New Sony A7s to shoot 4K video

[Todd Mizomi]

Sony's answer to the GH4?

(SR5) Sony A7s will shoot 4k video! Live announcement at 2pm Las Vegas time on Sunday!

http://blog.sony.com/press/28061/

[Roshdi Alkadri]

IMO this competition should show us some flavor of new 4k pro cams that will be announced.

[James Manford]

Looks like there will be some fantastic 4K cameras in the horizon then.

I think it would be best to wait atleast 2 years before any upgrade (if it's even needed for the work you do).

The hobbyist rather than the professional inside me just wants one for fun.

[Cliff Totten]

With the little bit of info that we have on this A7s, can anyone speculate on how he crop factor will work?

It looks like a 16x9 full sensor width crop will deliver the 8+ megapixels needed for 4K. (nice!)

But what about a 16x9 center crop for APS-C? It seems there wont be enough for any kind of real 4K image. (about 7 MP?)

Why not run a 16MP sensor so that FF and APSC could both get 4K?

Maybe I'm totally wrong on this?

[Ken Ross]

It's hard to believe that Sony would design the camera to only have 4K capability with only FF. That would be a huge blunder. I'm betting that's not the case.

[Dave Blackhurst]

Unfortunately, that's sort of the nature of "FF", you can in theory crop it in for a lens designed for APS-C, but you get a far smaller usable image area... the APS-C lenses simply don't create an "image circle" large enough to cover the whole sensor.

There are downsides to going FF... I've looked at it, tried to figure out the potential costs, and it's almost like building a new system from SCRATCH.... GRRRR.... EVERYTHING has to be "bigger" to work with the bigger sensor.

Sony does seem to be trying to make a big push into the FF/"pro" imaging market, with commensurate pricing.

Oddly, for me at least, I'm far more enamored of the little 1" sensor series of the RX/AX... good overall image quality, enough DoF to "pop", but not so big that the rest of the camera becomes bulky/heavy... and expensive.

For my use, an RX100M2 is the handy "pocket" cam, the RX10 is a solid "go to" for pretty much everything, and eventually the AX100 for video... makes a nice "system", and when the RX's add 4K, which they no doubt will by next year, I can upgrade! Still less $$ than one Zeiss FF lens, I reckon!

I still have Alpha/A mount APS-C gear, and maybe there will be a new 4K body soon for that, but I suspect the old Minolta lenses won't resolve 4K terribly well - they'll probably look all "Cinematic" and "filmic"... <wink>

[Ken Ross]

Dave, I agree. I've looked at those FF lenses and not only are they expensive, but they don't have the versatility of a lens like the 14-140 Lumix. You'd need several pricey FF lens to match the focal lengths provided by one good zoom.

I'm sure that won't deter the target audience though. Different crowd with different needs.

[Dave Blackhurst]

While the "look" from a larger sensor is certainly nice, everything else is also larger... body, lenses, MSRP...

It's easy to say you get "better" results, but to me, I have to ask "how much better" really, and at what cost - the cost/performance ratio is steep... not sure one really benefits THAT much! $500 premium to get 4k in the AX100 vs. the CX900 makes "sense" when you look at the output... dropping a couple "extra" grand on lenses and a body... to build a "system"... it better be pretty eye-popping!

I have a relative that's shooting some incredible shots with her dang cell phone... it's not the device, it's the operator. Sure, they'd be that much more eye-popping with a "real" camera, but it's back to that thing of "the camera you have with you..."

I'm not even dragging out the Alpha unless I'm being paid to look impressive, the RX10 shoots pictures and video that are stunning enough! Yeah, even if the 4K AX100 makes it look a little "soft"! I've seen some comparisons where the RX10 makes the already released A7/A7r look "soft" too, so who knows how the new "s" model will be?!

[Joe Ogiba]

The full frame A7 looks smaller than the MFT GH4 and legacy full frame lenses along with current fast F1.4 Samyang primes from 24mm to 85mm should be ok with 4K since it's still only 8mp.

[Cliff Totten]

Wouldn't it have been more beneficial for Sony to have built a 14-16 megapixel sensor?

This way, they would have had plenty of oversampling in FF mode for de-Bayer. And, if running under 16x9 APS-C center crop mode, there would have been enough to give at least an 8 million pixel "before" de-Bayer.

I have always heard of the single sensor Bayer pattern 20% oversample rule. If your target resolution is "X" than sample 20% over "X" and then after you de-Bayer you image, you will be close to your target.

I dont know,...if Sony made this a full frame lens camera only, that would be a big screw up in my opinion.

