Home >> Cyclopedia Of Photography >> Flashlight Powders to Optical Lantern Illuminants

Cyclopedia of Photography

Flashlight Powders
Flashlight Powders The Chief Two Kinds Of Flashlight Powders Are (1) Pure Magnesium Powder And (2) Mixtures Of Magnesium And Other Substances. Magnesium Powder Used Alone Is Blown Through A Flame, The Brightness And Duration Of The Flash Depending Upon The Quantity Of Powder Burnt And Upon The Length Of ...

Focal Length
Focal Length (pr., F.ongueur Du Foyer ; Ger., Brennweite) The Distance Between The Centre Of A Lens And The Screen Or Plate Upon Which The Image Of A Distant Object Is Sharply Depicted. This Defini Tion, However, Is Only Correct In The Case Of A Very Thin Lens, In Which ...

Focal Plane Shutter
Focal Plane Shutter A Shutter That Works Immediately In Front Of The Plate, And Now Commonly Fitted To The Highest Class Cameras. It Is Believed To Owe Its Practical Form To B. J. Edwards, Who In 188 Published A Description Of His Apparatus ; But Some Eighteen Or Twenty Years ...

Focusing
Focusing (fr., Mise Au Foyer, Mise Au Point ; Ger., Einstellung) The Action Of Adjusting The Extension Of The Camera Until The Image Is Sufficiently Sharply Defined On The Ground-glass Focusing Screen. A Focusing Magnifier Assists In Determining When The Image Is Sharp By Allowing Slight Differences In Crispness To ...

Focusing Screen
Focusing Screen (fr., Verre Cloud, Glace Doucie ; Ger., Visirscheibe, Mattscheibe, Mattglas, Mattglasscheibe) The Screen Upon Which The Image Formed By The Camera Lens Is Focused, Before Exposing The Plate, In Order To Secure Sharp Definition. It Is Usually Of Glass Ground On One Side To A Matt Surface. Some ...

Formulae In Parts
"parts," Formulae In The System Of Stating Formulae In " Parts " Has Some Advantages. A " Part " May Mean Any Thing : A Drop To A Gallon In Liquids, Or A Grain To A Ton In Solids ; And As Long As One Keeps To The Same Unit ...

Frederic Scott Archer
Archer, Frederic Scott Born At Bishops Stortford, 1813, Died In Lon Don, May, 1857. He Invented The Wet Collodion Process In 1848, And Published Working Details In The Chemist, Dated March, 185r, His Own " Manual Of The Collodion Photographic Pro Cess " Following In 1852. His Process Practically Displaced ...

Frilling
Frilling A Trouble To Which Negatives Are Liable While Undergoing Treatment In The Various Solutions ; The Edges Of The Gelatine Film Leave The Glass Plate And Are Cockled. It Is Due To The Uneven Temper Ature Of The Solutions, Excess Of Soda Or Other Alkali In The Developer, Handling ...

Gas Cylinders
Cylinders, Gas Annealed Steel Cylinders, Tested Hydraulically To Withstand A Pressure Of 3,000 Lb. Per Square Inch, And Charged With Compressed Gas—oxygen, Hydrogen (generally, Coal-gas), Dissolved Acety Lene, Etc. Periodical Re-annealing Is Necessary, And The Gas Compressing Companies Will Not Take The Risk Of Filling Cylinders Unless Their Regula Tions ...

Gelatine
Gelatine (fr., Gelatine ; Ger., Gallerte, Gelatin) A Colloid Of Extremely Complex Nature, Con Taining Carbon, Hydrogen, Nitrogen, And Oxygen, With A Small Proportion Of Sulphur. It Is Known Commercially In Fine Shreds Or Thin, Flat Sheets, Marked With The Diamond Pattern Of The Strings On Which It Is Dried. ...

