that's a relatively minor trade-off.

If you do make the switch to Sony, I'd also recommend getting one of their ultra-wide primes like the 20mm f/1.8 G lens which is tack sharp and lets in a ton of light. Just my two cents, but I've been thrilled with the Sony system for astrophotography use!

I have the Sony A7R IV and have used it extensively for astrophotography, solar imaging, and other specialized imaging applications. It's an incredible camera, but there are some trade-offs to consider compared to DSLRs:

Pros:

• Unbelievable resolution (61MP sensor) to capture incredible detail
• Impressive high ISO performance for a high res camera
• Compact/lightweight for portable astrophotography setups
• Outstanding dynamic range to handle high contrast situations

Cons:

• Shorter battery life than modern DSLRs
• Some issues with star trailing due to the sensor architecture
• Potential amp glow/noise issues at high ISOs

Overall, I do think the image quality and versatility of the A7R IV makes it a great option for astrophotography IF you can work around the battery life. But the A7S III with its lower resolution and better high ISO performance may be the better dedicated astrophotography camera.

Just my two cents having used the Sony system extensively for these purposes over the past year. Let me know if you have any other questions!

For pure astrophotography use, the Canon EOS Ra is worth a look as a direct competitor to Sony's low light kings like the A7S III. It's a specialized astrophotography camera with better optimization for things like full spectrum shooting and minimal IR pollution compared to regular DSLRs.

That said, I do agree that Sony's general mirrorless offerings like the A7S III and A7R IV are phenomenal for astrophotography with their outstanding high ISO performance, resolution, and video capabilities if you want to do things like timelapses as well. They give you tons of versatility, even if the Canon Ra is a little more specialized for pure astrophotography.

If I had to make a decision today, I'd probably go for the A7S III given the insane low light performance and fully articulating screen which is super useful for framing when your camera is pointed up at the sky. But both Sony and Canon have great astrophotography options these days.

I use Sony a7siii for astrophotography, works great.