Would an Rx10 IV be a suitable replacement for an a6400?

I just want to start out by saying I’m probably dramatically overthinking this, so please go easy on me. :slight_smile: Currently I have a Sony a6400 with the kit 16-50mm power lens and the 55-210mm lens. I’ve been thinking about selling those lens for a prime lens and a more versatile 18-135mm.

However, looking at lens prices and considering I don’t use this as often as I’d like has me thinking if I should instead consider one of the Sony RX cameras, specifically the RX10 IV. The 24-600mm lens is incredibly intriguing, especially at F2.4-4. Comparing any lens at a decent price would be no where near that aperture.

The question I have is if the 1” lens will produce a picture on par with my APS-C camera. Will the larger sensor simply be the better option over the faster lens on the RX10 IV? Or if I should consider the newer RX100 VII, or wait for the hopeful RX10 V, or possibly the Panasonic FZ1000 II if it would be decent for half the price. OR will a 1” sensor camera take a photo too close to my 12 Pro Max with all its image processing power?

I don’t need the 24-600mm as I have an HX99 for when I really need to zoom far. It doesn’t take the sharpest image, but I’ve taken some great photos and videos at concerts I never could’ve taken with my phone from the nose bleeds that still fits in my pocket. Still, a better camera with a zoom lens is still fun to have. I don’t do any quick motion photography, I just want to be able to take nice photos of family and some nice video. Just wanted to hear other opinions and thoughts.

1 Like

Do you use a zoom a lot when taking pictures of your family now? I think a lens for your a6400 sounds like a better option; I personally wouldn’t go for the RX10 unless you know you want to go to 300-600mm often.

As it is, your 55-210mm is getting you to a 82-315mm equivalent focal length on your a6400 already. While the 24-600mm lens on the RX10 is impressive, there’s quality tradeoffs in a zoom range that wide. With a smaller sensor to boot, I personally wouldn’t bother.

May I suggest keeping the 55-210mm for zoom stuff and try and sell the 16-50mm kit lens to put towards a good quality 35mm (approx. 50mm equivalent) prime instead? Think the optical quality of a prime, which will generally be available at a f1.8 or so for good low light performance, would provide a great image improvement for family shots.


The RX100 lens looks like it will be roughly one stop brighter than the 16-55 power zoom, which means you could shoot with one stop lower ISO. We can look at the DPreview image comparison tool and see that the image from the RX10 IV is noisier at ISO3200 than the A6400 is at ISO6400. In short, the brighter aperture does not make up for the worse noise performance in this case.

The 16-50 power zoom does not have a good reputation for image quality, and I’m inclined to agree that a good bright prime would be a big upgrade. As an example, the Sigma 30mm f/1.4 is well regarded and costs about $250 new. Spending some time with your zoom lens fixed to 30mm is a good test of whether you’ll be happy at that focal length.