Sensitivity in HD vs 4k? at DVinfo.net

Piotr Wozniacki · February 25th, 2015, 08:13 AM

DISCLAIMER:

Due to my sickness and disability, I vane't been shooting for a couple of years now; likewise I was much less active reading and posting to the forum - hence some of my questions may sound amateurish now, with the progress of technology in the meantime. Here is one of them:

With the FS7 sensor, do we get line-doubling and thus sensitivity boost over full 4k resolution when shooting in HD (1080p) mode?

Piotr

PS. Of course sensitivity to light remains the same but doesn't line-doubling brighten the picture in HD?

Les Wilson · February 26th, 2015, 09:33 PM

I don't know but welcome back. Good to see your name on posts again.

Mark Watson · February 26th, 2015, 10:52 PM

Piotr,

I don't know either, don't have that camera. I do have the FDR-AX100 (different sensor) and did lots of low light testing, against other cameras and also against itself in 4K vs HD. I didn't see any difference between HD and 4K as far as sensitivity. But.... I did find a way to take advantage of cropping 4K to get better low light than if shot straight to HD. Apart from this, the 4K looks better (compared to doing the same effects to HD footage) after doing some post video effects to brighten the image. I have been using the white balance effect in Sony Vegas to do this. Take a look at these tests...

Mark

Piotr Wozniacki · February 28th, 2015, 05:26 AM

Quote:

Originally Posted by Les Wilson

I don't know but welcome back. Good to see your name on posts again.

Thanks Les for your kind words :)

Quote:

Originally Posted by Mark Watson

Piotr,

I don't know either, don't have that camera. I do have the FDR-AX100 (different sensor) and did lots of low light testing, against other cameras and also against itself in 4K vs HD. I didn't see any difference between HD and 4K as far as sensitivity. But.... I did find a way to take advantage of cropping 4K to get better low light than if shot straight to HD. Apart from this, the 4K looks better (compared to doing the same effects to HD footage) after doing some post video effects to brighten the image. I have been using the white balance effect in Sony Vegas to do this.

Thanks Mark for those illustrative examples; I also edit in Vegas Pro and am hoping for it to support all codex FS7 is outputting in (how can a Sony camera not be fully supported by Sony's NLE bets me - unless it's only temporary).

As a side question: how is Neatvideo doing with the AX100 4k clips?

Mark Watson · February 28th, 2015, 05:59 PM

NeatVideo does very good on AX100 4K video. I'm no "power user" either. Just do the simplest method of using the plug-in, and getting fantastic results. This is in comparison with various HD video I've tried to clean up. I guess it has all to do with the "fineness" of the grain.

Maybe Sony figures anyone shooting with their FS7 won't be using Vegas to edit on? Or a "horse-before-the-cart situation where they figured out how to make the codec but not how to edit it, and I believe this has happened before with either Sony or another brand, can't recall the exact details, but that's exactly what happened. Sort of like the current situation with the X70, promised to put 4K in the camera at a later date and now it looks like they have no idea what flavor of 4K that will be. Lots of people who have handed over their money for the X70 in good faith are now left to wonder whether to dump their camera and just get something that shoots 4K out of the box already.

Mark

Dave Sperling · March 1st, 2015, 09:54 AM

I don't personally have FS7's, but one of the companies I shoot for has a couple, and I've done a few shoots with them.
I never noticed a significant exposure change between 2K and 4K, but in thinking about it I'd think that there could be significant aliasing issues if the camera grouped pixels to maximize exposure.
I also have Vegas (13), and was doing some tests the other day - noticed that it really didn't like XAVC-L. However I did notice that the new Catalyst Browser (The successor to Content Browser/ XDcam Browser/ Clip Browser) does play the XAVC-L footage quite nicely, and is capable of transcoding the footage to something more usable for editing. Obviously the XAVC-L can save you some recording card real estate if you are doing a long shoot and don't have enough cards for XAVC-I

