Site Sponsors
Results 1 to 45 of 45

Thread: Digital Sensor "Centerfold" correction

  1. #1
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Digital Sensor "Centerfold" correction

    It's bland white sky season again here and so a lot of my images are basically high-key in nature, at least as far as the sky is concerned. As a result I'm shooting and processing a lot of images to B&W, using C1 Pro 7 as the raw converter and Photoshop/Silver Efex Pro 2 for the B&W treatment. This has the capacity to stretch delicate tonality to a high degree and as a side effect it also really emphasizes any subtle sensor mosaic centerfold differences. (Thank goodness for PS's content aware fill / correction!!) It's always been there in colour but very very rarely visible unless a file was pushed & pulled.

    I was wondering if other folks had noticed their backs becoming more susceptible to centerfold calibration over time? My IQ160 is now some 15 months old and I'm beginning to notice the calibration differences more, exacerbated no doubt by me doing a lot more B&W conversions these days.

    Have you had to get your back recalibrated? Any feedback on turnaround times if so?

    I've submitted a case with Phase One and contacted my dealer already although it's holiday season so I don't really expect to hear much until next week. However, I was curious to know what experiences others might have had with this.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"
    Likes 1 Member(s) liked this post

  2. #2
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    I only notice it with my Cambo, with the 645 AFDIII there seems to be nothing.
    I think it has something to do with the angel of light from the large format lenses.

    LCC seems to take care of the issue for me...

    Peter

  3. #3
    Workshop Member
    Join Date
    May 2008
    Location
    NYC
    Posts
    3,275
    Post Thanks / Like
    Images
    7

    Re: Digital Sensor "Centerfold" correction

    Graham, can you send me a raw along with a description of what lens/movements it came from?
    Doug Peterson , Digital Transitions | Email
    Dealer for: Phase One, Mamiya Leaf, Arca-Swiss, Cambo, Eizo, Profoto
    Office: 877.367.8537. Cell: 740.707.2183

  4. #4
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Doug - Sure - will do.

    This particular case was with a Alpa/Schneider 150 XL Digitar on my Alpa STC. 8-10mm rise. I'll send you the raw and example B&W rendered image today when I'm home. The images were processed with ICC as I was actually putting together a pano. Normally I seldom bother with ICCs with the 150 XL.

    I've noticed it a few times before though but it's strictly been with bright portions of images. Not sure if from memory whether any have been from my DF since 90% of the time I use the IQ with my Alpa.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  5. #5
    Senior Member
    Join Date
    Dec 2007
    Location
    Little Rock AR
    Posts
    1,926
    Post Thanks / Like
    Images
    3

    Re: Digital Sensor "Centerfold" correction

    Graham:

    Is the centerfold the effect where you see the lines that correspond to the areas where the actual sensor is divided into 8 segments? I have never really known what the lines are from, stitching together of 8 sep sensors or coating or what.

    If it is the line effect, I often this with my 160 when viewing a LCC on the camera LCD. Much more rarely I will see it in a image file. Mainly in a situation like you describe white sky or us sky. So capture one seems able to adjust these out.

    On a recent loaner 180 I got this issue is spades. Especially with the 43 Schneider. All on a blue sky series. Even capture one could not fix them and they turned out to be very hard to remove with content aware. Problem did not manifest itself with any other tech lens or anything taken with a DF.

    Just got my 160 back but not sure it's the same camera as before. Mainly in the higher iso ranges. Still need to test it but weather conditions here are not that great at the moment.

    Paul

  6. #6
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Paul,

    Yes, centerfold effect is the very small difference in read out value between segments which may be only 1-2 levels in RGB but sufficient to show as a gradient line in the image. With B&W processing it becomes more obvious but I've had it in colour images too as you describe. If you stretch the tones then obviously the effect becomes more visible too.

    Btw, I see it both with shifted and non shifted images, with and without LCC.
    Last edited by GrahamWelland; 30th December 2012 at 15:13.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  7. #7
    Member
    Join Date
    Jul 2009
    Posts
    49
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    a little different topic... but is the recalibration recommended in general?
    I noticed that the censor is not even... I use LCC all the time and I thought that the unevenness is caused mainly by lens. But nowadays, I'm thinking that the censor also is not perfect too. Is there someone who did this recalibration? Do you want to share the experience and the process for doing it? And is it better after it? Maybe I'm too obsessed with it... maybe it's ok to have a little not-perfect censor.. since I know very well... that the perfect censor doesn't result in better images in general...

