Hi, thank you for sharing your project and ideas. I'd like to use leds for a 8x10 enlarger which matrix should I buy to cover 8x10 area? I feel more comfortable with raspberry pi, do you think your software could be used?
Thanks
Luigi
1x256 and 2x64 is enough for 8x10. It's not really much light buty I have no issues on my 8x10 enlarger so far. My code is only for Arduino: Rapberry PI is an overkill for tis task. I use Raspberry PI with Windows IoT for some other projects in my job (where it makes sense) but porting this simple code an a Raspberry is pointless. Maybe I'm a bit old fashioned but for me the Raspberry is a small PC ans should be used a such, not as low tier controller.
Thanks for sharing this amazing project!
I am daydreaming about using this for a battery-powered 4x5 enlarger.
Not sure about the best power supply solution, though...
My ideas so far:
- Several 5V USB power banks, each powering up to 50 LEDs
- Single >75W power bank with a 12V DC output, powering 12V LEDs
- Single RC battery pack and a DCDC converter to 5V or 12V
With several 5V power banks, could I face problems regarding uneven illumination?
Do I need to provide a "common ground"?
What do you think?
You definitely can use several 5V power banks. LEDs are non-ohmic so their brightness will not vary a significant amount with little inconsistencies in voltage. If all the LED panels are independent circuits then you don't technically need a common ground, however, it wouldn't hurt. Additionally, if the control signal is coming from a universal source then connecting the grounds would be necessary.
Personally, I would use a singular RC lipo battery. I think it would be smaller and cheaper, but any of those options can work.
Hi, thank you for share this project! My question is maybe naive but: how mapping the RGB values with the equivalent RYB filter in a Colors head for printing with VC papers? For every paper Ilford, Berger, foma, etc) there is a setting to achieve the proper contrast grade.Any ideas?
The problem is not to match the values. This values are based normally on a tungsten lightsource. Tungsten has a particular wavelength combination, while other lightsources have others. So even the YMC indication for the papers are relative. Anyway we have to differentiate from filteted light and originated light. Ilford for example indicates on the technical specification (can be found on their WP) the green and blue amounts in originated light values and the wavelength values needed to hit the graduations. I based my code on these values an compared it with a spectrometer to see how far I’m away from the ideal. For sure full contrast 5 is hard to get. As said each enlager will give different contrast result as long its lightsource is not calibrated with a spectrometer.
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Can I have some advice from those who have built an enlarger using this excellent controller?
I have built the controller and am now drawing out the enlarger itself (this is a DIY build not a conversion). I am using a 16x16 LED matrix (160mm square) but will be enlarging 5x7, so the dimensions of the diffusion box will be a bit bigger.
I'm planning on lining the side walls of the diffusion box with silver foil (aka baking foil or aluminium foil).
What distances are you using for LED to opaque perspex, and opaque perspex to film holder? Are there optimum values? And what thickness / 'model no' of 'opal' perspex works well? Is any of it critical?
(All this in the hope of learning from other's successes, and not 're-inventing the wheel' ).
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