How does the a9 shoot 20 fps?

[swibber]

Sony advertises 20 fps for the a9 in continuous. What technology makes this possible? As I understand it, the a9 has a Bionz X processor like my a7iii which shoots at about half that rate. Is it a new and better version of the chip? Some other technical development?

I'm curious as my passion is shooting birds in flight at about 10 fps. I think I would have little use for more than 10 fps, but still curious.

 

[juanmaasecas]

The a9 has a more advanced and expensive stacked sensor that is much faster to fully read, and has almost 0 rolling shutter.

 

[SurfFish]

Simplest explanation. No mechanical shutter to open and close. Image captures are done using electronic shutter.

:-D

 

[Lightshow]

It's all about the image pipeline.

• Faster readout of the sensor data. This includes bypassing a mechanical shutter, and a fast recycle time from readout, reset and the start of a new exposure. There isn't much difference between this and video capture, though a large sensor adds a few more hurdles that the engineers have to deal with to reduce rolling shutter effects, it won't be long till a global shutter takes over as all chip makers are working on this.
• Large fast buffer, to capture and temporarily store the raw data as it's processed for the jpg process and EXIF tags that are added to the RAW and or to the full jpg, till it's been written to the card.
• Large enough CPU bandwidth to do all the processing and not act as a bottleneck, this is usually where cameras fail for burst shooting, it fills the buffer and slows the shooting to as fast as it can make room for the next shot.
• Fast writing to the card. Which includes a fast card, this is the other bottleneck that usually slows things down.

The A7III could probably shoot faster bursts, but the bottlenecks would show up much faster, and they want to keep some differences between the models, so they will lower the frame rate to create some separation and reduce buffer requirements.

 

[Alfonso Bresciani]

Sony advertises 20 fps for the a9 in continuous. What technology makes this possible? As I understand it, the a9 has a Bionz X processor like my a7iii which shoots at about half that rate. Is it a new and better version of the chip? Some other technical development?

I'm curious as my passion is shooting birds in flight at about 10 fps. I think I would have little use for more than 10 fps, but still curious.

It only shoots 20 FPS with compressed RAW, otherwise is 16 FPS on uncompressed.

 

[TristanW]

Sony advertises 20 fps for the a9 in continuous. What technology makes this possible? As I understand it, the a9 has a Bionz X processor like my a7iii which shoots at about half that rate. Is it a new and better version of the chip? Some other technical development?

I'm curious as my passion is shooting birds in flight at about 10 fps. I think I would have little use for more than 10 fps, but still curious.

the key tech is CMOS from a9 is RS/stacked (BSI) CMOS, data transfer speed boosted to another level.

2nd is, a9's CMOS equips high-speed interface: SLVD-EC with high-speed setting. (while other ML camera just pairs with lower speed setting, even if SLVD-EC is embedded.)

for CPU, BIOZ X/Front-end LSI, what i've learned, are all the same for 3rd gen a7.

 

[rsser]

When you shoot birds at 20 fps you will get shots you miss at 10. And you get more choice of position to keep when you cull.

Fairy Martin



The A9's AF speed and stickiness is something else.

--
Cheers, Ern

 

[SergeyFromMoscow]

so it is 20fps RAW video - it is not a huge leap to 24fps RAW video, they only need faster cards.

 

[rsser]

Not video, stills.