8 



led up to, and trust you will see, my reason for 

 describing as I propose to do the method, or a 

 method, of obtaining a suitable negative for 

 enlargement purposes. In taking your negative 

 you will readily understand that as the image has 

 to be magnified, sharp definition is requisite, and 

 to get this a small stop is necessary, I couimonly 

 use F-i4., or still smaller if I have had to tilt the 

 camera and use the swing back. In American 

 cameras a lens with stop marked four is equal to 

 F8,andif marked eight is equal to FlI, etc. Return- 

 ing to our subject having focussed up, the important 

 item of length of exposure has tobe considered, and 

 in this all who have not yet used them will find an 

 actinometer invaluable, with its help mistakes 

 ought never to occur. Nciw, in exposing we wish 

 to obtain a negative with very little contrast, and 

 a long exposure is therefore necessary, say, half as 

 long again as for a negative for ordinary photo- 

 graphical purposes, as distinct from enlarging; 

 for example, say, the time required in the ordinary 

 case is four seconds, give six seconds. We may, 

 however, be taking a subject which has objects 

 close to the camera and others far off, say trees on 

 the left close at hand and a church on the right in 

 the distance. Now an equal exposure on this 

 subject would be apt to give considerable contrast, 

 the distant church being over-exposed and the 

 near trees under-exposed — this might be somewhat 

 overcome in the developing, but afar better course 

 is after exposing a sufficient time for the church 

 on the right to shade that portion of the lens (the 

 right hand side) by means of the lens cap or other 

 dark substance, allowing the trees on the left a 

 further and sufficient exposure — this to those who 

 have not already adopted it will be found most 

 useful in negative making. A great deal now 

 depends on thecorx-ectdevelopingof the plate, and 

 providing the exposure is correct, as with an 

 actinometer it should be, the developing can be 

 brought almost to a system. Firstly, we have to 

 aim at obtaining a thin negative without too much 

 contrast, and using either the Imperial plates fast 

 or slow, or Ilford chromatic plates. I have found 

 the following method produce the kind of negative 

 wished for : , — Using the Imperial pyro soda 

 developer and half plates ; take U ounces of the 

 pyro solution and the like quantity of the soda 

 solution, adding half-an-ouuce of water to make 

 three ounces. On pouring this developer on I 

 expect to see the first appearance of the high 

 lights in about 35 seconds, and I allow development 

 to proceed for about five times the time the image 

 took to appear — 35 by five, or a total of 175 seconds 

 from the time the developer was first poured on. 

 Now, supposing we have to enlarge from a negative 

 not treated as above or being so treated it still is 

 too dense or has too much contrast we can still and 

 with certainty make it what we desire by means of 

 thevarious reducing agents. Say we have a negative 

 which, although in the matter of contrasts is about 

 what we require is much too dense and would take 

 a weary amount of exposure in the lantern. 

 This we can easily rectify by soaking it for 

 some time ina solution containing cerum sulphate, 

 a new reducer, which in its action leduces both 

 the thin and dense portions of the negative at the 

 same time, which in the case before us is what we 



require. Now take a negative which has too much- 

 contrast, here the denser portions of the plate need 

 removing, and if they are in well defined groups 

 we may be able to do so by rubbing with cotton wool 

 damped in spirits. Care, however, is required, as 

 one is very apt to rub portions of the plate which 

 ought not to be reduced. A better course is to 

 use persulphate of ammonia ; this reducer reduces 

 contrast by eating away the dense parts before 

 attacking the thin. And like cerum sulphate it 

 leaves no stain, a matter of importance in enlarg- 

 ing, as it increases considerably the exposure. 

 Both these reducers can also be applied locally to 

 parts ot the negative requiring reduction by 

 means of a paint brush. I do not think either 

 the ferricyanide or perchloride of iron reducers 

 advisable on account of their staining qualities, 

 the former (ferricyanide) increases contrast, a 

 quality seldom required in a negative to be used 

 in the enlarging lantern. Before leaving the 

 subject of reducing I would strongly urge any 

 who have not yet used them to at once make a 

 beginning, many a negative will be saved and 

 still more improved by their intelligent use, and 

 there are practically no difficulties to master. The 

 plate, we should now have arrived at, will, to the 

 eyes of an ordinary negative maker, seem very 

 weak and flat, with a thin sky, which, if used to 

 print on P.O. P., will, unless shaded, give a very 

 dark and degraded sky — this, however, will not 

 affect the bromide paper, or, even if it did, steps 

 can easily be taken to prevent its doing so by 

 shading during the exposure. We now at length 

 come to the more immediate process of enlarging. 

 The lantern should be supplied with a lense cap, 

 with a niece of orange tinted glass ; this will allow 

 the image to shine through and assist in correctly 

 pinning up the bromide paper, while the tint will 

 prevent the paper being affected by the light, a 

 r*d light being quite unnecessary. We shall 

 require three developing dishes or trays, one to 

 hold water, a second for the developer, and a 

 third for the hypo bath. Although many 

 developers may be used, I believe amidol is very 

 generally used. For prints 12i by lOi I have- 

 found the following act satisfactorily : 



Amidol 18 grains. 



Potassiuminbromido 24 drops of 



10 per cent. sol. 



Sodium sulphite 3 drams. 



Water 9 oances. 



Some may think it unnecessary to make as many 

 as nine ounces for this size of paper, but I 

 have found that since using this somewhat large 

 quantity I have had hardly any instances of un- 

 even developing, pin marks, white spots and other 

 defects most distressing and disappointing — more- 

 over the amount of amidol used is very little more 

 than half that recommended by the maker's 

 formulas, so that a developer of about five ounces 

 becomes nine merely by the addition of water and 

 a little more of the sulphite of soda. This devC' 

 loper works perfectly on the Eastman, Ilford, 

 and Wellington papers. Of the three I prefer the 

 Wellington and Eastman, the former, perhaps, 

 for preference, and for most subjects the tinted 

 rough papers are a great improvement on the 

 ordinary grey. Placing the plate in the lantern 



