Sorry Anthony, to go on being pernickitty, but how does distance introduce haze?
D Dr E D F Williams http://personal.inet.fi/cool/don.williams Author's Web Site and Photo Gallery Updated: March 30, 2002 ----- Original Message ----- From: "Anthony Farr" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Tuesday, August 27, 2002 5:43 PM Subject: Re: Aerial photography question > Yes, anyone with a pernicketty bone in their body knows that a lens's focal > length has no direct bearing on perspective. But it is also true that each > particular focal length requires its own particular distance to subject to > maintain a constant subject reproduction ratio. So, while in theory and > fact you are correct, in real world practice photographers use focal length > choice as a tool for manipulating perspective. It's a win-win situation, > you can enjoy your correctness, yet the erroneous belief that focal length > and perspective are directly related still works successfully for the > ignorant masses ;-) > > BTW I was in fact referring to the haze that distance introduces. The > paragraph in question opened with this direct reference to haze, "Get as low > as the pilot will dare, because distance (and altitude) in aerial > photography introduce haze.". > > Regards, > Anthony Farr > > ----- Original Message ----- > From: "Dr E D F Williams" <[EMAIL PROTECTED]> > > > > Anthony writes 'tele shots from above will flatten out whatever precious > > little modelling you might have'. If he means that the lens will change > the > > perspective, he is wrong. If he means that haze will degrade the image he > is > > right. Light scatter from moisture, or other nastier particles, increases, > > the longer the path to the subject and contrast will suffer. > > > > But a telephoto lens does not change perspective - although this might > seem > > to be so. Trees in the distance, that might be miles apart seem bunched > > together in a picture taken with a 1000mm tele; or a picture down a long > > stretch of highway may seem to put cars, that may far apart, right next to > > one another. To demonstrate this, enlarge an area equivalent to that > covered > > by the telephoto lens of a landscape taken with a normal lens of the same > > scene. You will find the perspective matches - so does the contrast. Of > > course you have to ignore the increase in grain and loss of sharpness. > > > > D > > > > Dr E D F Williams > > > > http://personal.inet.fi/cool/don.williams > > Author's Web Site and Photo Gallery > > Updated: March 30, 2002 > > > >
