What causes photos to look like this?

[markbarendt]

Fresh film is a good thing and can help but its not a guarantee.

You may need to re-think how you are defining underexposure.

True underexposure is where you have lost real detail and can't easily print what you want, like the first two examples you provided.

If you got all the info you needed on the negative, like in post 9, you did not underexpose.

[Worker 11811]

I assume that you shot these photos somewhere on a college/university campus. Presumably in a common area of a dorm, a library or the student union?

I absolutely agree that low light and under exposure are the root cause of the problem but, further, I might add that most public areas in college buildings have icky light for photography. Usually fluorescent and/or indirect incandescent which often produces flat, lifeless and difficult to expose lighting conditions.

The human eye quickly adjusts to those conditions but cameras don't. Consequently, you have to be more conscious of the light you are shooting under when you go from one lighting condition to another, especially when shooting indoors.

For example, the first two shots probably came out crummy because you were in the middle of a room where there was little or no direct light. Only diffuse, room light. In the second two shots you seemed to be near a window or under a light fixture which gave you better, more direct light.

Bottom line: Learn to watch your light and use that to achieve the picture you want.

I don't know how many times I have been sizing up a picture and passed on it because the light wasn't what I wanted.
People often look confused when I tell them, "I don't like the light."

[batwister]

The photographer.

[kevs]

The lab's automatic printing machine compensated for thin negatives by giving too little exposure to the paper to give good blacks, thus showing up the grain. Machines are stoopid - if you want the low key look, print them so the shadows are black, not a dull grey.

[ic-racer]

Here is an example of what an underexposed shot looked like off my last roll:

Attachment 58034

Ok, I'll quantify it. The negatives from the first photographs presented in the original post are SEVERELY underexposed. If you post a scan of the negatives it will be much more clear (pun intended ).

[Andre Noble]

Underexposure.

[MattKing]

Underexposure, plus the effects of trying to adjust for it through the adjustments available to those who print or scan.

The OP is seeing variations in the results because the adjustments vary.