  8. #8
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Here's what it looks like. The recalibration is typically done back in Denmark I believe. Luckily I have a VA warranty so not really an issue. It takes certain types of images to make this visible and the attachments are small crops from a much much larger scene.

    LCC doesn't correct this unfortunately.

    It's getting sorted out by dealer / Phase One and so to both of them for responding even over the holiday weekend / new year.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  9. #9
    Super Duper
    Senior Member
    Shashin's Avatar
    Join Date
    May 2011
    Location
    Florida, USA
    Posts
    4,498
    Post Thanks / Like
    Images
    141

    Re: Digital Sensor "Centerfold" correction

    Well, I am disappointed. That is not the "centerfold" I was imagining.
    Likes 2 Member(s) liked this post

  10. #10
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Quote Originally Posted by Shashin View Post
    Well, I am disappointed. That is not the "centerfold" I was imagining.
    Ditto
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  11. #11
    Subscriber and Workshop Member MGrayson's Avatar
    Join Date
    Nov 2010
    Location
    NYC
    Posts
    1,575
    Post Thanks / Like
    Images
    4

    Re: Digital Sensor "Centerfold" correction

    A blast from the past - this is from one of my very favorite cameras of all time, the Canon 1D. Not s, not II or III or X, just "1D". Only 4MP, but each pixel was ELEVEN microns wide.

    It was extraordinarily fast for its day, and read the data off each side of the sensor. Sometimes (very rarely) this happened:



    It was either post this, or the results from a GIS of "Digital Sensor Centerfold"



    --Matt
    Likes 1 Member(s) liked this post

  12. #12
    Member
    Join Date
    Jul 2011
    Posts
    118
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Graham!

    Are all the images taken that day have the same problem?

    Amr

  13. #13
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Amr,

    All the images taken in the same light. Unfortunately I only really set up for one scene so basically the light was the same. I only see this with certain high-key situations. More contrasty lighting tends not to exhibit the behavior as the tones tend to be spread further I think.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  14. #14
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Now THAT's a centerfold

    Cute house Matt. That NY real estate certainly looks drafty though.

    Quote Originally Posted by MGrayson View Post
    A blast from the past - this is from one of my very favorite cameras of all time, the Canon 1D. Not s, not II or III or X, just "1D". Only 4MP, but each pixel was ELEVEN microns wide.

    It was extraordinarily fast for its day, and read the data off each side of the sensor. Sometimes (very rarely) this happened:



    It was either post this, or the results from a GIS of "Digital Sensor Centerfold"



    --Matt
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  15. #15
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    Graham, what being done to your back? Recalibration?

    I just got a DM33 which actually exhibits something similar. In some of the images LCC takes care of it on others unfortunately not.
    I have both vertical and horizontal lines in the images

    Peter

    Quote Originally Posted by GrahamWelland View Post
    Here's what it looks like. The recalibration is typically done back in Denmark I believe. Luckily I have a VA warranty so not really an issue. It takes certain types of images to make this visible and the attachments are small crops from a much much larger scene.

    LCC doesn't correct this unfortunately.

    It's getting sorted out by dealer / Phase One and so to both of them for responding even over the holiday weekend / new year.

  16. #16
    Workshop Member Woody Campbell's Avatar
    Join Date
    Dec 2007
    Location
    New York
    Posts
    2,120
    Post Thanks / Like
    Images
    66

    Re: Digital Sensor "Centerfold" correction

    This is actually very serious. Can it be traced to a firmware release? Are people seeing it in files that have not been tortured? In files that are exposed in daylight at base ISO? Does it affect both P1 cameras and tech cameras?

  17. #17
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Woody,

    This is nothing to do with the camera and everything to do with the back. I know a few folks ran in to it with the IQ180 when it first came out. As regardsa the image conditions, yes, base ISO in daylight. It'll be more obvious at higher ISOs. It's not specific to technical cameras either, although perhaps the glass quality exacerbates it.

