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"DigiPhoto Guide For Beginners" is now availableThe MYTCARD METHOD for the book is now released free to the public
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 6. Taken with Kodak Supra 800-135 |
Making sensitive emulsion is a specialized technique; individual manufacturer has different level of achievement. As users ourselves, we do not need to understand the production procedure. The most important is to know that sensitive material has to go through an ageing process to build up its sensitivity which we call film speed. Film speed is based on its physical state, size of crystal, and super sensitizer technology. Size of crystal is the direct factor; the bigger crystal has a higher speed and coarser grain. Physical state and super sensitizer will raise the film speed without any slight effect on granularity. |
 7. Same negative enlarged to 48"X72", and this is a part of the enlarged image |
Exposure will affect the granularity, because when film is over-exposed, the developing procedure will reduce much more silver forming a bigger grain, this mistake can decrease the quality of film. Besides, if the film has been heated or kept for a long time after exposed, it would have the same type of problem. High temperature developer or excess agitation will accelerate the reducing process, the combination of silver atoms will be greater giving a coarse grain image. For good photo, besides choosing a high quality film, all process from exposure until the last part of film processing must be handled properly before we can have the optimum granularity of the film. |
 8. Part of Image 7 |
Image 6 to 8 is based on a photo with Kodak Supra 800 135/36, Image 6 is the full frame enlargement to 6"x9", Image 7 is part of the 48"x72" full frame enlargement. Image 6 & 7 are scanned according to the display size to avoid the upsizing or downsizing problem that affects our judgement. Image 8 is scanned from a small part from the same photo for Image 7, fixing the size to 330x220, maintaining the graininess phenomena. We are astonished with the granularity of Supra 800. |
  This shows the position of Image 7 on Image 6, and Image 8 on Image 7. |
According to Kodak information, rms granularity will be used for B/W Films, which is a measuring method. Print grain index will be used for Color films, because Kodak has decided that the granularity of Color Films are different from B/W Films, which would be better to judge from the final enlarged prints. |
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Graininess of Photo P.3/3 |
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