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Cromatic Aberration


OHW
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I used to have loads of moire with super sharp lenses focussed on fine patterns with the "basic" 18Mp Leica M9 sensor.

The 47Mp of the SL2 vs 24 of SL2s should indeed be able to stomach the ultra-sharpness of Karbe's "why stop down" 🤓 lens designs.

Also the issue should all but disapear in multishot mode if you do landscape/object photography on a tripod.

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I wonder whether the regularity of the pattern of colour filters on the Bayer matrix may exacerbate the problem of Moire.  They are arranged as two green pixels diagonally with one red and one blue filter.  If the arrangement was altered maybe Moire would not be such a problem.  Of course it would mean reading the images form the sensor would have to take into account the different arrangements for each block of 4 pixels, and potentially slow things down.

Any comments from the forum?

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6 minutes ago, Eclectic Man said:

I wonder whether the regularity of the pattern of colour filters on the Bayer matrix may exacerbate the problem of Moire.  They are arranged as two green pixels diagonally with one red and one blue filter.  If the arrangement was altered maybe Moire would not be such a problem.  Of course it would mean reading the images form the sensor would have to take into account the different arrangements for each block of 4 pixels, and potentially slow things down.

Any comments from the forum?

Fuji has an alternate to Bayer. Downsides outweighed the advantages in my opinion. Increased sensor resolution is the answer. 

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  • 3 weeks later...

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Not chromatic aberration because it only occurs when the houses aren't overlapping the poplar trees.  If it was CA than it would also occur where the houses overlap the trees but it doesn't.  I would guess that it might be the way the sensor recorded the complex light (front lit and back lit) so perhaps sensor bloom or perhaps an aberration in the post-processing software used.

Pete.

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1 hour ago, OHW said:

Sl24-90,if this is not CA then what is it?
 

 

I bet you where playing with a gradient to darken the sky in Lightroom and used blending mode to luminosity. :lol:

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The problem seems to be periodic. I can take 50 photos to provoke the error without anything happening but then suddenly the error is there. The error always occurs in conditions where you would expect a little CA on a less exclusive lens.
The lens has been tested on SL and SL-S and photo has been converted on 2 different commuters a Mac and a Windows. The latest update of Lightroom has been used in both cases. The error occurs regardless of which camera and computer is selected. So it must be the lens!  Suggestions?
It seems that the lens needs a trip to Germany.

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1 hour ago, OHW said:

The problem seems to be periodic. I can take 50 photos to provoke the error without anything happening but then suddenly the error is there. The error always occurs in conditions where you would expect a little CA on a less exclusive lens.
The lens has been tested on SL and SL-S and photo has been converted on 2 different commuters a Mac and a Windows. The latest update of Lightroom has been used in both cases. The error occurs regardless of which camera and computer is selected. So it must be the lens!  Suggestions?
It seems that the lens needs a trip to Germany.

Can you provide more detail on this image: is this a raw image processed in Lightroom or a jpg? What processing has been used in Lightroom, if any? If it is a SOOC jpg, what jpg settings were used in the camera? Before concluding that the lens is at fault, you need to eliminate processing errors.

Edited by LocalHero1953
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In all cases and also this photo it is treated in Lightroom. Only process performed is crop. I work exclusively with RAW. I have tried to turn automatic correction on and off without it having any effect. It seems that the problem always occurs at 90 mm (should not one expect the problem to be greatest at wide angle?)
This photo: 90 mm, 1/160, f8, ISO400.
Tried a setting on f4 and there was nothing to see! But like I said, the problem seems to be periodic. The only sure thing is that it always occurs with a bright sky as a background and when the trees are bare. I know that many on this forum "mocked me" when I claimed that I have a problem with CA using a brand new SL-S with a quality lens from Leica SL24-90. That's why I'm a little frustrated.

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If you change the color temperature then the problem seems to disappear! But it can not be the intention that you have to artificially turn a gray weather day into sunshine!

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2 hours ago, OHW said:

I know that many on this forum "mocked me" when I claimed that I have a problem with CA using a brand new SL-S with a quality lens from Leica SL24-90. That's why I'm a little frustrated.

