Using Gphoto2 to control EOS 1100D

Canon EOS 1100D

EOS 1100D is an updated model replacing older 1000D. It's the cheapest one Canon has. That's why I bought it. While writing this I'm still a beginner at stargazing so any DSLR will do.

There are several differences between 1000D and 1100D. 1100D has a bit bigger resolution, better dynamic range and lower noise at high ISO. Astrophotographers talk about modding the camera (which I guess means taking off IR-filter) which should be an easy operaton for 1000D. I don't know about how it works on 1100D but maybe I'll try the camera unmodded first.

EOS 1100D can take photos with exposure time of 30s. To take good astrophotos one needs longer exposures. I guess with my EQ3-2 mount and 300mm lens I could take exposures of couple minutes without errors. How can I do it with my camera?

Gphoto

Gphoto is a piece of software to control digital cameras on computer. Mostly people use it to download taken photos from camera to computer but Gphoto can also use other controls.

Exposure time: Bulb

I really don't know the meaning of this word. I know a light bulb and I know the part of a plants root which can grow the rest of the plant, but those don't really apply here. I know on camera it means exposing as long as user pushes the trigger.

Gphoto can change cameras exposure time to bulb. Then I ran into problems. I assumed the thing works as 1000D, but not. Newer Canons work a little differently. Gphotos web pages, manual or anything I found on intenet didn't help, but Gphotos developers on IRC did. Now it should read on their web page as well.

With these commands I can take a photo with arbitrary exposure time:

gphoto2 --set-config iso=400            # chooses iso, obviously

gphoto2 --set-config shutterspeed=bulb

gphoto2 --wait-event=2s --set-config eosremoterelease=Immediate --wait-event=180s --set-config eosremoterelease=Off --wait-event-and-download=5s

The red one is what defines the exposure. On the example it's set to 3 minutes which probably is what I'll use the most (if my tracking mount can withstand it).


Why?

Why I want to use such a difficult method when EOS Utility would do everything a lot easier. I ordered a Raspberry Pi. I'm planning to use it to control camera. Ultimate plan is to have camera on EQ3-2 and connected to RasPi. RasPi on wlan and me being inside at my computer controlling all that via ssh. There are still some problems with this, such as me not having the Pi, or getting electricity to all that... But I'll write here on the system when it's done.

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