February 25th, 2015, 08:13 AM	#1
Piotr Wozniacki Inner Circle Join Date: Aug 2006 Location: Poland Posts: 4,086	Sensitivity in HD vs 4k? DISCLAIMER: Due to my sickness and disability, I vane't been shooting for a couple of years now; likewise I was much less active reading and posting to the forum - hence some of my questions may sound amateurish now, with the progress of technology in the meantime. Here is one of them: With the FS7 sensor, do we get line-doubling and thus sensitivity boost over full 4k resolution when shooting in HD (1080p) mode? Piotr PS. Of course sensitivity to light remains the same but doesn't line-doubling brighten the picture in HD? __________________ Sony PXW-FS7 \| DaVinci Resolve Studio; Magix Vegas Pro; i7-5960X CPU; 64 GB RAM; 2x GTX 1080 8GB GPU; Decklink 4K Extreme 12G; 4x 3TB WD Black in RAID 0; 1TB M.2 NVMe cache drive

February 26th, 2015, 09:33 PM	#2
Les Wilson Inner Circle Join Date: Jan 2004 Location: Boca Raton, FL Posts: 3,014	Re: Sensitivity in HD vs 4k? I don't know but welcome back. Good to see your name on posts again.

February 26th, 2015, 10:52 PM	#3
Mark Watson Major Player Join Date: Oct 2008 Location: Whidbey Island Posts: 873	Re: Sensitivity in HD vs 4k? Piotr, I don't know either, don't have that camera. I do have the FDR-AX100 (different sensor) and did lots of low light testing, against other cameras and also against itself in 4K vs HD. I didn't see any difference between HD and 4K as far as sensitivity. But.... I did find a way to take advantage of cropping 4K to get better low light than if shot straight to HD. Apart from this, the 4K looks better (compared to doing the same effects to HD footage) after doing some post video effects to brighten the image. I have been using the white balance effect in Sony Vegas to do this. Take a look at these tests... FDR-AX100 Low-Light Test - an advantage of cropped 4K on Vimeo FDR-AX100 Low-Light Test HD vs 4K on Vimeo Mark Last edited by Mark Watson; February 26th, 2015 at 11:13 PM. Reason: Addition of related video.

February 28th, 2015, 05:59 PM	#5
Mark Watson Major Player Join Date: Oct 2008 Location: Whidbey Island Posts: 873	Re: Sensitivity in HD vs 4k? NeatVideo does very good on AX100 4K video. I'm no "power user" either. Just do the simplest method of using the plug-in, and getting fantastic results. This is in comparison with various HD video I've tried to clean up. I guess it has all to do with the "fineness" of the grain. Maybe Sony figures anyone shooting with their FS7 won't be using Vegas to edit on? Or a "horse-before-the-cart situation where they figured out how to make the codec but not how to edit it, and I believe this has happened before with either Sony or another brand, can't recall the exact details, but that's exactly what happened. Sort of like the current situation with the X70, promised to put 4K in the camera at a later date and now it looks like they have no idea what flavor of 4K that will be. Lots of people who have handed over their money for the X70 in good faith are now left to wonder whether to dump their camera and just get something that shoots 4K out of the box already. Mark

March 1st, 2015, 09:54 AM	#6
Dave Sperling Major Player Join Date: Jan 2010 Location: Tinton Falls, NJ Posts: 780	Re: Sensitivity in HD vs 4k? I don't personally have FS7's, but one of the companies I shoot for has a couple, and I've done a few shoots with them. I never noticed a significant exposure change between 2K and 4K, but in thinking about it I'd think that there could be significant aliasing issues if the camera grouped pixels to maximize exposure. I also have Vegas (13), and was doing some tests the other day - noticed that it really didn't like XAVC-L. However I did notice that the new Catalyst Browser (The successor to Content Browser/ XDcam Browser/ Clip Browser) does play the XAVC-L footage quite nicely, and is capable of transcoding the footage to something more usable for editing. Obviously the XAVC-L can save you some recording card real estate if you are doing a long shoot and don't have enough cards for XAVC-I