Gelatine Reliefs
Gelatine Reliefs Probably More Ingenuity Has Been Displayed In Devising Processes For Making Gelatine Reliefs To Serve As Printing Surfaces Than In Any Other Form Of Photo-mechanical Work, And Yet There Is Not One Of These Processes That Is In Regular Commercial Use At The Present Day. These Pro Cesses ...

Geological Photography
Geological Photography Photography As Applied To Geological Inves Tigation May Be Roughly Classed Under The Following Headings : (i) Photographs Showing Plains, Valleys, Escarpments, Base Levels, Moun Tains, Lakes, Rivers, Glaciers, Etc., Taken For The Purpose Of Illustrating The Origin Of Landscape, And The Action Of Atmospheric And Other Pro ...

Glass
Glass (pr., Glace, V Erre ; Ger., Glas) Ordinary Glass Is A Fused Mixture Of Silicates Of Calcium Or Lead With The Silicates Of Sodium Or Potassium. While Practically Unaffected By Acids, Except Hydrofluoric, It Is Attacked By Strong Alkalis, Which Dissolve Out The Silica. Some Glasses Are Yellowed By ...

Gold Toning
Gold Toning (pr., Virage D L'or ; Ger., Tonen (schanen) Mit Goldsalz) The Purpose Of The Gold Toning Bath Is To Convert The Somewhat Unpleasant Yellowish Red Colour Of The Fixed Silver Image Into A More Pleasing Brown, Purple Or Bluish Purple. This Has Been Erroneously Described As " Gilding," ...

Grain In Negatives
Grain In Negatives In The Early Days Of Rapid Plates A Grain Was Perceptible In The Negative, It Being Coarser As The Speed Of The Plate Increased ; But The Defect Has Now Almost Vanished, Although It May Still Be Produced Under Certain Conditions. " Grainy " Negatives Are More ...

Group Arrangement
Group Arrangement There Is Some Truth Underlying The Saying That " Two Are A Group, Three A Crowd." The Difficulty Of Securing A Perfect Rendering Of A Single Figure Is Enormously Added To By Every Further Addition. In Fact, When Many Figures Are To Be Included At The Same Time ...

Gums And Resins
Gums And Resins The Photographer Uses Gums And Resins Chiefly In The Form Of Varnishes. Amber, A Fossil Resin, Ranging In Colour From Colourless To Reddish-brown, Is Slightly Soluble In Ether And Turpentine ; Treated In The Same Way As Copal In Varnish Making, It Dissolves In Turpentine, Petroleum And ...

Guttapercha
Guttapercha (pr. And Ger., Guttapercha) A Natural Product Having Many Similarities To Indiarubber, But Capable Of Being Made Plastic And Malleable By Heat, And Retaining, When Cold, Any Shape Given It While Hot. Whereas Gutta Percha Is Plastic, Indiarubber Is Elastic ; And Whereas Indiarubber Easily Combines With Sul Phur, ...

Haddons Formulie
Haddon's Formulie Many Useful Formulm Due To A. Haddon Are In Use, Three Of The Best Known Being Given Below : Reducer For Negatives And P.o.p.—this Con Sists Of Potassium Ferricyanide And Ammonium Sulphocyanide, And Is Compounded As Follows : For Negatives— Potassium Ferricyanide Io Grs. I I G. Ammonium ...

Halation
Halation (fr., Halation, Aureolage ; Ger., Licht Fleck) A Halo-like, Blurred Effect, Frequently Seen Surrounding A Brightly Lit Portion Of A Photo Graphic Image, Caused Either By Reflection From The Back Of The Glass Plate Or By Lateral Spread Ing Of Light In The Film. The Defect Has Been Observed ...

Hand Camera
Hand Camera (fr., Chambre A Main, Chambre Detective ; Ger., Handhamera, D Etectiv Hamer A, Geheimhamera.) A Camera Sufficiently Light And Portable To Be Used In The Hand, Instead Of On A Stand. A Collapsible Pocket Camera Having A Cloth Body Was Suggested By Edwards As Early As 1855. In ...