It's sad to hear that you feel you have been mocked because I don't see mocking on this thread and I certainly had no intention of mocking you in my posts (including this one) so perhaps it might be your interpretation of what you've read.  English is not everyone's first language here and while the English that's written is by and large of high quality it's a good idea to give posters the benefit of the doubt.

I haven't seen either lateral chromatic aberration (LaCA) or longitudinal chromatic aberration (LoCA) in the pictures you've posted so perhaps you're confusing another optical aberration with CA.  Here's an example from Google that clearly shows the red and green fringing that is a typical effect of LoCA. 

Others who have the 24-90 Vario-Elmarit-SL (I don't, so I have no skin in this game) have said that they haven't experienced CA in pictures from their lenses so if you're having a problem then if you can post a picture that shows it and we'll try to help.  (I now think that the blue in the trees in the picture you posted above is more likely to have been caused by a colour balance problem because the second version you posted shows no obvious fringeing even when expanded.)

Pete.

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3 hours ago, OHW said:

If you change the color temperature then the problem seems to disappear! But it can not be the intention that you have to artificially turn a gray weather day into sunshine!

That was was I suspected. I can suggest a solution. Don't try making the sky darker and blue.  Try using Luminary and do a sky replacement..  I think there is something in photoshop now too. 

The good news is don't have to send it the lens and be without if for 3 months 

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10 minutes ago, Photoworks said:

That was was I suspected. I can suggest a solution. Don't try making the sky darker and blue.  Try using Luminary and do a sky replacement..  I think there is something in photoshop now too. 

The good news is don't have to send it the lens and be without if for 3 months 

The poster says he has done NO processing.

Doing a sky replacement seems a bit extreme.

The poster can also tell us which image better reflects the colours on the day with respect to WB. The image in #33 certainly looks more natural than #26.

Edited by LocalHero1953
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No lens is totally free of chromatic aberrations.  An Achromat lens focuses two specific wavelengths to a single point; an Apochromat lens focuses three specific wavelengths to a single point; a Superachromat lens focuses four specific wavelengths to a single point.  All other wavelengths in the spectrum are focused to slightly different points; there will be fringing in high contrast situations even for superachromatic lenses.  Post-processing is not going to be able to fix all the fringing.  And there continue to be the five monochrome aberrations - coma, spherical, astigmatism, field curvature and distortion.  Of course a zoom lens is going to have more issues with all these aberrations than a single focal length lens.

The Leica lenses are no better and no worse than the comparable offerings from Nikon and Canon.

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4 hours ago, OHW said:

In all cases and also this photo it is treated in Lightroom. Only process performed is crop. I work exclusively with RAW. I have tried to turn automatic correction on and off without it having any effect. It seems that the problem always occurs at 90 mm (should not one expect the problem to be greatest at wide angle?)
This photo: 90 mm, 1/160, f8, ISO400.
Tried a setting on f4 and there was nothing to see! But like I said, the problem seems to be periodic. The only sure thing is that it always occurs with a bright sky as a background and when the trees are bare. I know that many on this forum "mocked me" when I claimed that I have a problem with CA using a brand new SL-S with a quality lens from Leica SL24-90. That's why I'm a little frustrated.

the 24-90 is not a perfect lens, Leica does lots of correction in camera with this lens and combines optical and software to get to the best possible compromise. The Lens is optically softer at 90mm, but not by much.
If you would like some help please share some RAW's and we can all looked at it to determine if it is a software problem or hardware.
Often software fails more then hardware.
I am only seeing it because I have seeing the limitations before especially on little details like that of the trees in the sky.

Hope we can help and all learn from it.

Thanks

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Thank you all for good advice and guidance. I just want to round up the local Leica rep. and get advice and guidance there. I do not think it should be necessary to change the color saturation, contras and sky to something that was not actually there in real time. I like to take the "artistic freedom" myself but it should be me and not the lens that decides when.
Notice that I wrote mocked in "". 🙂

Thanks again to everyone. I will return when I have resolved the issue. It can be a mistake # 40, it often is.

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