Julius Bjornsson Posted October 15, 2007 Share #1 Posted October 15, 2007 Advertisement (gone after registration) As I have been extensively testing my lenses and camera the last day, I now came across a new type of artifact that I have not seen before. This was taken with a CV Color Skopar PII 35 mm lens, which is new and appears to be very nice overall. I did not get this artifact from the 50 f 2.0 or the 90 f 2.8. when taking a photo of the same tower at the same time. Furthermore I tried converting this in Lightroom, PSCS3, and C1 with exactly the same result. This is strange, something I have never seen before and never from this lens but the effect came consistently over a series of photos. The phenomenon is on the right side of the tower, and the second photo is a 200% enlargement of the tower. Someone, opinions? Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/35768-new-type-of-artifact/?do=findComment&comment=377050'>More sharing options...
Advertisement Posted October 15, 2007 Posted October 15, 2007 Hi Julius Bjornsson, Take a look here New type of artifact. I'm sure you'll find what you were looking for!
brucek Posted October 15, 2007 Share #2 Posted October 15, 2007 Looks like a JPG artifact to me. Do you have the RAW file to look at? Link to post Share on other sites More sharing options...
brivadois Posted October 15, 2007 Share #3 Posted October 15, 2007 There are many posts about it. It's a problem of "demosaicing". This issue appears sometimes, because there is no AA filter in the M8. I've tried many softwares for raw conversion but nothing to do. Fortunately, it happens not very often ( 4 or 5 times with 2000 shots). Here is an example with my M8+Summicron Asph 35. François Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/35768-new-type-of-artifact/?do=findComment&comment=377058'>More sharing options...
joachimeh Posted October 15, 2007 Share #4 Posted October 15, 2007 This type of artifact seems to be the result of the so called "de-mosaicing" algorithm. It can happen in the camera and/or in the postprocessing. Please see more on that subject in the discussion about the new DxO RAW processing features. Link to post Share on other sites More sharing options...
Julius Bjornsson Posted October 15, 2007 Author Share #5 Posted October 15, 2007 Looks like a JPG artifact to me. Do you have the RAW file to look at? Definitely not jpeg, as this was a DNG file. In the example from Francois here above it appears to be an attenuation of an existing pattern, but in my example the horizontal lines in the artifact are added in, there are no horizontal lines in the tower itself. But I am happy this is not something new and that others have seen it. Might it have something to do with 35 mm as that is the only lens I have that produces this? Anyway, it appears that Leica have still some work to do on their software. Link to post Share on other sites More sharing options...
35mmSummicron Posted October 15, 2007 Share #6 Posted October 15, 2007 I have seen this type of artifacts on my Canon 5D RAW files in similar situations (IE: very fine patterns far away) aside from the colour those types of patterns will be hard to reproduce in print. /a Link to post Share on other sites More sharing options...
Jack_Flesher Posted October 15, 2007 Share #7 Posted October 15, 2007 Advertisement (gone after registration) It's a sensor (demosaicing) artifact similar to moire. You see them in any camera where high-frequency detail approaches the sensor's pixel-pitch creating the interference pattern, but they are more common in cameras without AA filters and/or with good lenses. Cheers, Link to post Share on other sites More sharing options...
Julius Bjornsson Posted October 15, 2007 Author Share #8 Posted October 15, 2007 It's a sensor (demosaicing) artifact similar to moire. You see them in any camera where high-frequency detail approaches the sensor's pixel-pitch creating the interference pattern, but they are more common in cameras without AA filters and/or with good lenses. Cheers, So a lens that does not resolve these fine details would not cause this on the M8? So the cause is the combination high resolving lens+small details +M8. Is this correct. I guess this then tells a good story really, the CV 35 PII has resolution to match the pixel pitch on the M8. Is this also correct? Then happy ending to the story, really shows how good my new 35 is! The power of positive thinking. Link to post Share on other sites More sharing options...
