Simple Process-Timer?

albada · Nov 29, 2020

I'd like a simple process-timer that merely counts seconds forever, and has a Zero button which zeroes the display (which is large red LEDs). Does anything resembling this exist? I time my develop/stop/fix/wash1/wash2/wash3 at 70/30/120/120/120/120 seconds, so a simple zero-able up-counter would be perfect.

Idea: Touching the Zero button with wet hands is not prudent. So put a microphone in it so it will zero when I yell at it.

Such a timer would be a simple circuit. It's tempting to make one if nothing like that can be found.
Mark Overton

seall · Nov 29, 2020

Hi Mark,

It is a simple circuit, have a look at this site:

https://lastminuteengineers.com/ds3231-rtc-arduino-tutorial/

Not sure about the shouting but most of what you need is there.

Deleted member 88956 · Nov 29, 2020

Arduino is certainly a way to go, but I don't think there is anything ready-made.

ic-racer · Nov 29, 2020

I think this is one of the best. Except for the metal spring, the rest of the mechanism is all plastic.
I use a Graylab to time development (B&W) and the Jingle Bell times the other steps which only need to be 30sec accuracy.
Omega made a plug-in version that is similar. This one, of course, requires no electrical power.

bdial · Nov 29, 2020

In my darkroom I use a Gralab and set the minutes hand to cover the full time plus a bit, start it off, then watch the seconds hand as it sweeps along.
A standard clock with a seconds hand works well to, and you don’t need to stop and start it. For most paper processes great accuracy isn’t needed.

AgX · Nov 29, 2020

Well, the OP asked for upwards, endless running devices, not for timers. (A timer never runs endless but for a certain period, up- or downwards, and gives a signal at its end or switches something).

The classic ones are plain stopwatch clockworks. I started with a handheld one, which I still find useful as alternative to timers.
Next to handheld stopwatches the same is in big, clock size, for darkroom work even with phosphorescent figures.

pentaxuser · Nov 29, 2020

What about an old fashioned pre-recorded tape that tells you when to do each bit and gives you a warning by making you listen to your own dulcet tones as you approach each of the times?

It's "old school" as those of over a certain age say in the U.K. but there was a time when this was an "old school," forum

pentaxuser

Sirius Glass · Nov 29, 2020

You can use your iPhone and use Clock. Set the screen to red and you have your darkroom timer. If you receive a call in the darkroom it will light up red and not interfere with our work.

gordrob · Nov 29, 2020

Vivitar made timer unit the allowed you to store up to six processing steps in one register and there was three registers that allowed up to a total of 12 processing time. It was great for timing the processing of E6 film with Kodak's 6 step chemistry. The unit was called the Vivitar Process Time Commander (PTC) and produced in the 1970s. There was a flaw in the power module with an under sized resistor IIRC but there was a fix to correct this issue.

removed account4 · Nov 29, 2020

too bad there isn't a simple metronome that counts seconds you can use.

Doremus Scudder · Nov 29, 2020

jnantz said:
too bad there isn't a simple metronome that counts seconds you can use.

There is. I use a GraLab 450 with a footswitch. I set it at 99 seconds and turn on the "beep" that sounds every second. When printing, I just step on the switch and count seconds. For those times where the total print exposure plus manipulations exceeds 99 seconds, I just step on the switch again. I keep count in my head. EZPZ

Doremus

voceumana · Nov 29, 2020

There are lots of very flexible kitchen timers these days at low costs--you might find something that works for you with one of those, without the MIC trigger. But, battery operated so no real safety issues about wet hands, and probably LCD display.

Pieter12 · Nov 29, 2020

It's called a stopwatch. Available at any sporting-goods store.

albada · Nov 29, 2020

pentaxuser said:
What about an old fashioned pre-recorded tape that tells you when to do each bit and gives you a warning by making you listen to your own dulcet tones as you approach each of the times?
It's "old school" as those of over a certain age say in the U.K. but there was a time when this was an "old school," forum
pentaxuser

That's a good idea!
I'll just record all the process steps with proper times on the tape, and play it each time. "Old school" wins again!
I also have a digital recorder that can do the same thing. I suppose a recorder phone-app would also work.
Mark Overton

pentaxuser · Nov 30, 2020

albada said:
That's a good idea!
I'll just record all the process steps with proper times on the tape, and play it each time. "Old school" wins again!
I also have a digital recorder that can do the same thing. I suppose a recorder phone-app would also work.
Mark Overton

Glad to have been of help. I'd have suggested a digital recorder if I'd known there were such things. That's how old school I am

pentaxuser

Chan Tran · Nov 30, 2020

Use a smart phone. Before the smart phone I used my HP41CV as the timer.

jvo · Dec 3, 2020

rh designs timer 3 - solid, simple and not cheap - a joy to work with!

