Point sources work better than arrays, so I use either one or four LEDs (from LG) depending on the power needed for the application (and how much someone is wil

Point sources work better than arrays, so I use either one or four LEDs (from LG) depending on the power needed for the application (and how much someone is willing to pay). With enough power (more than 50W or so), cooling the negative is required given the long exposure times on the order of tens of minutes, so there are more modifications to do than just changing the light assembly. Most people who do cyanotype print digital negatives with an inkjet printer as it has long been said that enlarging was not possible. Laser transparencies are too low in resolution to give good results. The advantage of digital negatives is that you can adjust the contrast curve to match the response curve of cyanotype to get the best contrast, since it's different from that of silver. But an all analog workflow is nice too.