90mm Apo-Summicron-M not apochromatic?

[LarsHP]

Advertisement (gone after registration)

Okay, it seems only two wants to guess which is which, so I will name them now: 

1) Voigtländer 50mm f/1.2 Nokton Asph VM 

2) Leica 90mm Apo-Summicron-M

3) Leica 90mm Elmarit-M 

As mentioned, all lenses were shot at the widest aperture. 

To my eyes, the Elmarit-M performs at least on the level of the Apo-Summicron-M regarding LoCA in this test. This is actually quite surprising given the apo designation and newer design of the f/2 lens.

The Nokton 50mm f/1.2 has less depth of field which means the tip is more out of focus, but it appears to have less or at least no more chromatic aberration than the two 90mm lenses IMO. It has obvious spherical aberration though, as mentioned. 

I should perhaps add, that I have downsized the 90mm lens shots to match the 100% crop of the Nokton f/1.2. 

Edited May 28, 2021 by LarsHP

[pgk]

1 minute ago, LarsHP said:

To my eyes, the Elmarit-M performs at least on the level of the Apo-Summicron-M regarding LoCA in this test. This is actually quite surprising given the apo designation and newer design of the f/2 lens.

The 90mm Elmarit-M is an undervalued lens! Its a modest f/2.8 and clearly the result of considerable design experience with a series of other 90mm lenses preceeding it. Likewise the 90mm f/4 macro is reputed (I don't have one) to be an excellent performer. Moving the full aperture up a stop in a relatively compact lens is clearly problematic in spite of prior designs.

[LarsHP]

16 minutes ago, pgk said:

The 90mm Elmarit-M is an undervalued lens! Its a modest f/2.8 and clearly the result of considerable design experience with a series of other 90mm lenses preceeding it. Likewise the 90mm f/4 macro is reputed (I don't have one) to be an excellent performer. Moving the full aperture up a stop in a relatively compact lens is clearly problematic in spite of prior designs.

I actually had the Summarit f/2.5 and quickly sold it because the Elmarit-M was better in every way, including transmission in practical use (the Summarit has so much more vignetting than the Elmarit-M, that the theoretical extra third of a stop is only seen in the very center, while it is clearly darker in the mid frame and corners).

[lct]

As far as color fringing is concerned i would rate my own Leica M lenses this way.
On a purely experimental basis and don't ask me about loca/laca plse i have no idea.
FWIW
1/ Elmar 90/4 collapsible
1/ Summicron 90/2 v2
2/ Summicron 90/2 apo
2/ Macro-Elmar 90/4
2/ Tele-Elmarit "thin" 90/2.8
2/ Elmar-C 90/4
3/ Summarit 90/2.4
3/ Elmarit 90/2.8 v2
4/ Elmarit 90/2.8 v1
5/ Summicron 90/2 v3

Edited May 28, 2021 by lct

[LarsHP]

17 minutes ago, lct said:

As far as color fringing is concerned i would rate my own Leica M lenses this way.
On a purely experimental basis and don't ask me about loca/laca plse i have no idea.
FWIW
1/ Elmar 90/4 collapsible
1/ Summicron 90/2 v2
2/ Summicron 90/2 apo
2/ Macro-Elmar 90/4
2/ Tele-Elmarit "thin" 90/2.8
2/ Elmar-C 90/4
3/ Summarit 90/2.4
3/ Elmarit 90/2.8 v2
4/ Elmarit 90/2.8 v1
5/ Summicron 90/2 v3

In terms of color fringing, you rate the second gen. Summicron to be better than the Apo-Summicron-M. That's interesting!

La vida loca! ... and laca 😉

Edited May 28, 2021 by LarsHP

[lct]

11 minutes ago, LarsHP said:

In terms of color fringing, you rate the second gen. Summicron to be better than the Apo-Summicron-M. That's interesting!

And understandable. V2 is a significantly bigger lens. Too big to sell much i guess so Leica designed v3 which was more compact and has in fact the same size as apo. V3 has too much color fringing though so the current apo version is the better compromise among 90/2 M lenses for now.  

