Today I got an iPhone 6s and the only feature that really excites me is the option to shoot in 4k video. As I've said before, I don't care to export videos in 4k, I just want higher quality 1080p footage. I decided to do a quick test comparing the 4k capabilities of the iPhone 6s to the hottest camera on the market today, the Sony A7RII.
Being that one of the cameras was an iPhone, the test couldn't be THAT scientific. We decided to keep the Sony camera at ISO 100 and F8 (to get a similar depth of field). We tapped on the iPhone to focus and lock our exposure and then we changed the shutter speed on the Sony to try to match the exposure. We found that the iPhone's lens appears to be around 32mm on the Sony 24-70mm lens. Nothing is matched perfectly but it's good enough to compare.
We captured a few clips and came back to the office to review the shots. We were certainly impressed with the iPhone but the Sony was noticeably sharper the closer we looked. Obviously Youtube is going to destroy a ton of data with its compression so we decided to zoom in to 200% and 400% on each clip so that you can see the differences no matter what monitor you are viewing it on.
The Sony is better (as it should be) but the iPhone is still amazing, especially if you just want high quality 1080p footage. Editing this 4k footage has me rethinking my stance on 4k video though. Putting two 4k video clips on top of each other and editing off of our server (I know we aren't suppose to do this but we always do and it works fine) really slowed down my computer and my editing. I really don't need 4k footage, I just want super sharp 1080p footage. The iPhone's 4k footage looks amazing downsized to 1080p. It probably looks better than our Nikon DSLRs at 1080p, but we still need to test this.
I will certainly use my iPhone for professional applications when I need something quick but if I have the time I'm still going to reach for the superior Sony. The iPhone is an amazing step forward for the world of video and it's basically a free addition to a smart phone that you were going to own anyway. I'm excited to see what film makers are able to create with it.