requesttype=0x1d
Command: 0x54 bytes
00000000 14 00 00 00 01 02 00 00 00 00 00 00 00 00 00 00 ................
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000040 02 00 00 00 1d 00 10 12 14 00 00 00 a4 e7 12 00 ................
00000050 00 00 00 00 ....
Response: 0x94 bytes
00000000 54 00 00 00 01 03 00 00 00 00 00 00 00 00 00 00 T...............
00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000020 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000030 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00000040 02 00 00 00 1d 00 10 22 54 00 00 00 a4 e7 12 00 ......."T.......
00000050 00 00 00 00 28 00 00 00 00 01 00 02 00 03 00 04 ....(...........
00000060 00 05 01 06 00 07 01 08 00 09 00 0a 00 0b 00 0c ................
00000070 00 0d 00 0e 00 0f 00 10 00 11 00 12 7c ae 10 00 ............|...
00000000 40 49 b1 ff 70 af 10 00 28 82 b1 ff 00 00 00 00 @I..p...(.......
00000010 00 00 00 00 ....
At 0x50 is a 4-byte status code followed by a 4-byte count of bytes (including the 4 bytes of the count), then apparently the custom function settings for the camera. Then at 0x7c is the same sequence as starting at offset 0x84 of the reply to Identify Camera. I suspect that this is garbage in the buffer.
Here are the meanings of all custom functions. Note that this table is not the same as that for the earlier EOS cameras.
Table 4.3. Custom function values for EOS 20D
| Function | Index | Values |
|---|---|---|
| SET button func, when shooting | 1 | 0: Default (no function) 1: Change quality 2: Change parameters 3: Menu display 4: Image replay |
| Long exposure noise reduction | 2 | 1: on |
| Shutter speed in Av mode | 3 | 0: auto 1: 1/250 |
| Shutter button/AE lock button function | 4 | 0: AF/AE lock 1: AE lock/AF 2: AF/AF lock, no AE lock 3: AE/AF, no AE lock |
| Disable AF-assist light | 5 | |
| TV,AV and exposure increments | 6 | 0: 1/2 stop 1: 1/3 stop |
| Flash firing | 7 | 0: Fires 1: Does not fire |
| ISO expansion | 8 | 0: Off 1: On |
| AEB sequence/auto cancellation | 9 | 0:0..-..+/enable 1:0..-..+/disable 2:-..0..+/enable 3:-..0..+/disable |
| Superimposed display | 10 | 0: On 1: Off |
| Menu button return position | 11 | 0: Previous (top if power off) 1: previous 2: Top |
| Mirror lockup | 12 | 1: on |
| Af point selection method | 13 | 0: Normal 1: Multi-controler direct 2: Quick Control Dial direct |
| E-TTL II | 14 | 0: Evaluative 1: Average |
| Shutter curtain sync | 15 | 0: first 1: second |
| Safety shift in Av or TV | 16 | 0: Disable 1: Enable |
| Lens AF stop button Fn, switch | 17 | 0: AF stop 1: AF start 2: AE lock while metering 3: AF point: MAuto/Autoctr. 4: ONE SHOT AI SERVO 5: IS start |
| Add original decision data | 18 | 0: Off 1: On |