While there are other differences between the two cameras, like a global shutter and 4K outputs on the F55, this hack shows that the over-$12,000 price difference between the two models may be more superficial than at first glance. Sony is aware of the hack, and has now given an official response.

Peter Crithary, who is a marketing manager in Sony's digital cinema division, had this to say in the Sony 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.

This is a standard corporate response, and at this point there isn't much else for them to say as they explore their options. It's pretty likely that the next firmware update for the F5 will disable this modification — though maybe Sony did intend to give F5 users internal 4K at some point down the road.

Paul Ream 4K for F5 Hack

Paul Ream, who found the modification, responded later in the same thread and said much of what he already did on the podcast just a few days ago, but added some interesting questions:

Yes, I think Sony now need to offer 4K on the F5 officially - even at a reasonable fee. They know it’s what their customers are crying out for, and we all know it’s now possible.  To do anything else would be petty.  Trying to sell us a £10K upgrade for items we didn’t want was when the long term plans for the F5 went wrong… now’s the chance to put that right.

What I am pleased about is the fact we’re all now discussing how these professional items are sold to professional users.

So two questions:

If Sony had produced one camera with different options that could be purchased and added when required, would any of us have felt as cheated?

What if it was one camera with paid options, and they failed to protect the keys to turn those options on?  Who would be to blame if someone stumbled on the switch?

Even though it might void the warranty, it's unclear whether there is any way for Sony to know you've actually enabled 4K (it seems unlikely based on the way the modification works, but certainly we don't know everything going on internally in the camera). The biggest thing with this hack is that it's not a perfect implementation since it wasn't intended to be made available at this point in the camera. There is no playback of the 4K material in the camera, and there have been some reports of gamma/clipping issues that are not happening in 2K/1080p. Your own mileage may vary, but if you have an F5 and the 4K modification, let us know if you've seen any issues with it. The longer it is out there, the more we'll know about how stable it is and if there are any problems.

We'll have to wait and see what Sony does from here on out.

Source: Sony Community Forum