Hardeners
Hardeners Solutions Used For Hardening The Films Of Gelatine Negatives And Prints With The Object Of Preventing Frilling And Blistering. Their Use Is Not So Necessary Now As It Was In The Early Days Of Gelatine Plates And Papers, As Means Of Hard Ening The Gelatine During Its Manufacture Are ...

Henry Fox Talbot
Talbot, Henry Fox Born 1800, Died September 17, 1877. Retired From Public Life In 1834 To Devote His Whole Time To Scientific Work. While Sketching At Lake Como With Wollaston's Camera Lucida In October, 1833, He Was Struck With The Idea Of Fixing Images Produced By That Instrument, And Six ...

Holiday Photography
Holiday Photography There Are One Or Two Special Considerations That Press For Attention In The Case Of Photo Graphic Work Undertaken During A Holiday. Frequently The Work Then Done Is Of Special Interest And Importance, And Any Failure Is More Serious Than In The Case Of Work Which Can Easily ...

Hydroquinone
Hydroquinone (fr., Hydroquinone ; Ger., Hydrochinon) A Developer, Known Also As Hydrokinone, Hydrochinone, And Quinol. The Use Of Hydro Quinone Was Suggested By Sir William Abney In 1880, But It Was Not Possible To Bring It Into General Use At That Date Owing To Its Expense. Since Then, However, Manufacturers ...

Hygiene In Photography
Hygiene In Photography Photography Does Not Now Involve Many Risks To Health, But It Is Necessary To Remember That There Are Still A Few Chemicals Used Which Injure The Worker's Hands If They Come In Contact With Them, And Of Which The Fumes Become Dangerous If Inhaled. Should The Dark-room ...

Incorrect Exposure
Exposure, Incorrect Correct Exposure Is The Basis Of All Successful Work In Photography. But In Some Subjects, Especially Those With Moving Objects Or Very Dark Interiors, It May Be Impossible To Expose Sufficiently Long ; And Occasionally Errors Of Judgment May Lead To Both Under- And Over Exposed Plates. Incorrectly ...

Indiarubber
Indiarubber (fr., Caoutchouc ; Ger., Kaut Schuk) Synonyms, Caoutchouc, Gum Elastic, Rubber. Insoluble In Water And Alcohol, Soluble In Carbon Disulphide, Chloroform, Benzene, Etc. A Natural Product, The Coagulated Juice Of Various Plants Belonging To The Natural Order Euphorbiacece. It Occurs In Brownish Black Cakes, Balls Or Hollow Shaped Pieces. ...

Indoor Photography
Indoor Photography Apart From Actual Studio Work, A Good Deal Of Photography Can Be Done Indoors In Almost Every House, And That Without Any Elaborate Or Unusual Addition To The Ordinary Outdoor Apparatus. Flashlight Work Comes Under A Special Category. A Good Deal Can Also Be Done Nowadays With The ...

Ink Printing
Ink Printing Poitevin's Pigment Process Depends Upon. Three Facts : Ferric Chloride Renders Gelatine Insoluble, Ferrous Chloride Has Not That Effect, And Light Converts The Ferric Into The Ferrous Chloride. If Paper Is Coated With Gelatine And Ferric Chloride, Printed Under A Negative, And Placed In Warm Water, The Shadow ...

Instantaneous Photography
" Instantaneous " Photography The Term " Instantaneous " Is Loosely Used In Photography, Being Generally Understood To Refer To Exposures Of Less Than One Second. The Photographing Of Ordinary Views " Instanta Neously " Was Vainly Attempted By Daguerre In 1841, And The First Authenticated "instanta Neous " Photograph ...

Intaglio Printing
Intaglio Printing Any Method Of Printing In Which The Lines, Dots, Grain, Or Other Elements Of The Engraving Are Sunk In The Plate, So That The Depressions Are Filled With Ink For Printing, As Distinguished From Relief Plates Or Blocks Where The Printing Elements Are Raised And Are Inked On ...

