04Apr New Sony A7s 4k 12MP full frame camera to be announced on sunday?
According to Sonyrumors.com, Sony is likely to release a full frame mirrorless camera labeled the a7s (catchy name right?), with a 12 mp sensor that’s capable of shooting 4k video. Sony already has the Sony FDR-AX100 4k Ultra HD camcorder which means they’ve already worked out the internals needed to create a 4k camera with their BIONZ X Processor at a prosumer price. This is the same processor used in the Sony a7 mirrorless full frame camera labeled on chip as the Sony CXD90014 processor. The AX100 uses a 1 inch 20 megapixel Exmor CMOS sensor and can handle 24 and 30 fps frame rates at 4k.
Now imagine dropping the megapixel count to 12 megapixel (probably an effective count closer to 11 Mp) and increasing the sensor size to a full frame 36x24mm. That would make each pixel unit on the sensor roughly 2 times larger than the 6.25 µm square pixel units on the Canon 5d mark III. Increasing the pixel unit size by that much would dramatically increase low light performance which is why the Canon C300 uses a 9.84 megapixel sensor.
By reducing the megapixel count Sony also decreases the sensor read times and processing power need by the BIONZ X processor to handle an incoming 4k image. This could mean 4k frame rates higher than 30 fps and far less rolling shutter issues. Combine that with low light performance that’s possibly better than the 5d mark III and you would have a very attractive camera.
Where this gets really interesting for me is that this could allow me to use all of my Canon L glass with a Metabones adapter to shoot 4k in a full frame format. That could mean even better low light performance than the 5d mark III, no need to buy a new set of lenses, and the same shallow depth of field i’ve gotten used to over the years. A single $500 adapter versus a couple $1000 in lenses.
Part of the eye opener I noticed this week while playing around with the GH3 is the big difference in DOF on a M4/3 body. While I could always pick up a 25mm f0.95 lens to replace my 50mm f1.2, it would be much nicer to simply keep using all of my Canon glass.
Sounds like we’ll find out on Sunday if the rumors are true. If so, the Panasonic Gh4 could have an uphill battle at which point the decision might come down to price. Might need to sell off my Canon c100 to finance a Sony a7s if the rumors prove to be true (still don’t like the c100 much).
April 4th, 2014 at 10:43 pm
I hope there is a xlr adapter grip like the Panasonic. I am sure that will sway buyers. Plus, the price.
April 5th, 2014 at 11:22 am
Thanks for the write-up, I’ve linked over to it at the new User Group:
http://facebook.com/a7Susers
http://twitter.com/a7Susers
http://vimeo.com/groups/a7s
April 6th, 2014 at 12:25 am
@John, I think the XLR-K1m might work with the A7 and this A7s, Deejay may know.
Sounds great, might even come close the FS100 or FS700 low light quality. If this A7s has a useable 12800 ISO and under $3,000 it’ll be worth looking into. I am (as always) a little concerned with the codec but I’ve seen nice AVCHD footage.
@Deejay, so you still don’t like the C100? Did you ever try black balancing after each ISO change to see if it improves noise? I too am not big on its image but I love its ergonomics. You should make an article about what you don’t like with the C100 and what you might prefer in its price range or “image quality range”. (maybe after NAB so that we know what else is coming)
April 6th, 2014 at 9:01 am
Although Sony does a horrible job of listing it, both the A7 and A7r support the XLR-K1m adapter which means the a7s most likely will as well. As for the codec, Sony will probably use XAVC or XAVC-S which is a much new flavor of AVCHD. My guess is that it’ll be XAVC-S which supports 60Mb/s 4k recording. The compression algorithm on XAVC-S seems to be more efficient than the GH4’s h.264 codec, so i’m guessing performance will be pretty close. The one caveat to that is that better compression means more CPU processing power to handle native playback. I suspect we will have the same problems that came about in the early days of AVCHD were editing natively was painful even on a high end system. Transcoding might become popular again.
As for the c100, I’ve made a lot of adjustments to the camera as well as black balancing thanks to everyones input. It has improved things and made it “usable” but cleaning up the noise in camera has put the c100 at about the image quality of a 5d mark III. So $2k+ upgrade for ergonomics and a 24Mb/s internal codec. It’ll be with me at NAB, but I think it’ll be on ebay shortly after that. Probably the last higher end camera I buy from Canon unless things change dramatically.
April 8th, 2014 at 4:42 am
Thanks Deejay! And I agree sell that C100 for an A7s with an EF to NEX speedbooster (I hear the A7s has an APS-C crop mode for video …hopefully it’s not just with NEX apsc lenses) and the Atomos Shogun! You would have a usable iso 100,000 4k 10bit image Lol