Sony's A7s could be the new low-light champion

John_Cline wrote on 6/9/2014, 5:15 PM
Looks like Sony's new A7s just might be the 4k producer's weapon of choice, it trades the 36.4 megapixels of the A7R for a 12.2 megapixel sensor optimized to shoot incredible low-light video in the darkest of conditions.

For comparison, the Sony A7 and A7R top out at a max ISO setting of 25,600, where the new A7S boasts a max ISO setting of 409,600. This test footage, shot by Yoshihiro Enatsu in the dark of night, only pushed the camera to between ISO 8,000 to 40,000 without a speck of visible noise. Impressive.

Comments

riredale wrote on 6/10/2014, 12:07 AM
That video just shows a girl walking around with a lantern.

Isn't the video you reference?

In any event, very cool.
farss wrote on 6/10/2014, 2:09 AM
I'm waiting to see what Sony does with this sensor. The A7s is certainly remarkable but appears to only support 24p and 30p which is problematic for 4K. Hopefully Sony will put the same sensor in a camera with a video friendly form factor and shoots at higher frame rates.

Bob.

John_Cline wrote on 6/12/2014, 2:29 PM
Bob, you're right, what's the point of having a glorious 4K worth of spatial resolution only to skimp on the temporal resolution. I'm not interested in 4K at anything less than 60p.
OldSmoke wrote on 6/12/2014, 4:41 PM
@Bob

Why is it problematic for 4K? It shouldn't be more problematic then it is for HD.

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ushere wrote on 6/12/2014, 11:39 PM
i'm going to be a real dumbo here (i'm of that age...)

what is this thing about low-light? i appreciate event producers having problems with badly lit venues, but isn't that the point - having that 'dim' look rather than the obviously 'pushed' false look i often see in wedding videos?

as for indie productions, well, you're in charge of the lighting, and if the production warrants it, you can always hire the right equipment. aka barry lyndon

i would be much happier with a camera that was ergonomically designed for the job, offered all the i/o's that i'd expect from a professional instrument, recorded in a choice of user friendly formats, and wouldn't be obsolete within a few months...

that said, i doubt i could afford an arri, let alone the glass to match it ;-(

i am watching the ursa, but certainly wouldn't be the first cab off the block...

btw - i simply can't see myself ever adapting to shooting video with a dslr - it's just so impractical on so many levels.
Marc S wrote on 6/13/2014, 10:49 AM
There are many times when I'm recording in a church and there is light but the cameras are just not sensitive enough to capture a clean picture. You either push the gain and end up with lots of noise or you end up with a very dark picture (not like you saw it with your eyes). With a low light camera like the A7 you could push it enough to get a good image while not taking away from the feel of the shot. It's the best of many worlds in my opinion. Current cameras are nowhere near the ability of the human eye to see in low light. This should bring us a bit closer. Looking forward to Sony implementing this tech on real video cameras.
NCARalph wrote on 6/13/2014, 1:25 PM
I do a lot of video for small theater groups and the plays tend to be very dimly lit and with a lot of variation in lighting.
wwjd wrote on 6/13/2014, 2:07 PM
I'll admit the A7 low light is an amazing breakthrough in price and would be fun to toy with, low light was never even on the list of needed features when I went camera shopping recently.
GeeBax wrote on 6/13/2014, 5:14 PM
It has been described elsewhere as a wedding shooter's camera. That seems to be an insult these days.
farss wrote on 6/13/2014, 5:46 PM
OldSmoke said:[I]" Why is it problematic for 4K? It shouldn't be more problematic then it is for HD. "[/I]

As the field of view increases judder becomes more apparent. I'm told the BBC were demonstrating this at NAB this year. They're pushing for 4K acquisition / presentation to be at 120fps for region60 and 150fps for region50.
Most of us seem to think of 4K as more resolution but the intent really is the same perceived resolution as 2K but on a larger screen so the viewer's peripheral vision is covered. That's why we're seeing a revival of the curved screens. This does sort of imply a change in how we shoot, we should be shooting with wider lenses and/or with a wider aspect ratio. There's going to be some creative issues to contend with.

Ushere said: [I]"what is this thing about low-light?"[/I]

It's not just for the ENG and events people. Being able to shoot at a higher ISO means the lens can be stopped down more to get more DOF, it can mean a significant saving in the lighting budget. It also means being able to shoot scenes that would be almost impossible otherwise such as a wide shot of a beach by starlight.

