[Bladejunkie]

I went out today to shoot a motive that I like to test on. In total I tested 16 M42 mount lenses. Among the tested lenses were a preset Takumar 55 2.2 (#160480) and a preset Takumar 58 2.4 (#154623). Presumably, the former is a Gaussian design with five elements in five groups, the latter a Heliar design with five elements in three groups (originally that design was for the Asahiflex).

When I came home I was floored by the fact that the two rendered images that were virtually exactly the same. Among the 16 tested lenses that was otherwise true only for three copies of the Schneider Xenon 50 1.9, all of which have the same optical design but are from different years [in other words, those three lenses should render exactly the same; the Taks should not]. In fact, the Takumar 55 2.2 had a field of view more akin to the other 58mm lenses I have, rather than to another 55mm lens I have.

That had me suspicious, so I went to collect some other evidence that maybe one of the lenses is not what it claims to be. I found additional pieces of evidence that maybe my 58/2.4 isn't one.

• Other than the numbers of the minimum f-stop markings, the lenses look exactly the same.
• The depth in which the front lens of my 58/2.4 is embedded in the barrel does not match photos I have seen of the lens, but matches photos of the 55/2.2
• The 2.4 aperture mark for the open aperture of the 58/2.4 is in the exact same distance to the 2.8 as is the 2.2 mark of the 55/2.2. On the photos I have seen, and logically, the 2.4 mark on the 58 should be closer to the 2.8 mark than the 2.2 mark on the 55, given that all other f-stop distances are the same.
• The minimum focus distance of the 58/2.4 is 60 centimeters, which is 2 feet. The minimum focus distance marked on the focus ring is 1.8 feet, which is 55 centimeters, which happens to be the MFD of the 55/2.2. I haven't seen any photos of the 58/2.4 that show the minimum focus distance mark on that lens. But I have never seen a lens that has a lowest mark smaller than the lens's MFD.

So if anyone has an M42 Takumar 58mm 2.4 and could upload either one or better all of these three details - front lens embeddedness, aperture ring marks, focus ring at minimum focus distance - I would greatly appreciate it.

I do not think that this is a fake lens, really. Instead I think that somebody at Asahi @#@%ed up when making the lens and might have mislabeled it. My last resort is to open it up to look at the lens elements, but I really don't want to, because I would not want to mess it up in case it were an original 58mm/2.4.

Thank you all

[Not a Number]

If you posted photos of your lenses no doubt it would be of enormous help.

[disconnekt]

Here is a link that shows some photos & info on the lens:

The Takumar 58 mm f/ 2.4 Lens. Specs. MTF Charts. User Reviews.

[Bladejunkie]

If you posted photos of your lenses no doubt it would be of enormous help.

I seriously don't see how. I know what it looks like, I need photos of things to compare it to.

[Wild Mark]

Perhaps the suggestion is all about sharing. I have said lens and would love to compare what I have with what you have.

[Bladejunkie]

Here is a link that shows some photos & info on the lens:

The Takumar 58 mm f/ 2.4 Lens. Specs. MTF Charts. User Reviews.

I have seen those and others from google images. They don't show the focus ring at MFD. If there is no variation between copies, then it definitely isn't one, but these were the early days of M42/Pentax, so there might be versionitis. What is strange, though, is that the 2.4 f-stop markings seem to be at the wrong distance from the 2.8 compared to the photos that I have seen.

[Ned Bunnell]

This blog post might be of interest to you...

Early Pentax Takumar Lenses

Cheers

[Bladejunkie]

This blog post might be of interest to you...

Early Pentax Takumar Lenses

Cheers

Thanks, I have seen it. After finding the test shots identical, his photos were the basis of my belief that my lens might be fake because of the wrong embeddedness/depth of the front lens and the wrong positioning of the widest aperture marking compared to his original. The other, few photos of this lens on the web also showed a configuration exactly like this and unlike mine.

