Japanese plate cameras, folding bed (edit)
No.0 (4×5cm) Alpha | Sweet | Pony Sweet | Taishō-shiki
atom (4.5×6cm) Monarch | Need | Palma
meishi (5.5×8cm) Eagle | Idea A | Idea B | Idea Snap | Idea No.1 | Iris | Lily (horizontal) | Pearl No.3 | Special Camera | Venis | X
daimeishi (6.5×9cm) Apollo | Arcadia | Crite | Special East | Eaton | Elliotte | First | First Etui | Gold | Happy | Hope | Idea No.1 | Idea (metal) | Kinka | Kokka | Lily (horizontal) | Lily (metal) | Tropical Lily | Lloyd | Lomax | Masnette | Mikuni | Need | Nifca Klapp | Nifca Sport | Ohca | Palma | Peter | Prince | Prince Peerless | Proud | Romax | Rosen | Rubies | Sirius | Sun | Super | Tokiwa | Venus | Weha Idea | Weha Light
tefuda (8×10.5cm) Eagle | Idea A | Idea B | Idea No.1 | Idea (metal) | Iris | Lily (original) | Lily (horizontal) | Lily (metal) | Palma | Pearl No.3, No.4 | Minimum Pearl | Special Pearl | Sakura Palace | Sakura Pocket Prano | Star | Tokiwa | Weha
nimaigake (8×12cm) Eagle | Idea | Idea Binocular | Sakura Prano | Sakura Binocular Prano | Star Premo
hagaki (8×14cm) Eagle | Noble | Pearl No.3, No.4 | Star
kabine (12×16.5cm) Idea | Noble | Sakura Prano | Star Premo
Japanese plate film: monocular, box, strut-folding and SLR ->
3×4 and 4×4, 4×5 and 4×6.5, 4.5×6, 6×6 and 6×9 ->

The Idea No.1 (アイデア一号) are Japanese plate folders made by Rokuoh-sha, the manufacturing branch of Konishiroku (predecessor of Konica). They exist in meishi (5.5×8cm), daimeishi (6.5×9cm) and tefuda (8×10.5cm) size, and replaced the Idea A and Idea B series in 1923. The Pearl No.2 released the same year is essentially a rollfilm version of this camera line.

See also the other Idea models.


The Idea No.1 models have a mixed construction, with a wooden main body and a metal folding bed.[1] The folding struts are quite large, and there is a handle at the top of the main body. The front standard mainly consists of a U-shaped metal part, and has no visible movement ability. The brilliant finder is attached to the top of the lensboard, straight in the middle. The bellows have single extension, and there is a distance scale on the photographer's left.[2] The name N°1 IDEA is sometimes inscribed at the bottom of the front standard; at least some examples also have an IDEA embossing in the top handle, and an Idea logo on the ground glass hood.

The larger tefuda (8×10.5cm) model has a focusing wheel on the photographer's right, and a rigid brilliant finder covered by a hood.

The smaller meishi (5.5×8cm), then daimeishi (6.5×9cm) model, has no focusing wheel but a lever in front of the lens standard, whose exact purpose is unknown. The brilliant finder is collapsible and has a square window.

Commercial life[]

The Idea No.1 was reportedly released in August 1923.[3] The November 1924 advertisement in Ars Camera shows an illustration of the smaller model. The camera is said to take film plates or pack film, and the format is not mentioned. Nothing is said of the shutter, and three lens options are listed:

  • RR lens, ¥29;
  • Deltas f/6.8 lens, ¥35;
  • Velostigmat (ベロ) Ser.IV f/6.8, ¥51.

The meishi and tefuda models were also offered in 1924 with Testar lenses; Tanaka suggests that this temporary measure was taken because the company was facing a shortage of lenses after its stocks were destroyed in the 1923 Great Kantō earthquake.[4]

The advertisements in Ars Camera June 1926, December 1926 and February 1927 show the same illustration as in November 1924. In June 1926, the cameras are said to have received the medal of honor (名誉賞牌) at the Second Chemical Industrial Exposition (第二回化学工業博覧会),[5] and prices are given for the versions with f/6.8 lens: ¥35 in meishi size and ¥45 in tefuda size, with a mention of "other models" (外種々). The December 1926 advertisement gives no specific information on the Idea No.1, and the February 1927 advertisement offers the camera from ¥29 in meishi size and from ¥45 in tefuda size.

