During my trip to New Orleans a week or so ago, I took a very nice picture of the St. Charles Avenue trolley. It was just a bit underexposed, and the entire thing was rather bland and gray. Through experimentation with my contrast filters, I was able to print an 8x10 using a #3 filter at 3 seconds exposure, around f/5.6 I think, and produce something that I like.

Last night I was thinking about trying a 16x20 of the same print, but I've only printed two 16x20's in my life and it was during my high school darkroom class. We mounted the paper on the wall, turned enlarger some wonky way, and winged it.

I know that I can reverse my enlarger and project it onto the floor, but that would at least double the distance between the enlarger head and the paper. Would that also change my exposure time? I'm assuming that its going to at least double it.

I am asking because It took me 3 5x7 sheets, and 3 8x10 sheets to get this one 8x10 right. I want to try and have an idea of how the distance may change my exposure time, before I start wasting 16x20 sheets...