Jack_Flesher Posted October 15, 2007 Share #9 Posted October 15, 2007 So a lens that does not resolve these fine details would not cause this on the M8? I wouldn't go quite that far... What I would say is the lens will need to resolve at least close to the native sensor resolution to generate the artifact. Moreover, you are going to see it more often with good lenses on a camera without AA filter than you will from a system with an AA filter using mediocre lenses. That out of the way, I will however state that I have found a few CV lenses to offer very good resolution, being quite crisp in center of field when stopped down. The 15 Heliar and new 21P are two such lenses, and I have no doubt many of the others are at least as good. Cheers, Link to post Share on other sites More sharing options...
joern Posted October 15, 2007 Share #10 Posted October 15, 2007 As I have been extensively testing my lenses and camera the last day, I now came across a new type of artifact that I have not seen before. This was taken with a CV Color Skopar PII 35 mm lens, which is new and appears to be very nice overall. I did not get this artifact from the 50 f 2.0 or the 90 f 2.8. when taking a photo of the same tower at the same time. Furthermore I tried converting this in Lightroom, PSCS3, and C1 with exactly the same result. This is strange, something I have never seen before and never from this lens but the effect came consistently over a series of photos. The phenomenon is on the right side of the tower, and the second photo is a 200% enlargement of the tower. Someone, opinions? Come on, what are we talking about? This part of the image is what, the 1/500 of the whole amount of pixels? This is common to those kind of sensor tech as others stated above. Or call it the price you have to pay for stunning 499 of 500 parts of the image. Normally no other but you will ever see this "fault" because of its size in print. Or did you hand out magnifying glasses while presenting your picts? Maybe an Leica cron or lux would have been the better choice if you are hunting after perfect quality within those very small parts. C1Pro has an anti-artefact button that has worked wonder with my Phase One p25 files. Maybe this will solve the problem with the posted problematic M8 files, too. After over 1.000 proceced m8 files (of 5.000 shot) i have noticed only 5 times strange pattern mostly in overexposed zones. Easy to remove / desaturate with photoshop. Nothing is perfect. But the quality of most m8 files came close ;-) Link to post Share on other sites More sharing options...
Julius Bjornsson Posted October 15, 2007 Author Share #11 Posted October 15, 2007 Come on, what are we talking about? This part of the image is what, the 1/500 of the whole amount of pixels? This is common to those kind of sensor tech as others stated above. Or call it the price you have to pay for stunning 499 of 500 parts of the image. Normally no other but you will ever see this "fault" because of its size in print. Or did you hand out magnifying glasses while presenting your picts? Maybe an Leica cron or lux would have been the better choice if you are hunting after perfect quality within those very small parts. C1Pro has an anti-artefact button that has worked wonder with my Phase One p25 files. Maybe this will solve the problem with the posted problematic M8 files, too. After over 1.000 proceced m8 files (of 5.000 shot) i have noticed only 5 times strange pattern mostly in overexposed zones. Easy to remove / desaturate with photoshop. Nothing is perfect. But the quality of most m8 files came close ;-) Hey I really agree with you, pixel peeping of this type is not very productive, but it can be interesting and for us technologically minded ones it is also fun. Trying to understand this type of phenomenon also gives a better understanding of the tool that the camera and lenses are. I also agree that any printing would probably not show this and the only really interesting point in all this is, the interaction between the sensor and it´s pixel pitch and the resolving power of the lens. Now that tells a story. But you´re right it has no effect whatsoever on the photograpy og quality thereof. Enough said. Link to post Share on other sites More sharing options...
