f/stop timer?

[David Aimone]

I have to agree. I just purchased one, and in the two darkroom printing sessions I've done it's transformed my printing process.

The timer i got from DA is the best peice of equipment I ever bought fro my little darkroom. And the footswitch is great also.You will love it.

[David Aimone]

Nicholas,

Is there any way to convert f-stops or 1/10 of an f-stop (on your timer) to percentage for drydown? I'm finding that I'm darkening somewhere between about .1 to .2 f-stops between wet and dry.

David

[nolindan]

The timer has dry-down compensation as a percentage.

1/10th of a stop is about 7%. So try 10% as a first go, not a very original number, I'm afraid. You can often get to the same end by decreasing the wattage of the inspection light.

[David Aimone]

Just came from a printing session. LOVE this timer...

[ac12]

I'm trying to understand how you make a multi segment test strip w an F-stop timer. Each segment will have a significantly different time of exposure to be 1 stop apart, i.e.,
2-4-8-16-32 seconds

[David Aimone]

I'm still fairly new to the process, but if I understand your question correctly:

With the f-stop timer, you can adjust the exposure by as small as 1/10 of an f-stop, but yes, the time intervals won't be the same. They will increase for each subsequent test strip segment.

So with the darkroom automation timer, you would select a base time to begin at in f-stop intervals, say 2.0. Then you can select the interval for each segment, say 0.2.
So your first exposure is the 2.0, the second is 2.2, the third, 2.4, etc. If you start with a base of 2.5 for example, with a segment interval of 0.5, your first exposure is 2.5, the second is 3.0, the third is 3.5 and so on.

The base number can be varied based on the aperture that the lens is set to. For example, 2.0 at f/16 is the same as 3.0 at f/22, so it's easy to change the timer base or the lens aperture. If you're at 2.0 and f/16, but you want to stop down to f/22, just change your base to 3.0. All the subsequent time intervals change automatically. In this case they would get longer.

So, the timer does count down seconds and fractions thereof when running, but everything is based on f-stops. On a test strip, each segment will be a fraction of a f-stop, so times will vary. In fact, as I said, they will increase for each segment as each additional exposure will take longer to apply the equivalent f-stop interval.

I hope this helps a "bit".

I'm trying to understand how you make a multi segment test strip w an F-stop timer. Each segment will have a significantly different time of exposure to be 1 stop apart, i.e.,
2-4-8-16-32 seconds