Rumor: Sony A7s will have 4K video
- Thread starter vanvideo
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Samuel H
Major Contributor
Bigger sensors, and sensors with more pixels, are slower to read, for a same basic design. This one is big and does a full read (skipping half the lines cuts the read-out time in half), but has few pixels. So: wait and see. We'll probably know before the camera hits the shelves.
The camera allows 4K full sensor, 4K APS-C (weird because it's an upscale from 2.7K), HD full sensor, and HD APS-C. AFAIK, the Scotland video was shot in internal HD using the full sensor.
edit:
Sigma just announced the price for the 50mm f/1.4 Art: 850 GBP, 900 EUR, and 950 USD
http://www.dvxuser.com/V6/showthread.php?321965-Rumor-Sony-A7s-will-have-4K-video/page45
With those implicit exchange rates, 2500 GBP is 2650 EUR and 2800 USD
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squig
Veteran
I'm with you there, the 5D MK3 rolling shutter is as much as I can tolerate but I don't expect the A7s will be any worse, but if it's on the level of the 5D that's quite a bit more than the FS100. I wasn't implying you're not a professional, I was just making the point that DSLR's don't perform well handheld. I've left a msg for Den asking how the camera was rigged on the boat.
I'm completely perplexed about the amount of "hate" the 5dmarkIII is usually getting. The image is absolutely breathtaking when shot the Magic Lantern RAW. The amount of colors and latitude and dare I say, even the DR, is really highend. And it is astonishing how well the lowlight RAW stuff gets cleaned up with neatvideo. Way better than any compressed material. I had to make a decision about shooting a bigger shortfilm with either the 5dmarkIII (which meant purchasing a bunch of 1000x cards) or renting a c300/fs700. I'm so glad I went the 5d way. Fullframe is just something else than even s35. What people kinda miss is that anamorphic s35 has more surface area than fullframe.
All that said. The A7s looks amazing. If the rolling shutter is ok, I'm soooo getting one.
All that said. The A7s looks amazing. If the rolling shutter is ok, I'm soooo getting one.
Samuel H
Major Contributor
No hate for the 5D3+RAW from me. The H.264 video is soft and has much worse DR, but with the hack it's probably the best camera I could afford today. It's just not compelling enough for me right now. If the A7s doesn't beat it handily for DR, I'd rather get the 5D3+RAW than the A7s. But it seems it will beat it by quite a margin.
cpc
Well-known member
+1 this, except I don't care about the FF aesthetic.
The appeal of the A7s for me is 4k shot for 2k. I am sure the camera will be at least a stop better than 5dmk3 in low light and DR, possibly more. On the other hand, as you say high iso ML raw cleans beautifully in NV. Add to this the hassle of LUTs for monitoring s-log (Atomos don't have monitoring LUTs AFAIK?), the lack of the excellent ML exposure and focus goodies which I KNOW I will miss, the 5d allure of raw, and the fact that at 700+ mbps 4K prores is practically the same bitrate as 1080p ML raw. Now take into account that rental prices for 5dmk3 are pennies a day these days. Consider the price rumors (yes, A7s is a specialty camera, but still - going higher than A7r just based on specialty? Dunno, doesn't sound right.). And suddenly A7s doesn't look THAT good.
Nirv
Carbonite Member
Yeah, I get that but this sensor is bigger in physical size but is only a 12MP part and one would've thought that readout would've been effectively no worse than the FS700 for example which is a 11.6MP part. The comment by EOSHD regarding RS would likely indicate the A7s is indeed worse than a Sony sensor with a comparable pixel density.
Samuel H
Major Contributor
* Both things matter: total size, and pixel count. The a7s should be slow because it's a big sensor, but should be fast because it has few pixels. Which one is more important, we'll know soon enough.
* Architecture matters a lot more than any of those. You can make an awfully slow small-and-lowres sensor, and a really fast huge-and-highres sensor. How much each costs, and what you win or lose in other areas, that's another story.
* The a7r doesn't get horrible RS in video because it skips lines. The a7s won't.
* Architecture matters a lot more than any of those. You can make an awfully slow small-and-lowres sensor, and a really fast huge-and-highres sensor. How much each costs, and what you win or lose in other areas, that's another story.
* The a7r doesn't get horrible RS in video because it skips lines. The a7s won't.
Nirv
Carbonite Member
I'm not sold on the idea a marginally larger sensor with a similar number of pixels should be much different in RS performance.
That's what I'm trying to understand is why Sony appear to have produced a camera for the shoot by candle light brigade yet produced a sensor with troubling levels of RS (if the reports are to be believed).
I don't know enough about sensors to know what are the limiting factors and the ones which necessitate a slower readout and hence increase rolling shutter but I would've thought a video camera would be best with as little RS as far as possible at the cost of light sensitivity if they are both linked. Maybe the bigger photo sites holding more charge takes longer to drain and that reduces the readout time, I dunno, I'm guessing.
It's 12 Mpixel - but that's for the whole sensor as used for stills - which are 3:2 aspect ratio.
Just do a simple 16:9 crop (losing top and bottom of the 3:2 frame) and that then becomes more like 10Mpixel.
In fact, I strongly suspect that when they say they are "reading the whole sensor in video mode", they are reading 3840x2160 - hence the thought of the 1.1 crop. Be very easy to confirm - does the horizontal angle of view tighten slightly between stills mode and video. (I suspect it does.)
In which case, same number of photosites/frame as the FS700. I won't speculate on rolling shutter until I've seen some tests that I'd consider reliable.
philiplipetz
Veteran
Official Sony low light demo turns night to daylight with some noise. Impressive.
https://www.youtube.com/watch?v=XgbUgNiHfXM
https://www.youtube.com/watch?v=XgbUgNiHfXM
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groveChuck
U-matic Member
Stu Siegal
Well-known member
Cosimo Bullo
Veteran
Looks pretty rough on the rolling shutter front.
philiplipetz
Veteran
True....but other worldly from a low light standpoint. It literally took my breath away. WOWSER!
Samuel H
Major Contributor
oh, my...
I don't get it: Den Lennie said it was not a problem
The only way to reconcile RS being fine for him and awful for others is that he shot full-frame 1080p internally, then external 4K with static shots. The sensor could have high-quality in-sensor binning, that allows for a much faster read-out without aliasing/moire artifacts when you read it at a lower resolution (it's not common, but for example the CMV12000 has this).
I don't get it: Den Lennie said it was not a problem
The only way to reconcile RS being fine for him and awful for others is that he shot full-frame 1080p internally, then external 4K with static shots. The sensor could have high-quality in-sensor binning, that allows for a much faster read-out without aliasing/moire artifacts when you read it at a lower resolution (it's not common, but for example the CMV12000 has this).
Simon Shasha
Well-known member
Den also used lenses that have Sony's OS technology - Sony have some of, if not the best, lens OS on the market.
Regardless, that rolling-shutter is horrific. I guess you gotta take into account that the camera they were filming the A7s with probably suffers from rolling-shutter too, however, even then, its probably not a major factor/inconsequential.
Samuel H
Major Contributor
In this case, the point by macgregor a few pages back is 100% valid. If you stop the video, you will see some ghosting in the front LCD, which is jumping between two grames; if the back camera has rolling shutter, the top part of the image will show more of the first frame, the bottom more of the second frame, but the skew is only determined by the A7s. And it's bad.