Developer Temperature/Time Calculator

[antonis]

Hello!
It's my first post here, but I'm reading a lot

I just create an app for Windows Phones (8.1) that calculates the develop time for a different temperature.

Here in Greece, the weather in the summer is hot, so it's difficult to cold the developer for 10+ Celsius degrees.
So I was changing the times, but most developers gives times from 18-24C.

After some search, I got the formula based on temperature from here and wrote a small script for Python.
You can find that simple script here:
https://github.com/vegos/DeveloperCalc

So, it was time for an application for my Windows Phone.

You can find it here:
http://www.windowsphone.com/en-us/store/app/developercalc/80c15b6f-bac1-4c93-8cb1-4d4cdcb42d0c

All you need to know, is the correct time for 20C/68F.
The program will calculate the new time based on the desired temperature.
It also converts from Celsius to Fahrenheit and vice-versa.

I hope it will be useful to you too!

Antonis.

Fahrenheit

 

[RalphLambrecht]

thanks a lot for this post!

 

[Kirks518]

Will this work on Android, or is it Windows only? I'd like to put it on my phone and tablet, but if not Android, I'll put it on my laptop.

As one who can (almost) never get my tap to 68°F/20°C, I welcome this app with open arms! Thanks!

 

[Photo Engineer]

The calculation may only work for Xtol, as each developer is different in rate and thus the constants would change.

Kodak has published a table of time-temp a while back and have some of it on their web site. If it is gone, try "way back".

PE

 

[antonis]

@Kirks518:
That was my problem too But sorry, this app is only for WP8.1. I quit programming for Android.
But I'm writing another one version for Windows. The python version is still published.

@Photo Engineer:
I guess It's not only kodak-compatible.
I tested the output with both Ilford/Kodak developers (tgot the ime from from the PDFs) and it looks that the calculations are fine. At least for the small amount of temperature changes as published.

But I'm using HC-110, ID11, D76 for the last 3-4 months, have changed the temperature from 20C -> 30C (that was the ambient temperature here) for about 30m of film, and I had no problems at all.

Ofcourse, I'm not a chemical. So, I'm open to corrections

 

[fotch]

Welcome to APUG.

 

[cliveh]

Welcome to APUG and I'm sure these tables will be of use to others. However, I use a chart based on one from the Ilford manual, as I find it more useful to have a chart on the darkroom wall rather than switching on a phone or computer.

 

[antonis]

Thanks

And here is the same calc, in a very simple version, for Win8.1:

http://apps.microsoft.com/windows/en-us/app/devtempcalc/23d39e4e-52c1-42fe-8cde-4d4dc8ed8190

Not it's time to stop programming, and develop some films

 

[antonis]

I needed a stopwatch/timer too, so here it is, for anyone who might be interested:

http://www.windowsphone.com/en-us/store/app/darkroom-stopwatch/4a3aae71-48fa-4070-a526-63cba3898d08

 

[one90guy]

Welcome to APUG and thank you.

 

[Sirius Glass]

Antonis welcome to APUG.

 

[Roger Cole]

The calculation may only work for Xtol, as each developer is different in rate and thus the constants would change.

Kodak has published a table of time-temp a while back and have some of it on their web site. If it is gone, try "way back".

PE

Ilford has one as well. I use it all the time, with success.

I have the same problem where the summer temperature in my darkroom can easily be 76-78F even though it is downstairs (no AC down there, nor is it needed as that's about as warm as it ever gets) and the "cold" water often comes out of the tap at as much as 78F. Since evaporative cooling means liquids are a few degrees cooler than the room I can almost always get (24C) and my Jobo has a heater to reach that temperature from lower but not a cooler. So I long ago standardized on 75F/24C as my B&W development temperature.