Daniel Ortego Posted October 15, 2007 Share #12 Posted October 15, 2007 Strange how some of these threads can go sideways with just one slip of a syllable. In any event, I learned a great deal from your post, so thanks for sharing. Regards, Link to post Share on other sites More sharing options...
lct Posted October 15, 2007 Share #13 Posted October 15, 2007 Moiré is a pita in cases like this (D70, Nikkor 135/2). Can be forgiveable for a $1,000 digicam perhaps (?) but certainly not for a professional-level camera. The M9 and R10 will have a decent built-in or removable AA filter hopefully. Link to post Share on other sites More sharing options...
bradreiman Posted October 15, 2007 Share #14 Posted October 15, 2007 i keep getting artefacts in my shots too... Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/35768-new-type-of-artifact/?do=findComment&comment=377375'>More sharing options...
bradreiman Posted October 15, 2007 Share #15 Posted October 15, 2007 sorry couldn't help it-really I have seen this mayan pattern once in a sunset shot. once in several thousand shots is ok by me.....Bradley Link to post Share on other sites More sharing options...
mjh Posted October 15, 2007 Share #16 Posted October 15, 2007 Moiré is a pita in cases like this (D70, Nikkor 135/2).Can be forgiveable for a $1,000 digicam perhaps (?) but certainly not for a professional-level camera. Try to persuade vendors of high-end cameras such Hasselblad to equip their models with AA filters … Yes, even with a 30,000 Euro Hasselblad H3D, moiré has to be eliminated in the raw converter, as the camera itself does nothing to suppress it. The M9 and R10 will have a decent built-in or removable AA filter hopefully. I very much doubt that would be a popular move. Link to post Share on other sites More sharing options...
lct Posted October 15, 2007 Share #17 Posted October 15, 2007 Interesting Michael. I've tried once the Phase One Demoirize filter myself and i have been totally unable to eliminate the moiré from pictures like the one above without getting unacceptable blur. Other people have more skills than me fortunately but some of my pics are shot for legal purpose and the studio my office has been using to develop them has proved unable to get much better results so far. Would you know a better software yourself? Link to post Share on other sites More sharing options...
mjh Posted October 16, 2007 Share #18 Posted October 16, 2007 Interesting Michael. I've tried once the Phase One Demoirize filter myself and i have been totally unable to eliminate the moiré from pictures like the one above without getting unacceptable blur. Other people have more skills than me fortunately but some of my pics are shot for legal purpose and the studio my office has been using to develop them has proved unable to get much better results so far. Would you know a better software yourself? For the DMR, Hasselblad’s FlexColor is a good choice, but this isn’t an option for the M8. There are two aspects to moiré removal, and apart from having an effective moiré-removal filter at your disposal, it is even more important to employ a demosaicing algorithm that isn’t quite as likely to create colour moiré in the first place. The various raw converters have their different strengths and weaknesses with different kinds of patterns, and when Phase One lets you down, Lightroom or (on the Mac only) Raw Developer may be yield better results. If everything else fails, you could always open the converted image in Photoshop, switch to Lab mode, selectively blur the problematic areas in the a and b (colour) channels, and finally switch back to RGB. It usually does the trick. Link to post Share on other sites More sharing options...
lct Posted October 16, 2007 Share #19 Posted October 16, 2007 Thank you Michael i tried Lab mode and Raw Developer already and my lab did even more i guess but the final result is blur. What strikes me is when shooting technical things like the containers above i get a lot of moiré with my D70 (also the D2H sometimes) which have a weak AA filter but no problem at all with the D2X or my Epson R-D1's so far. So knowing this why would Leica users be bothered by this problem when we can take photos confortably with other cameras? And then why not a built-in or at least a removable AA filter in the R10 or the M9? Link to post Share on other sites More sharing options...
brivadois Posted October 16, 2007 Share #20 Posted October 16, 2007 Ict, Same problem for me: no way to find a software : Capture One (even the plug in for PS), LR 4.2, ACR 4.2, SilkPix, Bible Pro, Light Zone, RawTherapee: nothing changes except by blurring the details. But I prefer this minor issue than a AA filter on my M8. François Link to post Share on other sites More sharing options...
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