@laura-aome said:
Would the picture not get too light at f/4 or f/2.8 having it on the bulb setting though?
This is a question best answered by thinking about the three basic factors of image lightness: ISO, aperature, and shutter speed.
The quick answer is that no, it wouldn’t necessarily, if you balance all three settings correctly.
Here is another great conversation from about seven years ago that you’ll probably find helpful.