GH4 4K strobing in viewfinder & LCD at DVinfo.net

Anthony McErlean · September 10th, 2015, 09:29 AM

I'm trying to record in 4K with my GH4

Camera set to M+ camera (Creative Video Mode)
Shutter speed 50.
Record Format MOV
Rec Quality 4K 100m 25p

I'm seeing strobing in VF and LCD and it will record it as well.

No strobing/flicker problems when I'm recording MOV 1920x1080 50Mbps 50p

Any ideas and thanks.

Matthias Claflin · September 10th, 2015, 10:31 AM

Lighting situation? Sounds like a lighting issue. What is your shutter speed when shooting in 1080p?

Anthony McErlean · September 10th, 2015, 11:23 AM

Quote:

Originally Posted by Matthias Claflin

Lighting situation? Sounds like a lighting issue. What is your shutter speed when shooting in 1080p?

Thanks, 1/50 shutter but it still strobes outside as well when recording 4K, not in 1080p

Colin Rowe · September 10th, 2015, 03:28 PM

I would get your camera checked Anthony. As I said before strobing under flourescent lighting, with the wrong shutter speed selected, is a very common issue. Strobing outdoors is something that I think needs looking into. Try shooting under flourescent lighting, and move into another room, with normal lighting to see if the strobing stops, its the refresh rate of flourescents that causes the strobing

Colin Rowe · September 10th, 2015, 03:49 PM

This is a good illustration of strobing under flourescent lights

Anthony McErlean · September 10th, 2015, 04:42 PM

Thanks Colin, hard to describe just what I see in my VF & LCD, perhaps strobing isn't the correct word, its more like the camera is set to the wrong shutter speed when recording in 4K, it doesn't look smooth in the VF even with nice slow pans.
Its the same inside or outside, flourescent or ordinary lighting.

But no bother with 1080p with the same fluorescent lighting, the VF/LCD image to look at, is as smooth, the way it should be.

Chris Harding · September 10th, 2015, 05:57 PM

I suggested Anthony post here as we have quite a few GH4 experts that stick around here. After some extra comments on the wedding forum I'm wondering if this is simply just LCD lag???

Anthony?? When you play the 4K video on a computer or in your NLE does it show the same traits? or is this purely an issue when you look thru the EVF???

Anthony McErlean · September 11th, 2015, 03:25 AM

Quote:

Originally Posted by Chris Harding

...this is simply just LCD lag???

Anthony?? When you play the 4K video on a computer or in your NLE does it show the same traits? or is this purely an issue when you look thru the EVF???

Hi Chris, LCD lag, perhaps this is what I see, then why do I not see it when 1080p recording with the GH4?

Playback on my Edius PC, it looks OK ish but I think not as smooth as my HD clips on the same 50i timeline. (my wife cant see what I'm talking about, she sees nothing wrong with the clips when playing them back on the PC :) )
I can mix 50i clips and AVCHD 50p clips on my HD Timeline and both work well together.

In the record Quality settings none of the other recording options I choose show this in the VF, only the 4K option.

If I choose say FHD 100M 50p and set the shutter speed to 1/40, instead of 1/50, its this the type of motion I see in the VF when I record in 4K.
I don't know if you can duplicate this on one of your cameras with a different shutter speed to see what I mean :)

Chris Harding · September 11th, 2015, 04:39 AM

If it's not on the footage then it's simply lag on the display. Set your shutter to 1/25th or lower and do a medium pan and watch the EVF ... it that's what you are talking about ...like jerky pan movements .. then that's purely the fact that the display cannot update fast enough and it shouldn't affect your footage at 1/50th at all. I would suspect that you are shooting 1080 at 50P so your wouldn't see and lag there.

On my cams I only have 4K at 25P or 24P and yes, the EVF will lag at 25 fps ... At 50i you are shooting interlaced so your 25fps frame rate actually uses an odd and even frame to make up 50 fps so again there shouldn't be any lag there.

Bottom line is that computers and TV refresh a lot faster than camera displays and as long as the lag isn't on your footage, don't worry about it... Just remember if you have to shoot 25P at low shutter speeds like 1/25th just pan slowly because that can affect footage! ... The fluor lights just assist the deception of a jittery EVF at 25P

Anthony McErlean · September 11th, 2015, 05:54 AM

Quote:

Originally Posted by Chris Harding

Set your shutter to 1/25th or lower and do a medium pan and watch the EVF ... it that's what you are talking about ...

