I’m going to be doing some synthetic slit scans with the Sony a7RII, and I needed to figure out what frame rate the camera could sustain on a continuous basis, so I did some testing. Thinking that others might be interested in the results, I’m sharing them here.
- Sony a7RII
- Lexar Professional 1000X (150 MB/s) 256 GB SD card
- Silent shutter on (as it turns out, this doesn’t make any difference).
- ISO 100 (no noise reduction)
- 1/500 second (no noise reduction)
- Manual exposure mode
- Manual focus mode
- Single shot shutter mode
- Autoreview off
- Nikon 200/2G VR I lens
- Vello smart adapter
- Sony AC power supply
- JJC wired intervalometer
- Full Frame, Raw, uncompressed: 4 seconds between exposures is the fastest rate with no missed exposures
- Full Frame, Raw, compressed: 3 seconds
- Full Frame, JPEG, Extra Fine: 2 seconds
- Full Frame, JPEG, Fine: 2 seconds
- APS-C, Raw, uncompressed: 2 seconds
- APS-C, Raw, compressed: 2 seconds
- APS-C, JPEG, Extra Fine: 2 seconds
- APS-C, JPEG, Fine: 1 second
The intervalometer’s setting precision is 1 second, so in some cases, the camera can easily obtain the rates above, and on others it can barely get there. For large file sizes, the camera appears to be limited by the speed with which it can write to the SD card. The maximum write speed of the card I used is substantially above the a7RII’s USB-2 write speed, so any fast card should yield the same results.
[Added 10/17: I’ve been asked how many shots until the first miss with full-frame, compressed raw.
- 1 second gets you 102 shots.
- 2 second gets you 243 shots.
These numbers aren’t particularly repeatable.]
I did the testing with a Vello adapter and a Nikon 200/2 VRI lens. I noticed that silent shutter didn’t mean silent operation. I listened closely and discovered that the diaphragm stopping down on the Nikon 200/2 makes a fair amount of noise. I’d never noticed that before, since, when used with a DSLR or with the a7x cameras in EFCS mode, the sound of the lens is masked by the sound of the camera’ shutter.