In the May 1927 advertisement in Ars Camera, important changes are announced for the Idea No.1 and Pearl No.2. The film size of the Idea No.1 is switched to 6.5×9cm, and an insert taking regular meishi-size plates is supplied as an accessory.[6] The price is given as ¥35 with a Deltas f/6.8 lens, six single-sided metal plate holders and one film pack holder. Another advertisement dated 1927 and mentioning the format change also lists a version with Trinar f/6.3 lens for ¥40.[7]

Surviving examples[]

Surviving examples of the larger tefuda model are known with the following combinations:

  • Wollensak Deltas Aplanat 13.5cm f/6.3 lens, Gammax No.1 shutter (T, B, 100–10);[8]
  • Trinar Anastigmat f/6.3 lens, shutter by Gauthier (T, B, 100, 50, 25), inscribed Rodenstock on the speed dial.[9]

Surviving examples of the smaller meishi or daimeishi model are known with the following combinations:

  • Wollensak Deltas f/6.8 lens, Gammax No.0 shutter (T, B, 100–10);[10]
  • Wollensak Velostigmat Ser.III f/6.3 lens, Betax No.0 shutter (T, B, 100–2);[11]
  • Trinar Anastigmat 10.5cm f/6.3 lens, Pronto shutter (T, B, 100, 50, 25).[12]


  1. Kikuoka, p.29 of Kurashikku Kamera Senka no.10.
  2. Single extension: Kikuoka, p.29 of Kurashikku Kamera Senka no.10.
  3. Chronology of the official company history Shashin to tomo ni hyaku-nen, reproduced in Tanaka, p.94 of Kurashikku Kamera Senka no.10; this is repeated in Kikuoka, pp.29 and 31 of the same magazine. The date is simply given as 1923 in this page and this page at R. Konishi Rokuoh-sha.
  4. Tanaka, p.33 of Kurashikku Kamera Senka no.10.
  5. Advertisement in Ars Camera June 1926: 於第二回化学工業博覧会名誉賞牌受領.
  6. Advertisement in Ars Camera May 1927: 名刺判を六½×九珊判に改め普通名刺用中枠附.
  7. Advertisement reproduced in this page at R. Konishi Rokuoh-sha; the date is given in this other page.
  8. Example pictured in Sugiyama, item 1093 (lens type reported only).
  9. Example pictured in Sugiyama, item 1094, and in Kikuoka, p.30 of Kurashikku Kamera Senka no.10 (lens type reported only).
  10. Example pictured in Kamera no ayumi, p.83 (lens type reported only, as "Deltas Anastigmat", perhaps a mistake for "Deltas Aplanat"). The same shutter is visible on the examples pictured in Kikuoka, p.30 of Kurashikku Kamera Senka no.10, and in this page at Asacame.
  11. Example pictured in Sugiyama, item 1092 (lens type reported only).
  12. Example pictured in Sugiyama, item 1095 (lens type reported only), and example pictured in this page of the Yamada camera museum.



In Japanese:

Konishiroku prewar and wartime cameras (edit)
plate hand cameras stereo hand cameras strut folders box telephoto SLR
Idea (original) | Idea A | Idea B | Idea Snap | Idea No.1 | Idea (metal) | Lily (original) | Lily (horizontal) | Lily (metal) | Tropical Lily | Noble | Ohca | Sakura Palace | Sakura Pocket Prano | Sakura Prano Idea Binocular | Sakura Binocular Prano Minimum Idea | Idea Spring | Korok Champion | Cherry | Sakura Army | Sakura Honor | Sakura Navy Idea Telephoto Idea Reflex (1910 and 1911) | Idea Reflex (1932) | Neat Reflex | Sakura Reflex Prano
rollfilm folders box or collapsible TLR
Pearlette | Special Pearlette | B Pearlette | Pearl (for plates and rollfilm) | Pearl No.2 | Pearl (Year 8) | Baby Pearl | Semi Pearl | Sakura Palace Record | Sakura (box) | Sakura (bakelite) Sakura-flex