DIY Temperature Compensation Metronome
Hi folks, I hope I'm not doubling up here but I recently found a page that has instructions for making software for a Zone VI temperature compensation metronome.
https://gitbucket.tundraware.com/tun...e/Version-1.00
I am not fluent enough to be able to decipher the instructions and my own timer still works, so I'm putting this out there for others to find and use if needed.
Maybe someone could have a look and determine what is needed to make the whole thing?
Re: DIY Temperature Compensation Metronome
IME, LED light sources doesn`t need compensation at all. It`s easier to turn to LED than to mess with obsolete tube based sources.
Re: DIY Temperature Compensation Metronome
It's not for LED light, it's for developer tray or tank !
Re: DIY Temperature Compensation Metronome
Ooops, my excuses. Anyway, same idea. Isn`t it much easier to check a chart?
Re: DIY Temperature Compensation Metronome
Quote:
Originally Posted by
jose angel
IME, LED light sources doesn`t need compensation at all. It`s easier to turn to LED than to mess with obsolete tube based sources.
I would not bet my print quality on that. There is a temperature dependence of LED properties (voltage-current curve, lumens-current curve) versus temperature. General characteristics for nominal conditions are listed for a nominal junction temperature, and there is a time constant (several probably) associated with the transient thermal response at turn-on, dependent of course on heat-sinking.
Such time constants, if you allow an educated guess, probably lie between 1/10 and 1s. Too short to be a matter of concern? Possibly. But I see some f-stop timers having increments of 1/12 stop and what not. So what is significant?
This said, I agree 100% with:
Quote:
It`s easier to turn to LED than to mess with obsolete tube based sources.
Re: DIY Temperature Compensation Metronome
I ordered all the parts (less than $50) to build this timer and I'm in contact with Tim, the guy who develop this project.
I'll let you know soon
1 Attachment(s)
Re: DIY Temperature Compensation Metronome
I confirm, it works well !!
You can choose Film (displays are dimmed), Paper or even no compensation, bip every 30s and you can adapt the factor compensation and more
Now, just need to put in a nice box and connect with foot switch
Thank Tim for your help, and s2art
Attachment 179561
Re: DIY Temperature Compensation Metronome
I've had the Zone VI for quite a while. Even with the compensation, I keep the temperature within about 1 degree F. The compensation is good, but not perfect.
Re: DIY Temperature Compensation Metronome
I am the designer of this device and wanted to clear up a few things after reading the various comments on this thread:
1) It is not an enlarger metronome or timer. It is a temperature-driven development timer for both film and paper.
2) It can also be used as a normal count up timer and as a digital darkroom thermometer.
3) Although this project was inspired by the original Zone VI device, it is in no way a reimplementation of that design. The Zone VI design is analog. This one is digital.
4) The design and code are copyrighted (which means I own it) but it is fully open sourced and there are no costs or licenses for building your own.
5) It is still undergoing improvements, albeit at a very slow pace. Generally, the stuff that makes it to the git site can be expected to be reasonably functional:
https://gitbucket.tundraware.com/tundra/devtimer
6) The current correction factors are build on formulae found in the spreadsheet in that git repo. I have not yet compared this to the Zone VI analog corrections.
Have fun ... :)
2 Attachment(s)
Re: DIY Temperature Compensation Metronome
In box with a foot switch, ready to use !
I added one switch to choose between Real Time or Compensated Time
Attachment 179698