M9 lens coding revalation

[01af]

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Although the info before exposure suggests a lens of 14 mm f/3.8, the EXIF info (try using exiftool on the file) lists the lens ID and lens type as "unknown (51-2)"

The EXIF data just contains the codes 51 and 2. The text "unknown (51-2)" is created by the EXIF viewer tool you're using (here: Phil Harvey's ExifTool). After all, how should Phil (or anyone) know that 51-2 is supposed to mean 14 mm f/3.8? Even M9 owners are not supposed to know that ...

 

 

... and the focal length as 0 mm.

Yes, that's the rub—the camera does store the 6-bit lens and the 2-bit frameline codes 51-2 and also (!) the proper max. aperture number of 3.8 but does not store the focal length. Weird!

 

 

The proper info is recorded in the EXIF when the picture is taken. This includes a text description of the lens used (this text seems to be the same for all programs that pull it up).

No, there is no text describing the lens stored in the EXIF data. The text you see displayed in ExifTool, ExifToolGUI, Adobe Lightroom, Adobe Bridge (or whatever EXIF viewer you're using) always is created by the EXIF viewer program as an interpretation of the 6-bit and 2-bit codes (or whatever code the respective camera maker uses to identify lenses) stored in the EXIF Maker Notes section.

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[cbretteville]

The camera data for the lens code and frame lines are combined and stored in a single 32bit data value in the exif maker notes data in the image files. Of these 32 bit Jenoptik chose to use only 1/4 of the available space; 1 byte. This byte's upper 6 bits are used fro the lens code (hence the 63 code limitation) and the lower two for the fame line position indicator ('1', '2' or '3' for codeable lenses and '0' for those that are manually selectable only).

 

In the M8's lens table the frame line is a value in the data set for each lens together with some other bits of info and a short text name, the one you see on the info display. The lens code value is the position of the lens' info in the array. Even if we can't be sure (as the M9's firmware is obfuscated) the cameras share do much DNA that I assume the engineers at Jenoptik haven't changed this from the M8 to the M9. Programmers like to reuse code and designs that work, it saves time (takes one to know one).

 

The textual lens description you see in CornerFix, LR, ExifTool, PhotoMe etc. is a mapping of the exif data value to a table of text entries. The actual text was lifted from my original work on the M8's maker notes data published back in 2007.

 

Carl

[Robert_M]

Yes, I had assumed that the text description was tied to a common central source of information and not the software reading it since the text appears identical in every program I've used to read it. You already listed several.

[a.feliziani]

I think it's a new lens.

Yesterday from his Facebook page Thorsten Overgaard linked this: http://www.overgaard.dk/Leica-Super-Elmar-M-14-mm-f-3-8-ASPH.html

 

But now the page is cancelled.

I think this 14mm will be the next Leica lens.

[gpwhite]

Also the vignetting at full aperture with automatic lens recognition on looks damn close to the 24 mm Elmar's when the lens recognition is off. I was expecting some over-correction ... so it seems I'm wrong and there is no profile stored for a future 14 mm lens. Oh well ...

 

01af, I want to encourage all of us about this exciting possibility. Leica would not be able to code an accurate vignetting/CA profile for the 14 SE until they had built it, tested it and Jaapv had received his freebie trial, . So I do not lose hope when you report that the 14 SE profile you fudged into your unwitting M9 did not alter the capture characteristics taken from your 24 Elmar.

 

A rangefinder-coupled 14SE with FLE would be well worth the Euro 6,500 Jaapv is estimating. That would be a signature perspective. I have been debating my purchase of the excellent 18 SE for some time now, but will await the outcome of the 14 SE story.

 

Oh my!!

[01af]

Leica would not be able to code an accurate vignetting/CA profile for the Super-Elmar-M 14 mm until they had built it, tested it ...

That's wrong. If they have an idea how the future 14 mm lens is going to look like then they also can create a lens profile for it from the blueprints before even the first prototype has been made. The fact the M9 doesn't have a profile inside (even though it can associate lens code 51 with "14 mm f/3.8") does not mean it was impossible.

 

 

So I do not lose hope when you report that the Super-Elmar-M 14 mm profile you fudged into your unwitting M9 did not alter the capture characteristics taken from your Elmar-M 24 mm.

I didn't lose hope yet, either. As a matter of fact, I am convinced the Super-Elmar-M 14 mm Asph is coming ... sooner rather than later. I might be wrong but I think I'm right until further notice.

 

 

A rangefinder-coupled Super-Elmar-M 14 mm with FLE would be well worth the Euro 6,500 Jaapv is estimating.

I think he gave this estimation in jest. Personally, I'd rather estimate a retail price that's closer to Euro 3,500 or so.

[jaapv]

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I called it a guess, not an estimate

[ho_co]

... A rangefinder-coupled 14SE with FLE ...

I'm sure it'll be rangefinder-coupled. I don't think Leica has produced any M lenses 135mm or shorter without rangefinder coupling. And with digital, guessing doesn't seem to work as well as with film.

 

But I doubt that a lens this slow would need from a floating element. I think that's more a solution for focus-shift, which is greater with high-speed lenses.

