M240 and lens profile (28/2 V1)

[Casey Jefferson]

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Hello all,

Recently acquired the first 28/2 summicron 11604 and been shooting it daily, quickly realize there's the magenta edge problem even with the correct profile detected. It's not very consistent, with some lighting it'll appear, and not with some others. Tried with the elmarit asph and it seems to fix the edges better, if somewhat overdone with cyan cast and also changed the tint of the rendering somewhat.

My M240 firmware isn't up to date, and I don't see 28 summilux in the lens list. Will newer firmware fix the edges better? There isn't any problem with the firmware and camera and I'm not going to fix it if not ain't broken...

Thanks for stopping by! Hopefully to get some insights! 

[a.noctilux]

Hello Casey,

I use the first version of the 28mm Summicron-M for years, but mainly on Monochrom.

Very nice lens, even if mine is coded, I'd load ( I invite you to do the same ) the last firmware,

maybe the trouble can be "corrected" for your M240.

 

As side note 1, I have some edge color problem with my other LTM 28mm, only with M240 but not with M9, very strange.

Side note 2, I rarely had same edge problem with Summicron 28 + M240 (when I use the combo scarcely)

[rpsawin]

In a related. question are the M Lenses Definitions universal or do they vary between camera bodies? Restated does my M262 define this lens the same as a M240?

Thanks in advance.

[Casey Jefferson]

@a.noctilux The edge problem seem to be prominent against blue sky/white cloud and white walls. But since you didn't experience problems, perhaps it's time to update the firmware, at least I've got nothing to lose. 😄😄 

On the side note though, now that I also realize my 35/2 producing the same magenta edges, particularly prominent when shooting portrait mode consist of blue sky, similar to the 28/2. Maybe it is the firmware.🤔

@rpsawin hard to imagine they'll code it differently, maybe between different generations as the microlens filter seem to be different between M9/240/10?

Edited March 24, 2021 by Casey Jefferson

[rpsawin]

2 minutes ago, Casey Jefferson said:

@rpsawin hard to imagine they'll code it differently, maybe between different generations as the microlens filter seem to be different between M9/240/10?

I agree with you. I'm just not technical enough to state it definitively. Maybe others could chime in as well.

[a.noctilux]

4 minutes ago, rpsawin said:

In a related. question are the M Lenses Definitions universal or do they vary between camera bodies? Restated does my M262 define this lens the same as a M240?

Thanks in advance.

That was the thing I wanted to know.

I think that the sensors of M240/M262/M-D are the "same" but in use not really.

With some of my lenses, edge color came with M240 but never with M-D or M262.

Maybe tolerance of microlenses or electronic "corrections"..

 

I don't use some combos of "M+lens", after having some troubles with the combos.

I don't investigate further, just don't use those lenses on M240, that's all.

Happy to have choices of some 28mm lenses.

[Ray Vonn]

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8 hours ago, a.noctilux said:

I think that the sensors of M240/M262/M-D are the "same" but in use not really.

That’s exactly what I was thinking from a simple look at the images from both cameras.

[Casey Jefferson]

After lots of reading and test shots, I arrived at a few conclusions. The M240 sensor filters/microlens was perhaps not a perfect design to remedy the color shifts. I've done a few test shots today using auto lens detect and blue sky show no traces of magenta shifts, compared to yesterday's ones with 28/2.8 asph profile it over corrects the shifts to cyan tints (albeit less offensive than magenta) and due to the corrections covering almost into the middle 1/3 of the frame it actually shift the white balance with same setting.

If the same lens behaves differently between 240/262, it probably means both camera has indeed different sensor stack. Probably none is better than the other. Out of curiosity, I searched pictures shot with M9 and M10 with the same lens, can't say I've seen the shifts on those, since the M240 being their first CMOS, Leica was probably experimenting. Seems like M10 has the best design to date.

Edited March 26, 2021 by Casey Jefferson