EOS M3 for Astrophotography

[RTS48UK]

Hi everyone, I am trying to use my EOS M3 attached to a Meade ETX125 telescope to capture stars, planets, moon etc. I have used my ETX125 before with DSLR bodies (5D Mk II and 1DS MkII) but they are very heavy. No matter how I try I cannot get the M3 shutter to release. The image is there in the viewfinder - sharp as a pin, I have set shutter speed and ISO. The aperture (not detectable by the camera) is F15. Does anyone know what else I need to do to take astro photographs?

[cicopo]

What modes have you tried?

[RTS48UK]

Just about everything really (but I do want RAW so that I can stack photos). I have certainly tried M, Tv. Av and even P modes as well as setting manual focus (which it is anyway). I have even tried exposing a shot with no lens or adaptor installed (disconnected from the telescope). I suspect that there is something in the settings or in the firmware that prevents shooting without a lens attached.

[kvbarkley]

Are you using a T-mount adapter?

[kvbarkley]

Did you try Manual focus mode?

[Waddizzle · Accepted solution]

If you want to use a fully manual lens, you have to go into the menu system, find the selection that says “Release shutter without a lens attached,” and enable it.

[RTS48UK]

Thanks Waddizzle. The toggle 'release shutter w/o lens' can be found in C.Fn.III Others. I'm looking forward to trying this out tomorroe!