Zone VI Drydown Timer -- how do you use it?

[John Schneider]

I was going through a box of darkroom stuff that a friend gave me when he left town a few years ago, and I came across a Zone VI Drydown Timer with footswitch. I understand enlarger timers and the principle of print drydown, but what does this piece of equipment do and how do I use it?

I currently use an Ilford MG500 system on a Durst 138; can this be used with the Ilford equipment? Thank you.

[Brian Ellis]

I really liked several of the Zone VI Studios products. This wasn't one of them. The drydown timer is a timer that allows you to enter a percentage that you've determined through testing (or guessed at) as the percentage by which a dried print looks darker than a wet print, set the timer for the exposure time you want, then the timer will automatically adjust the set time to the drydown time (e.g. you set one minute for the exposure, you've previously entered 10% as the dry down percent, and instead of exposing for 1 minute the print will actually be exposed for 54 seconds). The result is that your prints will look too light when wet, mainly in the highlights since that's where drydown has its biggest effect, but in theory they will look just right after drying.

Rather than paying for this thing, I thought it was just as easy to do the calculation in your head and set the actual time taking drydown into account as an initial matter (e.g. exposure time of one minute, drydown = 10%, set the timer for 54 seconds), especially since 10% is a pretty typical drydown percent which makes the calculation easy. And then there are those (e.g. Bruce Barnbaum) who don't think drydown is a real phenomenon in the first place.

[Doremus Scudder]

John,

Brian has it right. The drydown timer is an enlarging timer that allows you to make your "best wet print" and then automatically subtract a certan portion of the exposure to compensate for drydown. The idea is that the dry print made with the shorter exposure will match the "best wet print" in tonality. The timer reduces the light intensity (or maybe shortens the "seconds", I can't remember which...) allowing you to keep the same dodging and burning scheme you arrived at for the "best wet print."

The Zone VI drydown timer has (had) a connection to a photosensor in the enlarger light source. This was usually a cold light source marketed by Zone VI. They also sold sensors for mounting in other enlarger light sources. To take advatage of the drydown feature of this timer you need the sensor and the connecting cable to the timer. I don't know exactly what you have or if it will fit your enlarger or not.

In practice, I find that 1) drydown is a real consideration with some papers and 2) a simple reduction of exposure does not really "compensate" for the effect.

I feel that drydown is largely due to the shrinking of the emulsion when it dries, causing detail to appear in the highlights, and some detail in the darkest shadows to disappear in the dry print when compared to the same print when wet. My experience is that this change is not even over all the tonalities and cannot be exactly compensated for by simply reducing exposure. I always end up drying down my prints as I zero in on the exact exposure/development/manipulation scheme for a fine exhibition print so I can see exactly what the print looks like dry and under different types/intensities of illumination. I try to print so that prints look good under relatively bright gallery lighting as well as still having as much impact as possible under less intense room lighting (illumination that customers may display purchased prints under in a home, etc.)

There are some who simply make their best print in a poorly lit darkroom and then are "pleasantly surprised" when the print has a lot more detail under bright gallery illumination, and those that have managed to match their darkroom illumination to the usual display illumination so that the wet print (under the viewing light in the darkroom) looks approximately like the dry print under display lighting. I prefer to be a bit more precise with the process, although there is a point at which nit-picking has no further advantage.

Your drydown timer can be used as a regular enlarging timer. You can choose to use the drydown feature for its intended purpose, or, as I sometimes do, use it to fine-tune exposure on a print when subtracting time would make dodging and burning more difficult. Sometimes I will make the same print, but set the drydown dial at 0, 5%, 10% and 15%, develop everything the same, dry the prints and look at them under different illumination to find which exposure I prefer. Then I simply make the subsequent prints at the chosen "drydown factor," and note this in my printing record. (Usually, however, when getting around to making reprints some time later, exposure has to be re-determined anyway. Only if I were reprinting on the same paper batch with the same developer, etc. would I be able to simply use the identical exposure and its accompanying "drydown factor.")

Hope this helps,

Doremus Scudder

[Toyon]

Bruce Barlow authored a magisterial survey of drydown for View Camera magazine a few years ago (I think he is still waiting for payment). He found that the effect varied by paper from 4% - 10%. So how useful would it be to standardize on 10%? Bruce's article can be found at http://www.circleofthesunproductions.com/.

[ic-racer]

I never really understood what this timer is supposed to do. I mean if you best print is at 60 seconds, then use 60 seconds; what is the deal? Or are you guys trying to guess something about a dry print by looking at a wet print(???) I thought everyone these days has a microwave or blow dryer for test prints.