Intensification Of Negatives
Intensification Of Negatives (fr., Renforcement ; Ger., Verstdrkung) A Process Whereby Density Or Contrast Is In Creased. Intensification Processes In Common Use Vary In The Degree Of Strengthening Rather Than In Their Character ; With Slight Exceptions They Do Not Change The Gradation, But Strengthen All Parts Of The Scale ...

Intensification With Copper
Copper, Intensification With A Process For Intensifying Gelatine Negatives. A Solution Of Bromo-iodide Of Copper Is Prepared As Follows : Copper Sulphate . Zoo Grs. 76 G. Water . . . 3 Oz. R,000 Ccs. When Dissolved, Add With Constant Stirring The Following, Which Must Also Be Dissolved : Potassium ...

Isochromatic Photography
Isochromatic Photography Photography In Which Colours Are Rendered In A Monochrome Picture According To Their True Visual Brightness. Known Also As Orthochro Matic Photography. It Is Well Known That Yellow Or Red Objects Appear Very Dark In An Ordinary Photograph. The Ordinary Plate Is Chiefly Affected By Violet And Blue ...

Isochromatic Plates
Isochromatic Plates Plates Specially Sensitised For Colour, And Used With Compensating Light Filters Or Isochromatic Screens. They May Be Roughly Grouped Into Three Classes : (i ) Those Which Are Sensitised For Green And Yellow Rays Of Light, And Give An Approximately True Colour Rendering ; (2) Those Which Are ...

Isochromatic Screens
Isochromatic Screens Only Those Rays Of Light That Are Visible To The Eye Should Be Allowed To Affect The Photographic Plate ; Besides The Visible Rays Of The Spectrum, There Are Two Sorts Of Invisible Ones—the Ultra Violet And Infra-red—situated Respectively Before The Violet And After The Red Rays. The ...

Isotypie
Isotypie A Process Of Half-tone Negative Making Pro Posed By Vittorio Turati, And Expounded In An Elaborate Treatise. The System Depends On The Use Of Variously Shaped Diaphragms In Con Junction With A Suitable Screen Distance. The Latter Is Determined By Means Of What The Inventor Termed A " Finder ...

Ivorytype
Ivorytype An Imitation Of Prints Upon Ivory. The Working Directions Arc As Follow : Select A Print Upon Plain Salted Paper, Strong And Brilliant ; Prints From Flat Negatives Do Not Give Pleasing Effects. Edge A Glass Plate With Mountant To The Extent Of About I In. ; Damp The ...

Joseph Bancroft Reade
Reade, Joseph Bancroft Born At Leeds, 18o1 ; Died At Bishopsbourne, 187o. Chemist, Microscopist And Photographic Experimentalist And Discoverer. He Was The First To Employ " Hypo " As A Fixing Agent (x837), And Tannin As An Accelerator ; He Was Also The First To Produce A Negative On Paper ...

Kallitype
Kallitype A Printing Process Invented By Dr. W. J. Nichol In 1899. Paper, Coated With A Mixture Of A Ferric Salt And Silver Nitrate, Gives, On Expo Sure To Light Behind A Negative, An Image In Ferrous Oxalate And Silver Oxide Which, On The Application Of A Suitable Developer, Precipitates ...

Kinemacolor
Kinemacolor A System Of Producing Kinematographic Pictures In Colour, Devised By Charles Urban And G. Albert Smith. Only Two Colour Filters Are Used, Both In Taking The Negatives And In Projecting The Positives, But The Projected Pictures Exhibit A Remarkable Range Of Intermediate Tints, Due Partly To The Fact That ...

Kinematograph
Kinematograph A General Outline Of The Whole Process Or Manner Of Taking And Projecting Kinematograph Pictures Must Be Given To Render Intelligible A Description Of The Necessary Mechanism. Briefly, The Camera Consists Of A Light-tight Chamber Fitted At The Top With A Magazine For Holding A Long Roll Of Negative ...