[luigi bertolotti]

Advertisement (gone after registration)

I never focused (😁) specifically on the color fringing issue... but it's some years that I consider my Elmarit-M the best of my 90 (haven't the APO).

 

[LarsHP]

A few follow up-shots. The 90mm Apo-Summicron-M shot at f/2.8 and wide open. Shows quite strong proper LoCA wide open, which is practically gone at f/2.8.

Both are 100% crops from the center. Moderate sharpening, no lens corrections ("Remove chromatic aberrations" ticked off).

Refocusing every time, I took several shots at both apertures and chose the best result for each.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Edited June 6, 2021 by LarsHP

[LarsHP]

And here the 180mm f/4 Apo-Lanthar SL (first) and then the 90mm Elmarit-M, both wide open.

The Elmarit-M is of course also a 100% crop from the center, while the Apo-Lanthar is downsized to 50% to match the other crops. Again, same moderate sharpening, no lens corrections ("Remove chromatic aberrations" ticked off).

The Apo-Summicron-M looks great at f/2.8 (above), but wide open it doesn't look as impressive as it often does with landscapes.

The reflections in the metal is a real LoCA torture test, and while the Apo-Lanthar looks stellar wide open, the Apo-Summicron-M doesn't handle it that well (wide open). Stopping down to f/2.8 improves it greatly, though.

The Elmarit-M performs admirably well for a "non-apo" lens.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

Edited June 6, 2021 by LarsHP

[pedaes]

22 minutes ago, LarsHP said:

A few follow up-shots

If you had caught a mermaid leaping out of the water in the background , no one would worry about the detail you are fussing about.

[lct]

F/2 vs f/2.8 vs f/4... You like apples and oranges don't you .

[ianman]

40 minutes ago, LarsHP said:

A few follow up-shots. The 90mm Apo-Summicron-M shot at f/2.8 and wide open. Shows quite strong proper LoCA wide open, which is practically gone at f/2.8.

Both are 100% crops from the center. Moderate sharpening, no lens corrections ("Remove chromatic aberrations" ticked off).

Refocusing every time, I took several shots at both apertures and chose the best result for each.

Welcome, dear visitor! As registered member you'd see an image here…

Simply register for free here – We are always happy to welcome new members!

From your text I can’t decipher which apertures are used but I can see plenty of purple on both images.

[ianman]

10 minutes ago, lct said:

F/2 vs f/2.8 vs f/4... You like apples and oranges don't you .

I hope this doesn’t sound rude but you are a fruit short there 🍐

[pedaes]

4 minutes ago, ianman said:

I hope this doesn’t sound rude but you are a fruit short there 

Lemons?

[LarsHP]

8 minutes ago, ianman said:

From your text I can’t decipher which apertures are used but I can see plenty of purple on both images.

The images should give you a pointer. If not, then the top image is stopped down to f/2.8 while the second is wide open. (Both in the first post are the 90mm Apo-Summicron-M.)

[ianman]

2 minutes ago, LarsHP said:

The images should give you a pointer. If not, then the top image is stopped down to f/2.8 while the second is wide open. (Both in the first post are the 90mm Apo-Summicron-M.)

Like I said I can see purple in both although you wrote that it’s almost gone at f/2.8

[ianman]

6 minutes ago, pedaes said:

Lemons?

😂😂😂😂 brilliant!

[LarsHP]

14 hours ago, ianman said:

Like I said I can see purple in both although you wrote that it’s almost gone at f/2.8

Then we agree. I wrote practically gone, as in not completely, but quite reduced. There are still traces even if stopped down further, but stopping down to f/2.8 improves considerably.

[LarsHP]

As I have demonstrated more than once in this thread, my sample of the M 90 Apo performs brilliantly at infinity, so no reason to speculate about it being a "lemon".

I don't feel there is much appreciation in the comments for what I post here, so I will stop it. Goodbye.

[Advertisement]

Hallo,

Look here: Leica M

[pgk]

Even in the movies you will see traces of fringing and their lenses are far costlier than Leica's M range. I also still question whether what is being posted has a simple explanation and I'm pretty sure that it does not - more likely its a combination of additive causes. I cannot see anybody other than a technically obsessed photographer actually noticing such phenomena unless they are actually pointed out and complained about.