[2]The Stanley dry plate has all these qualities in the highest perfection.
It is most provoking to have an otherwise perfect negative marred or ruined by opaque or transparent spots appearing in its most important portions.
For development, ferrous oxalate or alkaline pyro are equally useful, and either may be employed, as suits the fancy or convenience of the operator. My own preference is for the latter, and I always use it with ammonia well restrained, having had no success with either soda or potash in this class of work. For all objects possessing much color it is best to continue the development until full density is obtained, but for very thin or transparent subjects, such as diatones or unstained vegetable tissues, it is far better to stop the development as soon as all details are out and resort to after-intensification, for which purpose bleaching with mercury followed by a ten per cent. bath of sulphite of soda will be found eminently satisfactory. I always use the alum bath, and invariably secure a clean negative of a cool gray color, resembling iron development.
Printing. The best ready sensitized paper can be depended on for producing satisfactory prints, showing the most delicate lines and markings of diatones and turning to any desired shade. Avoid over-printing, wash but slightly in two changes of water, the last slightly acidulated with acetic acid, and use an acetate of soda toning bath. Undesirable portions of the negative may be stopped out with a mat of suitablep236shape. Any ordinary cabinet card makes a neat mount of convenient size, upon which may be written the name of the object or specimen objective and magnification employed, and any other matter referring to print or negative which may be necessary to note.
A carefully kept note-book is a most important aid to the worker in photo-micrography, and it should contain all his failures and successes alike. Notes should be made of the specimen objective, magnification, exposure, plate and developer, which, carefully studied, will almost certainly enable him to secure a success with each exposure.
Lantern Slides.—It is well to make the negative as far as possible of a suitable size for producing the positive by contact printing, which is convenient and satisfactory, though there can be no doubt that reproduction in the camera affords better results. Slow gelatino bromide plates, such as Carbutt makes for this purpose, produce very satisfactory work, but the chlorides are so far superior that there can be little doubt of their being exclusively employed for positives in future. There is a richness of tone, combined with great transparency in the shadows and clear glass in the high lights, quite unattainable with bromide emulsions, and rivaling the best wet work.
Opaque Objects.—These may be photographed by the light from a lamp quite as well as transparent ones, through which the light is thrown, a matter of which I have thus far spoken only. A strong illumination must be obtained by the employment of a suitable bull's-eye condenser or a silvered reflector. Thep237most satisfactory method, however, is by sunlight, allowing its direct rays to fall upon the object without the intervention of any condenser whatever. Very short exposures suffice with such illumination, varied only by the reflecting capacities of the object itself. A successfully exposed plate of this class of objects will give a print of the subject, standing out most brilliantly upon a black ground.
To secure the best results, most objects should be specially mounted for photographing. Some are best in a resinous medium, such as Canada Balsam, but most tissues are obscured or entirely obliterated in this medium. So far as possible all preparations should be mounted in a fluid of some description that will distinctly render visible many tissues and markings which would be lost in balsam. This subject, however, is one of so great extent that it would require a special paper, and I merely refer to it now because of its importance, hoping at some future time to enlarge more fully upon it.
You will notice that my remarks have been confined to work that may be done with objectives of low or moderately high powers, in no case exceeding one thousand diameters, having preferred to speak only of that which I have demonstrated by actual work as being practical. From recent experiments I am fully convinced that the lamp light, such as I have described, is capable of producing satisfaction, work with very much higher powers, and shall hope, at no distant day, to show prints made from magnification of not less than two thousand diameters, that will be satisfactory in all respects.W. H. Wamsley.
W. H. Wamsley.
p238
When preparing for an outing, consider the kind of work you intend to do and select your plates accordingly.[3]If it is intended to make instantaneous exposures, get the most sensitive plates possible; those of the highest sensitometer number should be procured. For subjects from still life, inanimate objects, landscapes, etc., etc., slower plates are preferable. When filling your holders, carefully brush all dust from the surface of the plates, ascertain that the lenses are clean, and wrap them in chamois. Carry no useless weight.
[3]The Stanley lightning is particularly recommended to amateurs for all quick work.
