I was asked:
I've got a diana f+ and i took pictures with the lomography film 400 ISO 120mm and lomography film 100 ISO 120mm. Some of the pictures I took was cropped. I thought my results will be exactly like the one my eyes saw through the hole when you take a picture of something. But it turned out to be in a different angle. For example, I took a picture of a glass of drink and when i printed it, it turned out only half of the glass. Is there a way to fix that?
What you are experiencing is viewfinder parallax error. The viewfinder sits over the lens, and doesn't exactly display what the lens sees. Normally, with most subjects, you don't really see this effect causing a problem. The subject is usually far enough away from the camera that the difference in the higher position of the viewfinder from the lens isn't noticeable. However, the closer you get to the subject, the more pronounced the effect. So when you are trying to shoot a glass on a table, that is only a few feet away, you need to compensate for the viewfinder offset by slightly tilting the camera up.
Parallax in a normal scene is not a problem.
But when the subject is close to the camera, then parallax error can be a big problem.
In order to compensate for Parallax error, you have to adjust how you frame the photo in the viewfinder.
If you are shooting with a Holga 120 or 135, you will also have to compensate for the fact that the viewfinder sits to the left of the lens. This means that to compensate, you will have to slightly tilt the camera to the left if you are shooting a subject that is very close to the camera.