Solargraphy Baseline Exposure Time
Tried posting this in the Alternative forum on here but didn't get any responses yet. Was wondering if anyone in this forum could help me out with a question I have. Here goes:
Tried to figure this out before posting but couldn't seem to find anything. I recently came across some solargraphy image and really want to give it a shot. I was simply wondering, what is the shortest exposure time to get an image on the photo paper without developing? While doing my looking around, I've seen the famous 6 month shots but I've also seen one's that have only taken a day. That's quite a large range. I realize that the exposure time will have a lot to do with pinhole diameter. However, I'm sure .25mm - .50mm difference between pinholes sizes wouldn't make THAT much of a difference in exposure times. I'm sure there has to be some kind of baseline exposure time to get a visible image on the paper? Does photo paper not "overexpose" without developer? Any help would be great, thanks.