GH4 Mixing Gh4 1080p60 slo-mo footage with 4k 24fps

B

bbigelow0621

New member
Hello,


I'm planning a feature production and would like to utilize the 4k on my gh4. However, I'm considering some sequences to involve slow motion, shooting the slo-mo most likely in 1080p60, though possibly some shots in the VBR higher frame rates up to 96.


My question is, if these slo-mo shots must be in 1080, is it worth shooting the other stuff in 4k? How bad does 1080 look scaled up to 4k? Will it look like it's out of place in a 4k viewing?


I know there are advantages of shooting in 4k and downsampling to 1080. But I'm more curious about the other way around, trying to keep a delivery of 4k.


Anyone made this decision before and have experience to share?


Thanks a bunch.
 
I've done quite a bit of 4K nature shooting with 2X digital zoom (a 1080 1:1 frame), which is up-sampled to 4K pixel dimensions in camera, and very smoothly done. Carefully focused, cutting from regular 4K at normal viewing distance on my 55" UHD screen, this change is imperceptible except for the apparent increased detail with the expanded image, and you've got to get to 3' or closer to see the difference.

Peter
 
I've had great results with 96fps VFR in 1080-30p. It's got quite a pleasing image if you ask me albeit extremely soft relative to 4K in a 1080 output. Not sure the usefulness of outputting 4k yet though. 4K displays just aren't the common yet. Even my Blu-ray burner has gone untouched as very few people actually have one. Virtually everything coming out these days is 1080 HD for web distribution.

If you are going to give it a go, make sure to use the fastest lenses at very shallow depth of field. Keep the subject to at least 1/3 of the frame. This way you are bringing the attention to the detail you want to convey in that slow motion scene. The sharpness difference will be nicely hidden in the softer out of focus areas. Content is king !!!

Here's my sample of a bunch of old dudes who've been fishing together almost every year for over 30 years now.
https://vimeo.com/128570651

Cheers,
Pete
 
Why do you want 4k delivery? If this is for theatrical release, you should budget to rent a kit that can get you 4k at high frame rate. I imagine an external recorder can accomplish this. Otherwise a camera kit with an external can get high speed 4k footage to fit your needs. If it's not for theatrical release, then you probably don't need a 4k output.

The other thing to keep in mind is that, as amazing as the GH4 is, it really doesn't provide real cinema level detail. That's why I shoot everything in either 60fps or 4k, depending on priorities, but output 1080 30p. That gets the missing detail back, or allows for speed ramping, depending on priorities.
 
Thanks for everyones feedback!

Yeah I'm just going to do some tests when I get my camera and see what's what.

To your point, Agafilm: The intention with the piece is theater distribution and VOD. Seems like most theaters are still 2k and VOD is also rarely 4k. Am I wasting my time trying to keep it 4k? I always like my stuff to be as future proof as possible. But do the benefits of shooting 4k and downsampling to 2k with the gh4 out way keeping it 4k delivery? This also allows me to use other 1080 sources more easily, scale shots, and if i want to down the line use other cameras (canon cameras, go pro etc, if multicamera becomes necessary in certain settings).
 
Different people would answer that differently. I don't think it's worth worrying about doing a 4k delivery. In the worst case scenario, if you shoot 4K with the intention of delivering 1080, you'll still have the raw files to do a higher resolution version of later.

To clarify my statements before, 4K looks better than 1080 on the GH4, no matter what you export it as. So if you don't want 60p, shoot 4k both for the extra detail and in case you want it later. You can even pull publishable stills with that resolution. If you do, shoot 1080p60, knowing you'll still be getting the full quality of the camera if you deliver that way.

One other thought, on re-reading your post: the detail loss, from what I can tell, is actually more noticeable at framerates above 60. So if you have high detail scenes, it might be best to try interpolating from 60 to get what you want. Or, again and best of all, rent an external recorder for that one day you need specialty shots.
 
again and best of all said:
Do you mean renting another camera for slowmotion work above 60p? I don't think the gh4 can record anything higher than 60 with an external HDMI recorder?

Yeah will probably just aim for a 1080p delivery using the 4k at 24p scaled down, will make for a better 1080p as a 4k viewing is unlikely. And though there's probably a way, I highly doubt I would be able to move my project through editing and VFX while maintaining 4k and 2k deliveries simultaneously. If I have 4k that I know will be scaled to 2, I'm sure I'll want to utilize some reframing and stabilizing etc.

Will do some tests on the 96fps 1080 in the same sequence with the 4k footage. But depending on budgets/days needed, I think you're right and renting a high frame rate camera would be the way to go.
Click to expand...
 
You must log in or register to reply here.
Back
Top