View Full Version : advantages of cropping 4K


Noa Put
August 9th, 2014, 04:07 AM
Last wedding I was shooting the ceremony with my ax100 and a cx730, when the vows started I quickly pointed my ax100, which was on a tripod, towards the position where the couple and priest would be standing, because I was not exactly sure where they would be positioned I just left the lens wide and see what I could do in post afterwards.

In below frames you see a before and after cropping in post, before shows me and the photog in the image and the second the 4k image cropped on the 1080p timeline, the 4k image is now shown at it's full resolution and eventhough I could even zoom in further image degradation would start to show from this point.

So now I can safely take out any unwanted parts from the frame and mix it without any issue with my other camera, the cx730. This is THE reason why I wanted 4k. in my case, especially during ceremonies when shooting solo it makes all the difference and allows me to provide a higher quality product, it ofcourse can't remove a photog if they will stand in front of the camera :) but it will dramatically improve framing mistakes.

(Don't pixelpeep the image, it's a lower quality export from photoshop after I blurred all faces as I don't have permission to show this online)

Dave Partington
August 9th, 2014, 06:01 AM
Perfect example Noa. I'm loving this aspect from 4K too and in fact is the main reason I bought it 4K.

Of course I'm going to be stuffed when I have to deliver in 4K in a couple of months for a trade show exhibit, but oh well.

8K camera anyone ?

James Manford
August 9th, 2014, 10:41 AM
Great example. To be fair, i'm doing those crops with HD already ... and you can hardly tell the difference going from 1080p to 720p in post. Especially when your clients are receiving DVD only.

Noa, did you buy your AX100 brand new at retail prices ???

I'm waiting for it to come down to sub £1000 in the UK. As a matter of fact, the next time I see a used one being sold at that price i'll buy it straight away and replace my current B cam.

I'm still 50 / 50 about 4K ONLY because clients aren't willing to pay more. So I can't justify spending the £1500 price tag at the moment.

Noa Put
August 9th, 2014, 11:09 AM
I got the ax100 just after it dropped 15% in price, all dealers in Belgium still have it at the old prize but one, where i got mine from, still has it at that reduced prize.

Noa Put
August 20th, 2014, 04:26 AM
As I have been editing a few weddings now which include 4k footage another great advantage I discovered is that using framegrabs from a 4k timeline, I exported to frames shot at a photoshoot to use for my dvdcover prints and those contain much more detail then my 1080p prints, perfect to select just that frame where the couple looks their best and have photoquality prints ready for the dvdcover.

Craig McKenna
August 21st, 2014, 12:29 PM
As I have been editing a few weddings now which include 4k footage another great advantage I discovered is that using framegrabs from a 4k timeline, I exported to frames shot at a photoshoot to use for my dvdcover prints and those contain much more detail then my 1080p prints, perfect to select just that frame where the couple looks their best and have photoquality prints ready for the dvdcover.

This is one of the reasons I'm interested in shooting 4K next season!

I want to get your new camcorder first and then shoot 4K with both the GH4 and the AX100.

Can anyone explain how I go from a frame in FCPX to a still photograph though? I have been shooting some images, as well as shooting video to ensure that I have a DVD cover with some good results... but those shots are now photos - not video - which means that I lose a great video shot as a result!!!

Clive McLaughlin
August 21st, 2014, 12:55 PM
If I were to go 4k, it would be to replace my b cams (cx730s) with AX100s. I's still use the A7S for beauty shots.

The cropping is the only benefit of 4K I'm bothered about.

i don't necessarily want the detail and sharpness, nor do I think its called for.

Dave Partington
August 21st, 2014, 01:03 PM
Can anyone explain how I go from a frame in FCPX to a still photograph though? I have been shooting some images, as well as shooting video to ensure that I have a DVD cover with some good results... but those shots are now photos - not video - which means that I lose a great video shot as a result!!!

You can save the current frame from any timeline as a still. Done!

If you want to take a 4K still instead of grabbing it from a downsized 1080p, right click the clip in the event browser and open in in it's own timeline. Find the frame you want then export as a still. It's really that simple.

I've been totally blown away by the stills I've grabbed form the timeline using the GH4 as a 4K (UHD) source.

Craig McKenna
August 21st, 2014, 02:42 PM
Thanks a lot Dave! I just cropped an image from a 1080p timeline and I'm impressed, can't imagine how good 4K must look!!!

