dimanche 30 janvier 2005

Coloured Monochrome... Split-Selenium Toning What is particularly attractive about the technique of split-selenium toning is the opportunity you have after the normal darkroom printing process has been completed to lift your carefully crafted print to another level. In this example, featuring the somewhat drastic action being taken to trim the old trees in a Wiltshire churchyard, the scene was interesting but the weather was awful... the lighting was flat and smoke from several bonfires was swirling around making the scene even hazier at times. I took a few shots thinking that as the work was probably going to take the best part of a week to complete I could return another time if and when the weather changed... it didn't and I didn't. So I had to make the best of what was on my one roll Agfapan 400 developed in Rodinal at 1:50 for 12 minutes. I'd been using a Canon F1n fitted with either a 17mm f/4, 20mm f/2.8 or 28-85 f/4 Canon FD zoom... I can't remember which although looking at the print the distortion doesn't look too exaggerated so I think I used the 20mm. This three lens selection was a favourite when photographing churches and it got me out of many a cramped space with many an interesting image... and, all three lenses took the same 72mm size of filter. There are pros and cons with Kodak Rapid Selenium Toner... it's very versatile... but it's also poisonous and highly toxic by ingestion through the skin. However, unlike some other popular sepia toners no initial bleaching stage is required... the print is simply placed in the toner and removed once it starts to change colour... that's what you do with selenium toner according to the instructions. However, by concentrating the solution (and mixing it warmer to accelerate the process) it's possible to create a multicoloured image from a black-and-white print. This is best attempted with a fibre-based paper rather than a resin coated RC type... so you have to be printing with intent, by using "proper" paper, to start with. What happens visually (to describe it chemically is beyond me!) is that during the change of colour created by the selenium toner, the shadow areas - those most heavily exposed areas of the paper - start to change colour much more rapidly. At this point - and it's a second by second decision - the paper has to be snatched from the toner and immersed in water to stop the toning action. If you have caught the action of the toner in mid-change of colour, so that the deepest shadow areas show a purple-reddish appearance and the mid-tones remain a light grey, you have a split-toned print. If you pull the print a few seconds after the "split" happens it is generally too late and the mid-tones will show toning as well, negating the effect. In the detail image scanned from about 1/20th of the print the reddish-purple split-tone effect is clearly seen in the shadow areas of the pile of twigs, the twigs themselves remaining grey, as well as in the *bodger's pullover, which adds contrast in an attractive and pleasing way. When working with Kodak Rapid Selenium Toner it's advisable to either have a well-ventilated darkroom with some form of extractor fan (good general practice anyway)... or work in the open-air. It's also good advice to wear a protective mask of the type used in paint-spraying booths when using any toxic darkroom product. However, I choose to work out of doors when selenium toning because I have better light (daylight) to work in and the air is fresher. And I always wear rubber gloves to protect my skin... as I do when using Pyro to develop sheet film in open trays. Safety advice should always be double-checked... I'm only fairly cautious having worked in darkrooms for more than 30 years... I have techniques and practices which I wouldn't want imitating. Nevertheless, caution and safety are the watchwords... tap-water is just as dangerous as any toxic darkroom chemical if handled in the wrong way... but shouldn't stop you trying different photo techniques for real rather than with a computer. * I've used the description "bodger" for the man pollarding the trees... although the Shorter Oxford Dictionary only gives derogatory descriptions for the word I've seen and heard "bodger" being applied to skilled craftsmen working with wood and in woodland. 10:39:38 PM    comment []