---------- Post added 09-03-17 at 06:02 PM ----------

I have determined that the lens I have (#145623) is a fake - most likely a factory fake (or error - like the Blue Mauritius). It's a 55/2.2, not a 58/2.4. I determined that after removing the back element of the lens. The grave crimes committed by the Asahi Pentax Corporation 60 years ago shall not go unnoticed or unpunished.

---------- Post added 09-03-17 at 06:11 PM ----------

Perhaps the suggestion is all about sharing. I have said lens and would love to compare what I have with what you have.

I assume that the photos shown here Early Pentax Takumar Lenses are accurate.

My lens has 2.4 f-stop markings on the two rings, a 58mm/2.4 front ring, and a 2.4 DOF gauge at the lens mount. However, it sits in the barrel of a 55/2.2, the front element is too deeply embedded, its focus ring is from a 55/2.2 (because it shows 1.8 feet MFD, the 58mm/2.4 shows 2 feet), and the f-stop marks on the two rings sit where the 2.2 should be and not where the 2.4 should be (even though the numerals show 2.4). The latter makes me think that this is a factory fake. It would strike me as being way too much effort to recreate exactly the two aperture rings with the correct f-stop numeral and font but then make the error to put the mark in the wrong place. It's such an odd combination of wrong though.

[G and T]

I have determined that the lens I have (#145623) is a fake - most likely a factory fake (or error - like the Blue Mauritius). It's a 55/2.2, not a 58/2.4. I determined that after removing the back element of the lens. The grave crimes committed by the Asahi Pentax Corporation 60 years ago shall not go unnoticed or unpunished.

Almost certainly you have a frankenlens,these were usually produced by camera repair workshops when a lens was repaired cheaply with available parts instead of correct parts or a "good" lens was produced from two broken lenses that were mostly the same.
Glenn

[Bladejunkie]

Almost certainly you have a frankenlens,these were usually produced by camera repair workshops when a lens was repaired cheaply with available parts instead of correct parts or a "good" lens was produced from two broken lenses that were mostly the same.
Glenn

Normally, I would agree with that. But the peculiar thing about this lens is that it has the correct f-stop numerals for a 2.4, but that the 2.4 f-stop markings are in the wrong place, that is, they are to the right of where the 2.4 should be and are where a 2.2 would be. It would strike me as requiring extraordinary effort and skill for anyone but the original manufacturer to make two wrong aperture rings that otherwise resemble the original to the mu.

Regards
Dan

[Bladejunkie]

Perhaps the suggestion is all about sharing. I have said lens and would love to compare what I have with what you have.

Here are my photos. Please share yours.

Everything would speak for what someone called a Frankenlense before, except the aperture rings with the right f-stop markings in the wrong place. They look like they were made by Asahi Pentax. Otherwise, they would have had to be made by a very skilled craftsman. Getting the numerals in the same font, and the paint in the same shade is no small feat, I would think.

Photos of the glass elements are of the rear groups. Note the dismounted skinny convex element, which is the last element toward the mount. Note also the concave element in its housing, which is the first element behind the diaphragm. They are not from the Heliar 2.4, but from the Gauss 2.2.

Finally note the DOF gauge from the 2.4, but the focusing ring from the 2.2 with MFD 1.8 feet instead of 2 feet.

What would be interesting to know is if this lens is stamped with its serial number anywhere on the inside. Then I could confirm whether it is a factory original Blue Mauritius or just a very good fake.

[Bladejunkie]

I have identified one more lens that seems to have the same specifications as mine and was recently sold on ebay. This suggests that there might be an entire batch of lenses that are marked 58mm/2.4 but that are not Heliar design. In addition to my own (#154623), the other lens had serial #154662.

[Bladejunkie]

Perhaps the suggestion is all about sharing. I have said lens and would love to compare what I have with what you have.

Preaching water; drinking wine.

[Wild Mark]

Preaching water; drinking wine.

I see you are a major contributor to this forum - congradulations

[BigMackCam]

Preaching water; drinking wine.

I see you are a major contributor to this forum - congradulations

Folks, let's keep this friendly, please. Thank you in advance