I am not sure whether it is on-topic here, but the following question was asked on English Language and Usage.
What does the word “Canon” (the digicam brand) mean?
I searched the word and its company name キヤノン株式会社 on the internet, but I couldn't find any useful information. Is the brand キヤノン related with キャメラ?
I believe I've always used カメラ before, but are the two words キャメラ and カメラ completely interchangeable?
The name of 「キヤノン」 was the registered brand name of the first camera model developed by 精機工学研究所 - Seiki Optical Technique Laboratory, which was later developed into today’s Canon Inc.
The company was founded by Goro Yoshida and his brother in law in 1933. They named their first camera they developed as “Kwannon” after one of the most popular Buddhist character, 観音 - Avalokiteśvara Bodhisattva in Sanscrit in the wish that they can send the highest standard and the best ever camera into the world, supported with the miracle power of 観音 they believe in.
In the printing material of the early period of Seiki Optical Technique Laboratory, the picture of 千手観音 - Kannon with a thousand hands (actually 24 hands shown on the statue) of relief was featured above the logo of Kwannon. They registered 「キヤノン」 and 「Canon」 as their official trademarks in 1935
The Laboratory (精機工学研究所) was reorganized into 精機工学株式会社、and then changed their name into キヤノン株式会社 in 1969. The growth of the company started with two men thereafter is just as you see it now.
Searching for キヤノン 由来 one quickly finds the relevant official page for the origin of the name Canon.
It seems that the company name itself was derived from the English word "canon":
Canonの語源には、「正典」「規範」「標準」という意味があります。
It was also a welcome coincidence that the pronunciation of キヤノン was close to 観音＝カンノン (Kannon, Kwannon, Avalokiteśvara):
また「キヤノン」の発音が「観音＝カンノン」と似ているため、名称の交替は違和感なく行なわれました。
In any case, the meaning of Canon was never meant to be directly related to カメラ.
As for the difference between キャメラ and カメラ we should first point out that カメラ is far more common. E.g. the Balanced Corpus of Contemporary Written Japanese (BCCWJ) gives
カメラ 5133 results
キャメラ 57 results
For the string キャメラ there are a number of false positives from words such as キャメラマン, キャメラ・オブスキュラ. Looking at the results, it looks like キャメラ, if used at all, is more likely to be used in the context of filming.
The Canon name brand comes from 観音, Kannon, or in Sanskrit Avalokiteshvara. The Buddhist bodhisattva "Hears the cries of the world." But there is also a description of her/him have a thousand hands with an eye on the palm of each hand observing the world. It's kind of a beautiful image for a camera name since the camera sees all.
