Sony A7S III vs. Blackmagic Pocket 6K Pro for Event Filming – Which One Do You Regret Not Buying?

I've been shooting weddings with the A7S III for two years now, and honestly, the battery life is the biggest selling point. I use the NP-FZ100 batteries, and with the LCD flipped out and using the EVF intermittently, I get about 90-100 minutes of continuous recording per battery. For a 10-hour day, I carry four batteries and never run out – I swap them during natural breaks like the ceremony processional or when the couple is signing the register.

Overheating? I've shot in 95°F outdoor ceremonies and never got the temperature warning. The A7S III has that internal fan, and it really does work. I've recorded 4K 60p for over an hour straight without issues. The autofocus is a lifesaver – I use the touch-tracking on the rear screen and it sticks to the couple even when they're dancing and moving fast. I can't imagine doing that with the BMPCC 6K Pro's contrast-detect AF.

In post, the Sony's 10-bit 4:2:2 S-Log3 is pretty forgiving, but you have to nail your exposure – the highlight recovery is decent, but the shadows get noisy if you push them more than two stops. I'd say the BM has better dynamic range, but for event work, the Sony's speed and reliability outweigh that for me. My only regret is the lens cost – I invested in GM primes, but you can use adapters with EF glass if you want to save money.

I'm going to play devil's advocate and say the Pocket 6K Pro is the better choice for events if you're willing to rig it out. I shoot corporate conferences and live streams, and the 6K Pro's built-in ND filters are an absolute game-changer. No more screwing on variable NDs in the middle of a changing lighting situation – I just dial in the density from the LCD. That alone saves me minutes of setup per location.

Yes, the autofocus is not great – I'll admit that. But for events, I mostly use manual focus with focus peaking, and if you're shooting on a gimbal or tripod, you can pull focus yourself. The battery life is the real issue – the LP-E6 batteries last maybe 45 minutes of recording, so I had to buy a V-mount battery plate and a small V-mount battery that lasts all day. That adds weight and cost, but it also powers my monitor and wireless video transmitter, so it's a clean setup.




I've also heard the A7S III is great, but the 6K Pro's dual native ISO (400 and 3200) gives you a cleaner image in low light than the Sony's second base ISO (12800) – you just have to use a fast lens. And the BRAW files are incredibly forgiving – I've pulled back blown-out highlights by three stops and they look like they were never clipped. For corporate work, that's huge because you can't reshoot a keynote speaker. The only thing I'd warn is that you need a fast CFast card or a high-end SD card – I use CFast 2.0 and it's pricey, but you can also record to an external SSD via USB-C, which is cheaper per GB.

If you're a one-man band and want to just grab and go, the Sony wins. But if you're okay with a bit more setup and want the best image quality and built-in NDs, the BM is worth it. I've never regretted my choice – I just had to learn to love the rig.

Thanks both – this is exactly the kind of real-world feedback I needed. I think I'm going to go with the A7S III, mainly because I'm a solo shooter and the autofocus and battery life are just too important for me. I can see the BM's appeal for studio-style shoots, but for moving fast at a wedding, I don't want to worry about pulling focus or swapping batteries every 45 minutes.




I appreciate the honesty about the AF – that's what I suspected. I've also watched a few videos on the 6K Pro's color science, and it's gorgeous, but I think the Sony's 10-bit S-Log3 gives me enough room to grade nicely. I'll invest in a couple of extra NP-FZ100 batteries and maybe a small V-mount plate for the Sony if I ever need to power a monitor, but for now, the Sony's ergonomics are perfect out of the box.

I'm also going to grab a fast SD card (V90) and maybe a CFexpress Type A for the higher bitrates – I heard the A7S III can record 4K 120p in 10-bit, which is amazing for slow-mo shots of the first dance. Thanks again for the detailed answers – you've saved me from a costly mistake. I'll post my first event footage in the forum once I get it!