Transcode and downres 4K to 1080

Some questions here about working with 4K. I almost feel I should know the answers myself but I’ve not yet found clear guidance – any input gratefully received.

I work entirely in 1080 timelines, on FCP7.

Increasingly, there’s footage available now in 2.7 and 4K, from cameras like the GoPro4, and I’ve been making various test shoots.

My workflow has been to transcode the GoPro h264 to ProRes, and at the same time downres to 1080.

Here’s where the problem arises. After the transcode/downres, what looked like very clean and crisp footage in its native form has developed an unnacceptable amount of noise.

I’ve tried the conversion via both Compressor and Streamclip, and the effect is just the same.

Is this something to do with ‘squeezing’ 4K of data down into a smaller frame – or is there some other mistake I’m making?

My other question is to do with getting the best out of the 4K – even putting this transcode issue to one side.

I can really see the potential of cropping into the 4K frame and resizing – but how do I do that given that I’m working in a 1080 environment – therefore the 4K material is going to render down in any case. Is this an issue with still working in FCP7, that FCPX is supposed to get over?

FCP7 7.0.3 MacPro 2x2.66 /6core/ 12G RAM Blackmagic Decklink HD Extreme2

Not sure if this may do some help. but I think when you downres , it may cause some influence,what converter you used to convert your video into prores? my suggestion is to update to FCPX. FCPX may handle 4K movie much better

Thanks - I've tried several different programs to downres - Steamclip, Compressor, GoPro Studio - all of them result in the same very 'noisy' file.

[I'm surprised I seem to be the only one with this experience?]

I hear what you say about FCPX - it can handle 4K natively - but this downres problem seems to be a separate issue.

What are your compressor settings? Did you use GoPro studio with any ProTune preset?