Ilford Ilfodata HS23 - continued

Graffiti, Ive Farm, Ilford Ilfodata HS23, shot at 25 EI, stand developed in Rodinal 1:150 for 1 hour

Following the exposure tests with the Ilfodata film in my last post, I also wanted to experiment with the dilution of the developer to see how this would affect contrast. With the first couple of rolls, I had stand developed the film in Rodinal diluted 1:100 for one hour. Taking a cue from the development of Tech Pan at 1:150, I shot another roll with the exposure index of 25, although this film I shot using my Kodak Retina IIa, and used the 'sunny 16 rule' as a guide for exposure, bracketing the shots, such as the one below where the two frames overlap.

Ive Farm Lane, Ilford Ilfodata HS23, shot at 25 EI, stand developed in Rodinal 1:150 for 1 hour

There's a stop difference between the two shots that overlapped on the film, I'm not sure which one is 'at' 25 EI, but both exposures provide a usable negative, although the shadow areas in the left hand image are beginning to lack detail. I developed this roll of film at a dilution of 1:150, and, although I did not shoot the same subjects with the same lighting conditions as the second test roll for an accurate comparison, this increased dilution may have reduced the contrast: certainly it is low enough to use for pictorial purposes.

Hackney Substation, Ilford Ilfodata HS23, shot at 25 EI, stand developed in Rodinal 1:200 for 1 hour.

I then shot another roll, with the same camera and the same exposure index, and developed this with a dilution of 1:200. In practical terms, this meant reducing the amount of developer to 5ml, and making this up with water to a litre (as opposed to 6ml to 900ml for a dilution of 1:150). The results at 1:200 showed up the limitations of further increasing the dilution. The development was visibly uneven in any large dense areas of the negatives, which meant the sky. In the shot of Hackney Substation above the cloudy sky obscures this, but in the picture of the flood relief channel below, the clear sky shows it well enough. Examining the end of the film exposed to the light when loading the camera proved uneven development to be the case: on any normally developed film, this will usually be a featureless black, but on this film there are lighter patches and streaks. This may be due to simply not having enough developer present, and it's certainly compounded by a lack of agitation while developing. A solution to this problem would be to increase agitation during development.

Lea Flood Relief Channel, Ilford Ilfodata HS23, shot at 25 EI, stand developed in Rodinal 1:200 for 1 hour.