 

Eliminating the floating element may let Leica bring it in at Jaap's guess price.

 

Or even lower, if you don't count the finder.

 

 

... Oh my!!

My feeling exactly. Looks like a good addition.

[gpwhite]

 

But I doubt that a lens this slow would need from a floating element. I think that's more a solution for focus-shift, which is greater with high-speed lenses.

 

Eliminating the floating element may let Leica bring it in at Jaap's guess price.

 

Or even lower, if you don't count the finder.

 

 

 

My feeling exactly. Looks like a good addition.

 

Ho_Co, my feeling is that this lens will be most exquisite in creating the perspective of a nicely balanced central subject, close to the camera, with a rapidly receding and a bit distorted periphery. The very fine Nikon 14/ 2.8 can do this, although it looks like a Nikon image, and the DOF is counter productive because that lens needs f/8 (I think). So my thought is that the FLE would allow crisp details at f/4 within 1 or 1.5 meters focusing distance. When I tested the 18 SE (courtesy of David Farkas' test drive program), I felt that lens lost a bit in close focusing. I would like to use the 14 SE very close, like the 21 SX. Also, my 15 ZM Distagon, which I sold after acquiring the 21SX (and an M9), was not as sharp in close focus.

 

I think Jaapv's guesstimate is not far off because Leica will have invested in making a superlative lens that does not sell many copies. Also, the front element (or two) of a 14 f/3.8 SE ASPH will be rather large pieces of glass.... Leica charges by diameter, doesn't it?

 

Perhaps the finder will be included, although I have a really nice 12mm Voigtlander finder if Leica is entirely mercenary about it.

 

I guess I should enter a pre-order now?

[01af]

I called it a guess, not an estimate.

Umm ... yes. I guess that's better.

 

 

But I doubt that a lens this slow would need from a floating element. I think that's more a solution for focus-shift, which is greater with high-speed lenses.

A 14 mm 1:3.8 lens for 35-mm full-grame format isn't what I'd call "slow". It's pretty fast actually ... although even faster lenses do exist. A 14 mm 1:2.8 lens can be considered "super-fast".

 

Anyway—the purpose of floating elements is not primarily the elimination of aperture-related focus shift but to keep lens performance constant across the whole focusing range from infinity to the minimum focusing distance. When focusing closer, a lens' performance will degrade the more the faster the lens is, the wider the angle of view is, and the more asymmetrical the lens design is. A 14 mm lens will be wide enough and asymmetrical enough for floating elements to make sense—no matter what the lens speed is.

 

On the other hand, Leica M lenses cannot focus closer than 0.7 m (at least not rangefinder-coupled), and for an ultra-wide that's not too close. So while a 14 mm 1:3.8 lens definitely would benefit from floating elements, as an M lens it might still get away without.

 

So I would neither dare to bet on nor against floating elements. And moreover, there are more options to consider—like internal focusing or rear-part focusing. For example, the Tri-Elmar-M 16-18-21 mm 1:4 Asph has internal focusing which naturally includes the effects of floating elements.

[ho_co]

ONEaf, a couple points:

 

Where "fast" begins and where "super-fast" is a matter of judgment. If you consider f/4 fast in a wide-angle, that's fine with me.

 

Yes, the stated reason for floating elements is often to correct near focus. But that's not the only effect the design has. Remember, Leica's stated reason for adding a floating element design to the 35/1.4 aspheric was correcting focus shift.

 

... A 14 mm lens will be wide enough and asymmetrical enough for floating elements to make sense—no matter what the lens speed is.... [A] 14 mm 1:3.8 lens definitely would benefit from floating elements....

"Asymmetrical enough"? Come on!

 

BTW, I'm glad you're psychic enough to be able to tell the need for floating elements from focal length and speed specifications.

 

... [T]he Tri-Elmar-M 16-18-21 mm 1:4 Asph has internal focusing which naturally includes the effects of floating elements.

Totally meaningless to compare a zoom design with a prime lens.

 

 

... So I would neither dare to bet on nor against floating elements....

Wow, ONEaf, I'm flattered to know you took my surmise as a wager, and doubly flattered to know you won't enter into it. [sorry, out of smilies ;-) ]

[01af]

Remember, Leica's stated reason for adding a floating element design to the 35/1.4 Asph was correcting focus shift.

Please don't confuse your imagination with the facts. Leica never stated anything like that—because actually, floating elements DO NOT address aperture-related focus shift. Not directly.

 

Instead, focus shift reduction merely is a (most welcome) indirect side-effect from the improved level of correction at the shorter distances ... but that makes a difference for the better only when all other sources of spherical aberrations also are reduced to a minimum. So in fighting focus shift, the floating elements are just one (minor) factor among many others. The primary reason to include them still is what it always was: improving the close-range performance, which they actively and directly do.

[ho_co]

Now, ONEaf, don't accuse me of your errors.

 

You may be right that Leica hasn't acknowledged focus shift in lens descriptions. Until the M8, many of us were unaware of how Leica put focus shift to use.

 

 

In the case of the 35/1.4, you could verify what I've said through previous forum posts, LFI, and Erwin Puts.

 

At any rate, thanks for entertaining the question.