When you have selected your standpoint, plant the legs of the tripod well apart to insure steadiness of support and make sure that the camera is level and firmly screwed to the tripod. If you use a drop shutter, slow exposures may be made by holding the slide in the hand and passing it down slowly over the opening in front of the lens. When using double holders mark the side exposed as soon as made. Carry a piece of cetaceum paper, which may be used as a substitute in case you break your ground glass. The head cloth may be used as a changing box by covering the holder and box of plates with it and folding the ends around the wrists, securing them by rubber bands; then proceed by the sense of feeling. Before exposing draw the slides, so that no light may enter the plate holder.
Be sure you are right, then go ahead.
Before developing plates that have been exposed instantaneously, let them soak a few minutes in waterp239with a small portion of soda or ammonia, then wash them and develop with the normal developer. Mr. Inglis suggests that for extra rapid exposures a very slow development with weak developer will give better detail and strength.
The paper films must be developed always with a strong developer to secure best results.
TRANSCRIBER'S ENDNOTE.Go to Coverpage.The headings in the Table of Contents do not necessarily correspond to headings in the text. A few examples will be mentioned. There is no heading for "PART I." in the text, though "PART II." is present. There are two headings "CAMERA BOXES" in the Table of Contents, but only one in the body. A second, matching one, has been added on page 110. The Table of Contents lists several types of pneumatic shutter for pp 124-129 that do not appear in the text under the same names.In the Table of Contents, under the level-three heading "GELATINO EMULSION" at page 38, the two level-four headings "Preparation of Glass" and "Coating Glass" occur in the text under a level-three heading "DESCRIPTION OF APPARATUS USED IN MAKING AND WASHING EMULSIONS." on page 44, which corresponds to a level-three heading in the Table of Contents "APPARATUS USED IN MAKING EMULSIONS". This heading seems to refer to the same section of text as the level-four heading "Apparatus for Making" in the Table of Contents under page 38.In the Table of Contents under heading at page 181, "How to Use the." was changed to "How to Use them." A few other such simple printing errors have been fixed silently.Some captions of images or tables function in situ as section headings; some of these have roughly corresponding entries in the Table of Contents.Section headings or captions of images or tables may also function in situ as part of the body text. In this html version, such captions and illustrations have been retained. Many images were originally embedded within paragraphs. Some such images were moved out of paragraphs to between or beside them, when such a move did not disrupt the text.In the table on page 43, showing the formulæ for gelatine emulsion, the fifth row duplicates the third row, probably erroneously.The name "Ever" appears in the table of contents twice, in connection with Emulsions C and D, under the section starting at p 38. This name is spelled "Eder" on pp 43 and 44.
The headings in the Table of Contents do not necessarily correspond to headings in the text. A few examples will be mentioned. There is no heading for "PART I." in the text, though "PART II." is present. There are two headings "CAMERA BOXES" in the Table of Contents, but only one in the body. A second, matching one, has been added on page 110. The Table of Contents lists several types of pneumatic shutter for pp 124-129 that do not appear in the text under the same names.
In the Table of Contents, under the level-three heading "GELATINO EMULSION" at page 38, the two level-four headings "Preparation of Glass" and "Coating Glass" occur in the text under a level-three heading "DESCRIPTION OF APPARATUS USED IN MAKING AND WASHING EMULSIONS." on page 44, which corresponds to a level-three heading in the Table of Contents "APPARATUS USED IN MAKING EMULSIONS". This heading seems to refer to the same section of text as the level-four heading "Apparatus for Making" in the Table of Contents under page 38.
In the Table of Contents under heading at page 181, "How to Use the." was changed to "How to Use them." A few other such simple printing errors have been fixed silently.
Some captions of images or tables function in situ as section headings; some of these have roughly corresponding entries in the Table of Contents.
Section headings or captions of images or tables may also function in situ as part of the body text. In this html version, such captions and illustrations have been retained. Many images were originally embedded within paragraphs. Some such images were moved out of paragraphs to between or beside them, when such a move did not disrupt the text.
In the table on page 43, showing the formulæ for gelatine emulsion, the fifth row duplicates the third row, probably erroneously.
The name "Ever" appears in the table of contents twice, in connection with Emulsions C and D, under the section starting at p 38. This name is spelled "Eder" on pp 43 and 44.