I am using the light sensitive Lap-V plates, I was hoping someone could specify a wavelength that is required for the safelights to handle these plates.
Im pretty sure not just any yellow light will do... however My first thought was to have one of those battery powered LED click lights to use while im loading the plates into the cassette.... If i did this ... could i just buy any old yellow LED's and stick them in the click light ?
You could always try doing a safelight test.
In a completely dark room, take out a plate and place it on a table emulsion side up. Cover about 4" of plate with an opaque card that is taped to the plate. Then completely cover the plate with a second opaque card that crosses the first at a 90 degree angle. Turn on your "safelight". Pull the card back so that about 2" of plate is exposed to the light. After 30 seconds, pull the card back to reveal another 2" of plate. Do this perhaps another 5 times.
The result, in this case, will be a plate that has been exposed for a total of 3 1/2 minutes in 30 second intervals with an area that has not been exposed. Turn off the safelight so that the room is dark again. Remove the cards and process the plate. Comparing the unexposed area along the bottom to the exposed area will show you whether the safelight is indeed safe and for how long it can be exposed before the plate is fogged.
The resulting plate might look something like this:
On the left is the section of the plate that has been exposed to the safelight the longest. Each strip to the right represents less exposure in 30 second increments.
The bottom area is the area that remained covered during the plate's exposure to the safelight.
In this case, the leftmost area has been exposed for 210 seconds, then 180, 150, 120, 90, 60, and 30 seconds respectively. It shows that this plate can be exposed to this particular safelight for no longer than 30 seconds.
best, gordo
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