Do we get to know how we did? S. Shapiro, Carmel, CA ----- Original Message ----- From: "lea" <lea@xxxxxxxxxxxxxxxxx> To: "List for Photo/Imaging Educators - Professionals - Students" <photoforum@xxxxxxxxxxxxxxxxxxxxxx> Sent: Wednesday, November 17, 2004 6:12 PM Subject: Re: Quiz re: shutters - FYI > Just when you think you know a lot about photography read this quiz and > see how much you really know. > > Ugh. > > But on the up side...you don't have to know how a clock works to tell > time. Of course the more you know the funner it is..... > > Lea > > ----- Original Message ----- > From: "SteveS" <sgshiya@xxxxxxxxxxxx> > To: "List for Photo/Imaging Educators - Professionals - Students" > <photoforum@xxxxxxxxxxxxxxxxxxxxxx> > Sent: Wednesday, November 17, 2004 7:53 PM > Subject: Re: Quiz re: shutters - FYI > > > > 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 > > > Xclose to the film plane > > > > > > > > > Kerr cells incorporate > > > > > > polarizers > > > RGB filters > > > ND filters > > > Xa photocell > > > > > > > > > Leaf or diaphragm shutter exposure times are calibrated with > > > > > > Xthe 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: > > > > > > XFocal Plane shutters > > > Leaf or Diaphragm shutters > > > Kerr cells > > > Venetian Blind shutters > > > > > > > > > Easy interchangeability of lenses is associated with: > > > > > > XFocal Plane shutters > > > Leaf or Diaphragm shutters > > > Kerr cells > > > Venetian Blind shutters > > > > > > > > > The ability to synchronize with flash at all speeds is associated > with: > > > > > > XFocal Plane shutters > > > Leaf or Diaphragm shutters > > > Kerr cells > > > Venetian Blind shutters > > > > > > > > > Possible distortion of fast moving subjects is associated with: > > > > > > XFocal 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 > > > XLeaf or Diaphragm shutters > > > Kerr cells > > > Venetian Blind shutters > > > > > > > > > Malfunctioning focal plane shutters tend to produce: > > > > > > Xuneven exposure > > > no exposure > > > overexposure > > > underexposure > > > > > > > > > A shutter that overexposes by 100% increases exposure over normal > by: > > > > > > X1 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: > > > > > > X1 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?: > > > > > > X10% > > > 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: > > > > > > X1 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: > > > > > > X1/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 > > > Xdecreasing 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 > > > Xit takes time to open and close the blades > > > > > > > > > > > > >
