SCANNING

if you're going to be a good lookout you need more than a good pair of eyes a good pair of binoculars and a place from which you can look you must know how to look you can't glance haphazardly around the horizon you must follow a definite step by step search pattern so that you will cover thoroughly all of your sector of the sea or sky notice that this lookout pauses for a second or two at regular intervals this step-by-step scanning as you would see it through binoculars is the right way to do it untrained lookouts often do it incorrectly this is wrong the lookout is sweeping the horizon he is not using the step-by-step scanning pattern this illustrates how difficult it is to identify an object when the binoculars are moving while you can see large objects on the horizon you would be unable to detect small objects or ships far beyond the horizon and showing only a Thomas in the step-by-step scanning pattern the lookout pauses long enough to search an area carefully then he moves to the next overlapping area and searches it notice also that he returns quickly in a broad sweep to the starting point to repeat the scanning pattern the step-by-step pattern of scanning is actually the identical method your own eyes use in looking at any seem entirely unconsciously the eyes shift in short jumps from part to part as they take in a whole scene the brain has learned to partially disregard impressions received while the eyes are in motion so it is only while the eyes are fixed between jumps that visual impressions are made you will appreciate the basic soundness or common sense of the step-by-step scanning pattern when you know something of the structure of the eye only the front part of the eyeball of course is exposed light passes through the center of the iris diaphragm by opening the eyeball the location of the interior parts can be pointed out the transparent cornea passes light through the pupil or opening in the iris diaphragm the IRS contains the pigments giving eyes different colors light next passes through the lens and onto the retina to reach the retina the light passes through a transparent jelly-like substance represented here by the ball shaped part the retina is the receiving membrane of the eye and corresponds to the film and a camera images of objects directly ahead of the I fall on the center of the retina where the vision is clearest and sharpest with trained lookouts it has been found that in good light the pause for searching is about one second although it may be slightly longer for some individuals this one second pause allows the image to rest on the center or sharp vision portion of the retina long enough for the brain to comprehend it this is a demonstration of the step by step pattern as seen through binoculars it is only during the pause that the eyes can detect small objects on the surface or distant objects projecting above the horizon it is very important that the search areas overlap enough so that any marginal object missed in one pause will be sure to be included in the next each of these circles shows a seven degree area as it appears through your binoculars the standard Navy 750 binoculars cover a field of seven degrees a search pattern with a pause every 5 degrees along the horizon allows enough overlap for you to cover the horizon thoroughly having reached the end of your sector sweep rapidly back to the starting point to avoid a dangerously long lapse in searching any one area this search pattern is very easily used with the surface lookout alidade by pausing each five degrees as shown on the bearing dial all look out use the step-by-step method of search but the sky lookout applies it somewhat differently since she must search vertically as well as horizontally watch this look out as he applies the step-by-step method in a vertical direction on reaching a position angle of 25 or 30 degrees he leaves his binoculars at regular intervals and searches the remaining distance to the zenith with his naked eyes this speeds the search and helps to relieve his eyes of binocular strain this diagram shows how the sky lookout binocular pattern makes use of the same overlapping steps used in horizontal searching because of the wider field of the naked eyes the search to the zenith need be made only each third time up or each 15 degrees the broken circles showing areas already searched make a very tight pattern and show how thoroughly a well-trained sky look out searches his sector after completing the search sweep back to the starting bearing and begin again the search interval near the horizon is slightly longer because this is where planes are most likely to be discovered in clear weather in smaller ships there may be only one or two sky lookouts due to the extremely wide sectors at such a lookout must search he can use binoculars for only two or at most three steps above the horizon he searches the rest of the sky above position angle 10 or 15 degrees with his naked eyes this speed up in searching gets a look out back to his starting bearing without dangerous delay to be a good sky look out you must know more than how to search your sector properly before you can spot planes you must know how they look in different conditions since the enemy knows that you're trying to spot him while he's far away he'll try to make his approach from some region of the sky where you cannot spot him easily he tried to slip in concealed by clouds or smoke to make his attack from an unsuspected quarter when you know how planes look in varying conditions you can make your contact reports the instant you cite a plane you must be able to recognize a plane without a second's hesitation and report it immediately to enable your anti-aircraft batteries to ward off the attacks a distant plane heading directly toward you is especially difficult to spot this is due of course to the fact that you're looking at the edge of the wings and the frontal area is very small when the sun is in back of you planes may reflect enough light to stand out against the blue sky when the planes themselves are not brightly illuminated they will appear as dark objects almost in silhouette when such planes are seen in the distance against dark clouds you may lose sight of them blue sky appears dark when seen through some goggles for this reason lookouts wearing the variable density polaroid goggles should be very careful in adjusting them too much light control will darken the blue sky so greatly that a dark plane will be difficult to detect a plane difficult to spot against the dark sky will instantly become clearly visible when it crosses in front of a white cloud such clouds can be washed for planes which may show up against them the surface lookout uses a step-by-step method of search in practically the same way as it used by the horizon lookout however the surface lookout keeps the horizon just above the center of his binocular field and so is able to search the entire surface of the sea from very near his ship to the horizon the lookout can search the entire surface by moving his binoculars in a straight horizontal path due to the fact that the height of the binocular field is comparatively great notice that he pauses at close intervals by watching the alidade bearing dial which measures the movement of the binoculars we have visual proof of the thoroughness of the search the pauses are about 5 degrees apart each pause in the step-by-step method of search gives your eyes a chance to detect any object which doesn't fit into the whole picture you will soon become accustomed to using the search pattern and you'll find it with it you can cover a wide area in a fairly short time