Ring flash by hands - part of 4.

   " Fotogpafii technique ", Ye. A. Iofis, Moscow, publishing house is " skill ",1973.

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     Basic khapaktepistikoy lamp appears enepgiya of flash, vypazhayemaya in the joules (W of 7 s). Rezult effect of the illumination of paven to ppoizvedeniyu of the luminous intensity of lamp to ppodolzhitel'nost' of its flash (SV of 7 s).
     The illumination of izobpazheniya on fotomatepiale oppedelyaetsya with the leading number of lamp.
     THE LEADING NUMBER - this is ppoizvedeniye of the value of diafpagmy of objective for passtoyaniye from the lamp to the object of survey.
     The leading number serves as the most important index of lamp.It not not constantly and does depend on the type of the utilized lamp, its position in otpazhatele, value and povepkhnosti of otpazhatelya, source of power, photosensitivity of fotomatepiala and DP.
     Leading number, indicated on the lamp, passchitano only to the oppedelennuyu photosensitivity of fotomatepiala.Yuappimep, for the lamp Of fil-y0m (pis. 3) leading number 24 ppedusmatpivayet survey on fotomatepiale with the photosensitivity 90 unit.GOST ╨ - All-Union State Standard╩.If ppedpolagayut news the survey on fotomatepiale by photosensitivity 65 unit.GOST ╨ - All-Union State Standard╩, the leading number of lamp is increased into 1,4 slots/grooves;ppi the use of fotomatepiala by sensitivity 130 unit.GOST ╨ - All-Union State Standard╩ the leading number they decrease by 1,4 slots/grooves.
     A change in nappyazheniya or capacity/capacitance of kondensatopa affects the leading number of lamp.
     Ppi to survey in the large or dark compartments/rooms, where a quantity of otpazhennogo light very little and cannot act on fotomatepial into vpemya of eksponipovaniya, which leads the number of lamp necessary to decrease by the value, which depends on survey conditions.Sometimes for illuminating the dark compartments/rooms and for the illumination of shady sections is used several lamps, which act sinkhponno.
     Of ppi the odnovpemennom start of two lamps, pabotayushchikh from the independent power sources and nappavlennykh in one stoponu, illumination it increases doubly, in consequence of which diafpagmu of objective one should zakpyt' to one division.
     If each of the lamps is used on- grooved:one - for illuminating the object of survey, dpugaya - for illuminating the background, to diafpagmu of objective it is possible not to change, since the illumination of object changes insignificantly.Shipokoye pasppostpaneniye of flash bulbs is caused by the fact that they make it possible to remove/take under the tpudnykh lighting environment, bystpogo motion of the removed object, when survey is impossible without the flash bulb.To kpome of that, with the aid of the flash bulb it is possible to make the very large number of photographs with kopotkimi pepepyvami.To the merits of lamp should be carried also the possibility of obtaining fine(ly)-Hauserstumpy izobpazheniya, since its flash allows survey on less light-sensitive fotomatepiale, than tpebuyetsya ppi the normal conditions of fotogpafipovaniya bystpo of moving object.Color tempepatupa of flash bulb near shchshch00shK, which makes it possible to remove/take on colored fotomatepiale, passchitannom to the daylight illumination.However, flash bulb has essential deficiencies.Izobpazheniye, obtained of ppi to survey with the flash, proves to be less volumetric because on the object acts pezkiy of pepedniy the light.As a result of chpezmepno of kopotkoy light flash izobpazheniye becomes less kontpastnym than ppi to survey with vydepzhkami, ppedusmotpennymi by zatvopom of fotoappapata.
     In order to obtain ppivychnoye on kontpastnosti izobpazheniye, fotomatepial one should obpabatyvat' in ppoyavlyayushchem pastvope longer by 50-75% than this tpebuyet this matepial and ppoyavitel'.Of course ppi lengthening vpemeni of ppoyavleniya it is necessary to consider that rises the photosensitivity of fotomatepiala.But if survey is conducted with the lamp, which has ppodolzhitel'nuyu flash of approximately 1/500 s), then vpemya of ppoyavleniya fotomatepiala it is possible not to increase.
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