NEED TO ADJUST? Without doubt you will know full well just how many beans make five! You probably know too, how to adjust the amount of chemical needed when making up a solution to a different volume than that given in the formula from which you are working.

Say you have a formula which calls for 50 grams of a chemical in a total of 500 mls of solution, but you need only a solution of 250mls. Easy, of course. Just half the water - just half the chemicals!

But suppose you need from 500mls to 300mls. Not quite so easy or straightforward... especially should the chemical involved be 27.6 grams!! So heres the route. DIVIDE the amount of chemicals (50 gms or 27.6 grams) by the volume of water, 500mls in this example. This will give 0.1 (or 0.0552). Then MULTIPLY the answers by the amount of water - 300mls - this will give 30 (or 16.56) which are the amounts of chemical required for 300mls in the two examples.

A PORTA DARK ROOM!! Should you be one of those people a shade fed up with blacking out the bathroom window and processing with the aid of the bath and wash-basin, there`s an inflatable darkroom on the market.

The 73lb. contraption measures 4 x 6 1/4 x 71/2 feet and includes built-in ventilation!! Optional extras include a sink and stand weighing 47lb. and water pump (14lb).

The portable dark-room is already on sale in America - where else? - and full information is available is available from Peter Hemenway, 349. Hope Street, Providence, R.I. U.S.A.

REDUCE YOUR WASHING. The thought occurred to me that years ago we used a chemical bath to remove or reduce the fixer content in films and/or prints and so drastically cut down the length of time needed for the washing stage.

As I remember there was a commercially available liquid for the purpose, which again, from memory, was sold as "Hypo-Lim". There was, until recently, and American equivelent called "Chem-clear" which, like it`s British predecessor, is no longer on the market.

I have seen it suggested that a two-per-cent solution of Sodium Sulphite can aid the removal of "Hypo". I have no experience of this but a more generally accepted formula consists of a very weak bath of Potassium Permangate - clear-pink - into which the film is immersed after a wash for one minute. The pink colour will vanish quickly if there is much "Hypo" present. Then transfer to a further bath until the colour goes. Water will also dilute the colour but not so quickly as the "Hypo".

Films can be hung to dry within three minutes by this method. Prints, especially double-weight, fibre-based, should be pre-washed for around five minutes.

IN GROWING TOE-NAILS? A strong solution of Sodium Sulphide can be a boon for softening an in-growing toe-nail and thus allowing the nail to be cut with considerable ease. Oh Yes! The same solution can be re-used to enable a hitherto black & white print to be re-developed - following bleaching, of course - to a sepia colour!

PEARLES OF WISDOM! This column I feel would be incomplete without giving a mention to those prodigious work-a-holics, Major & Rita Pearle.. not forgetting son, John and Saxon, their Red Setter, for they are forever searching, usually successfully, yet another project to be tackling.

A while ago, I remember, Major came across a discarded plastic sewage pipe in a ditch. Quick as light - well almost he jumped from his invalid buggy and that same sewage pipe (which I am assured was unused), new and unsullied! ... well it would need to be wouldn`t it?) has now been converted into the Pearles` version of a Paterson developing tank, complete with a light-tight, screw-on lid. Such ingenuity one seldom comes across.

But tarry awhile: for now I hear, they`re at it again! Having come across two ancient and simple Italian cameras, marketed by Korrel, they propose to convert those into a 3-D outfit. The cameras use 120 size film, giving a 3cm x 4cm x 4 1/2cm format. I`ve little doubt that the "stereo" outfit will be completely successful and will, inevitably lead to the manufacture of a companion 3-D viewer. Well they`re like that! Indeed, already I hear whispers of an in-line fully automatic film processor for E6!! Keep your ears to the ground! All hush hush at the moment! So keep it dark!

TO WASH OR TO RINSE! There still appears to be considerable confusion in relation to the washing, or rinsing, of a film between baths.. particularly following the reversal and conditioner stages.

members are often reminded that the E6 process was, and is, intended as a commercial in-line tank system and this is arranged for the film to be squeegeed at the end of its immersion in a particular bath. Thus there will be a minimal quantity of chemical from the bath carried over to the next. The reference is that this tiny contamination is intended and, therefore, far from harmful, indeed is actually and aid to the working of the next solution. Can the commercial processors, then, discard a washing stage altogether? I know not, but I have distinct reservations when I`m persuaded to transfer chemical from a previous bath to following one. For are we not constantly exhorted to avoid contamination at all costs? Indeed I consider it sounds sensible advice.

Mind you, the carry-over of a tiny amount of Conditioner, for instance, would not harm the Bleach. But look out for big trouble should a modicum of First Developer be carried over into the Reversal Bath!!

Me? I`m one of those individuals who enjoy delving into the unknown so I`ve tried most of the available alternatives. But I must confess, when I have a film I hope will carry worth-while shots, I tend to give a wash between each stage. That way makes sense to me.