[Neisey]

I am looking at a couple of lenses for my K10D:

FA 75-300 and the DA 50-200

What do the FA, DA (and all the other letters) mean? I know they are for different mounts but what other things are they distinguished by/for?

Thanks!

[Blue]

I don't know that there is a clear cut answer for all of them. However, "A" showed up with the contacts for the program cameras in the A series that could set the aperture automatically based on the meter reading. The F and FA were the autofocus series. I would guess that DA has to do with digital. The letters naming the lens series loosely follow the body series, K for the K series, M for the M series and A for the A series. The M42 lenses and bodies are a whole different ball game. Asahi Optical liked the letter K. The companies official name was Asahi Kogaku.

Edit: This site should help get you up to speed. http://kmp.bdimitrov.de/technology/index.html#general

[Ash]

Blue's right:
Pentax kept the letters to the lenses that signify their capabilities on the cameras:

Any Pentax lens with A in the name has electrical contacts that give the camera the ability to set ('dial' in) aperture on the camera, rather than having to do it on the lens.

Any Pentax lens with F in the name is autofocus, and has the ability to transmit some of the information about the shots taken (like aperture, shutter speed and focal length) with the lens to the camera for use in the EXIF data attached to the photos.

FA lenses are just the next generation of F lenses, which allow for even more data to be transferred to the photo. They are optically very similar to their F counterparts AFAIK.

DA lenses are designed for Pentax digital SLRs, which have the 1.5x crop factor. These DON'T have aperture rings as they can be set on camera. And they are NOT designed for any Pentax film cameras.

DFA lenses are versatile digital AND film lenses with aperture rings.

As mentioned, the pre-A lenses (M, K, M42) don't have any electrical contacts and therefore need manual setting of everything for a proper exposure to be taken. Having said this, all Pentax dSLRs have the ability to stop-down meter, so that it can at least calculate the right exposure based on the aperture and ISO set.

All Pentax lenses are K-mounts (except M42s like the old Takumars, where you need an adapter to fit it on the camera)

Hope this helps.

[Neisey]

Thanks! Now I can be better prepared when looking at used lenses.

[alohadave]

Asahi Optical liked the letter K. The companies official name was Asahi Kogaku.

Kogaku is Japanese for Optical or Engineering.

It translates to Asahi Optical. And according to Google Translate, Asahi translates to Morning Light. The full name was Asahi Kōgaku Kōgyō Kabushiki-gaisha.

Nikon was originally Nippon Kōgaku Kōgyō Kabushikigaisha, which means Japan Optical Industries Corporation

The point is that K likely had nothing to do with Kogaku.

[saien]

Ash covered it very thoroughly, but if you wanted to read more I found this page very useful when I had the same question in the past:
Pentax Lenses Explained

[Blue]

Kogaku is Japanese for Optical or Engineering.

It translates to Asahi Optical. And according to Google Translate, Asahi translates to Morning Light. The full name was Asahi Kōgaku Kōgyō Kabushiki-gaisha.

Nikon was originally Nippon Kōgaku Kōgyō Kabushikigaisha, which means Japan Optical Industries Corporation

The point is that K likely had nothing to do with Kogaku.

Actually, Asahi Kōgaku Kōgyō is actually also associated with the predesor of Ricoh. They even used the name Asahi Kōgaku Kōgyō briefly in the late 1930s but are completely unrelated to Pentax. More about that below. Kabushiki-gaisha refers to a "joint stock company."

The origin of the use of the K is just speculation and a guess and not many have put forward any better guess. I do not see why there isn't a possibilty that "K" came from Asahi Kōgaku Kōgyōthere most not be much logic in where the name for the Asahiflex series cameras came from. I merely said that that could be the possibilty for the K since there seems to be few better ideas about. However, you seem to forget that cameras sold in the U.S. and Europe had English letters and model names on them.

However, since you want to get into the name prior to the 1950s, lets do it. The company was originally founded in 1919 and the name was Asahi Kogaku Goshi Kaisha (Asahi Optical Joint Stock Co) a forerunner of Asahi Optical Company, Ltd was established in 1919 in Tokyo by Kumao Kajiwara.

Up until 1931, Asahi Kogaku had liitle to do with photography and made spectackles, telescopes and military intrusments etc. Around 1931, they made same lenses for the early fore runner of Minolta. These lenses were 105mm that went onto a comera made by the Molta Company known as The Happy and was the first fully Japanese made camera in 1933. They subsequently worked with other camera companies as well.

The irony is that in 1937, the Riken founded a company named "Asahi Optical Works" but they changed to Riken Optical Industries in 1940. The company changed status in 1938 to Asahi Kōgaku Kōgyō K.K., but broke up after World War II but reappeared in 1948 as Asahi Kōgaku Kōgyō (Ashai Optical Co. to Americans).

While we are on the subject, the Takumar lenses were named for a Japanes painter named Takuma who was a friend of the President of Asahi Optical Co.

Some of my Sources:

Danillo Cecchi. 1990. Asahi Pentax and Pentax SLR 35mm Cameas 1952-1989. Hove Foto Books.

White, Derek J., "A Brief History of the Asahi Optical Corporation, Spotmatic Magazine, April 2002.

Pentax Corporation: Information from Answers.com

Pentax - Camerapedia.org


Early Ricoh History: Asahi Bussan - Camerapedia.org

Edit: I agree that K may not have anything to do with the company name. It could also have something to do with the name of the CEO and founder that pushed them into the Camera business in the 1930s, Kumao Kajiwara. The company used K for the third model under the Pentax name first in 1958, and then in the mid 70s it was used on the K series of cameras and bodies and mount. Even more recently, K was brought back for the use on the digital SLR bodies. The recent use of K probably has more to do with the 1958 K or the 70s K series than why the original use of K was used.

Edit: Edit: According to the time line on the Pentax Imaging site (Pentax USA), "K" for the 1958 Pentax stood for "King" as in "King of the SLRs" and I have heard that before as well but think it is speculation also. Go here and select 1958: http://www.pentaximaging.com/about/history/

---

Last edited by Blue; 08-19-2009 at 10:24 AM.

[K-9]

The whole F, FA thing can be a little confusing, as every lens that has had an 'A' setting has had the A in their name except the F series (A, FA, FA-J, D-FA, DA). If you weren't savvy to Pentax, you might think the F series did not have an 'A' setting, but it does.

[WMBP]

What do the FA, DA (and all the other letters) mean? I know they are for different mounts but what other things are they distinguished by/for?

Check out this page on Pentax's web site:

Camera Lens - Official PENTAX Imaging Web Site

I think you'll find it helpful.


Will