MagicLantern show temperatures, which are metered somewhere in the camerabody. In canon-firmware, these temeratures are called efic_temp, so maybe they are metered on the efic_chip. These efic_temp-values are raw values, which have to be converted to Celsius or Fahrenheit for to know, what they mean. This convertion is done by MagicLantern.
For the convertion, a mathematical function is needed. And tests are needed to find out this function. These tests have to be done for all types of camera, because it is hardly probable, that all cameras show a steady behaviour.
There are two sorts of tests, which can be done
You can meter the temperatures in the camera-body with a infrared thermometer. With these temperatures and the corresponding efic_temps, you can develop a function. Done!
A little problem is, that not so many guys own an infrared thermometer, I guess. And when you have such a thermometer, where exactly in the camerabody do you want to meter the temeratures?
If you take a picture, a temperature is written into exif-data. I don´t know, where the temperature-sensor is located, canon uses for the exifs. Maybe, it is the efic_temp-sensor, maybe it is another one. But no matter what sensor it is, the temperature-values are in the exifs. And it is much easier to extract these temperatures from the exifs, than metering temperatures with a thermometer, which you don´t have.
So I decided to use the second methode with the exifs to find out the convert-functions. But I have only a nice little 600D. For this camera I can do this test. But for all other cameras, I need your help.
How can you help testing
1.1 Take a piece of paper and write down the camera-name and the firmware-version, you have.
1.2 Write down, which ML-build you use during the test
2.1 Turn on your camera in video-mode and start recording a normal mov-video to heat the camera
2.2 While recording, push the shutter release from time to time, to capture a CR2- or jpec-pic.
2.3 In the debug menue, you can see the camera-temperatures.
2.4 Write down Celsius (if available) and raw-temperature in the moment, you take a picture.
2.5 I at least need exif-temperatures from 20°C to 60°C to be able to work out accurate converting-functions.
2.6 The video-lenght will be 30 minutes, maybe more to get enough temperature-values.
3. test finished
3,1 Download the pictures to your harddisk
3.2 Extract the exif-temperatures from these pictures
3.2.1 On linux you can do this in a terminal: exiftool -CameraTemperature *.CR2
3.2.2 On windows and mac, I don´t know, how to do this
3.3 Write down these exif-temperatures with the corresponding ML-temperatures, you have listed before.
4.1 Show your measurements here in this thread.
4.2 Write down the ML-temperatures and the corresponding exif-temperatures. Follow this form:
4.3 raw-temperature Celsius (if available) temperature extracted from the exif-files
4.3 Use code-tags for your list
And the results?
The functions, created with your help, will be used to show more accurate temperatures in ML.Why do I want to do this testing-stuff?
Easy to say:
I´m using raw-video for my astonomical shootings. And to are sure, saturn is and stay in focus, I regard the camera-monitor. But it don´t make me happy, what I see there:
0 minutes: Start recording: All is fine, temperature normal, 10°C
3 minutes: temp grows, expected behavior
5 minutes: next video, 40°C and temperature grows
6 minutes: 50°C, ML-temperature warning is coming
8 minutes: 60"C, ML-warning becomes red!
20 minutes: 70°C, I begin suffering from nerves
25 minutes: 75°C, I need a beer
30 minutes: 80°C, I need more alcohol to endure the pain regarding the camera-temperatur
I want my liver to stay healthy. So I don´t want to see this 80°C on the display. 60°C would be enough, especially because exiftool tells me, this 80°C are in reality only 60°C. Cameras tested up to now1100D by dmilligan1200D by m1k65D2 by SpcCb5D3 by RenatoPhoto, alex50D by ayshih500D by Hey, Tralfaz550D by stoopkid6D by 1percent, zloe60D by dmilligan600D by escho650D by Walter Schulz700D by mk111747D by Walter Schulz, RenatoPhotoEOS-M by gmalin54, dfort
The plots can be seen here: https://seescho.wordpress.com/2016/04/24/temperaturanzeige-mit-magiclantern/Tests from other users for these cams are welcome.
And tests for other cams are welcome too.
And remember, only cameras, testerd by you, will show celsius and or fahrenheit, created from your test-results, all other cams only show raw-valuesThanks for you help