reply to post by Ophiuchus13
Ophiuchus, it would be easily explained with a little lesson in photography.
You know how a camera works, right? (talking about the older ones, before digital). There's the lens, the shutter, the aperature, and the film.
The exposure on the film depends on the size of the aperature and the length of time the shutter is open.
If your subject is well-lit, then you control exposure by 'stopping down' the aperature (making it smaller) and increasing the shutter open time, or
vice-versa. Depends on what effect you want...good depth of field, or a sharp subject in the foreground and a blurred background. A portrait, for
instance, with the trees or mountains blurred behind, makes your subject stand out.
For Lunar pics, the Hasselblad was semi-automatic...Astronauts turned a ring estimating the distance to the subject, the F-Stop and shutter speed
would adjust to get the best possible, using the available light, and the best depth of field as well. The sunlight was just too bright for the stars
to be visible, because they are comparatively so dim.
This helps, I hope. But, just in case, something else to ponder: Even on a clear night on Earth, if you want to photograph stars, you need a large
aperature and a semi-long exposure time...problem is, as the Earth rotates, the stars will blur....UNLESS you have the proper device mounted on your
tripod, so that it moves the camera to compensate. AND, of course, the 'speed' of the film is a consideration....'faster' film takes light
faster, but is more 'grainy'. Slower film provides sharper images, but needs longer exposure times.....