Kodak’s discontinuance of T-Max films larger than 4×5 left my friend, Dick, an expert user of 8×10 T-Max 400, wondering where to turn. My suggestion of Ilford HP5 Plus was received a bit skeptically, but he tried some and was entirely satisfied. This article was motivated by that incident and the likelihood that others, especially sheet film users, will soon be making film choices. In May, 2013, Kodak and Ilford supplied lists of their current black & white film offerings, which are summarized in Figure 1.
Kodak will cut any size for which Canham Cameras, Inc. can accumulate sufficient orders. This provides a way to get a size not normally available, but with some delay and at a higher cost. Ilford sizes marked I in Figure 1. can be ordered from Ilford. As they plan to accumulate orders for an annual cutting.
Figure 1 suggests that a comparison of HP5+ with Tri-X (film speeds 400 and 320 respectively) would be relevant for 5×7 users and perhaps for many others. I printed a step tablet on these two films, developed them normally in a Jobo processor, and plotted the characteristic curves with zones I and IX coinciding. Please note that this curve applies to Tri-X with a speed of 320, not 400.
The HP5 Plus curve is fairly straight, as are the T-Max films, while the Tri-X curve is more curved, lower in the middle of the range. Consequently, it renders midtones darker, shadow values with slightly less local contrast and light areas with slightly more local contrast. The greater local contrast of HP5 Plus around zone III is especially welcome, since shadow detail is subtle in this area. This unusual curve shape may help to explain why many Tri-X users develop in Pyro, which depresses the high end of the scale, making the Tri-X curve a little straighter.
Photographic film typically requires longer exposures than the meter indicates when the indicated time is 1 second or longer. This is called reciprocity departure.
In 2003, I tested a number of films to discover the needed corrections for indicated exposures of 1, 2, 4, 8 up to 240 seconds and interpolated to find values for 1/3 and 2/3 stop points between them. My test method consisted of finding a longer exposure time that would yield the same density in zone III as would occur if reciprocity departure weren’t involved. Since bright parts of a subject don’t need as much extra exposure, they tend to gain extra density with the reciprocity correction. I included both zone III and zone VIII in the test targets for the 2003 chart in Figure 3 in order to study this increase in density range and see when it was enough to call for reduced development. With rare long exposures beyond those in the chart, any film will gain enough density range to require reduced development, but this gain can be safely ignored with all of these films when the meter calls for exposures of up to a minute.
Figure 3. shows my 2003 results. I recently confirmed the accuracy of the table for HP5 Plus and 4×5 Tri-X at 60 seconds indicated, giving 2:36 and 3:00 respectively. It’s interesting to note that Kodak is still recommending drastically longer reciprocity correction times for Tri-X, as they have for several decades. For example, when 10 seconds are indicated, they recommend 50 seconds, whereas I found 17 seconds to be appropriate.
Ilford’s FP4 Plus and HP5 Plus (I didn’t examine Delta 100) have a welcome feature: the non-emulsion side has a minute texture similar to that found on anti-Newton-ring glass. That prevents Newton rings when a negative contacts the upper glass of a negative carrier or glass in some scanners used in preparation for making digital prints.
Although the supply of film in my freezer is likely to be all I will ever use, I join other sheet film users in hoping that at least one manufacturer will continue making the film we need.