Apart from my film costs - which I convinced myself were actual savings through using bulk loaded stock - I should really have added the outlay costs of producing the initial visuals... the contact sheets.

Without contacts I don't know what's on my negatives... I can't read grey tones in reverse. So in addition to my film costs I should have added the costs of the chemistry and the contact printing paper... and that's before I've even made a test print or finished print for personal appraisal or sending to an editor... and not taking the cost of my time into account. The thought of the additional numbers are beginning to worry me even before I've started to calculate them... arrrggghhh!

Monochrome Processing
To process the 8,000 monochrome films I've exposed, assuming a best case scenario of four films per tank of chemistry, I've done 2,000 processing runs (at least... perhaps 3,000 runs if the real facts were known!). Using an economical developer such as Agfa Rodinal at £7.50 for a 500ml bottle and diluting it 1:50 with water means using 20mls per processing run... or 80 bottles of developer which comes to £600. I now use cheap purified water for all my processing but filtered tap water for the first 25 years so I'll ignore that factor. I'm going to add 50% to the developer cost because many times I've used a stronger concentration... or more expensive developers such as PMK Pyro... and then double the cost to account for the necessary stop-bath and fix chemistry... so I have £1,800 for processing (or US$3,600 at May 2007 rates).

All 8,000 black-and-white films needed contacting so I could see what was on them... and at a 30-year average of £20 per box of 100 sheets for a black-and-white multigrade resin-coated paper such as that from UK photo-chain Jessops (good stuff... probably manufactured by Ilford), plus, 12.5% wastage through poor exposure, incorrect processing, white-light fogging or whatever mistakes you make which all add up... and I've bought 90 boxes of paper at a cost of another £1,800 (US$3,600).

My monochrome throughput is adding up fast at the checkout and I calculate it has come to £16,000 (US$32,000) or more... minimum!

Colour Transparency Processing
And to process my 2,000 transparency films shot in that same period would have used, again at a reasonably prudent rate of four films in a tank and four runs per kit... equates to sixteen films from 1,200 mls of juice - or around one hundred and twenty five 1,200 ml E-6 processing kits. I used to buy Paterson's Chrome-Six kits at a discounted price of around £18 each between five and ten years ago. The price now is averaging £25 and was probably half that 30 years ago so an average of £18 seems reasonable for this calculation.

Therefore 125 kits at £18 each tots up to £2,250 (US$4,500) before mounting the transparencies in plastic slide holders at £3 per box of 100... or an additional £2,000 (US$4,000) for the mounts... but the maths get worse!

Hidden storage costs
There's the cost of storing something like 24,000 35mm colour transparencies... I estimate from the numbers of slides in my office that I've retained an average of ten images per film shot. Clear suspension-hung filing sheets holding 24 mounted slides each cost around £1 each and I have 1,000 of them for which I've apparently paid £1,000 (much to my horror). The £95 cost of the 4-drawer filing cabinet almost seems to be an incidental at this stage.

All added together the 2,000 rolls of colour transparency film, the E-6 processing, the mounting and eventual storage comes to just under £12,000 (US$24,000).

Add the monochrome to the colour transparency film costs and it comes to approaching £28,000 (US$56,000)... near enough to £30k over a thirty year period to become £1,000 per annum. Now this figure doesn't sound too much to get worried about... but, I'm becoming much more careful with photographic output as costs increase... and in doing so am losing an increasing amount of photographic pleasure. Also, I haven't begun to calculate the cost of making prints yet...

As is often pointed out by experienced (or, more accurately, knowledgeable) photographers who've made the transition from traditional to digital - the underlying advantage of digital is that you can shoot much more, edit on the fly and delete at will... and the more you shoot and delete the more you can learn... and the more you shoot the better you can become (remember Gary Player's quip, "The more I practice the luckier I get!").

None of these calculations take into account my darkroom costs such as £2,000 (US$4,000) for the building conversion, around £5,000 (US$10,000) for my Durst Laborator 1200 Multigraph enlarger... but as there's no bouyant sellers market for used darkroom equipment (there is for astute buyers though!) no matter how good the specification, I'll keep what I have and enjoy printing from the archive of negatives I've taken dating from the days my now grown-up and married children were born.

But for the future... the economics and ease of use have to be with one of those cool cameras I can connect to my computer. It's strange to come to terms with the fact that by saving £1,000 a year (a conservative minimum) on film and processing I could increase my photo output digitally by two, three, five, tenfold even... at which point it starts to sound very exciting to traditional old me. Maybe it's a good job I brushed up my maths!