LCD monitor as VC light source for contact print

[Flea77]

Here is a different take on it. We strip old LCDs for the backlight for my bosses translucent arrowheads. You take out the backlight, the voltage inverter, and the power module (assuming an older LCD with a seperate brick power supply). This is all mounted in a wooden frame like a picture frame with a frosted piece of glass covering it. The electronics are mounted in a small project box (think Radio Shack) with a simple toggle switch.

The advantage here is that the whole thing is the size of a picture frame and about 1/2" to 3/4" thick. You could easily place this on the counter, place a negative on top, then paper (emusion down) on top of there, toggle the switch on for the correct time, then off, then develop. Very little room used, and no little LED power light on the front of the monitor, no monitor stand, no bezel in the way, no computer to run.

I have considered doing the exact same thing. Good luck!

Allan

[salihonba]

Here is a different take on it. We strip old LCDs for the backlight for my bosses translucent arrowheads. You take out the backlight, the voltage inverter, and the power module (assuming an older LCD with a seperate brick power supply). This is all mounted in a wooden frame like a picture frame with a frosted piece of glass covering it. The electronics are mounted in a small project box (think Radio Shack) with a simple toggle switch.

The advantage here is that the whole thing is the size of a picture frame and about 1/2" to 3/4" thick. You could easily place this on the counter, place a negative on top, then paper (emusion down) on top of there, toggle the switch on for the correct time, then off, then develop. Very little room used, and no little LED power light on the front of the monitor, no monitor stand, no bezel in the way, no computer to run.

I have considered doing the exact same thing. Good luck!

Allan

but what about the grade change? how to change the color of light?

[Robert Hughes]

For grade change you could consider buying some stage light gels like 1/4 blue, 1/4 orange, CTB (correct to blue) or CTO (correct to orange) for starters. Place those right over the LCD.

[Flea77]

but what about the grade change? how to change the color of light?

I actually would not change the color of the light. The reason I would do contacts (which may be very different from yours) is to judge how well the image was exposed, composed, focused, etc. None of that requires changing the light.

If however you wanted to do dodging and burning, etc, you could simply place the backlight assembly on top of a support of some kind (say a stack of books on each side) facing down, place the paper on the counter below it, then go to it. It would likely require a longer exposure though.

Allan

[salihonba]

Yes my goal is to build a system that for large format film that do contact print as final output, no enlargement, like those huge size film 20x24. So I am looking a way that can do all the techs that on enlarger.

And not only it copy all the tricks you can have on enlarger, most important part is, it records and plays your tricks again, and again.....

For enlarger, you got light path as space for dodging and burning, you got VC light source to change grade, or area splitting prints......

So in traditional way, you utilize all these tools and tricks in darkroom, struggling to make a perfect print, finally it came out, fit your standard, and now you want to make a second print, you have to do those process again!

explore a way to make a perfect print is an creative challenge, but do the same thing again and again, is a hard labor work.

But if we use LCD monitor as a light panel, and through color control, area intensity control, we can do all enlarger does, all these can be precisely set in digit, and the greatest part is, these setting (color, intensity) can be saved as a file (through image software).

I treat this as a tailored light source specifically for this film.

For the first perfect contact print, you need to play all the tricks, just like on enlarge, struggling to make a satisfying print, but after that, to make a second, third, of even years later you want to make the same print again, just use that light source file, it saves those tedious job for you.

Now is a digital era, but we insist on analog output because it is not replaceable, at least at this time, but we can take the advantage of digital tech, to make the creation process easier and consistent. traceable and has a record to discuss later.

[biggerthebetter]

I think Salihonba is right on track. The LCD is not just a light source (like the soup can with a 10 watt bulb suggestion), but also control colour (for contrast control) and all dodging and burning, so one cna have reproduceable results.

I shoot 8 x 10 now, and am shopping for 20 x 24, so this is EXACTLY why I stumbled on this thread. So I can contact print my negs, but in a very very consisten way. If I print one today, I want to get the exact same print 5 years from now. This is especailly needed if one use expensive processes like platinum printing.

Salinhomba, did you make one yet? I am very impressed.

by the way, I live in bangkok. I go to Hong Kong next week and if you live there would like to see if you have made on of these yet.

[SAShruby]

Why don't you go for LCD Big screen TV and a card with tv output? Then you can do 20x24 easy... Maybe little bit expensive but over the long run, effective