Kilgallb · Dec 6, 2020

The old Kodak red timer. Just let it run. Note when you drop the paper in the dektol.

Yukon Alvin · Dec 10, 2020

jvo said:
rh designs timer 3 - solid, simple and not cheap - a joy to work with!

Just got my timer 3 in the mail last night, looks very good.
40 years of photography and had never heard of f/stop printing, i think this will be a game changer.
How was the learning curve in the f/stop mode?

Sirius Glass · Dec 10, 2020

Yukon Alvin said:
Just got my timer 3 in the mail last night, looks very good.
40 years of photography and had never heard of f/stop printing, i think this will be a game changer.
How was the learning curve in the f/stop mode?

Double or cut the time in half for an f/stop change.

Pieter12 · Dec 10, 2020

Yukon Alvin said:
Just got my timer 3 in the mail last night, looks very good.
40 years of photography and had never heard of f/stop printing, i think this will be a game changer.
How was the learning curve in the f/stop mode?

There's not much of a learning curve, since you're already able to judge f/stop (or increment thereof) exposure changes to an image. The beauty is the scalability--if you keep notes on burning/dodging or if you split-grade print, the number of stops remains the same, just the base exposure changes with enlargement size. And most common paper sizes increase by a factor of 2, the base exposure increases by approximately 1 stop per size increase. For example, when going from 8x10 to 11x14, you would increase the base exposure by 1 stop, either by opening the lens or doubling the base exposure for a starting point and fine-tune from there.

albada · Dec 11, 2020

f/stop times are a good way to shift exposure by fractions of a stop without changing the aperture.
We know that boosting exposure by 1 stop (doubling it) can be done by doubling the time.
But suppose your exposure was 10 seconds, and you need to boost exposure by 1/4 stop. What time is that?
An f/stop timer will know to use 11.9 seconds.
You can compute these with a scientific calculator (as I just did), but an f/stop timer makes it easier.
Mark Overton

Rmaydana · Dec 11, 2020

Si

ic-racer said:
I think this is one of the best. Except for the metal spring, the rest of the mechanism is all plastic.
I use a Graylab to time development (B&W) and the Jingle Bell times the other steps which only need to be 30sec accuracy.
Omega made a plug-in version that is similar. This one, of course, requires no electrical power.
View attachment 260557

es una buena opción siempre que la unidad sean minutos,
hay uno opción de bs 777 process timer (baeuerle)
tiene 5 programas con 9 secuencias cada uno
Permite configurar en minutos o segundos
cuenta con avance automático o manual (en un mismo programa se puede hacer mixto)
tiene una señal auditiva de 5 segundos antes de finalizar.
el punto no tan lindo es manejar con las manos húmedas, a la larga daña el sistema o lo degrada.

otra opción de vieja escuela son los crometros Jhungas
van algunas de las fotos de los equipos..
Arduino es el camino, hay varios desarrollos de f/stop y de timer, por el momento no he visto algo comercial.
se que hay código abierto con la programación y el plano para el desarrollo del timer..

It is a good option as long as the unit is minutes,

There is a choice of bs 777 process timer (baeuerle)
has 5 programmes with 9 sequences each
Allows to configure in minutes or seconds
It has automatic or manual advance (in the same program you can do mixed)
It has an audible signal 5 seconds before it ends.
The not-so-cute point is to drive with wet hands, in the long run it damages the system or degrades it.

Another old-school option is the Junghans chrometers
Here are some photos of the teams.

Arduino is the way, there are several f/stop and timer developments, for the moment I haven't seen anything commercial.
I know that there is open source with the programming and the plan for the development of the timer..

Simple Process-Timer?

Deleted member 88956

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