    Basically it's manifesting what you've no doubt seen in live view where the different sections of the sensor are read but the same tonal values differ by 1 or 2 points or more between segments which leaves a perceptible edge between them. This may be both horizontal and/or vertical as the image is essentially built up from multiple square sections.

    As mentioned, I only ever really see it with white/grey skies although snow would also show it. Stretch the tones in a B&W image and you'll exaggerate the effect.

    It's not really just an IQ issue. Any camera can exhibit this if abused sufficiently. Since clouds, snow & overcast conditions are a big part of my environment and subject matter it's a particular concern for me. Once you see it, you'll start seeing it more and more ...
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"
    Likes 1 Member(s) liked this post

  18. #18
    Workshop Member Woody Campbell's Avatar
    Join Date
    Dec 2007
    Location
    New York
    Posts
    2,120
    Post Thanks / Like
    Images
    66

    Re: Digital Sensor "Centerfold" correction

    Graham - I disagree with your first sentence (I almost never disagree with you). I lived with this issue with my 60 meg Hasselblad kit - it's ultimately why I sold it. Centerfolding was not a problem with images taken with the hasselblad body and Hasselblad lenses - presumably because the mirror requires a minimum distance between the rear element and the image plane, there are no shifts so the geometry of how light hits the sensor doesn't change, and the manufacturer has a chance to fully optimize firmware for issues like centerfolding in the controlled environment is its own lenses on its own body. That all goes out the window once you introduce all of the variables associated with a tech camera.

  19. #19
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    I certainly can understand how the lens distance of a DSLR lens would cause light to strike the sensor in a cleaner, straighter angle and with a wide Schneider lens it makes total sense that the image would be less "balanced" across the frame and sensor boundaries. If i had an IQ180 I'd be all over the Rodie retro focus lenses for this exact reason.

    The only thing is that my example is from a 150mm tech camera lens which has it's rear element perched literally a mile away from the sensor, arguable further away in fact than the rear element of a 150mm DSLR lens actually. Now it does have a huge image circle so perhaps my rationale is flawed and there's still a significant light angle involved even with this lens?

    I have to wait until the weekend until I can give the system a full test with the DF in addition to the Alpa. I'll let you know if I can reproduce it with both systems on demand.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  20. #20
    Member
    Join Date
    Jan 2009
    Posts
    103
    Post Thanks / Like
    Images
    11

    Re: Digital Sensor "Centerfold" correction

    In the past, when we were discussing the possibility of a square (eg 48mmx48mm) CCD, it was often considered that the cost would be prohibitive. I think at that time, few of us realized that the CCD was actually being "stitched" together?

    For this problem, the root cause is the stitching. What the software/firmware can do is just to "hide the line". Because there is no physical CCD area overlapping for this kind of "stitching", the tolerance must be very high.

  21. #21
    Senior Member
    Join Date
    May 2011
    Location
    Hong Kong
    Posts
    691
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    I've experienced this problem in the past, in particular with the HR40 on an IQ160. In fact I'm on my 3rd back, however the problems were much worse than shown here and were all visible lines showing, not just the centre one.

  22. #22
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    So the back you're having now doesn't show this?

    Peter

    Quote Originally Posted by wentbackward View Post
    I've experienced this problem in the past, in particular with the HR40 on an IQ160. In fact I'm on my 3rd back, however the problems were much worse than shown here and were all visible lines showing, not just the centre one.

  23. #23
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    Here is what I'm seeing.. Cambo WRS, DM33 (Leaf Aptus-II 7) SK47XL. Just a tiny bit of shift.
    The first image has had no LCC applied, the second has, using Leaf Capture and converting to B&W in Lightroom with Nik Silver Efex Pro.
    Is this what to expect? Is everybody who do a lot of B&W on a tech cam seeing this?




  24. #24
    Workshop Member Wayne Fox's Avatar
    Join Date
    Nov 2009
    Location
    Draper, Utah
    Posts
    871
    Post Thanks / Like
    Images
    134

    Re: Digital Sensor "Centerfold" correction

    I think the greyscale conversion on mid to lighter tones can accentuate the sensor seams. Also if you push too hard in processing C1 it can cause it to be more noticeable.

