Imperial Exposure Meter

1901

Early Model

Imperial Dry Plate Co. Ltd

Cricklewood

England

Image of Imperial Exposure Meter Early Model

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 600 H&D. Shutter speed: 1/250 - 90s. Aperture: f4.5 - f64.

Construction:

Green cloth cover.

Attributes:

Actinometer time: ½ - 128.

Identification:

Flowing script on cover.

With:

Packet of sensitive paper, price 3d.

Early Model

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 600 H&D. Shutter speed: 1/250 - 96s. Aperture: f5.6 - f64, US 2 - 256.

Construction:

Green cloth cover.

Attributes:

Actinometer time: ½ - 128.

Identification:

Flowing script on cover.

With:

Instructions (American).

Early Model, Italian

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 400 H&D. Shutter speed: 1/250 - 96s. Aperture: f5.6 - f64.

Construction:

Green cloth cover.

Attributes:

Actinometer time: ½ - 128.

Identification:

Flowing script on cover.

Early Model

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 600 H&D. Shutter speed: 1/250 - 96s. Aperture: f5.6 - f64.

Construction:

Green cloth cover.

Attributes:

Actinometer time: ½ - 128.

Identification:

Block typeface on cover. Plates listed (H&D speed): Special Sensitive 275, Special Rapid 225, Sovereign 180, Ordinary 90, Process 15, Lantern 6, Orthochrome Special Sensitive 275, Orthochrome Special Rapid 200, Orthochrome Non-Filter 200.

Notes:

Price: 50c.

With:

Instructions. Envelope with agents name - G. Gennert. Packet of sensitive paper, red wrapping 'Free with meter'.

Early Model

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 600 H&D. Shutter speed: 1/250 - 96s. Aperture: f5.6 - f64.

Construction:

Green cloth cover.

Attributes:

Actinometer time: ½ - 128.

Identification:

Block typeface on cover. Plates listed (H&D speed): Flashlight 300 - 350, Special Sensitive 250 - 275, Special Rapid 200 - 225, Sovereign 150 - 180, Ordinary 80 - 100, Orthochrome Special Sensitive 275, Orthochrome Special Rapid 200.

Notes:

Agents name on cover: G. Gennert. New York & Chicago.

No. 1 Bright Light

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 600 H&D;. Shutter speed: 1/500 - 60s. Aperture: f4.5 - f64, US 1 - 256.

Construction:

Green cloth cover.

Attributes:

Actinometer time: 1/5 - 100.

Identification:

Plates listed (H&D speed): Flashlight 300 - 350, Special Sensitive 250 - 275, Special Rapid 200 - 225, Sovereign 150 - 180, Ordinary 80 - 100, Orthochrome Special Sensitive 275, Orthochrome Special Rapid 200, Orthochrome Non-Filter 200.

With:

Instructions. 2 packets of sensitive paper (1920s), price 4d. Envelope for meter.

No. 1 Bright Light

Meter Type:

Actinometer.

Notes:

In unopened packet, NW2 address (after 1917). Price 1/6.

No. 1 Bright Light

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 600 H&D. Shutter speed: 1/500 - 60s. Aperture: f4.5 - f64, US 1 - 256.

Construction:

Green cloth cover.

Attributes:

Actinometer time: 1/5 - 100.

Identification:

Plates listed (H&D speed): Flashlight 400, Special Sensitive 275, Special Rapid 225, Sovereign 175, Ordinary 80 - 100, Orthochrome Special Sensitive 275, Orthochrome Special Rapid 200, Orthochrome Non-Filter 200.

No. 2 Dull Light

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 600 H&D. Shutter speed: 1/25 - 240s. Aperture: f4.5 - f64, US 1 - 256.

Construction:

Green cloth cover.

Attributes:

Actinometer time: ¼ - 120.

Identification:

Plates listed (H&D speed): Flashlight 300 - 350, Special Sensitive 250 - 275, Special Rapid 200 - 225, Sovereign 150 - 175, Ordinary 80 - 100, Orthochrome Special Sensitive 275, Orthochrome Special Rapid 200, Orthochrome Non-Filter 200.

Duplex Model

Meter Type:

Actinometer.

Calibration:

No 1 - Plate speed: 5 - 600 H&D. Shutter speed: 1/500 - 60s. Aperture: f4.5 - f64, US 1 - 256.
No 2 - Plate speed: 5 - 600 H&D. Shutter speed: 1/25 - 240s. Aperture: f4.5 - f64, US 1 - 256.

Construction:

Mauve cloth cover.

Attributes:

Actinometer time - No 1: 1/5 - 100. No 2: ¼ - 120.

Notes:

This is a war time issue bound in cloth rather than leather.

With:

Two instruction books. Packet of sensitive paper. In box marked 3/6.

Duplex Model

Meter Type:

Actinometer.

