Busy developing. Do not disturb
In place of an enlarger, since I’m contact printing, I’m using a 20 watt light bulb with an iPod box as a shade (props to Kris for finding the right box to use). A wall clock regulates my 12 second count while I have the light switched on. I slip the exposed paper into a black bag in an old film box, then do another set. When I get to twelve exposures, I start developing them two at a time.
For full annotations, see this photo on Flickr.
Darkroom Math & Other Notes
- To double the amount of light (and halve the exposure time), measure the hole in the bottom of your iPod box, multiply by 1.41 and cut the hole to the new size.
- Negatives go emulsion side to the paper to decrease accidental blurriness.
- Negatives (in this case) turned emulsion side to paper print backwards.
- Ensure the contact glass is not casting a shadow on the edge of the negative
- Center the glass under the light if you want to evenly expose two sheets at once.
- High contrast paper works better than medium contrast paper when contact printing
- If you switch from ISO P 640 paper to ISO P 250 paper, increase your exposure by 2.56 times. 12 seconds becomes 31 seconds.
- Don’t neglect to clean the contact glass between batches
