Leica M11 JPEG Lens Corrections?

[bcaslis]

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I got my M11 a few weeks ago and I'm trying to understand some things for processing the images. I would expect that lens corrections (such as distortion) are done in camera in the JPEGs. I have four lenses, Leica 21mm Super Elmar, Leica 35mm Summicron, Leica 50mm Summilux, and Leica 75mm Summicron (lens detection is set to auto). I'm shooting both DNG & JPEG. When I bring the images into Lightroom the distortion correction looks different (when using Lightroom lens profiles for the DNG) which doesn't surprise me too much. But when looking at the JPEGs it seems in most cases the JPEG is not corrected but the DNG looks correct with the Lightroom lens profiles applied. This varies by lens but seems the biggest difference with the SEM 21.

Here's the out of camera JPEG:

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Here's the converted DNG:

 

 

Maybe it's me, but JPEG looks like it has barrel distortion but the converted DNG looks correct. I've gone through the menus and I don't see anywhere I could have turned lens corrections off. Any hints what I could be doing wrong?

 

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[Photoworks]

I think the vignetting is giving an optical illusion .

this are the 2 images overlapping, the difference is minimal

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[bcaslis]

Thanks but when I overlay them there is a clear doubling as soon as you get away from the center. While it can be debated how significant it is, it's clearly not an optical illusion.

 

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[hmzimelka]

3 hours ago, bcaslis said:

I got my M11 a few weeks ago and I'm trying to understand some things for processing the images. I would expect that lens corrections (such as distortion) are done in camera in the JPEGs. I have four lenses, Leica 21mm Super Elmar, Leica 35mm Summicron, Leica 50mm Summilux, and Leica 75mm Summicron (lens detection is set to auto). I'm shooting both DNG & JPEG. When I bring the images into Lightroom the distortion correction looks different (when using Lightroom lens profiles for the DNG) which doesn't surprise me too much. But when looking at the JPEGs it seems in most cases the JPEG is not corrected but the DNG looks correct with the Lightroom lens profiles applied. This varies by lens but seems the biggest difference with the SEM 21.

Here's the out of camera JPEG:

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

 

Here's the converted DNG:

 

 

Maybe it's me, but JPEG looks like it has barrel distortion but the converted DNG looks correct. I've gone through the menus and I don't see anywhere I could have turned lens corrections off. Any hints what I could be doing wrong?

 

It's my understanding that the M11 corrects only for colour shading and vignetting for a lens, and ads the exif for the lens attached. For a DNG file, the vignetting and colour shading correction is actually applied to the raw data, as in, it cannot be reversed. Accidentally choose the wrong lens profile in camera, and one can't undo it later.

So an out of camera JPG will not have distortion correction applied when looking at the image, but neither would the DNG. However, Lightroom defaults to applying lens corrections that it reads from the EXIF tags embedded in the DNG file. 

At least in my case, if I shoot JPG and DNG, my images look the same in terms of geometric distortion since my defaults in LR are set not to apply lens corrections.

These defaults in LR can be turned off, at least for the M11. No such luck with some other cameras.

 

[bcaslis]

If that is correct then it explains what I am seeing. If I turn off corrections, then the DNG and JPEG match. Seems odd coming from other cameras, they either always apply corrections to the JPEGs or give an option to turn on and off. If you wanted to use a JPEG flow, you would need to manually apply a correction to the JPEG, in Lightroom there are no Leica M profiles listed for the JPEG, only the DNG.

Does anyone know if this is documented anywhere? I can't find anything in the user manual.

 

[01af]

vor 2 Stunden schrieb bcaslis:

If that is correct ...

It is.

.

vor 2 Stunden schrieb bcaslis:

If you wanted to use a JPEG flow, you would need to manually apply a correction to the JPEG ...

You don't want a 'JPEG workflow.' Using JPEG as in-camera taking format will make sense only if you plan to use the JPEG files directly and immediately, without any additional processing.

As soon as you load the files into an image processor, even if it was just for cropping or downsizing, you may just as well use DNG; using JPEG will provide no advantages whatsoever. JPEG is for exporting finished pictures, not for taking exposures.

[bcaslis]

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Thanks, that is the root of my question. Why would anyone want JPEGs without lens corrections applied? Every other camera system I have used either does this or provides an option. That is why I am asking if it is documented anywhere that JPEGs do not apply distortion corrections. I do know many people who use JPEGs with minor tweaking for their workflow. It's not unheard of. I plan to primarily use DNG, but I am trying to understand the differences between the DNG and JPEG output I have been seeing.

 

[01af]

Leica M cameras don't apply distortion corrections to image files, period.

Image processors such as Lightroom etc. possibly do. And if they do, they might handle DNG and JPEG files in different ways, such as: Apply distortion corrections to DNG files automatically by default (via image-processor-specific lens profiles) and to JPEG files on demand only.