Calibration:

No 1 - Plate speed: 5 - 1000 H&D. Shutter speed: 1/500 - 60s. Aperture: f4.5 - f64, US 1 - 256.
No 2 - Plate speed: 5 - 1200 H&D. Shutter speed: 1/25 - 240s. Aperture: f4.5 - f64, US 1 - 256.

Construction:

Green leather cover, gold lettering.

Attributes:

Actinometer time - No 1: 1/5 - 100. No 2: ¼ - 120.

Identification:

NW2 postal address, after 1917.

Ilford Exposure Meter

Duplex Model

1935

Ilford Ltd

Ilford

England

Meter Type:

Actinometer.

Calibration:

No 1 - Plate speed: 5 - 1200 H&D. Shutter speed: 1/500 - 60s. Aperture: f2.5 - f64, US 1 - 256.
No 2 - Plate speed: 5 - 1200 H&D. Shutter speed: 1/32 - 240s. Aperture: f4 - f64, US 1 - 256.

Attributes:

Actinometer time - No 1: 1/5 - 100. No 2: ¼ - 120.

With:

Instruction books for No.1 and No.2. Packet of sensitive paper, blue wrapping 'Free with meter'. In box marked 3/6.

Duplex Model

1935

Meter Type:

Actinometer.

Calibration:

No 1 - Plate speed: 5 - 6000 H&D. Shutter speed: 1/500 - 60s. Aperture: f2.5 - f64, US 1 - 256.
No 2 - Plate speed: 5 - 1200 H&D. Shutter speed: 1/32 - 240s. Aperture: f4 - f64, US 1 - 256.

Attributes:

Actinometer time - No 1: 1/5 - 100. No 2: ¼ - 120.

Notes:

Retailer's label: J.H. Thompson, 23 Elm Grove, Southsea.

With:

Instruction books for No.1 and No.2. Packet of sensitive paper, blue wrapping 'Free with meter'. In box marked 3/6.

No. 2 Dull Light

1935

Meter Type:

Actinometer.

Calibration:

Plate speed: 5 - 1200 H&D. Shutter speed: 1/32 - 240s. Aperture: f4 - f64, US 1 - 256.

Construction:

Blue cloth cover.

Attributes:

Actinometer time ¼ - 120.

With:

Instructions. Packet of sensitive paper, red wrapping. Packet of sensitive paper, blue wrapping 'Free with meter'.

The Imperial is a simple actinometer made of card and bound as a book in cloth. Later two forms were issued, one for normal light the other for dull light. The two could be bought bound together known as the Duplex. The Actinometer time is judged in the normal way and the value set against the plate speed by moving a sliding scale, the exposure pairs could then be read. When introduced the price was 1/-, during World War I this rose to 1/6 and by 1924 it was 2/-. Imperial also produced a Reckoner which was a calculator type of meter. This was also produced bound up with the Actinometer. The meter was issued by Ilford following the takeover and integration of Imperial.

Variations

Early model - issued before the No.1 and No.2 designation. Flowing script on cover. Apertures to f4.5 or f5.6.
Early model - issued before the No.1 and No.2 designation. Block typeface on cover. Apertures to f4.5 or f5.6.
Later model - No.1 and No.2 designation. Block typeface on cover. Apertures to f4.5.
Later model - No.1 and No.2 designation. Block typeface on cover. Apertures to f2.5.
Ilford model - No.1 and No.2 designation. Block typeface on cover. Apertures to f2.5.

References & Notes:

BP 3873/1901. BJA 1935, p. 285.

Imperial Combined Meter Reckoner

No. 1 Bright Light

Imperial Dry Plate Co. Ltd

Cricklewood

England

Image of Imperial Combined Meter Reckoner No. 1 Bright Light

Meter Type:

Actinometer and Calculator.

Calibration:

Actinometer - Plate speed: 5 - 1200 H&D. Shutter speed: 1/500 - 60s. Aperture: f2.5 - f64, 1 - 256 US.
Reckoner - Plate speed: 5 - 1000 H&D. Shutter speed: 1/250 - 60s. Aperture: f3.5 - f64, 1 - 256 US.

Attributes:

Actinometer value: 1/5 - 100 (actinometer). Light Value scale: ½ - 16 (Reckoner).

Identification:

Red leather cover.

Notes:

NW2 postal code.

With:

Instructions for No. 1 and Reckoner. Light Value Tables booklet. Two packets of Deadmatch paper refills. Box.

Company Details:

Ilford

Imperial Dry Plates

Early Photography

Imperial Exposure Meter

1901

Early Model

Imperial Dry Plate Co. Ltd

Cricklewood

England

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Early Model

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Early Model, Italian

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Early Model

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Early Model

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No. 1 Bright Light

Meter Type:

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No. 1 Bright Light

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No. 1 Bright Light

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No. 2 Dull Light

Meter Type:

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Identification:

Duplex Model

Meter Type:

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With:

Duplex Model

Meter Type:

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Identification:

Ilford Exposure Meter

Duplex Model

1935

Ilford Ltd