Noa Put
November 20th, 2014, 03:19 AM
I"m editing a stage performance that was shot on the ax100 in 4K which was set wide and a cx730 was used to zoom in and follow the action, if I really wanted I could have locked the focus on the ax100, set the exposure to auto (light was constant on stage), then have a cup of coffee and enjoyed the play without looking at the camera and do all my cropping and reframing in post.
The footage from my ax100 cropped looks almost identical to the cx730 footage zoomed in, from a normal viewing distance you can't see the difference, only if you export the frames and compare in photoshop you can see the cropped 4k footage is more coarse in fine detail.
I thought I just mention it as this can be another advantage of shooting in 4K and editing in 1080p.

Roger Gunkel
November 20th, 2014, 06:20 AM
I remember having this discussion a few months back when we were all thinking about 4k. The only thing that interested me and still does, is the ability to crop close, particularly when I currently shoot stage productions with 4 cameras and two operators and I could use one 4k camera to do the whole thing single handed.

That means that Claire and I could double our School production workload, by each taking on different productions. Also of course not having to follow the action would be a Godsend.

Roger

Noa Put
November 20th, 2014, 06:43 AM
I can't show anything with the actors inside but I have a view of both camera's on the empty stage, the camera where from the same distance from the stage.

This is the first framegrab from the ax100 how it was set wide as a locked off safetyshot: (this is already downsized to 1080p, so it's not the native 4K resolution.)

Noa Put
November 20th, 2014, 06:44 AM
This is a crop up to the native resolution of the ax100: (in a 1080p project)

Noa Put
November 20th, 2014, 06:45 AM
and this is zoomed in by the camera from my cx730:

Noa Put
November 20th, 2014, 06:47 AM
and one last, here I cropped the ax100 footage even more to match the frame from my cx730, so at this stage image deterioration is starting to appear because I"m going past the native 4K resolution but it is still usable:

Noa Put
November 20th, 2014, 06:53 AM
and finally for those that want to play with a 4K framegrab in a 1080p project: here is a 4K frame exported from the ax100

Roger Gunkel
November 20th, 2014, 09:05 AM
Very interesting Noa and very welcome Jpegs. Claire, my wife has driven into the nearest big town today to see if she can locate a Lumix FZ1000 with a view to taking some footage on an sd card and trying things like smooth zoom, zoom speed etc. If she finds one and we get the results we want, then we won't be far off buying.

Roger

Mark Ahrens
November 27th, 2014, 09:02 AM
Noa, do you have any issues with multicam editing on your system. Assuming you have one 4k and 3x1080 streams.

For stage productions with variable lighting, how active are you in exposure adjustment?
Does the AX100 have a spotlight mode with manual exposure shift?

Simon Denny
November 27th, 2014, 08:12 PM
Hi Noa,

Which camera model is this?

Cheers

Noa Put
November 28th, 2014, 01:52 AM
Noa, do you have any issues with multicam editing on your system. Assuming you have one 4k and 3x1080 streams.

For stage productions with variable lighting, how active are you in exposure adjustment?
Does the AX100 have a spotlight mode with manual exposure shift?

The camera has ae shift but I couldn't find spotlight mode back in the camera menu, I only shoot a few of these stageperformances every year and some others are dance performances with changing light colours and intensity, for those I have always used my sony cx730's and then set one camera wide as safety, lock focus but let the camera handle the exposure as I can't handle 2 camera's simultaneously, I do set the ae-shift to -1.
The second camera I use to follow the action more closer and there I manually adjust the exposure with the small wheel.

I have a i7 3770 processor with 8gb of memory, a quadro k420 card for 2 pc screens and a spark card for a direct feed towards a tv from what's on the timeline and edit from a single 2tb wd black disc to give you an idea of my system setup. I can edit 1 stream of XAVC S 4K 25p and 2 streams of 1080p avchd 50p in real time though I do get a occasional stutter while Edius is building a buffer. If I add a 3rd 1080p stream it starts to stutter more but I could still do a edit if I wanted.

Currently I"m editing a wedding where I have one 50mbs 4K file from the ax100, one 100mbs 4K file from a gh4, two 28mbs 1080p files from 2 cx730'x and one 50mbs 1080p file from a rx10 all in a multicam edit (it is a ceremony where I used 5 camera's)
I"m maybe getting a bit over half realtime playback speed and it stutters constantly but I"m halfway through that part to edit so it can be done, but it's no fun. Only when the edit is done edus allows to compress the entire multicam edit to one track so it's back to realtime performance after that.

Which camera model is this?
The sony ax100

Simon Denny
November 28th, 2014, 04:41 AM
AH, thanks Noa
Images look great from that camera.

Cheers

Jon Robertson
November 28th, 2014, 08:57 AM
Hi Noa

Thanks for putting those images up. Is there any gain being used by the camera on the stage shot?

Cheers

Jon

Noa Put
November 28th, 2014, 09:09 AM
There was gain used but I don't know anymore how much.