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Magenta Cast appeared when using 28mm Elmarit


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This evening I have downloaded some photos taken over the past few days on my M262.

 

Most of the photographs were taken with an Elmarit 28mm f2.8 lens which I bought in October.

 

When I put the images into Lightroom I found that there is a magenta colour cast on the right of almost every image taken over a period of 4 days.

 

Here is an example, some are not as bad as this one: 

 

 

This is just the DNG file converted to JPG.

 

What I also noticed is that unlike when normally importing into Lightroom - the program did not recognise the lens profile - normally it does. I had to set these myself after import both for the 28mm Elmarit and the 75mm Summarit.

 

I did take a number of photographs on Sunday using my 75mm f2.4 Summarit and these are fine - no sign of a colour cast, also I can't detect the magenta cast on several indoor available light images taken with the 28mm Elmarit.

 

Any ideas?

 

Thanks

 

John

Edited by jhluxton
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Hello,

 

Strange.

With M262 and Elmarit-M 2.8/28 Asph. , never encountered this magenta cast.

With another 28mm (Ricoh LTM or Canon LTM), it occured on some bright sky like this.

 

Do you have a coded lens (if it's not the 28mm asph.) ?

Filter on the lens ?

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This evening I have downloaded some photos taken over the past few days on my M262.

 

Most of the photographs were taken with an Elmarit 28mm f2.8 lens which I bought in October.

 

When I put the images into Lightroom I found that there is a magenta colour cast on the right of almost every image taken over a period of 4 days.

 

Here is an example, some are not as bad as this one: 

 

 

This is just the DNG file converted to JPG.

 

What I also noticed is that unlike when normally importing into Lightroom - the program did not recognise the lens profile - normally it does. I had to set these myself after import both for the 28mm Elmarit and the 75mm Summarit.

 

I did take a number of photographs on Sunday using my 75mm f2.4 Summarit and these are fine - no sign of a colour cast, also I can't detect the magenta cast on several indoor available light images taken with the 28mm Elmarit.

 

Any ideas?

 

Thanks

 

John

 

Which Elmarit do you mean? The Elmarit-M 28/2,8mm or the ASPH one ore the Elmarit Typ II? ( a serial number will suffice also..)

Edited by Paulus
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Which Elmarit do you mean? The Elmarit-M 28/2,8mm or the ASPH one ore the Elmarit Typ II? ( a serial number will suffice also..)

 

Sorry its a 6 bit coded Elmarit ASPH - a nearly new model bought early October.

 

I have been using it as my standard lens instead of the 35mm Summicron since then and have shot many photos without problems.

 

Its been great - no problems with it, until now! I might have suspected the camera if I hadn't taken some images with the 75mm Summarit and noticed they were okay. 

 

John 

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Not a 28mm Elmarit owner myself and therefore not being able to offer any useful help here, may I nevertheless say that while reading the title of this thread for a moment I genuinely thought it said:

 

Magna Carta appeared when using the 28mm Elmarit

 

 

Imagine the extent of my curiosity!

Edited by Rus
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Either lack of coding, or menu not set to recognize the code.

 

It is a coded lens and the camera menu set to Automatic lens detection.

 

Interestingly the images taken with the Summarit which is also 6 bit coded also showed as having no profile information available.

 

I have this evening pressed the reset option on the camera and will do some test exposures in daylight with each lens tomorrow.

 

John 

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Sometime, the lens detection can't see which lens is attached (set on "auto detect").

I saw that the mount ( 6bit reader ) on the body is a bit muddy.

When cleaned, the auto detection works.

 

Now, when not sure, I push "Info" to see which lens is "detected" or "set" as I swap lenses.

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Did the camera have a knock? A mounting flange just a few hundredth of a mm out of true can cause this.

 

Not as I am aware of. 

 

Not dropped it, bumped it.

 

Camera spends its time in a case usually inside a Billingham camera bag when not in use, so doubly protected. 

 

However, just prior to my recent trip I did have the lens off doing a quick sensor dust check and clean.

 

I have just now taken the lens off and put it back on, inserted a card and taken an indoor available light shot, imported into Lightroom and the lens profile has shown up.

 

The images do not appear to have the colour cast - but this did not appear on available light indoor images taken over the past few days.

 

John 

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Sometime, the lens detection can't see which lens is attached (set on "auto detect").

I saw that the mount ( 6bit reader ) on the body is a bit muddy.

When cleaned, the auto detection works.

 

Now, when not sure, I push "Info" to see which lens is "detected" or "set" as I swap lenses.

 

Thanks - didn't think of doing that, will do in the future! 

 

So am I correct in assuming that as well as not recording the profile - if the camera doesn't know that the 28mm Elmarit is on it can give magenta casts in some conditions?

 

Or do I have two separate issues on the go here?

