Strange colors when shooting wide open

[PetersDreams]

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Hi all

I'm new to the M9 (received about three weeks ago) and I'm slowly learning to use it (coming from DSLR world)

 

Sometimes I have strange colors on high contrast edges (both on the 90mm asph pictured here as well as on the 21 lux) when I shoot wide open, especially when the image is slightly overexposed. I never had something comparable on my D3.

 

There are strange colors (red on the 21 lux and red and green on the 90 asph)

 

Any hints or clues?

 

Regards

Peter

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[ho_co]

Peter--Welcome to the Forum! You'll find a lot of experience here to tap.

 

There have been a number of threads on similar topics. I'm no techie, so I'm only regurgitating the following:

 

1) This kind of thing can happen to digital sensors when they're faced with severe overexposure. "Blooming," some call it, but there are other explanations as well, including color aberrations caused by the microlenses. For some reason, the problem seems to clear up when the lens is stopped down to f/4 or so.

 

2) Some raw processors do better about suppressing the defects than others. Generally, many feel that Capture One does the best job.

 

 

So: Don't shoot tree branches against bright sky except as a torture test.

 

And: When you run into something like this, try another raw converter.

 

If that doesn't work, some of the threads suggest simple procedures for making corrections in post processing.

[Nikkor AIS]

Welcome to the forum, Peter. Your sample image doesn't look overexposed to me. I can't image that hearing that you just shouldn't shoot trees wide open is much of a solution to a new Leica owner. I shoot wide open all the time with Nikon D3 and I've never seen anything like that. Quite bizarre. I'm not sure what the problem is but it's not good.

 

Gregory

[adan]

.DNG or JPEG?

 

Are you using some kind of highlight recovery settings for the "slightly overexposed" images?

 

If DNG, which program, and which version number, are you using to develop the DNGs? There was a version of Camera Raw that caused artifacts with highlights.

[Dave Robertson]

I received my new M9 yesterday and noticed the same thing. In my case it is a picture of our old house with white porch railings against old brick behind. The lens was set at about f5.6, so not stopped down. The color fringes are quite pronounced, not only with the white on red, but also on other edges. I am using Aperture, but downloaded the Lightroom beta but did not see much improvement there. I attached a sample from a small section of the photo here. Thanks for the collective wisdom of this group.

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[adan]

Dave - In your sample I'm not seeing anything like what Peter is showing (thick color blobs around thin black lines)

 

I AM seeing some 1-pixel-wide moire color artifacts in your shot - e.g. under the tree, the vertical white seam in the porch has some red/cyan barberpoling, and the rough white porch rails have little color patches on the lines of wood grain.

 

This is "normal" for the M8/M9 sensors. In order to maximize resolution and fine detail, Leica intentionally does not use the image-blurring anti-aliasing filters common on most other digital cameras.

 

Most of the time this is a great benefit - but on occasion, if there are fine textures - or in your case, thin lines, that fall across the borders of pixels at a slight slant, they are read alternately by red and blue pixels (plus green) and these little colored confetti marks or stripes are the result.

 

Some RAW processing programs have moire-reduction tools. Otherwise, turning up the Color Noise Reduction can help blend the color blotches into the surrounding solid color.

[meino]

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In my experience, this is not restricted to some lenses. I have it with a summicron 50 and summicron 35 (IV).

I suspect it is caused by the lack of an AA filter and oversaturating pixels in high contrast situations. However in my experience it is only visible when you use Lightroom out of the box. When I use CaptureOne pro, these color fringes are not present. In Lightroom you have to set the defringe option to all edges.. That setting doesn't remove them all like CaptureOne, but what is left is minor. The defringe option is part of the Chromatic Aberation pane in Lightroom.

 

Meino

[PetersDreams]

Thanks for your feedback, all .-)

 

Ok, I get the same color blobs in JPG directly out of the camera, in DNGs in Lightroom and in DNGs in capture 1 trial version. The color fringes get better in Capture 1 compared to Lightroom, but the BLOBS??? That can't be normal .... and it seams the blob has a very defined lower edge, it's totally straight even though there is no contrast there, just white background. THAT's what I'm really concerned with.

 

any help with that, or should I return my M9?

 

Thanks again and thanks for your patience

 

Cheers

Peter

[PetersDreams]

Ah and I forgot:

 

Don't really understand why it should matter, but here you go:

 

Lightroom 2.6.1 on Mac (with the Leica fix), latest M9 firmware, Capture 1 latest release (just downloaded the software yesterday) and I haven't done any corrections yet, that's how the picture appears in the Software when it loads.

 

slight blooming or fringing I would understand .... but that ... in a Leica?

 

Cheers

Peter

[250swb]

Can you re-produce the blob, or is it only in this one image? If it were me and I saw that I would be alarmed. But if its not repeatable it would seem not to be a sensor problem. This may narrow down the field.

 

Steve

[mjh]

Ok, I get the same color blobs in JPG directly out of the camera, in DNGs in Lightroom and in DNGs in capture 1 trial version. The color fringes get better in Capture 1 compared to Lightroom, but the BLOBS??? That can't be normal .... and it seams the blob has a very defined lower edge, it's totally straight even though there is no contrast there, just white background. THAT's what I'm really concerned with.

The calibration of the data read out from one half of the sensor appears to be off. I cannot say whether there is an easy fix for this or the sensor unit needs to be replaced, but that’s for Leica’s customer service to decide.

[35mmSummicron]

Have any of the knowledgeable members of this forum been able to figure out what Leica did to 'fix' the green blob issue first seen in the M8?

 

I did a shoot with a number of strobes purposely flaring into the camera and got a few frames with the M9 and green blobs. The thing is, they only appeared because the camera was acting up--wasn't recording the images to card properly. I turned the camera off, popped the battery out, and then couldn't reproduce it again......I wrote it off as a temporary software glitch (this was also with the old firmware that I thought was very glitchy).

[Dave Robertson]

Thanks, Adan, for the very clear explanation. Now I'll know how to deal with it. Other than this issue, the M9 is a truly lovely camera and I feel right at home with it, having used the M6 for quite a few years before being sucked into small digital cameras.

[adan]

35mmSummicron: it was a hardware fix (replacement) to circuitry downstream from the sensor itself. Not sure what - there was speculation about the "clock" circuit at the time.

 

Petersdreams - I think you and Michael H. have nailed done the core problem - a difference in how the two halves of the sensor are being read.

[ho_co]

I hadn't noticed the central straight line. You're right. I retract my earlier entry.

 

Sorry to see this.

 

Welcome to the forum, BTW.

[PetersDreams]

Right ...

 

So you're saying it's about the reading of the information from one half of the sensor is wrong in some way?

 

Why isn't this happening in every shot?

 

I think I will experiment a bit more and contact Leica tec support if I can consistently reproduce it. Most shots are just fantastic ...

 

Thanks for your help !! Will tell you if I have an update ...

 

Cheers

Peter

[mjh]

So you're saying it's about the reading of the information from one half of the sensor is wrong in some way?

 

Why isn't this happening in every shot?

It may be dependent on the image being overexposed within that area. But it isn’t normal behavior, overexposure or no overexposure.

[PetersDreams]

Sorry if I'm late in posting this and in order to make sure the loop is closed:

 

I checked with Leica and sent them the picture. They say something is wrong with the camera software that can only be fixed in Solms. So off she goes.

 

thanks to you all for your help in this matter, highly appreciated

 

Cheers

Peter