The low light capability from the bigger photosites in the sensor also means more dynamic range in the image with cleaner blacks. I think the A7s makes use of this to record SLog.

Bob.
john_dennis wrote on 6/13/2014, 5:57 PM
"They're pushing for 4K acquisition / presentation to be at 120fps for region60..."

The thing that I find most appealing about 120fps is that it can be rendered to any common frame rate without worrying about interpolated, blended or otherwise manipulated frames.

120/24=5 (a whole integer).

120/60=2 (a whole integer).

120/30=4 (a whole integer).

I doubt if any of my presentation will be 120 fps any time soon.

As for low light capability, I would welcome it. I usually have zero lighting budget or even planning for much of the ad hoc video that I shoot. I've also shot a lot of noisy material because of that fact.
OldSmoke wrote on 6/13/2014, 7:35 PM
As the field of view increases judder becomes more apparent. I'm told the BBC were demonstrating this at NAB this year. They're pushing for 4K acquisition / presentation to be at 120fps for region60 and 150fps for region50.

If that is all true, we should stop shooting 24p even for HD. Don't get me wrong, I am all for 4k in 60p and I shoot HD exclusively in 1080 60p but I don't think that 30p is more problematic for 4K then it is in general. I see 4K as a way to push for new products such as bigger, 80" TVs. We have come to a point where Full HD is no longer sufficient.

Proud owner of Sony Vegas Pro 7, 8, 9, 10, 11, 12 & 13 and now Magix VP15&16.

System Spec.:
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Spectralis wrote on 6/13/2014, 7:43 PM
4K at 120fps sounds great in theory but the size of the files are enormous. I wouldn't like to try to edit them even on my high powered PC.

In terms of viewing very few have the space to unleash a 60" curved screen TV in their living rooms (here in London anyway.) The difference between HD and 4K at most home TV viewing distances isn't significant enough from what I've seen to encourage me to upgrade any time soon.

On the internet, which most people view on small screens, 4K seems pointless due to file size and bandwidth limitations which isn't going to improve in the UK for a very long time. HD files already look great on smaller screens.

For public performance I can see the benefits so maybe a commercial operation is going to use 4K but then I suspect they'll buy or hire pro or semi-pro equipment - not this digital camera.

What I do think is useful is the low light performance. Sony are really innovating in this area which is always welcome.

farss wrote on 6/13/2014, 8:10 PM
Spectralis said: [I]"In terms of viewing very few have the space to unleash a 60" curved screen TV in their living rooms (here in London anyway.) The difference between HD and 4K at most home TV viewing distances isn't significant enough from what I've seen to encourage me to upgrade any time soon."[/I]

I know Londoners live is shoe boxes but I cannot imagine a living room with a smallest dimension of less than 9 feet which is enough for a 120 inch screen, sitting 6 feet away from a 120 inch screen would be about right.

Of course one could well query how many are going to want the IMAX experience in their living room but that's a different question.

Bob.
Spectralis wrote on 6/13/2014, 11:20 PM
If it was mounted on a wall then maybe a 120" screen might work not that many people I know with a 9ft room could afford a 120" screen (unless it was projected.) A 60" screen looks OTT in most flat (apartment) living rooms unless mounted on a wall. But the point I was making is that the image would not appear significantly better than an HD TV at that distance (9ft) based on my experience.

The recommended viewing distance for a 60" set is about 10 ft away. According to this calculator the difference between 4K and HD kicks in at about 7ft for a 60" so it might just be visible in a 9ft room but then the recommended viewing distance is too close. The difference is barely visible 7ft away from a 50" screen which is probably the largest size for comfortable viewing in a 9ft room.

http://referencehometheater.com/2013/commentary/4k-calculator/

When I visited family in Australia they could not comprehend the size of most London living spaces which I imagine are as cramped as apartments in any densely populated and expensive urban area such as New York. They are used to relatively cheap single story three bedroom spacious houses which I assume many parts of the US enjoy. My brother who lives in the US has plenty of space and finds London expensive and very cramped. A huge TV in a small space takes over and gives the impression of over-compensation (like a small person with a huge car?) Not to mention the potential effect on eye sight of viewing too close to the screen.