    I had this problem last March, and did send my IQ180 in for recalibrating, and it did help ... at least I haven't noticed it since.
    wayne
    My gallery

  25. #25
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    Thanks Wayne, I'm really starting to think my back is in serious need of a recalibration...

    Have anybody else experienced something like what I'm seeing?

    Peter

  26. #26
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Not as severe but I'm in the same boat - mainly because I'm doing more B&W vs colour I think and therefore more sensitive to this.
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  27. #27
    Senior Member
    Join Date
    May 2011
    Location
    Hong Kong
    Posts
    691
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Quote Originally Posted by Pemihan View Post
    So the back you're having now doesn't show this?

    Peter
    Peter, Yes, my current back seems fine.

  28. #28
    Subscriber & Workshop Member GrahamWelland's Avatar
    Join Date
    Nov 2007
    Location
    Vancouver, WA
    Posts
    5,801
    Post Thanks / Like
    Images
    564

    Re: Digital Sensor "Centerfold" correction

    Doug,

    One of the issues I have with the KB article listed is that it covers the edge fall off and fine line introduction associated with the wides and light angles but how does that apply to the centerfold concerns? I know in my own case that I'm running in to the issue with a 150mm SK XL lens with no shifts whatsoever which wouldn't really fall in to this use case whatsoever.

    Also, it would be better if that tech note differentiated between LCC correction with & without the use of a centre filter too. This makes a significant difference in my experience at least with the SK 35 XL with the IQ160. Shifts need to be limited certainly if you want to avoid extreme colour issues (I never go beyond 10mm for example).
    Remember: adventure before dementia!

    As Oscar Wilde said, "my tastes are simple, I only like the best"

  29. #29
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    Graham, did you ever get a solution to the problem?

    Peter
    Likes 1 Member(s) liked this post

  30. #30
    Senior Member etrump's Avatar
    Join Date
    Jan 2009
    Posts
    1,206
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Quote Originally Posted by Wayne Fox View Post
    I think the greyscale conversion on mid to lighter tones can accentuate the sensor seams. Also if you push too hard in processing C1 it can cause it to be more noticeable.

    I had this problem last March, and did send my IQ180 in for recalibrating, and it did help ... at least I haven't noticed it since.
    I understand the calibration can be done remotely with an LCC exposure.

  31. #31
    Senior Member stngoldberg's Avatar
    Join Date
    Apr 2011
    Location
    newport, RI
    Posts
    801
    Post Thanks / Like
    Images
    12

    Re: Digital Sensor "Centerfold" correction

    Several years ago, Woody posted about his problem with "centerfold' on his HD60, and I discussed the issue with him I think in a PM. He correctly assured me that I wouldn't experience the "centerfold" with a tech camera and an HD50. I subsequently bought an Arca Swiss RM3DI and have been centerfold free.
    Woody was the first person, I think to discuss this problem, and thanks to him I escaped it.
    Stanley

  32. #32
    Senior Member etrump's Avatar
    Join Date
    Jan 2009
    Posts
    1,206
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    My IQ180 is coming back from Phase this week after being calibrated. It got to the point where even without adjusting the image the lines were visible, especially in an LCC. A slight saturation increase would exaggerate the effect.

    Seemed like it did increase with the age of the back.

  33. #33
    Senior Member ondebanks's Avatar
    Join Date
    Feb 2009
    Posts
    518
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Quote Originally Posted by yongfei View Post
    In the past, when we were discussing the possibility of a square (eg 48mmx48mm) CCD, it was often considered that the cost would be prohibitive. I think at that time, few of us realized that the CCD was actually being "stitched" together?

    For this problem, the root cause is the stitching. What the software/firmware can do is just to "hide the line". Because there is no physical CCD area overlapping for this kind of "stitching", the tolerance must be very high.
    It's not a problem of just the thin join line where the sensor segments abut - you wouldn't notice that. It's a problem of entire halves/quadrants/sixths of the sensor being read out through different channels, with their own amplifier characteristics.

