Testing the temperatures of my 600DResulting plot600D_result
1. External heating. Warming up the camerabody very slow during 5 hours.
1.1 The blue points show the ambient temperatures, measured with an external thermometer.
1.2 The red points show the corresponding camera-temperatures, extracted from the exifs.
2. Internal heating, capturing a mov-video, video-duration 45 minutes
2.1 The green points show the results
3. Function for converting ML-temp into real-temp
3.1 The violett graph show th converting-function, as it is used by ML at the moment
4. External heating
4.1 The slope of the graphs in 1.1 and 1.2 are quite the same. It is "efic_temp - 128", like it is used now (little differece of 4°C in y-axis)
5. Internal heating
5.1 The resulting function differs to the default one very strong. On higher temperatures, there are differences of more than 20°C.
It seems to be sure, that there are different sensors used for exif-temperature and the temperatures , shown by ML (efic_temp). Heating the camera in normal use (capturing a video) results in wrong temperatures. The "efic-sensor" meter very high temps, the "exif-sensor" follow these temperatures much more slow. The more cold the camerabody is, starting the test, the more difference is between the default function and the resulting function.Conclusion
1. The temperatures, shown by ML on the LV-screen are not useable.
2. The ML-warnings are hardcoded to 50°C btw. 60°C. Looking at the temperatures on the LV-screen and the ML-warnings, you think, something is wrong with your 600D. You think, your camera is much too hot.Other cameras
1. 5D3 seems to react like the 600D. Highly wrong values, which cannot be corrected, because they depend on the starting temperature on your recording.
2. 7D fits to the default function. No problem with this camera
3. 650D looks a bit like 7D, but I´m not sure about this.What do I think about this
1. Showing temperatures on LV-screen should be disabled on LV-screen
1.1 Seeing these high temperatures makes me nervous
1.2 I see no useful information in showing the temperatures on the LV-screen, too much info in this screen
1.3 If somebody wants to know temperatures, he can look in the debug-menue
2. The ML-warnings should be disabled
2.1 No useful info, for the best a double info, because Canon warns too.
3. Debug menue
3.1 A hint should be shown, that these temperatures may be wrong ("measured somewhere in the cam" is not enough)What do you thing about this stuff?