Then there is the type of content being watched on the TV. Many stores display 4K TV's so that the viewer needs to approach the screen much closer than normal viewing distances and these displays play 4K content which is virtually unattainable yet. In time it will be but right now these TV's will be playing HD content at best.

I think a 4K TV might be worth buying in a couple of years when content has caught up and HD TV's are gradually being withdrawn from sale. But I don't think it's worth trading in a decent HD TV for a 4K one right now especially for those with a small viewing space.

Having said that, tech development is constantly advancing and prices falling so if a 60" 4K TV is available, in a years time, for the same price as an equivalent sized HD TV then it would be daft not to go 4K. But I still think that would be overkill in a 9ft room.
John_Cline wrote on 6/14/2014, 2:26 AM
"Not to mention the potential effect on eye sight of viewing too close to the screen."

And what negative effect might this be?
ushere wrote on 6/14/2014, 2:39 AM
boredom? ;-)

oh, and perhaps dry eye syndrome from less blinking?
Spectralis wrote on 6/14/2014, 12:08 PM
Sitting too close to a 60" TV for extended periods isn't going to damage the eyes permanently but it can cause eye fatigue and associated symptoms. The immersive quality of viewing a large screen close up is very impressive but in my experience, after awhile, I experienced headaches and slight nausea (during fast action scenes) sitting about five feet away from a friends 60" TV. Although he seemed unphased by it. I haven't tried watching 3D content in those conditions.
RalphM wrote on 6/14/2014, 1:28 PM
While the file sizes may be large, another advantage of 4K is the ability to crop the image in post and still end up with a good 1080p result.

Progress is also being made in getting manageable file sizes while retaining good quality (PanasonicGH4 for example).
Spectralis wrote on 6/14/2014, 3:40 PM
If they can find a way to reduce 4K files sizes without unduly affecting quality then that would be a huge advantage. One of the problems I have even with compositing HD film and animation is that very quickly I can end up with huge projects. Rendering different test versions of each of the parts of the composition soon add up. I can delete a lot of it after rendering the final composite but I prefer to keep some of the preparatory work in case I need to go back to it for reference.

As much as I complain about the difficulties I perceive with 4K there's no going back and I'll eventually end up working with it if my PC's can manage it. I'm not sure I could accommodate or even want another jump in resolution though but, just like 4K, that day will eventually arrive.
OldSmoke wrote on 6/14/2014, 5:01 PM
I did actually manage to compress some of my 4K footage from my FDR-AX100 with Handbrake down to around 10Mbps and it still looked very good. I am quite certain it can be compressed to a suitable BD format, even if it where 60p.

Proud owner of Sony Vegas Pro 7, 8, 9, 10, 11, 12 & 13 and now Magix VP15&16.

System Spec.:
Motherboard: ASUS X299 Prime-A

Ram: G.Skill 4x8GB DDR4 2666 XMP

CPU: i7-9800x @ 4.6GHz (custom water cooling system)
GPU: 1x AMD Vega Pro Frontier Edition (water cooled)
Hard drives: System Samsung 970Pro NVME, AV-Projects 1TB (4x Intel P7600 512GB VROC), 4x 2.5" Hotswap bays, 1x 3.5" Hotswap Bay, 1x LG BluRay Burner

PSU: Corsair 1200W
Monitor: 2x Dell Ultrasharp U2713HM (2560x1440)

riredale wrote on 6/14/2014, 6:06 PM
Hoping that 120 would be the Holy Grail might be premature. Yes, 120 goes into 30 or 60 cleanly, but not 59.94.

Furthermore, shooting at 120 implies a much faster shutter speed, which might make motion look somewhat worse.
Rory Cooper wrote on 6/17/2014, 2:40 AM
. I have never been a big fan of still cams for filming but, That is impressive. Well I am blown away by its capabilities
farss wrote on 6/17/2014, 3:59 AM
[I]"Hoping that 120 would be the Holy Grail might be premature. Yes, 120 goes into 30 or 60 cleanly, but not 59.94."[/I]

I suspect those numbers are rounded up for the journalists :)

[I]" Furthermore, shooting at 120 implies a much faster shutter speed, which might make motion look somewhat worse."[/I]

The faster shutter speed is offset by having more frames per second. That's why shutter speed if often specified as an angle. What it does mean is having less light.

Bob.