Kinematography
Kinematography The Art Of Photographing Objects In Motion And Projecting The Images Upon A Screen. It Derives Its Origin From A Toy Called The " Zoetrope " And Depends For Its Results On What Is Known As " Persistence Of Vision." When Light Is Reflected From A Moving Object It ...

Kite Photography
Kite Photography (fr., La Photographie Par Cerf-volant ; Ger., Drachenphoto Graphie) Photography By Means Of A Camera Attached To, Or Suspended From, A Kite Is Of Frequent Use In Obtaining Bird's-eye Views For Military Pur Poses, And As An Aid To The Surveyor And Meteor Ologist. A. Batut, Of Enlaure, ...

Labelling Bottles
Labelling Bottles Special Care Is Necessary In Labelling Bottles That Are To Contain Photographic Chemicals. First Make The Outside Of The Bottle Per Fectly Clean And Dry ; Use Gummed Labels, Or Attach By Means Of Liquid Gum, And Smooth Into Close Contact. When Quite Dry, Write On The Label ...

Lamplight Effects
Lamplight Effects Lamplight Scenes Which Do Not Include Figures Present No Difficulty, Providing A Suffi Ciently Long Exposure Can Be Given. Out-of-door Lamplight Effects Are Described Under The Heading " Night Photography." Indoor Lamplight Effects, With Figures, May Be Obtained By Concealing A Piece Of Magnesium Wire In The Lamp, ...

Landscape Photography
Landscape Photography In Modern Landscape Photography The Hand Camera Has Naturally Taken A Very Prominent Place, But It Must Be Recognised That The Best Work In Landscape Photography Results From Studying And Arranging The Picture On The Focusing Screen, This Generally Involving The Use Of A Stand. As On Many ...

Lantern Slides
Lantern Slides Transparent Positives, For Projecting By Means Of The Optical Lantern, Are Made In England To A Standard Size Of 3+ In. Square. Specially Prepared Slow Plates Are Used, The Object Being To Secure A Fine Transparent Quality In The Image, Combined With Good Rendering Of Gradation And Cleanliness ...

Latent Image
Latent Image (fr., Impression Latente ; Ger.,,latentes Bild) The Action Of Light Upon Many Sensitive Sub Stances Is At Once Visible By A Change Of Colour, As In The Darkening Of Silver Or Bichromate Salts On Paper. This Is Known As A Direct Light Action. In Other Cases There Is ...

Latitude Of Plates And
Latitude Of Plates And Papers In Negative-making Variations May Be Made In Exposure, Within Moderate Limits, Without Any Loss Of Printing Qualities. The Latitude Is, However, Influenced Considerably By The Subject And The Conditions. A Subject With Good Con Trast, Or Exposed In A Clear And Brilliant Light, Will Allow ...

Lengthening Camera
Lengthening Camera For Copying, And In Photographing Small Objects At Close Quarters, The Bellows Extension Of An Ordinary Camera Sometimes Proves Insufficient. The Professional Photographer In Such A Case Makes Use Of A Wooden Tube Or Cone, Fitting On The Front Of The Camera And Carrying The Lens At The ...

Lens Mounts
Mounts, Lens Photographic Lenses Are Usually Mounted In Brass, But In Certain Cases, Especially With Tele Photo Combinations, The Lighter Metals, Alumin Ium Or Magnalium, May Be Used. The Iris Dia Phragm Should Be Made Of Metal, Especially In A Lens For Use In An Enlarging Lantern, As The Heat ...

Lettering Negatives And Prints
Lettering Negatives And Prints The Advantage Of Lettering A Negative Rather Than A Print Is That The Work Requires To Be Done But Once, And Then Any Number Of Prints Can Be Made, Each With The Lettering Printed Upon It. The Usual Way Of Writing On A Negative To Produce ...

