I was trying to take some nice pictures of the Toronto city skyline from the shores of Lake Ontario under a full moon night. Now I put my nikon d5200 on a tripod and set f/4 and shutter = 30 sec. I am using 18 mm focal length. But from time to time, it tells me that 'Subject is too Dark' and the shutter won't even press all the way down! I am in 'M' mode.
The lens keeps rotating clockwise and counterclockwise to try and focus and gives up.
How to get around this? Do I need to experiment with manual focus? The funny thing is I point the camera directly at the bright full moon and still it says 'Subject too Dark'.
Now the funny thing is that when I look at exposure meter in view finder , it shows that the image is over exposed by 3 bars. And I expect this while looking at a full moon for 30 sec with a wide aperture.
How can it be overexposed and still be Too Dark ?