Amateur film photography

The journey into film photography of an Amateur

4×5 Scanner project – The birth of a project

 by Henrik Andersson

I made a really bad decision when I bought my scanner to scan my negatives. I went for the cheap alternative which has a restriction that it only will scan medium format film (6×6). The scanner of choice at the time was Epson v600. Now I stand in front of a new problem, I want to scan 4×5 and for that I need to sell and spend big bucks on another model, namely the v700. I gave it some thoughts and wondered if I could use my v600 for scanning a 4×5 negative and it all turns into a birth of this project.
My goal is to find a way to scan a full A4 area as negative using my v600 spending less money than buying a new scanner for the job.
The idea is to create some kind of light box which will have an A4 sized surface evenly lit that is placed on the scanner. To use this light source instead of the built in light in the lid which is restricted to medium format. I have looked into several ways to do this, CCFL, LED, LED panels etc. But to keep this project on budget I will go with a normal led strip. The led should be place into a matrix on a surface with same distance between each other. To get an evenly lit surface out of it I need some kind of diffuser placed on a distance from the leds based on their light spread radius and distance to each others. I will post more information and details about this light box in future blog after is solved following problem.
The scanner will signal an error if lid is open. This only happens if negative scan mode is selected which is the mode I must go with to turn of the lights from the scanner head used for reflective scan. I looked around for a mechanical switch used to detect if the lid was closed but didn’t find any. But I did discovered that for each scan I started, the light in the lid turned on, went forward to meet up with the scanner head and started to blink. That’s it, the lid is talking to the scanner to indicate it set to go. I logged the sequence of the lid lights and tried to reproduce it with a flash light but failed. It probably needs to be in sync with a clock. Looking into the lid and the light head it seems that there are just two cables that controls the light, I assume I could jack into those cables but I’m not to fond of the idea to do harm to my scanner so maybe, I just should have a photo diode that registers and replicate the light signal from the open lid into the light box…
Anyway, the conclusion are that it seems the the hardware in the scanner is signaling through the lid light to detect if lid is closed, I need to copy this behaviour.
This leaves me with two things to investigate; Explore the little lid placed at the cable connection between lid and scanner to see if I easily could jack into the light control signal into my lightbox without to much harm on the scanner itself. Investigate if it’s possible to use a photo diode to control the box. I would prefer the latter approach due to no physical modifications on the scanner itself.