Better Light 7 Manuel D’Utilisation

Page de 99
87
  The philosophy of stopping down to f/32 (or smaller) that was often done with film and 
strobes is not the best practice for high-resolution digital capture. Most lens manufacturers 
say that the best overall image quality is obtained 2 f-stops below “wide open” (e.g. f/11 is 
best on a f/5.6 lens). As the lens is stopped down to small apertures (f/22, f/32,...) optical 
diffraction will reduce the optimal sharpness that the scan back is capable of recording.
  It is also possible to move the camera farther from the subject or change to a shorter focal 
length lens to make the image smaller in the frame and consequently increase the depth of 
focus. You can often crop into the frame and increase the resolution setting to capture an 
equivalent file size. This technique also reduces bellows extension and will increase usable 
light from less “bellows factor”. This can be especially helpful with close-ups of small prod-
ucts, such as jewelry. A shorter bellows extension also makes the camera more stable and 
reduces the possibility of any camera shake artifacts in your images.
Lighting
Lighting is the basis of all photography, of course, and is not a digital camera adjustment. Light-
ing is usually set up for a desired mood and emphasis, sometimes without much regard for the image 
capture technology. Digital cameras prefer plenty of light, and can produce exactly the mood and 
emphasis desired in the final image, even though the set itself may appear “too bright” to the pho-
tographer. Adding additional lighting can significantly decrease the required exposure, which should 
indirectly reduce background noise. When possible, moving the lights closer to the subject will also 
increase the light level at the rate of 1/2 distance = 2 EV (f-stop) gained (the Inverse Square Law). 
Fluorescent sources, or the new ceramic HID lamps, are beneficial since the lack of radiated heat 
allows the lamps to be used closer to the set.