setExposureCompensation returns "Illegal Argument"

Question

I have to change the exposure compensation of a Sony Alpha 7II by using the Sony Camera API (versions: Firmware 3.3, PlayMemories 4.31, API 2.40).

The three commands:

1. getAvailableExposureCompensation (result: [0,15,-15,1]),
2. getSupportedExposureCompensation (result: [[15],[-15],[1]]),
3. getExposerCompensation (result: [0])

are returning correct response objects.

The command setExposureCompensation:

• ("{\"method\":\"setExposureCompensation\",\"params\":[\"2\"],\"id\":1,\"version\":\"1.0\"}")

fails with the response:

• "{\"id\":1,\"error\":[3,\"Illegal Argument\"]}"

Regarding the syntax and value I don't see a reason why it fails. Any ideas?

Looking forward for any hints, Yvo

Answer 1

I just stubbled uppon the same problem with my A6000 camera, but found out the correct way to call the api. You have to send an integer between -15 & 15, so without the quotes.

So

,\"params\":[\"2\"],

becomes !

,\"params\":[2],

The range -15, 15 came from the actual exposure compensation range of -5.0, 5.0 with a incremental step of 1/3 of light stop. (-5.0*3steps=-15, 5*3steps=15).