    Ray

  34. #34
    Senior Member ondebanks's Avatar
    Join Date
    Feb 2009
    Posts
    518
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Quote Originally Posted by GrahamWelland View Post
    Woody,
    It's not really just an IQ issue. Any camera can exhibit this if abused sufficiently.
    If by "camera" you mean digital back or sensor, that is not always the case.

    As I explained here, some Kodak-sensored backs will never show this problem, because there is only one readout channel for the entire chip.

    Dalsa sensors are more likely to show it because they use multi-channel readout architecture in all of their CCDs. That makes them faster to read out, but the penalty is what you see here.

    I hope that with recalibration, it can be cured to everyone's satisfaction.

    Ray

  35. #35
    Senior Member
    Join Date
    Sep 2012
    Location
    Moscow
    Posts
    462
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Quote Originally Posted by ondebanks View Post
    If by "camera" you mean digital back or sensor, that is not always the case.

    As I explained here, some Kodak-sensored backs will never show this problem, because there is only one readout channel for the entire chip.

    Dalsa sensors are more likely to show it because they use multi-channel readout architecture in all of their CCDs. That makes them faster to read out, but the penalty is what you see here.

    I hope that with recalibration, it can be cured to everyone's satisfaction.

    Ray
    It also depends on other factors like how the readout channels are laid out, and how fast the data can be read, for example DSLRs have 8~12 readout channels that read data off the sensor in rows, and you never see this kind of anomaly.

    If medium format sensors went over to using a more tried and true method such as this one, this wouldn't be a problem. I'm honestly surprised that many MF sensors are read in quadrants, though it could be a limitation of CCDs.

    After reading "The story of the IQ260" on LuLa, I get the impression that Phase One pushed the limits of CCD sensor design with the IQ260, but it seems to me as effective as developing a new CRT monitor using 2013 technology. Potentially very good in some aspects, but inherently flawed.

    What I'm leading to here is that I often see the argument that new sensor tech is difficult to develop in a high-margin/low-volume market, but take a look at what RED is doing in the world of cinema. They started in roughly 2006, funded out of the owners pocket (admittedly a deep one), and though thick and thin, and people calling them scam artists for having the audacity to declare that they will sell a $30,000 or so camera that shoots 4K Raw video, what do we have now 6 years later? A 6000x3000 pixel, 30x15mm sensor that has a solid 16-17 stops of dynamic range and can shoot at 100 frames per second, developed, manufactured and assembled from scratch 100% in the USA. And they want to go for bigger sensors.

    Unlike RED, Phase One and others are long-established players in imaging technology, which makes me wonder why one doesn't attempt to break the flow and develop a genuinely out of this world sensor or camera design. The new RED costs $30-50k depending on configuration, which is similar to digital back prices, and you could argue that the number of film makers that can afford one is similar to the number of photographers that can buy a digital back - that is, if a thousand units sell worldwide, it can be considered a runaway success

    Sorry for the tangent.
    Likes 1 Member(s) liked this post

  36. #36
    Senior Member etrump's Avatar
    Join Date
    Jan 2009
    Posts
    1,206
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    My IQ180 back just returned from calibration at Phase and it now shows absolutely no centerfold effect even when cranking full saturation or clarity sliders. Prior to returning it, almost any adjustment would exaggerate the problem.
    Ed Cooley Fine Art Photography
     
    Likes 1 Member(s) liked this post

  37. #37
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    Ed, are you using Schneiders or Rodies?

    Peter
    Peter
    My website

  38. #38
    Senior Member etrump's Avatar
    Join Date
    Jan 2009
    Posts
    1,206
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Quote Originally Posted by Pemihan View Post
    Ed, are you using Schneiders or Rodies?

    Peter
    Both

  39. #39
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    I got my DM33 replaced with a new Aptus II 7, which is much better, but I still see the centerfold, especially when shifting, but some times also straight on.
    Contemplating sending it in for calibration..
    Peter
    My website

  40. #40
    Member AreBee's Avatar
    Join Date
    Dec 2012
    Location
    Highlands, Scotland
    Posts
    171
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Can the Leica S2 and S suffer from the centrefold effect, given that they also use a CCD sensor?