Levelling Slab
Levelling Slab (fr., Dalle D Niveler ; Ger., Nivellierplatte) A Flat, Smooth Plate Of Glass, Slate, Marble, Or Other Material, Either Attached To A Frame Work That May Be Levelled Accurately By Means Is Written In The Reverse Way With This Solution, Which Must Be Used With Care And Not ...

Light
Light (fr., Lumipre ; Ger., Licht) Light Is Generally Considered To Be Due To Minute Undulatory Waves In The Ether That Pervades All Space. The Molecules Of Any Luminous Body Are In A State Of Rapid Vibration, This Movement Being Communicated To The Adjacent Ether Particles And Transmitted By A ...

Lighting Of Landscapes
Lighting Of Landscapes An Astonishing Variety Of Effects May Be Obtained From The Same Landscape, Due Entirely To Differences In Its Lighting. Some Views Are Most Effective As Seen Under A Soft Grey Light, Whereas In Other Cases A Strong Lighting Gives The Best Result. In A Bright Light The ...

Limelight
Limelight An Illuminant For Use In Optical Lanterns, Etc., In Which A Spot On The Surface Of A Cylinder Of Lime Is Heated To Incandescence By A Gas Flame Fed With Oxygen Under Pressure. Oxyhydrogen Limelight Has A Photometric Value Of 16.6, As Compared With That Of A Multiple-wick Lamp ...

Lines In Composition
Lines In Composition What Are Spoken Of As Lines In The Composition Or Arrangement Of A Photograph May Not Exist As Actual Lines At All. For Instance, The Tops Of A Row Of Trees Would Not Be Connected By A Line, But They Would None The Less Suggest One. Simi ...

Lippmanns Process
Lippmann's Process A Process Of Colour Photography In Which The Phenomenon Of Stationary Or Standing Waves Is Utilised. The Process Consists In Exposing A Transparent Emulsion In Contact With A Reflecting Surface, Such As Mercury. Prof. Gabriel Lipp Mann First Used Taupenot's Albumen Process, And Krone, Who Has Been Extremely ...

Local Development
Local Development The Development Of Some Portions Of A Negative To A Greater Extent Than Others. There Are Two Methods Of Working, Opposite In Their Character And Effect. The First, Which Is More Correctly Termed " Local Development," Consists In Applying To Certain Parts Of The Negative A Stronger Solution ...

Lumiere Colour Processes
Lumiere Colour Processes Reference Is Made Elsewhere To The Starch Grain Process (see " Autochrome Process " And Screen-plate Colour Photography "), But The Brothers Lumiere Had Worked Out Various Processes Before This. In The Bleach-out Process They Suggested (1894) The Use Of Cyanine, Quino Line Red And Turmeric, And ...

Luminous Photographs
Luminous Photographs Photographs Which Appear Luminous Or Phos Phorescent At Night. They May Be Prepared In Several Ways. The Simplest Is That Of Making A Positive Transparency—as, For Example, A Lantern Slide—varnishing The Film Side, And Coating With Luminous (balmain's) Paint. When Dry, The Transparency Is Backed With Thin Wood ...

Magnesium Ribbon Or Wire
Magnesium Ribbon Or Wire Metallic Magnesium In The Form Of Ribbon Or Wire. Lamps Are Supplied For Holding The Ribbon, But It Is Sufficient To Cut Or Break Off The Length Required, Hold In Pincers Or In Any Other Way, And Apply A Light. The Ribbon Will Give Slightly More ...

Making Up Solutions
Solutions, Making Up The Method Of Making Up Photographic Solu Tions Should Not Be A Haphazard One. The Salts, In Making Up A Stock Solution, For Example, Must Not Be All Placed In A Dry Bottle And The Water Added, For This Conduces To Slow And Often Incomplete Solution. Another ...

Marine Photography
Marine Photography The First Supposed Successful Instantaneous Photograph Is Of A Marine Subject—new York Harbour, Taken In The 'fifties. In The Same Year Baron Gros, Of Athens, Made Some Daguerreo Types Of Breaking Waves On The Shores Of Greece —in Phalerum Bay. Marine Work In General Resembles Other Hand Camera ...

