M6 Mark ii will not take picture in low light

[MtnHiker]

Wanted to take pictures of the planet line up this morning before dawn. Would not take a picture.

Lens was an EFS 10-18, was set to MF (with Canon EF-EOS-M adapter). Camera switch was in MF. Camera in Manual Mode. Settings were ISO 3200, AP = 4.5, Shutter = 20 seconds.

After several attempts I shined a flashlight on an object in front of the lens and it captured the image. I am thinking this was due to focus or light level. Does manual focus turn off AF? Does manual mode ignore exposure level?

[Tronhard · Accepted solution]

The camera needs a certain degree of contrast some some clear delineation of light and dark, such as edges of objects or changes on texture.  If the light is extremely low it cannot get that information and will not focus.  If it cannot focus it will not take the photo.

One technique is to shine a light on the (static) subject, focus and then switch to manual FOCUS mode - or focus completely manually.  The camera will not then change focus and you can get your shot.