Chris, in FHD 50M 50p and I set shutter to 1/25, yes, that's what I see in the VF when recording in 4K
Change the shutter back to 1/50 and all is well.

4K playback does look what wee bit different on my HDTV compared to the HD clips.

Perhaps this is all normal in the GH4 after all :)

Steve Burkett · September 11th, 2015, 06:01 AM

Okay, this is something that the latest firmware seemed to resolve, but the lack of smooth motion in 4K recording was something I noticed with my GH4. Basically I put it down to the LCD showing a 4K image on screen but lacking the ability to show it smoothly. Oddly it would be worse on some days than others. This seemed to resolve itself with the latest firmware and I've not seen evidence of since then.

As for on the computer, well unless your PC is up to date, then the same issue can be presented on playback there too. You need a good graphics card to support playback of 4K.

Anthony McErlean · September 11th, 2015, 06:16 AM

Hi Steve, thanks for your input, I think my PC should be ok that way, its not the timeline stutter you would see if the PC isn't up to scratch.

I have i7-2700K/ Edius 8WG/ 16GB HyperX/ GTX 560Ti ...not the fastest now I know but plenty fast for me.

Just looked at the firmware version and its Body V2.1 Lens V2.1

Should I update or leave alone?

Thank you.

Steve Burkett · September 11th, 2015, 06:20 AM

No that's the firmware I have. There's a new one for v log if you wish to pay for the feature.

Given the specifications, I'm at a loss why you should be having such an issue. It could well be a fault with the camera. Something specific to 4K recording. Is there anyway you can get another one and see if the issue is the same. Go into a store and try one.

Anthony McErlean · September 11th, 2015, 06:35 AM

OK Steve, I'll have a look to see if a store has one.
So did you think you also seen this in the VF before you updated the firmware.
I see firmware 2.2 and 2.3 mine is V2.1

Chris Harding · September 11th, 2015, 06:40 AM

Hi Anthony

In your initial post you say the "strobing" is recorded as well??? Have you recorded 4K with a stationary camera?? or use OIS ...I can hand hold mine in 4K mode and the image is perfect but I have never tried wild zooms at 25P in either 4K or FHD ..Stick the cam on a tripod or on a table outside and see if it does the same thing. There shouldn't be any lag if the camera is still

September 10th, 2015, 09:29 AM	#1
Anthony McErlean Trustee Join Date: Oct 2008 Location: Northern Ireland Posts: 1,081	GH4 4K strobing in viewfinder & LCD I'm trying to record in 4K with my GH4 Camera set to M+ camera (Creative Video Mode) Shutter speed 50. Record Format MOV Rec Quality 4K 100m 25p I'm seeing strobing in VF and LCD and it will record it as well. No strobing/flicker problems when I'm recording MOV 1920x1080 50Mbps 50p Any ideas and thanks.

September 10th, 2015, 10:31 AM	#2
Matthias Claflin Regular Crew Join Date: Mar 2013 Location: PA, USA Posts: 87	Re: GH4 4K strobing in viewfinder & LCD Lighting situation? Sounds like a lighting issue. What is your shutter speed when shooting in 1080p?

September 10th, 2015, 03:28 PM	#4
Colin Rowe Major Player Join Date: Jan 2004 Location: Cornwall UK Posts: 793	Re: GH4 4K strobing in viewfinder & LCD I would get your camera checked Anthony. As I said before strobing under flourescent lighting, with the wrong shutter speed selected, is a very common issue. Strobing outdoors is something that I think needs looking into. Try shooting under flourescent lighting, and move into another room, with normal lighting to see if the strobing stops, its the refresh rate of flourescents that causes the strobing __________________ Colin

September 10th, 2015, 03:49 PM	#5
Colin Rowe Major Player Join Date: Jan 2004 Location: Cornwall UK Posts: 793	Re: GH4 4K strobing in viewfinder & LCD This is a good illustration of strobing under flourescent lights 5d's Achilles' heel? Bizarre banding/ flicker while shooting PAL on Vimeo __________________ Colin

September 10th, 2015, 04:42 PM	#6
Anthony McErlean Trustee Join Date: Oct 2008 Location: Northern Ireland Posts: 1,081	Re: GH4 4K strobing in viewfinder & LCD Thanks Colin, hard to describe just what I see in my VF & LCD, perhaps strobing isn't the correct word, its more like the camera is set to the wrong shutter speed when recording in 4K, it doesn't look smooth in the VF even with nice slow pans. Its the same inside or outside, flourescent or ordinary lighting. But no bother with 1080p with the same fluorescent lighting, the VF/LCD image to look at, is as smooth, the way it should be.

