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  1. #1
    Les McLean's Avatar
    Join Date
    Oct 2002
    Northern England on the Scottish border
    Multi Format

    Dealing With Dry Down


    Fine black and white prints should “sing” when matted and presented for an exhibition or when offered for sale in a gallery. What are the qualities needed to make a print “sing”? My view is that the brightest highlight on the paper should be crisp and clean in tonality and when brought together with rich luminous shadows the print will be singing. However, unless we have considered dry down, the glow and luminosity we see in the wet print will almost certainly have disappeared when we view the dried print the following morning. I think we have all experienced that disappointment. There can be no doubt that dry-down is responsible for a high percentage of failed prints. When I first realised that my prints were darker when dry I couldn’t figure out why this happened (I was a newcomer to photography). I set out to find the reason for this phenomenon and discovered that the fibre of the paper base contracts when dry causing the emulsion to shrink which in turn causes the grain to close up and consequently the image becomes darker. For a short time after that discovery I carried out a crude adjustment to my final print by reducing the exposure to the step before the one that I felt was correct on the test strip. Sometimes it worked but at best it was a guess.
    The method to determine the dry down factor that I adopted more than 20 years ago is consistent and has proved to be a tremendous benefit in my black and white printing. I can make prints certain in the knowledge that when dry they will match the tonality of the wet test strip and in my judgement, is correct for the image that I am printing. I now test all papers that I use once each year to take into account possible changes made by the manufacturer. The test will take about 1 hour for each paper you use but will save you a lot of frustration and time spent making a second print having found the first dried down too much.

    The method is as follows:
    Select a negative that has a good tonal range, from dark shadow to bright highlight. The prints need only be 4” x 5”. Size is not relevant when calculating dry down. Make a test strip and select the correct exposure to produce the highlight and contrast you require. Using this exposure make two identical prints and number them 1 and 2 on the back. You don’t need to burn or dodge for this will only add variables when you need to be as consistent as possible.

    Calculate 8%, 9%, 10%, 11% and 12% of the exposure used and make 5 prints, deducting these percentages from the exposure used for the first print. The spread of 8% to 12 % will cover all available papers, for each manufacturer’s paper is likely to have a different dry down factor. In the years that I have been doing this test I have never found a factor over 11% but I always test to 12%.

    You should now have 7 prints, 2 given the same exposure and 5 where the exposure is reduced as described above. After processing leave print number 1 in a holding tray of water and dry the remainder. A microwave oven is useful to speed this up. Take the dry prints to the holding tray and first compare the dry number 2 print with the wet print given the same exposure to see the extent of the dry down. Compare the remaining dry prints with the wet print and decide which dry print matches it. The percentage noted on the back of the dry print is the dry down factor for that paper. Thereafter when using that paper make all decisions relating to exposure on the wet test strip and only apply the dry down factor when making the final print.

    I use a Stop Clock Professional f stop timer that includes a programmable dry down calculation feature. Having decided the required exposure from the tests strips, I dial in the dry down factor for the paper that I am using and activate the dry down feature and the timer automatically adjusts the exposure, including all burning and dodging. I use a Zone VI cold cathode VC enlarger that requires a compensating timer, a function also included in the Stop Clock. R H Designs, the manufacturer can be contacted by email on info@rhdesigns.co.uk and on their web site at www.rhdesigns.co.uk. The calculation for the adjusted exposure can be made manually, if you do not have a timer with a dry down feature the table I used for many years until I started to use the Stop Clock timer is reproduced here and will save you having to make calculations each time you make a print.

    (at this point please view the graph1 attachment at the bottom of this page)

    All times are in seconds. To adjust for dry down, reduce the final print exposure to the time shown in the column opposite the wet test strip time at the dry down factor for the paper you are using.

    Tonality is very personal, I prefer my prints to have very delicate highlights that are just above paper base white and tends to produce a final print that is quite high in contrast. When my final print is wet the brightest highlight appears to be paper base white but always dries down to the desired tonality. There are papers that dry down by as much as 11% and I have to say that when I first started to use this method of dealing with dry down I did doubt that the highlights would show in the final print and made a second, giving it more exposure. The second print always dried down more than I wanted and the first print was perfect. I soon learned to have faith in the system.

    Judgements are made at every step in making a fine black and white print; the paper grade; whether the print is high key or low key; the overall contrast or the local contrast; whether a Zone VIII highlight or a Zone V highlight. These and many other judgements influence the way in which the final print expresses the impressions and views you wish to communicate to the viewer. All these judgements can be changed by the effect of dry down. Highlights will be dull and lack sparkle, and the dark rich luminous shadow just on the edge of blackness that you saw in the wet print will block up and be dead in the final print. All the vision you employed in seeing and making the image will be lost to a phenomenon that you can control by spending a couple of hours in testing a few different papers. Perhaps deciding that you should carry out the test to determine dry down factors will prove to be another very important judgement. One thing is certain and that is when you do apply dry down factors your prints will begin to sing, and those disappointing dull prints will be confined to history.

    Les McLean
    Attached Thumbnails Attached Thumbnails graph1.gif   photo1.jpg   photo2.jpg   photo3.jpg  
    Last edited by Sean; 12-06-2006 at 04:33 AM. Click to view previous post history.

  2. #2
    Sean's Avatar
    Join Date
    Aug 2002
    New Zealand
    Multi Format
    Blog Entries
    comments from the previous article system:

    By Dave Miller - 08:34 AM, 07-25-2004 Rating: None
    Follow the Guru, children of the Dark(room).



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