 

John 

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Thanks - didn't think of doing that, will do in the future! 

 

So am I correct in assuming that as well as not recording the profile - if the camera doesn't know that the 28mm Elmarit is on it can give magenta casts in some conditions?

 

Or do I have two separate issues on the go here?

 

John 

 

Yes - with wideangles (35mm or wider), and pretty much all the time, although subject matter/tones may disguise the magenta casts.

 

See: https://www.l-camera-forum.com/topic/280176-purple-corner-when-used-minolta-g-rokkor-28mm-f35-l-mount/

 

....for the detailed explanation.

 

In his case, he has an old non-Leica non-coded lens - in your case the code reader itself may not be (or have been) functioning. In both cases, the camera fails to correct for special problems that compact Leica/"rangefinder-sized" lenses have with digital sensors, leading to the color casts.

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hi,

 

seems to me it is the same problem as with some voigtlander glass, mainly wide angle lenses.

if the same lens is used on a film camera it will perform perfect but on a digital camera this is

what happens, but not in all light conditions... something to do with the rear piece of glass being to close to the sensor and reflecting some light or something like that, google for more info...

 

identical problem happens to me with my voigtlander 28mm f2 ultron... and 21mm f4

the old 15mm were even worst, but the newer 15mm and wider lenses have been

redesigned to prevent that, but now they are much bulkier...

 

about the cast - i got used to it, easy to remove in post...

 

samples

 

corrected 

Bohinj lake by Silvester Franz, on Flickr

 

not corrected

color cast on the right by Silvester Franz, on Flickr

 

sometimes it is much more noticeable...

 

but again, if it is some other issue I really want to know also

 

cheers,

S

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The lens coding works by having the coding (6 black or white dots on the lens' mounting flange) read optically by IR sources  and sensors on the camera's lens mount. Roughly like the bar-code scanners at grocery checkouts - the IR light bounces off white dots and is absorbed by the black dots. If the camera's reader gets dirt or dust on it of any kind, it can block the IR light and the detection will fail. If the lenses 6-bit coding dots (especially the white ones) get crud on them, that can also spoil the lens detection.

 

Or of course, failure can be a lost electrical connection, sensors out of alignment with the coded dots, or simply the detection unit failing internally.

 

The camera's 6-bit reader is a thin slit-like slightly-curved red-glass window on the lens mounting flange at about the 5 o'clock position as seen from the front.

 

https://www.reddotforum.com/ArticleImages/Photokina2012_Day_1/small/L1050449.jpg

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Why does it seem that magenta appears more often on the left of the presented image?

 

The Bayer pattern is not symmetrical - there is always a 1-pixel bias towards red in one direction and blue in the other, left/right and up/down. Which doesn't seem like much, but cumulatively across a couple of hundred pixels, you get a color cast that "fades in" as you get closer to one edge or the other.

 

http://renderingpipeline.com/wp-content/uploads/2013/04/bayer-pattern.gif

 

Now, perhaps the M9 sensor started with a red pixel in the top left corner, and maybe the M262/M240 starts with a blue or green pixel in the top left corner - thus one Leica may end up magenta on the left and another model may end up magenta on the right.

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It does sound like perhaps the lens wasn't being recognized to make corrections. As far as your test shot indoors, the edge coloring may be worse when focused near infinity when the lens is closest to the sensor, and the edge angle is worst.

I notice my M10 seems more resistant to this than my M9 with the same difficult lens (CV 21 f4) and same coding. I don't know if this is generally true of both models, or just my samples.

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It does sound like perhaps the lens wasn't being recognized to make corrections. As far as your test shot indoors, the edge coloring may be worse when focused near infinity when the lens is closest to the sensor, and the edge angle is worst.

I notice my M10 seems more resistant to this than my M9 with the same difficult lens (CV 21 f4) and same coding. I don't know if this is generally true of both models, or just my samples.

I have seen reviews saying M10 does works well with Zeiss 18mm f4 ZM lens. 

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It is a coded lens and the camera menu set to Automatic lens detection.

 

Interestingly the images taken with the Summarit which is also 6 bit coded also showed as having no profile information available.

 

I have this evening pressed the reset option on the camera and will do some test exposures in daylight with each lens tomorrow.

 

John 

 

 

John,

 

there's no Code in your Exif. The "28mm" is missing. 

 

Check your menu first. Then check if your camera / lens is really clean where the code would be read. It has to work. 

 

 

Next question:

Are you interested in correcting the pictures you have taken?   -  If yes; it's possible. To explain how it would be necessary to know with which software you work. 

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I have tried different presets on the camera, manually selecting different types of lens profiles...

Noticed mainly big difference in vignetting... Will try more what it does to color cast in my setup...

 

One thing I have not tested, does different lens profiles effect only JPEG or the RAW file too???

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