I need to return my AX100 by next Wednesday. (the day I get home from NAB.. I'm cutting this REALLY close)

I love the clean HDMI, I love a FF sensor like that, I''m OK with the form factor and 29 minute limit too.

I'm NOT OK with FF lenses only! I have 8 APS-C and 2 FF lenses. Uggggg!

CT

[Peter Siamidis]

Originally Posted by Dave Blackhurst

There are downsides to going FF... I've looked at it, tried to figure out the potential costs, and it's almost like building a new system from SCRATCH.... GRRRR.... EVERYTHING has to be "bigger" to work with the bigger sensor.

I have a complete Rokinon e-mount full frame cine lens set, you can get them for around $1600 or so for 4 lenses. They are full manual, but with full frame going with auto focus can be a bit of a crap shoot. I'm a huge fan of the Rokinon's, love them! If you want to go automatic you can get this one:

Amazon.com: Sony SEL2870 FE 28-70mm F3.5-5.6 OSS Interchangeable Lens for Sony Alpha Cameras: SONY: Camera & Photo

It gives you 28 to 70mm range, full frame and auto focus. I tried this on my vg900 but found auto focus just not good enough for video use so I returned it, but your mileage may vary. It's the main reason I'm using the AX100 when I need full auto as it's smaller sensor gives deep dof so the auto focus doesn't have to be super perfect, but I switch to the VG900 and full manual when I need super shallow dof and that nice full frame look.

[David Heath]

Originally Posted by Cliff Totten

Wouldn't it have been more beneficial for Sony to have built a 14-16 megapixel sensor?

The way I see it, then no, 12 Mpixels is a very sensible move.

Firstly, that figure relates to the full sensor, which may be assumed to be 3:2 as it's primarily a stills camera. Hence, the 16:9 crop (cutting off top and bottom) of this will be about 10.1 Mpixels.

That corresponds to around 4240x2386 photosites.

Yes, you could simply deBayer that, then downscale to normal 4k resolutions - but it would take a lot of processing to do it well. That's why nearly all DSLR type video has had to simplify the readout in the past - typically pixel/line skipping in various ways.

Much simpler to just take a 3840x2160 crop and make the processing far easier - and you're starting off with the same basics as such as the C300, F5/55 use. No - not true 4k due to the lack of oversampling, but.... if it's good enough for the F55.....? :-)

And by starting with 12 Mpixels, the linear crop factor is then only about 4240/3840 or about 1.1. Start with 14/16 Mpixels and it would have to be a higher crop factor.

The only disadvantage I see with 12 versus 16 Mpixels is a lower resolution for stills, they've effectively gone for a big positive to the video side at the cost of a relatively small hit to stills performance. The more I think about it, the more it seems like quite a brave thing to do.

[Cliff Totten]

Yeah, this makes an APSC option not viable. Unless this FF sensor is actually a 16×9 ratio at 12mp.(nah...thats actually an even crazier idea)

Ill prolly wait for whatever new Sony 4k super 35mm "FS-200" replacement comes out.

So far my AX100 stays..lol

CT

[Joe Ogiba]

Originally Posted by Peter Siamidis

I have a complete Rokinon e-mount full frame cine lens set, you can get them for around $1600 or so for 4 lenses. They are full manual, but with full frame going with auto focus can be a bit of a crap shoot. I'm a huge fan of the Rokinon's, love them! If you want to go automatic you can get this one:

Amazon.com: Sony SEL2870 FE 28-70mm F3.5-5.6 OSS Interchangeable Lens for Sony Alpha Cameras: SONY: Camera & Photo

It gives you 28 to 70mm range, full frame and auto focus. I tried this on my vg900 but found auto focus just not good enough for video use so I returned it, but your mileage may vary. It's the main reason I'm using the AX100 when I need full auto as it's smaller sensor gives deep dof so the auto focus doesn't have to be super perfect, but I switch to the VG900 and full manual when I need super shallow dof and that nice full frame look.

I use the 28-70mm FE OSS with the VG900 and AF is slow but usable if the camera movements to and from the subject is slowed down a bit. But I agree the MF Rokinon F1.4 primes from 24mm to 85mm is the way to go along with my 50mm F1.4 Pentax FA for super shallow DOF.

BTW will the 4K A7s cost $2K or $4K ? The 4K AX100 cost $2K.
https://blog.sony.com/nab/

[Ken Ross]

4K recording ONLY to an external recorder. Man, did everyone get faked out by that or what?

Panasonic is breathing a sigh of relief.