  41. #41
    Member
    Join Date
    May 2010
    Posts
    46
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Hello Rob,

    Yes the Leica S and S2 can suffer the "Centerfold" problem. I had to replace a sensor on my S2P. One way to spot the problem is to convert an image to black and white. It will pop up when you thought the dng image did not have a problem.

    Scott

  42. #42
    Workshop Member
    Join Date
    May 2008
    Location
    NYC
    Posts
    3,275
    Post Thanks / Like
    Images
    7

    Re: Digital Sensor "Centerfold" correction

    No Phase One back should show centerfold when:
    - using a supported lens (see official lens list or DT's unofficial but more up to date in-house list)
    - using reasonable photographic adjustments (e.g. [+30 contrast & +20 saturation] is fine, but [+50 contrast & +50 saturation & +strong_curve] is not)
    - a proper LCC is created and applied

    Any Phase back that shows a centerfold or other artifacts under the above circumstances would be eligible for warranty repair (assuming it's under warranty), including a loaner during the repair if a trip to Denmark is required (assuming the customer opted for the Value Added warranty).

    I've seen very little change in calibration that seems like a cumulative/consistent "aging" effect. But I have seen backs spontaneously develop a calibration issue when there was no such issue weeks/months before.

    In general we recommend Rodenstock over Schneider wides in order to reduce potential headaches like this. With "limited" support Schneiders (e.g. 35XL) it's hard to define for a customer exactly what amount of movement will be acceptable as it can depend on aperture, ISO/exposure-length, and orientation of the sensor.
    Doug Peterson , Digital Transitions | Email
    Dealer for: Phase One, Mamiya Leaf, Arca-Swiss, Cambo, Eizo, Profoto
    Office: 877.367.8537. Cell: 740.707.2183

  43. #43
    Member AreBee's Avatar
    Join Date
    Dec 2012
    Location
    Highlands, Scotland
    Posts
    171
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Scott, Doug,

    Thanks very much for the information.

    Over the previous two days I have scoured the GetDPI forum for information in order to educate myself about DMF, in particular tech cams. I'll be honest, when I:

    1. Read a thread that was started by owners who, upon receiving their then new-to-the-market IQ180 discovered severe lens cast with their Schneider lenses, or;

    2. First read this thread discussing the centrefold effect...

    ...it made me extremely nervous, to the extent that I would say I was fairly 'spooked' by the threads in question.

    However, having read through (1) above in its entirety it is clear that, at least with Rodenstock wideangle lenses, the issue of lens cast can be addressed. In addition, Capture One v7 apparently significantly improved upon LCC processing compared to its v6 predecessor that existed at the time the IQ180 was released. Moreover, one has only to see the clean, white image that results after an LCC has been processed, shown in this thread, to obtain visual proof that lens cast can (IQ160 was used in that test) be addressed...at least when a lens is unshifted.

  44. #44
    Senior Member etrump's Avatar
    Join Date
    Jan 2009
    Posts
    1,206
    Post Thanks / Like

    Re: Digital Sensor "Centerfold" correction

    Centerfold and lens cast are two different issues. Lens cast is a normal issue with wide angle lens on tech cameras. Centerfold issues are caused by calibration differences in the wafers of large sensors showing up as a straight line or other anomalies at the edges where two wafers meet.

  45. #45
    Senior Member Pemihan's Avatar
    Join Date
    Aug 2012
    Posts
    1,114
    Post Thanks / Like
    Images
    1

    Re: Digital Sensor "Centerfold" correction

    Doug, what about Leaf backs?

    Peter

    Quote Originally Posted by dougpeterson View Post
    No Phase One back should show centerfold when:
    - using a supported lens (see official lens list or DT's unofficial but more up to date in-house list)
    - using reasonable photographic adjustments (e.g. [+30 contrast & +20 saturation] is fine, but [+50 contrast & +50 saturation & +strong_curve] is not)
    - a proper LCC is created and applied

    Any Phase back that shows a centerfold or other artifacts under the above circumstances would be eligible for warranty repair (assuming it's under warranty), including a loaner during the repair if a trip to Denmark is required (assuming the customer opted for the Value Added warranty).
    Peter
    My website

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •