BOOT CAMP 264 (25/02/03)

DIGITAL PHOTOGRAPHY part 4

One very welcome spin-off from the massive growth of the digital still camera (DSC) market has been the dramatic improvement in the quality of colour printers. Early models were expensive and the results, when it came to printing photographic images, were generally quite poor. Now you can buy ‘photorealistic’ colour ink jet printers for less than £100, capable of producing prints that are almost indistinguishable from conventional photographs.

Incidentally, there are at least two other colour printer technologies besides ink jet. Dye sublimation, which uses a thermal process to bond coloured films to special paper, is capable of excellent results but the cost of the paper and film cartridges is still quite high and tends to be mostly used in professional and commercial processing labs, though a number of consumer ‘dye-sub’ printers are now available for post-card sized prints. Colour laser printers have come down in price recently but they are better suited to producing documents.

Whilst photorealistic ink jet printers are relatively cheap to buy the cost of ‘consumables’ – i.e. ink cartridges and special photo printing paper – can make them expensive to run, but there are ways around that, which we’ll come to in a moment.

If you haven’t yet bought a colour printer to partner your digital still camera there are few things to watch out for. Firstly, not all colour inkjet printers are suitable for printing photographs; the telltale sign is the number of coloured inks it uses. In order to achieve natural looking colours it needs to have six colours, any less and the results may be disappointing. For the record the colours in question are cyan (C), magenta (M), yellow (Y) and black (K), known collectively as CYMK (there are usually two shades of cyan and magenta).

Secondly, take note of the resolution figure, which is a measurement of a printer’s ability to reproduce fine detail, though various techniques used to increase sharpness and eliminate ‘banding’ confuse the issue somewhat. The majority of printers have a claimed resolution of 2400 x 1200 and 4800 x 1200 dots per inch (dpi) but this can be increased using enhancements such as ‘interpolation’ ‘dithering’ and colour layering to over 5000dpi. Suffice it to say more isn’t necessarily better but shortlist models with at least 2400dpi and you won’t go far wrong.

You might also want to check printing speed in colour photograph mode. It can be excruciatingly slow, taking four or five minutes per print on some models, though between 1 and 2 minutes per A4 page is the norm these days.

There’s no substitute for seeing what a printer can do first hand. Many PC dealers will happily demonstrate a particular model for you and may even be persuaded to print one of your own photographs, so take your camera or a memory card along with you and compare the results for yourself.

One thing you’ll rarely see on a printer brochure is the cost of consumables and this can vary enormously, from a few pence, to a pound or more per print. Printer ink can be spectacularly expensive, worth more than its weight in gold in some cases! Several models use an all in one cartridge for the coloured inks, others have separate tanks. At first glance this seems like a more economical approach since you can replace a single colour when it runs out, rather than the whole cartridge, which may be only partially empty. However, the cost of some ink tanks can be almost as much as a multi-colour cartridge, moreover they may run out faster or contain less ink than a cartridge.

The cost of running a colour printer can be drastically reduced by using compatible or remanufactured cartridges and refill kits but be aware that cheaper ink may not have the same light-fastness properties or colour accuracy of the manufacturer’s own product. Some inks can fade within a matter of months if exposed to strong sunlight, others, it is claimed, will last for at least 70 years -- though one of the many advantages of digital photography is that if a picture fades you can always print it again, provided of course that your image files are safely backed up.

Many printer manufacturers warn that using ‘compatible’ cartridges will invalidate the guarantee, in practice the chances of something going wrong are relatively small but if you’re worried wait until the guarantee has expired before you experiment.

Some printer manufacturers go to extraordinary lengths to prevent you using ‘compatible’ cartridges, including fitting them with microchips. However the replacement cartridge industry usually catches up quite quickly and ‘chipped’ compatible cartridges are normally available within a few months of a new model going on sale. Check prices on the Internet, there are some amazing bargains to be had for both original and compatible cartridges if you shop around.

Generally speaking the best results will be obtained when you use the printer manufacturer’s ink in conjunction with the recommended photo paper, however, there’s nothing to stop you trying different combinations, and price isn’t necessarily an indicator of quality. I have been getting excellent results from my printer using remanufactured cartridges and unbranded paper, costing less than half the price of the maker’s own products. You can also save time and money by printing several pictures at once. Most printer software lets you fit two, three or four pictures per sheet to make the most economical use of the space available.  Where necessary resize your photos or crop out large empty expanses of sky or boring backgrounds and this is something we’ll be looking at in more detail next week.

Next week – Manipulating images

JARGON FILTER

BANDING

Straight lines or bands across a printed picture caused blocked nozzles, poor alignment or design defects in the printer head, as it criss-crosses the paper

DITHERING

Sharpening edges and creating additional colours and shades by randomly interspersing pixels of other colours

INTERPOLATION

A software technique that basically fills in the gaps between the ‘dots’ on a printed picture by analysing the surrounding dots and taking an educated guess at what should be there

TIP OF THE WEEK

The settings on your printer can have a big effect on the quality of prints. Most printers have a paper selection option, for different finishes (gloss, matt, silk etc.) and ‘weights’ (the thickness of the paper), try them all on series of test prints and compare the results. Clean your printer regularly, a build up of gunge and dried ink on the rollers can leave streaks, lines or scratches on the surface of the print, refer to your printer manual for guidance.