Masking Lantern Slides
Lantern Slides, Masking, Binding, And Spotting When A Lantern Slide Is Developed, Fixed And Washed, It Requires Finishing In Such A Manner That It Can Be Shown Effectively In The Lantern, And Handled Without Injury. The Picture Requires Masking, That Is, The Portion Of The Plate Not Required Needs To ...

Medical Photography
Medical Photography Every Year Sees The Wider Application Of Photography To Medical Science. At The Present Day Photomicrography And Radiography Are Of The Very Greatest Importance, The First Making It Possible To Obtain A Permanent And Exact Record Of The Normal And Abnormal Appearance Of The Tissues, Of The Blood ...

Mercury Vapour Lamp
Mercury Vapour Lamp (fr., Lampe D Vapeur De Mercure ; Ger., Quecksilber Lampe, Quecksilberdampflampe) A Lamp In Which The Vapour Of Mercury In A Vacuum Tube Is Raised To Incandescence By The Passage Of An Electric Current. The Illus Tration Shows The Cooper-hewitt Lamp. In This, Four Tubes Are Supported ...

Methods Of Exposing
Exposing, Methods Of The Usual Methods Of Exposing Dry Plates In A Camera Are By Means Of A Cap Or Shutter. The Cap Method Was The Original One, And Although It Is Considered Old-fashioned It Still Has Advantages. In Landscape Work The Cap May Be Made Tp Serve As A ...

Metol
Metol (pr. And Ger., Metol) A Salt, Generally The Sulphate, Of Methyl Paramidophenol (oh)(nh According To Andresen, And Of Methylparamidometa Cresol Co According To Hauff. It Is A White, Greyish Or Pinkish-white Powder Easily Soluble In Water. When Mixed With An Alkali It Forms An Energetic Developer. Bromide) Is Often ...

Metol Hydroquinone Metol
Metol - Hydroquinone (m Etol Quinol) A Mixture Of Metol And Hydroquinone Is A Popular Developer, Being Clean In Working And Suitable For Most Kinds Of Plates And Bromide And Gaslight Papers. It Is Sometimes Known As Metol-quinol, Quinol Being Another Name For Hydroquinone. Scores Of One, Two, And Even ...

Micrometry
Micrometry The Measurement Of Minute Divisions Of Space. The Best Known Device For Obtaining Micro Metrical Measurements In Microscopy And Photomicrography Is The Stage Micrometer Ruled Into Lines To Rya Or O In., Or And Mm. A Fairly Accurate Estimation Of The Size Of An Object Can Be Made By ...

Microphotography
Microphotography The Production Of Photographs Of Micro Scopic Size By Means Of The Microscope. Micro Photographs Were At One Time Produced In Large Numbers For Inserting Into Penholders, Etc., But Since The Introduction Of Dry Plates Micro Photography Has Become Practically Obsolete. The Wet Collodion Process Is Essential For This ...

Microscope
Microscope (fr., Microscope ; Ger., Mi Kroskop) The Simple Microscope, Which Was The Earliest Type Of Instrument, Consists Of A Stand Provided With A Single Lens Or Combination Of Lenses Known As The Objective, Which Is Focused By Mechanical Means. This Type Of Microscope Is Still Used In Laboratories For ...

Mixed Or Combined Developers
Developers, Mixed Or Combined Mixed Developers—as, For Example, Hydro Quinone And Metol—have Become Popular. Developers Are Of Two Distinct Kinds : (1) Those That Give Detail Quickly And Density Afterwards ; These Include Metol, Rodinal, Etc ; (2) Those That Give Density First And Detail Gradually—for Example, Hydroquinone And Pyro. ...

Moonlight Effects
Moonlight Effects Real Moonlight Views Are Possible In Very Favourable Circumstances, But Most Of The So-called Moonlight Photographs Are Taken In Daylight, The Usual Method Employed Being To Take The Photograph With The Sun Facing The Lens, But Not Included In The View. A Cloudy Day Should Be Chosen And ...

