Ways Of Exposing

A plate can be exposed in three "ways, that is, by removing the cap and replacing it, when the exposure is made; by folding the camera cloth and placing it over the lens (the cap having been removed), before the shutter of the dark-side is drawn, and then quickly withdrawing and replacing the cloth and sliding back the shutter; and thirdly by using a mechanical aid, called a shutter.

"Instantaneous shutters."

Quick exposures.

"Instantaneous."

Classification Of Exposures

The first method needs no comment save that the cap should be withdrawn in an upward direction. The second method has been of invaluable service to us, and is much practised by Scotch photographers. By this means very rapid exposures can be made, and yet detail obtained in dark foreground masses. The third method is so well known that hundreds of mechanical contrivances, called "instantaneous shutters," have been invented. We have always done all the work we could by quick exposures, and here we may at once say that for artistic purposes "quick exposures" are absolutely necessary where possible. We do not say "instantaneous exposures,"' because it is high time that this unmeaning word should be relegated to the limbo of photographic archaics. Is it not obviously illogical to call exposures of 1/200 of a second, and of one second, both instantaneous? - yet such at present is the custom. "Instantaneous" means nothing at all, for a quicker exposure can be obtained by the second method we have described than with some shutters. It is in fact difficult to classify exposures, for obviously the classification must be based, coeteris paribus, on the time the plate is exposed, and this, especially in quick exposures, is not to be measured save by special apparatus, which of course is of no rough working use. We offer as a suggestion the following rough working classification for describing exposures. We would define as Quick exposures.

Quick Exposures

Uncapping and capping lens as quickly as possible. Snatching velvet-cloth away and replacing it as quickly as possible. All shutter exposures which cannot be timed by the ordinary second-hand of a watch; a note being added in the case of shutter exposures, giving make of shutter, and stating whether it was set to quickest, medium, or slow pace.

Time Exposures

All other exposures might be called time exposures, it being understood by this term, that the exposures were long enough to be counted by the second-hand of an ordinary watch. A note could always be added giving the number of seconds the plate was exposed.

We are perfectly aware this method would give only approximately rough statements of the times of exposure, but that is all that is wanted for ordinary work, for after all, except in delicate scientific experiments, the times given to exposure must always vary greatly, for exposure, as we shall show, can never be reduced to a science. On the other hand, in cases of delicate scientific work, it may be required to measure exactly the length of the exposure, and this is easily done with the proper apparatus, as applied by Mr. Muybridge and others. Our nomenclature is intended for the use of ordinary operators, so that they may describe more accurately than they now do the exposure given to a particular plate; and it is at any rate more accurate than any nomenclature now in use, for, as we have shown, by the camera cloth method a quicker exposure can be made than with many shutters working slowly. The fundamental distinction, it seems to us, for everyday work is, whether the time of exposure is measurable by the seconds-hand of an ordinary watch, or not, and that is the point on which our nomenclature is based. Hence, when we use the term "quick exposures" in this work, we mean it as already denned. The shutters themselves should, we think, be called "quick exposure shutters," or simply "exposure shutters," instead of instantaneous shutters. We will say but few words on "shutters," as these mechanical aids to exposure are called. Theoretically, the best shutter is that which allows the lens to work at full aperture for the longest time,andwhich causes no vibration or alteration of the position of the apparatus during exposure. The mechanism should be simple and strong, and the whole small in bulk. Mr. T. R. Dallmeyer's new central shutter, in our opinion, best fulfils these requirements. Another important matter is the correct position of the shutter, and this, theoretically again, is behind the lens, providing the aperture be large enough to prevent any of the rays of light admitted by the lens being cut off. But in practice, a shutter working in the diaphragm slot of the lens answers best, and the very worst way of all is to work the shutter on the hood of the lens.

Exposure Shutters. Quick Exposures

All portraits should be taken by shutter, and by quick exposure, if possible; in fact, we feel sure a first principle of all artistic work in photography is quick exposure. There is nothing to be said for time exposures, although we are fully aware how much has been written on their advantages, and the beneficial effects on the resulting negatives. We, however, have never seen these wonderful gains, and for quality we have seen very rapidly exposed plates result in negatives which will hold their own in quality against any, whilst in every other respect, there is everything to lose in "slow" or time exposures. There are cases, of course, when time exposures are admissible, and even necessary, as in certain grey-day landscapes, but when dealing with figures or portraits in good light, let the exposure be as quick as possible, ere the freshness and naturalness of the model be lost.