I love your school quizes. When I got a Continuing Education Grant as an adult, to study photography, it was very hard to take instruction from instructors of lesser experience. In the end, of course, I was to profit from such simple things like: What is a camera? A: A light tight box that holds filmn and supports a lens. It is the understanding that students know the simplest express manner to explain an understanding that we can then progress to greater and more profound understandings. A Focal Plane shutter is close to the film plane. Steve Shapiro, Carmel, CA ----- Original Message ----- From: "ADavidhazy" <andpph@xxxxxxxxxxxxxxxxxx> To: "List for Photo/Imaging Educators - Professionals - Students" <photoforum@xxxxxxxxxxxxxxxxxxxxxx> Cc: <andpph@xxxxxxxxxxxxxxx> Sent: Wednesday, November 17, 2004 2:48 PM Subject: Quiz re: shutters - FYI > Something to ponder and for someone to possibly use ... andy > > > > Focal Plane shutters are located > > just behind the lens > inside the camera's lens > next to the diaphragm > close to the film plane > > > Kerr cells incorporate > > polarizers > RGB filters > ND filters > a photocell > > > Leaf or diaphragm shutter exposure times are calibrated with > > the lens wide open at 50% light level > a .3 ND filter > shutter set to 1/500 second > at f/32 > > > The ability to achieve short exposure times with 35mm cameras is associated > with: > > Focal Plane shutters > Leaf or Diaphragm shutters > Kerr cells > Venetian Blind shutters > > > Easy interchangeability of lenses is associated with: > > Focal Plane shutters > Leaf or Diaphragm shutters > Kerr cells > Venetian Blind shutters > > > The ability to synchronize with flash at all speeds is associated with: > > Focal Plane shutters > Leaf or Diaphragm shutters > Kerr cells > Venetian Blind shutters > > > Possible distortion of fast moving subjects is associated with: > > Focal Plane shutters > Leaf or Diaphragm shutters > Kerr cells > Venetian Blind shutters > > > If digital cameras incorporate a mechanical shutter it is usually a: > > Focal Plane shutter > Leaf or Diaphragm shutters > Kerr cells > Venetian Blind shutters > > > Malfunctioning focal plane shutters tend to produce: > > uneven exposure > no exposure > overexposure > underexposure > > > A shutter that overexposes by 100% increases exposure over normal by: > > 1 EV or stop > 2 EVs or stops > 3 EVs or stops > undefined amount > > > A shutter that consistently underexposes by 100% causes the film to receive: > > 1 stop underexposure > 2 stops of underexposure > 3 stops of underexposure > no exposure > > > A .3 Neutral Density filter transmits what percentage of light incident on it?: > > 10% > 50% > 100% > 200% > > > In a given situation an automatic camera's shutter delivers perfect exposure > at f/8 and 1/1000 second but when it is used under 1/100 the amount of light > present for that case it exposes at f/8 for 1 second. The second exposure is > off by about: > > 1 EV or stop > 3 EVs or stops > 6 EVs or stops > 10 EVs or stops > > > The rule of thumb is that to ensure sharp photographs the exposure should not > be longer than: > > 1/ISO speed of the film > 1/the f number of the lens > 1/the focal length in inches > 1/the focal length in mm > > > Modern focal plane shutters maintain even exposure across the film plane by: > > putting increased drag on the accelerating curtain > adjusting lens f/number during exposure > increasing slit width proportionally to the increase in curtain speed > decreasing slit width proportionally as curtain speed increases > > > Achieving a 100% efficient shutter leaf shutter is impossible because: > > these shutters are not capable of short exposure times > the shutter is located between the lens elements > the shutter first has to open 50% before reaching full aperture > it takes time to open and close the blades > >
