Temperature question

[Tbar23]

Last night I was taking photos with my Canon EOS RP and Backyard EOS.

The first set of photos showed a temperature that settled out around 12C during an ~75 min session (ambient temp of ~5C).

I was watching a movie when the session ended, so it took me about 20 minutes before I got outside, put the telescope lens cap on and then started a series of Darks.

What I find odd is that the first Dark photos are up at 21C and drop down to 13C over the next ~20 minutes.

What would cause the temp to go up nearly 9C with no imaging session going on?

[admin]

That would be a question for Canon.  Even the camera is not taking pictures, there is still some electronics generating some heat if the camera is still on. This said, no one really knows (I don't at least) know where those temp sensors are located inside the camera and if near-by electronics affect its reading.

[s3igell]

Remember that the Temperature Sensor is measuring the Internal Electronics - the combined Digic Processor(s) and Sensor Assembly.  The Sensor doesn't generate too much heat while performing a Long Exposure (Light or Dark), but does generate a good bit when Capturing Video (and LiveView).  The Digic Processors generate bursts of heat when each Image is Read from the Sensor, while Focusing, and during Video.

[Tbar23]

I guess the question is what mode is the camera in when BYE finishes a capture? If it defaults to LiveView, then perhaps that is why the temp went back up so quickly.

[astroman133]

LiveView is not ever on when you are on the Imaging screen.

[Tbar23]

26 minutes ago, astroman133 said:

LiveView is not ever on when you are on the Imaging screen.

Hmm, so that gets me back to wondering why the temp went up so much when my imaging session completed.

During the 20 minutes between finishing my first imaging session and the start of a new session for Darks my camera should have just been sitting there in whatever state BYE leaves it in at the end of a capture sequence. LCD closed. Definitely no video and no focusing. And image download happens after each image is taken so that shouldn't have been occurring either.

I'll have to do some experiments on a cold night and see what I learn.

[admin]

1 hour ago, Tbar23 said:

I guess the question is what mode is the camera in when BYE finishes a capture? If it defaults to LiveView, then perhaps that is why the temp went back up so quickly.

BYE does not do anything once the capture is finished, aside from download the image over USB, that is. BYE triggers a shutter the same way you would if you were pressing the shutter button physically.