[LargeFormat] will a darkslide skim across a pond from the shore?

[Ken Hough]

I'll try this,
Every transparent material has a refractive index. This includes metallic 
coatings. Unfortunately I do not have my book handy showing the angle for 
MF2 or the myriad of other alloys that make up multicoatings. The coatings
are tuned to the wavelength of light that they are to reflect.
Ken

From:           	"Dave Southwood" <lava@mweb.co.za>
To:             	<largeformat@f32.net>
Subject:        	[LargeFormat] will a darkslide skim across a pond from the shore?
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Date sent:      	Sun, 2 Dec 2001 23:03:40 +0200

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1)i have a basic knowledge of the physics which govern the passage of light through air, 
coatings and then into glass. what i would like to know, please, is what formula determines 
the maximum angle of incidence which light must have to the surface of the lens before it 
reflects, and does not penetrate and refract?

or in other words, by way of hypothesis: suppose a stone-skimmer were, with an
 identical action each time, skimming the same stone at the same spot on a surface of 
water while climbing a ladder. on reaching a certain rung his stone(having been flung) 
would penetrate the surface of the pond, the angle of incidence being too great for the tension 
of the surface to bear up under the force of the stone.

i know that the curvature of the lens affects things. how is this accomodated in the calculation
 of the aforementioned angle?

phew!

2)i have old linhof darkslides which are home to inordinate amounts of dust particles. would it 
be safe to wash the critters gently to try and make dust, which i think is coming from the fabric 
hinges, settle? either that or i am going to see if my technika skims off cape point, the situation is 
dire my friends. i have even employed my lungs and an empty ballpen case as a bellows-hoover,
 much to the delight of my assistant

3)i am a fine-artist preparing for a large solo exhibition called 'nothing in the particular' which draws 
a bit on the way an american LF user (hi, my name is stephen and ive been using LF since the tenth 
grade. all my friends said it wasnt very sharp......) called stephen shore saw the american landscape
 in the 70's. anyone, anyone, anyone else a fan? 

thanks





dave southwood
flat 1, coronation mansions
42 warren street
tamboerskloof
cape town
8001
south africa

+27 82 8543363 mobile
+27 21 4247992 home


        ******Ken Hough Photographic Repair******
         Specializing in Deardorff Refinishing
          Lens Recementing and Shutter repair
          Contribitor to McKeowns Price Guide
                   Deardorff Section
           Custom machined Photographic items
           Text Contents Copyright 1999 KHPR
          http://deardorffcameras.0catch.com/
                   Est. 1980