September 10th, 2015, 05:57 PM	#7
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Re: GH4 4K strobing in viewfinder & LCD I suggested Anthony post here as we have quite a few GH4 experts that stick around here. After some extra comments on the wedding forum I'm wondering if this is simply just LCD lag??? Anthony?? When you play the 4K video on a computer or in your NLE does it show the same traits? or is this purely an issue when you look thru the EVF???

September 11th, 2015, 04:39 AM	#9
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Re: GH4 4K strobing in viewfinder & LCD If it's not on the footage then it's simply lag on the display. Set your shutter to 1/25th or lower and do a medium pan and watch the EVF ... it that's what you are talking about ...like jerky pan movements .. then that's purely the fact that the display cannot update fast enough and it shouldn't affect your footage at 1/50th at all. I would suspect that you are shooting 1080 at 50P so your wouldn't see and lag there. On my cams I only have 4K at 25P or 24P and yes, the EVF will lag at 25 fps ... At 50i you are shooting interlaced so your 25fps frame rate actually uses an odd and even frame to make up 50 fps so again there shouldn't be any lag there. Bottom line is that computers and TV refresh a lot faster than camera displays and as long as the lag isn't on your footage, don't worry about it... Just remember if you have to shoot 25P at low shutter speeds like 1/25th just pan slowly because that can affect footage! ... The fluor lights just assist the deception of a jittery EVF at 25P

September 11th, 2015, 06:01 AM	#11
Steve Burkett Trustee Join Date: Jul 2012 Location: Romsey, UK Posts: 1,261	Re: GH4 4K strobing in viewfinder & LCD Okay, this is something that the latest firmware seemed to resolve, but the lack of smooth motion in 4K recording was something I noticed with my GH4. Basically I put it down to the LCD showing a 4K image on screen but lacking the ability to show it smoothly. Oddly it would be worse on some days than others. This seemed to resolve itself with the latest firmware and I've not seen evidence of since then. As for on the computer, well unless your PC is up to date, then the same issue can be presented on playback there too. You need a good graphics card to support playback of 4K.

September 11th, 2015, 06:16 AM	#12
Anthony McErlean Trustee Join Date: Oct 2008 Location: Northern Ireland Posts: 1,081	Re: GH4 4K strobing in viewfinder & LCD Hi Steve, thanks for your input, I think my PC should be ok that way, its not the timeline stutter you would see if the PC isn't up to scratch. I have i7-2700K/ Edius 8WG/ 16GB HyperX/ GTX 560Ti ...not the fastest now I know but plenty fast for me. Just looked at the firmware version and its Body V2.1 Lens V2.1 Should I update or leave alone? Thank you.

September 11th, 2015, 06:20 AM	#13
Steve Burkett Trustee Join Date: Jul 2012 Location: Romsey, UK Posts: 1,261	Re: GH4 4K strobing in viewfinder & LCD No that's the firmware I have. There's a new one for v log if you wish to pay for the feature. Given the specifications, I'm at a loss why you should be having such an issue. It could well be a fault with the camera. Something specific to 4K recording. Is there anyway you can get another one and see if the issue is the same. Go into a store and try one.

September 11th, 2015, 06:35 AM	#14
Anthony McErlean Trustee Join Date: Oct 2008 Location: Northern Ireland Posts: 1,081	Re: GH4 4K strobing in viewfinder & LCD OK Steve, I'll have a look to see if a store has one. So did you think you also seen this in the VF before you updated the firmware. I see firmware 2.2 and 2.3 mine is V2.1

September 11th, 2015, 06:40 AM	#15
Chris Harding Inner Circle Join Date: Jul 2009 Location: Perth, Western Australia Posts: 8,441	Re: GH4 4K strobing in viewfinder & LCD Hi Anthony In your initial post you say the "strobing" is recorded as well??? Have you recorded 4K with a stationary camera?? or use OIS ...I can hand hold mine in 4K mode and the image is perfect but I have never tried wild zooms at 25P in either 4K or FHD ..Stick the cam on a tripod or on a table outside and see if it does the same thing. There shouldn't be any lag if the camera is still