I shot my first negative with my foamcore camera, at one minute, and it was way overexposed. It's sunny today again so if I try today I'll go less. I'm thinking 15 seconds actually, because it looks more than one stop overexposed to me. But with reciprocity I'm not sure if I should try 30 seconds first. I intentionally shot myself skylined for a really high-contrast scene so I could adjust exposure, but I'm thinking the blue light from the sky just blew out the scene.