Hi Niranjan,
It's a lot of fun and honestly I'm just kind of goofing off and going with it. I think the Amur Maple is more red, these big leaves are bright yellow. I actually took some digi-snaps of the leaves and a couple different trees and sent them to a N. Cal tree expert to see if he can tell me what it is. It's a fairly common landscape tree around here. The one I'm going to post below was from the same tree... some of the leaves have lobes and others don't, even on the same branch!
From the start, I figured it was going to take a lot of UV to make an "x-ray" and see structure of the leaves. So these are all pretty long exposures. I've been putting the cyanotypes out in the yard in the early afternoon and then picking them up when I get home ( I'm not sure exactly how many hours until the sun goes behind some trees, but at least 2 or maybe 3 ). Then I've put some of them under my BLBs for another couple/few hours. I don't think I've seen a cyanotype yet that I thought was overexposed.
For the sepiaprints, I can't remember how long I put that maple leaf under the BLBs, maybe an hour or probably 2. But the ones I've done since in the sun have all been overexposed -- I can't make positive cyanotypes from them very easily ( but they still look neat even if they don't make good negatives ) One positive cyanotype I left under the BLBs for 8 hours and it wasn't nearly enough. Yesterday I left that one just above in the sun all afternoon and then under the BLBs for a couple hours, and it looked neat but I knew it was going to all wash out and it did. Yesterday I made the sepiaprint I'm about to post below, and only left it in the sun for 1 hour, and even that was probably too much.
The leaves have been yellow, light green and the liquidambar had green and yellow and red in them. The leaf definitely matters... I tried a green fig leaf cyanotype, left it in the sun all afternoon and then under the BLBs all evening, and it looked neat at first, and even after washing it was okay, but when it dried it became all white.
There have been surprisingly few failures... maybe I'll make a post with some of them. Anyway, the sepiaprint is a lot faster! I remember when I first tried sepiaprint thinking it was about twice as fast as salt, so probably for a salt photogram with leaf details, it will take a few hours of sun at least.
