General Information

Serial #

N/A

Part Number

7

Total Parts

9

AKA

cap

Patents

N/A

General Description

metal (probably brass)

Dimensions

Note: These reflect the general size for storage and are not necessarily representative of the object's true dimensions.

Length

N/A

Width

N/A

Height

5.3 cm

Thickness

N/A

Weight

N/A

Diameter

2.5 cm

Volume

N/A

Lexicon

Group

Exploration and Survey

Category

Photogrammetry

Sub-Category

N/A

Manufacturer

AKA

Wild

Country

Unknown

State/Province

Unknown

City

Unknown

Context

Country

Canada

State/Province

Ontario

Period

c. late 1960s- early 1990s.

Canada

Accessory used with Wild A8 Autograph [2004.1361], used in Canada's national mapping program c. 1960s-early 1990s, an example of one of the last analogue plotting devices used by the Topographic Service of Canada. With the exception of the Wild A10 [few of which were used in Canada], the A8 was the most sophisticated plotter available before digital technology.

Function

To protect magnifier eyepiece when not in use; can be used to limit observer's field-of-view when fitted to magnifier.

Technical

Cover for magnifier or eyepiece for centring device used with A8 model (also A7, and possibly other models] plotter. The two holes in the light box top match the two holes on the camera body where the plate holder sits. When using the plotter for aerotriangulation or plotting, the operator would set the plate carrier on this device and use it to centre the film positives [this is called "inner orientation"]. [Ref.2] Fiducial marks for all widely used types of aerial cameras are located on the picture carriers: because preparation of the images is done on the light box [as opposed to the plotter itself], an assistant can prepare images in advance, for rapid fitting to the plotter. Four magnifiers allow operator to independently view and match markings on images with picture carrier. (Ref. 3) The magnifiers can be adjusted within their body tube, and come with an eyepiece cover.

Area Notes

Unknown

Details

Markings

None evident.

Missing

None.

Finish

Metal (probably brass) cover has darkened finish. Edge is crosshatched, to improve grip.

Decoration

N/A