We've been following progress of the Sony F5 'hack' story, as it moved from rumor to confirmed. We reached out to Sony and received a response very similar to what was communicated by a Sony moderator 'PeterC' (presumably Peter Crithary, Marketing Manager for Production) on the F55/F5 forum:
Sony is aware of the All File modification that was done by some F5 owners to enable 4K XAVC recording in the camera head. As a matter of policy Sony cannot approve any modifications that are not part of an official firmware release. All firmware updates from Sony come with quality assurances that guarantee high quality performance. Furthermore, unauthorized modifications to the product are not covered by, and may void, Sony’s product warranty.
Let's backtrack a bit and revisit how this all came to be. Cinematographer Paul Ream teases, through his Twitter account, that he had unlocked 4K internal XAVC recording on the F5.
This is a big deal, as the capability of internal 4K recording on the F55 was a major differentiator between it and the F5, which costs around $12,000 less. There are, of course, other differences that this intervention doesn't change, like the F55's global shutter versus the F5's rolling shutter, but internal 4K recording on the F5 is a big deal, if it is real and sustainable.
Ream upped the ante by releasing this footage (and publishing it through ExtraShot, a podcast for video pros). It's purportedly F5 4K footage, internally recorded:
The full explanation of the Sony F5 'hack' was revealed on ExtraShot. Basically, it really isn't a 'hack' at all, as there's no re-working of the firmware's code. It's even less of a hack than the Magic Lantern 'firmware add-on'. In fact, to get an F5 to record 4K XAVC internally, all you need to do is change one line in the 'All File' .txt document that functions like a set-up/preferences file (referenced in Crithary's quote). And, it gets even more simple: the process involves replacing one line from the F5 set-up file with one line from the F55 set-up file, and voila! - if you're an F5 owner, you immediately have a more useful camera, as evidenced by the F5 hack vids popping up, like this one:
The further implication, which some Sony F5 owners find troubling, is that Sony essentially crippled functionality which was there all along. Personally, I don't see a problem with what Sony is doing, as it spends a lot to develop and market these cameras, and it needs to do what it can to protect its product tiers, and limiting a camera's functionality through the set-up file is likely the most cost effective means to do so. Next time, however, Sony should hide what it's doing a little better. And while this 'hack' is relatively safe, by all accounts, it still voids your warranty (if Sony determines that your camera was 'hacked'). It's up to you whether it's worth the risk on a camera that runs $16,500 for just the body.
In summary, it's a hack that isn't, but at least an interesting and easy-to-apply modification, which could prove very useful. But internal 4K recording on the F5 is not functionality borne of an official Sony firmware release, so it's essentially unsupportable, which should be taken into account when determining if a gently-modded F5 is right for your next production.