Mountants
Mountants (fr., Colles ; Ger., Kleisters) The Adhesive By Means Of Which A Print Is Attached To Its Mount. Of The Very Many Mountants Available, Starch Is By Far The Most Widely Used, Yet It Keeps Badly And Is Unsuitable For Glazed Prints. A Glazed P.o.p. Print Mounted With Plain ...

Mounting
Mounting (pr., Montage; Ger., Einfassung) There Are Many Ways Of Sticking Down A Print Smoothly On A Support Or Mount, But All Of Them Are Not Necessarily Suitable In The Case Of Photographs, Where The Image Is Often Of Such A Character As To Be Readily And Seriously Affected By ...

Multiple Mounting
Multiple Mounting In The Simplest Form Of This Style Of Mounting A Trimmed Print Is Mounted On A Sheet Of Paper, Which Is Then Trimmed So As To Show A Narrow Margin All Round The Print. This In Its Turn Is Mounted On Another Sheet Of Paper, Preferably Already Laid ...

Natural History Photography
Natural History Photography The Equipment Of The Naturalist Photographer Largely Depends Upon The Subjects To Which He Intends To Devote Attention. (for Example, The Reader Will Find Further Useful And Suggestive Hints Under Such Headings As " Insects," " Fish," " Birds," Etc.) For Much Natural History Photography A Good ...

Negative Emulsions
Negative; Emulsions The Manufacture Of Negative Emulsions Is By No Means Such An Easy Matter As Positive Emulsion Making, But With Care Slow Emulsions Of Very Satisfactory Quality Can Be Produced. The Beginner Is Not Advised To Attempt Very Rapid Emulsions, As They Are Extremely Difficult. There Are Two Principal ...

Night Photography
Night Photography Photography By The Aid Of The Artificial Light Of Towns Or By That Of The Moon. The Practice Of Producing " Night Photographs " By What Is Known As A Double Exposure—a Very Short One By Day And Then By Leaving The Camera In Position And Giving A ...

Objective
Objective The Lens In Any Optical System—such As A Telescope, Microscope, Or Photographic Camera— Which Forms Or Projects An Image Either For Examination By Means Of An Eyepiece Or For Reception By A Sensitised Surface. The Objectives Of Ordinary Telescopes And Microscopes Are Usually Corrected For Visual Use Only, And ...

Oil Ozobrome
Ozobrome, Oil Oil Ozobrome Is A Modification Of Bromoil. A Bromide Print Is Treated In Such A Manner That The Altered Image Will Retain Greasy Ink While The Unchanged Portions Will Repel It. A Bromide Print Is Bleached In The Following Bath :— Ozobrome Pigmenting Solution . . . I ...

Omnicolore Plate
Omnicolore Plate This Is A Screen Colour Plate Of French Manufacture, The Patent Of Ducos Du Hauron And De Bercegorol. By Means Of A Printing Machine Two Lines In Greasy Ink Are Printed On Gelatinised Glass At Right Angles To One Another, Thus Leaving Little Rectangles Between The Lines Of ...

Optical Lantern
Optical Lantern An Appliance, Popularly Known As The " Magic Lantern," By Means Of Which Transparencies Are Optically Projected By Artificial Light Upon A Screen, The Diameter Of The Image Being Thereby Increased By From 24 To 15o Times. The Enlarging Lantern (which See) Is An Optical Lantern, But The ...

Optical Lantern Illuminants
Optical Lantern Illuminants Given In The Order Of Their Efficiency, Optica Lantern Illuminants Include The Oil-lamp, Incan Descent Gas, Acetylene, Limelight, And The Arc Lamp. Metallic Filament Electric Incandescent Lamps Are Also Used Occasionally, But These Share With The Oil-lamp And Incandescent Mantle The Disadvantage Of The Light Being Emitted ...