A7s sample footage

macgregor said:
https://dl.dropboxusercontent.com/u/13362047/a7s vs d800.rar
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Hehe. You gotta feed it more light, it's hungry, you starved the sensor. Blow the highlights, you'll get them back. I know you're just testing the extremes but we've already determined that the sensor can't cope with underexposure in S-Log. You won't get that kind of shadow noise if there's a good overall exposure. +1.7 - +2 EV looks to be the sweet spot, even +1 EV is quite noisy. I'm happily shooting 20,000 ISO with minimal noise. The beauty of the A7s is my DOF is no longer restricted by high ISO noise like it was with the 5D.

S-Log Not perfect but it's not raw. Damn good for 8bit.
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Please can someone give me some advice on the strongest ND filter, with great quality, free from color contamination that I can purchase for use with screw on 72mm lenses, so that I can shoot with the slog in sunny conditions on the a7s. Have a shoot coming up soon and I'm using canon glass and wanted a high grade but something relatively inexpensive.
 
Hoya Pro ND are the most neutral. I'm about to buy a couple myself. The shot above was taken with an old 3 stop Hoya ND @ 3200 ISO and a 125 shutter. Can't recall the F stop, somewhere around 11 I think.
 
Cool, thanks squig. Just looked at a hoya 10 STOP online. I think that sould allow me to open up my lens and keep a 45 shutter.
 
Boz said:
Hmmm... a few stills posted at dpreview.com show none of the noise MacGregor is finding.

ISO 100:
http://www.dpreview.com/galleries/r...988629/?inAlbum=sony-alpha-7s-samples-gallery

ISO 125:
http://www.dpreview.com/galleries/r...988627/?inAlbum=sony-alpha-7s-samples-gallery

ISO 250:
http://www.dpreview.com/galleries/r...631-acr?inalbum=sony-alpha-7s-samples-gallery

(Click on "Original" to view fullsize)


Granted these are JPEGs and dpreview gives no numbers in regards to how they were processed.

I'm not saying MacGregor is wrong, I'm just saying I'm not seeing it in other low ISO photos that are out there. I also looked at a few of the RAW ISO 100 images here and found no evidence of such noise either. Weird.

Edit: I guess a bit more information on 'pushing RAW files to their limits' would be helpful.
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"pushing RAW files to their limits" is the key here, I think macgregor chose a very demanding situation, and confirmed what dxomark had already told us: that, surprisingly, the a7s has clearly less DR than the D800 at ISO 100 RAW stills. Those pics macgregor posted are the visual representation of that 1.3-stops difference. This is the dxomark comparison of D800 vs a7r vs a7s.

Not a big deal for me: I'm seeing 11 stops of usable DR in slog2 video in this test, which is really, really, really impressive. BTW it seems Cine4 loses at least 5 stops over slog2...
 
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Samuel H said:
Not a big deal for me: I'm seeing 11 stops of usable DR in slog2 video in this test, which is really, really, really impressive. BTW it seems Cine4 loses at least 5 stops over slog2...
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I've finished my tests with the A7s and they'll be published soon at DSLRmagazine.
11 stops of usable dynamic range in Slog.
11 stops of usable dynamic range in Cine4.
4K test charts will be provided. :D
 
I'm seeing less shadow noise in the A7s S-Log (APS-C) than the 5D MK3 MLraw @ 3200 ISO. The difference being I have to denoise the 5D files and they're still noisier than the A7s files. Of course you can shoot below 3200 ISO with the 5D and it's much cleaner.
 
macgregor said:
I've finished my tests with the A7s and they'll be published soon at DSLRmagazine.
11 stops of usable dynamic range in Slog.
11 stops of usable dynamic range in Cine4.
4K test charts will be provided. :D
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Great: that lines up perfectly with the other test :)
I guess the Cine4 thing is a matter of playing with the other settings: did you tweak the knees and slopes? Or maybe cine4 works better at lower ISOs (this other test was going up to 50K ISO IIRC)
Looking forward to your detailed results, and, even more, to your detailed opinion about the camera.
 
squig said:
I'm seeing less shadow noise in the A7s S-Log (APS-C) than the 5D MK3 MLraw @ 3200 ISO. The difference being I have to denoise the 5D files and they're still noisier than the A7s files. Of course you can shoot below 3200 ISO with the 5D and it's much cleaner.
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They are different tools and should be used in different ways. The 5D3 is best at ISO 100, the a7s seems to be best at around ISO 1600 (slightly overexposed ISO 3200). Forcing them to use the same settings means you are imparing one of them (the 5D3, in this case).
 
Yeah the MK3 and the D800 have the highest DR and least noise at 100 ISO. Trouble is when you want deep DOF you need a lot of light, that's where the A7s shines. 3200 ISO is about the limit for me with the MK3 but I can go to 30,000 ISO on the A7s!

I'll mess around with cine 4 tomorrow.
 
The Cine gammas look beautiful so far. Unlike s-log2, you can actually underexpose them and get decent results.
 
11 stops of "usable" range (sure we're not talking latitude?) is interesting but what that doesn't account for us the crazy amount of contrast you can get within that seemingly same range by using slog2 over other gammas. I think that would suggest it can't be that simple. Just adding observations, I'm no chart scientist as of yet ;)
 
Latitude has more to do with how far in the exposure you can recover or flex whereas DR is the total space you can do that within, no? So, underexposing backlots subjects and seeing which one can recover more while maintaining a cleaner noise floor is really a latitude test.
 
DR is the real-world brightness difference between the brightest highlight that will not appear clipped and the darkest shadow that will not be just black noise.
Latitude is a similar concept but I've never found a technical definition that sounds good enough. It does involve the flexibility with which you can tweak the image in post, so it's a combination of DR plus how good the color space of the recording is and things like that.

With the a7s, you can have in your scene a bright spot that is 11 stops brighter than the shadows in your talent's face, and you'll still be able to see a nice unclipped highlight and some not-too-noisy face shadows. If you expose pefectly.
 
strancali said:
I returned mine already. As much as i loved the low light, the colors are too weird looking :(
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Did you try S-log with cinema colour? It's a lot more Canon like. S-Gamut is a bit weird. My biggest mistake was trying to use S-Log LUTs. Now I just get things looking right in R11 and then apply the default Filmconvert profile and everything looks how it should. The F55 S-log profile colours are all wrong.
 
squig said:
Did you try S-log with cinema colour? It's a lot more Canon like. S-Gamut is a bit weird. My biggest mistake was trying to use S-Log LUTs. Now I just get things looking right in R11 and then apply the default Filmconvert profile and everything looks how it should. The F55 S-log profile colours are all wrong.
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Hey Squiq, I was looking at all footage too and not just mines. Even the Phillip Bloom one above this post, the colors are just off. I don't man, it's driving me nuts. I wanted so much to like it but I guess I'll wait for something else to pop up.
 
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