What's -1.7, lol. 4-5sec, is your shutter speed. What kind of camera are you using? Does it have a full manual feature? If so, go back and take that shot again(if possible) with, um.... ~15sec shutter and about ~F/10. See how that comes out. Tweek it a little if you need it. Use a tripod, also.
Longer shutter, more light comes through. Higher aperture("F"), the more is in focus. You gotta balance it out. With a higher aperture, you need a high shutter speed to compensate. Smaller aperture, you get a wider DOF, and need a shorter shutter speed to keep the exposure right.