Depth

Series — page 8

A field says what an essay is about. A series follows one idea essay by essay — from the question that introduces it to the one that assumes all the others.
horizon1234the fifth pointcorrect from 23 cm, at 160 mm widecross-ratio 1.627695 at position 1 of 22

Chasles

  1. 1 Four points on a conic look the same from anywhere on it
1 essay · foundations
the ruler's markthe plan's markcorrect from 19 cm, at 160 mm wide46° across

Circleinsquare

  1. 4 The circle in the square wants a number
1 essay · construction
horizontread 1correct from 14 cm, at 160 mm wideelliptic · trace² 2.0000 · back after 4

Classify

  1. 1 Three kinds of map on a row of posts
1 essay · foundations
02401020304050degrees off the optical axis, inside the reprojected framemarks the target wants, per mark the source laid downone mark for one mark×5.49 at the edge68% of the source unusedcorrect from 6.7 cm at 160 mm wide

Composite

  1. 1 Shot on one surface, shown on another
1 essay · curved
an anchorcorrect from 19 cm, at 160 mm wideflat 1e-13 px · rolled 30.5 px

Composition

  1. 3 A projection of a projection
1 essay · foundations
drawn: 1.309 : 1subtended at the station point: 1.000000000 : 1the faint circle is the mean radius, for comparisonthe drawn centre sits 3.42 px from the axis's own mark

Cone

  1. 4 The sixty-degree cone of vision
1 essay · wrong
eye, on the axisa cone 29 cm across and 22 cm highthe design lies from 0.17 m to 0.47 m out

Conemirror

  1. 5 The cone that reads the floor
1 essay · mirrors
fitted conic: a circle to 1e-9stereographicdashed: the fit, not the samples

Conformal

  1. 1 Stereographic keeps every angle, and only stereographic
1 essay · curved
horizonthe middle of what is leftthe principal pointcorrect from 22 cm, at 160 mm widecrop 20% · centres 81 px apart

Crop

  1. 1 The centre of the picture is not the centre of the paper
1 essay · construction
fitted conic: 1.467 from being a circlecylinderthe samples, fitted

Cylinder

  1. 1 The cylinder, and the price of going all the way round
1 essay · curved
horizonequal stepshalve thetaper byworst error, in metres of depthequal steps to the horizon11.72 mhalve the remaining gap225.13 mtaper by eye347.80 mcorrect from 26 cm, at 160 mm wide34° across

Deptheye

  1. 4 Dividing depth by eye
1 essay · wrong
floorwallfloor 36.3° · wall 29.3°dihedral 6.9°

Divergent

  1. 2 The room a divergent picture is a photograph of
1 essay · conventions
projectorthe seatcorrect from 19 cm, at 160 mm wide23.6° worst

Dome

  1. 1 A projector that is not at the dome's centre
1 essay · curved
02468020406080angle off the optical axis (degrees)area scale, relative to the centreplanecylinderstereographicequidistantequal-areaequirect.measured by differencing on the spherethe plane leaves the frame

Fisheye

  1. 1 Every fisheye is a different rule
1 essay · curved
00.2500.5000.7501020406080angle off the optical axis (degrees)image radius, against the radius the same lens gives at 90°equidistantequal-areastereographicorthographicflat planeeach curve divided by its own radius at 90°54.0% apart at 45°

Fitlaw

  1. 1 Which rule a fisheye obeys, from straightness alone
1 essay · curved
centrefaint dots: before · solid: afterhomologyratio 2.4000

Fixedstructure

  1. 3 What a flat map leaves alone
1 essay · foundations
one platethe otherthe hingedrawn at 94.3° · reads as 100.0° or 86.6°an orthographic drawing of a foldtwo readings, 13.4° apart

Foldreversal

  1. 4 A drawn fold has a phantom
1 essay · parallel
the eyenear 0.90 mfar 4.20 mfocal 740 pxprincipal 345, 210

Frustum

  1. 2 Four numbers and a window
1 essay · pipeline
correct from 14 cm, at 160 mm wide33° · 0.20 m out

Grazing

  1. 1 The lamp a low shadow cannot locate
1 essay · light
correct from 14 cm, at 160 mm wide12×12 cells · worst 1.57 px

Gridcopy

  1. 1 Copying square by square
1 essay · construction

All essays