LCC

Jason821

• 29. Januar 2011 15:38

Hello,

I've recently upgraded to v6 Pro and I want to take advantage of the Lens Cast Correction. I need a calibrator plate but I can't seem to find one... I was advised on another forum to use a "Pocket LCC" but the only one I can find can't apparently be shipped to the U.K. ☹️

Well, OK, on eBay there is an official Phase One LCC kit but it looks like just the plate in a black wallet and costs £60GBP! The Pocket LCC costs about $17US and so I want something for around that price. This is for a Leica M9, by the way.

Any ideas? Thanks in advance...

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  Timandrews

  • 29. Januar 2011 17:42

  Jason,
  When I bought my p45+, I paid the $100 for the official Phase One LCC calibrator. When going back and forth between 2 studios, I accidentally left it behind. I picked up a scrap of matte 1/8" white plexiglass for $1.00, and it works perfectly. I love this digital back, and the guys at Phase have been responsive to helping with any issues I have had, but I must say that this kind of markup is very annoying, to put it mildly.
  
  I have found out that when using my p45+ on a view camera with movements, running a LCC test and new Macbeth gray card check is CRUCIAL each time a change of camera angle is made. I shoot a lot of product on white, and nothing shows a color shift more than shooting on white or grey. I can be perfectly calibrated for a given shot, then do another one with the exact same setup, lens, lighting, but tilt my lens a bit more or less to change the plane of focus. If I don't run another LCC I will usually see a color shift top to bottom. The bigger the difference in the amount of lens movements, the bigger the color shift. It's usually in the magenta to green spectrum, and looks terrible.
  
  The lens cast can be hard to detect when not shooting on a seamless background, and I'm willing to bet that a lot of images have been shot without knowing that it's there. I know that I shot some improperly calibrated images when I first got my p45+, because I was told by a well meaning source that once a calibration was made for a given lens, I could then use that calibration for that lens without problems for future shots. Not true! I didn't notice the shift when a file left my studio, but the client had problems once it went to the printer.
  
  As you probably know, the problem occurs when light hits the sensors at an angle, so if you're not shooting on a view camera with movements, you might not experience such problems. I've read that a wide angle lens on a Phase or Mamiya body might also be problematic. When I slow down in my shooting schedule, I'm going to test my Phase body and lenses.
  
  I hope the guys at Phase One can work on this problem, because it's very easy to forget the LCC for a shot when you have a busy shoot day, and the results can be very unsatisfactory.

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  Baxter Bradford

  • 29. Januar 2011 18:10

  As Tim has said, it is possible to use something else. I've recently used a piece of white plastic card from a modelling shop with my camera to use the dust facility with my 645FD and P45+.
  
  Presume that you might be getting cyan drift like issues as with M8 using wide lenses. I would expect that the white plastic card would suffice, an A4 sheet won't be much more than a pound. I can't remember the thickness I'm using, but hold them up to light and you want translucent, but not too thin. Apparently you can also use an Expo-disc, but like the proper LCC device, these aren't cheap!
  
  A tech camera is more demanding and I borrowed a proper Phase LCC when using a linhof Techno and associated camera movements.

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  Jason821

  • 29. Januar 2011 18:50

  Thanks very much, both. Your replies are reassuring in that I can improvise with confidence. I'll keep an eye out for something suitable to use in front of the lens.
  
  This is being talked about quite a lot on the Leica forum. With the M9 and certain wide angle lenses many people, including myself, are experiencing what is being called the "Italian flag" effect, with magenta on one side and cyan on the other. As you correctly say Tim, it's due to the steep angle of incidence at the outside of the frame, with the lenses' rear elements being closer to the sensor that with, say, an SLR (although no-one can explain why it's asymmetric). Some people are saying that they are profiling their lenses just once (at a choice of apertures), and are using these profiles successfully to correct all images for that lens. If I were varying the angle of incidence with a camera which had movements, then I'd probably not question forking out for the "official" calibrator but as Tim says, not even that seems to be a necessity 😄
  
  Thanks again,
  Jason

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