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Thread: Grid pattern in C1 processing

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    Grid pattern in C1 processing

    A mystery! Files from IQ180, Rd 23mm lens with RM3di processed with C1, the images appear with an intermittent grid pattern in the 4 corners, fading towards the centre of the image.

    Any clues?

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    Re: Grid pattern in C1 processing

    You're using a recent version of v7 using the "wide angle tech lens" option when creating the LCC?
    Doug Peterson , Digital Transitions | Email
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    Re: Grid pattern in C1 processing

    mmm. V7.1.1 No option for wide angle tech lens. Will a software upgrade and that option remedy the issue?

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    Re: Grid pattern in C1 processing

    Can you post a picture? What you are describing sounds like centerfolding or tiling. This is an issue that may show up with either the 60 or 80MP backs.

    However with centerfolding, you tend to the the lines in correspondence to the faint lines on the chip of the back. Each back is calibrated for this but you may need to have the back re-calibrated if C1 can't remove the lines with a processed LCC. The faint lines divide the chip into 8 smaller segments, even though it's one piece of silicon. I believe the lines are read outs for the image data so the chip can process the image faster. If one of the segments is out of calibration, you can see a hard line show up between two of the segments.

    I have been told that it may be possible to have this adjustment made working with a dealer, so that they can send you a new calibration file. Other times the back has to back to Phase to be re-calibrated.

    Paul

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    Re: Grid pattern in C1 processing

    With tech wide angles calibration won't help 100% as the tiles also differ a bit in how they react to light coming in at a low angle, ie one tile may darken a bit more than another and then the tile lines reappear even if the back contains 100% perfect calibratation data. In the tech cam case the back doesn't know which lens that were used and which movements that were applied so even if it had calibration data for all possible combinations it would not know which combination to apply.

    The solution is an LCC shot and a purpose-made LCC algorithm to solve the issue. Latest C1 should be able to work that out. In other threads I've seen that there's been some recent issues with the LCC algorithm in C1 so upgrading to the latest is and try again is probably a good idea. To get a perfect result that really removes all traces of tile lines it's also important to have a well-exposed LCC shot.

    Also note that the IQ180 is considerably worse at dealing with tech cam wides than an IQ160, this is due to the narrower pixel pitch and possibly some other pixel design differences. Without LCC shot applied you may see both tiling and micro lens ripple. For large shifts it will be hard even for the best LCC algorithms to make a perfect result.

    It's best if you post a screenshot of your problem though, it's hard to know what the problem is from a verbal description. It could be something else.

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    Re: Grid pattern in C1 processing

    Here's my case: http://www.getdpi.com/forum/medium-f...ing-issue.html
    My experience is that even with a properly exposed LCC shot C1 often fail to correct these tiling issues.

    As others have said please post a image showing your problem as it might be something else.
    Peter
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    Re: Grid pattern in C1 processing

    I've reprocessed the raw files with the updated software and the issue has not recurred, so hopefully that's it (although its occurrence was sporadic and unpredictable before). Attaching an example, made a little more complex because this is a focus stacked image of about 8 files, each of which had the individual grid at the corners.

    http://www.getdpi.com/gallery/files/...f9301_copy.jpg

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    Re: Grid pattern in C1 processing

    Huh, I have never seen something like that..
    Happy for you updating C1 seems to have solved the issue.
    Peter
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    Re: Grid pattern in C1 processing

    Oh... clearly not anything to do with color cast, tiling or any other hardware-related thing, instead just some processing bug. Great that it was fixed in latest version.

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    Re: Grid pattern in C1 processing

    Thanks for help!

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    Re: Grid pattern in C1 processing

    Glad to see the update fixed that issue, as like the others, never seen that before. Centerfolding would not show up on your image as you don't have any solid areas like sky or water where the lines would show up.

    Paul

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