what is this?

[Dragomir Spassov]

Hi, guys! I'm a Luminous reader from about a year, but now I think I have a reason to write.. Before one month I bought a digital back for my Contax. I'ts a Phase One P25+  Every single image have been produced by this back, suffer from a strange artifacts at the fine details zones. Its look like the back cannot render a thin line without aliasing! (please look zone2) When the photographed object have a bunch of thin lines or others fine details, the back shows other strange artifact. For me its look like as Jpg at strong compression.. Maybe its due to interferential and aliasing, I'm sure not. Please look to the zone1. They are a small (few pixels at size) lines which is always horizontal.

I'll be grateful for yours comments and opinions!

This is a 100% crop:
http://bliss.bg/work/issue/ZBR285crop.jpg

Here you can find the original file exported as jpg. Both files are without sharpen. Sharpening make things worst..
http://bliss.bg/work/issue/ZBR285.jpg

[Bart_van_der_Wolf]

Hi, guys! I'm a Luminous reader from about a year, but now I think I have a reason to write.. Before one month I bought a digital back for my Contax. I'ts a Phase One P25+  Every single image have been produced by this back, suffer from a strange artifacts at the fine details zones. Its look like the back cannot render a thin line without aliasing!

Hi Dragomir,

Yes, it's aliasing or Moiré. It is caused by trying to image detail that is finer than 2 pixels wide (the finest detail that can be reliably resolved with a discrete sampling device). The issue is aggravated by the Raw conversion process that confuses the detail for resolution of differently colored detail. Try using a different Raw converter, some allow to address moiré as a step in the conversion process. You can also try and make one normal conversion and one with a significant amount of noise reduction. If you layer them in Photoshop you can selectively mask the blurred detail in and hide the trouble spots.

Cheers,
Bart

[amsp]

There's a moire removal tool under the "details" tab in Capture One.

[Doug Peterson]

That's minor color moire. Minor meaning that the tool in Capture One should handle it quite nicely with minimal negative impact on the image. If you shoot this type of subject as your mainstay then you could add 20-30 points of moire reduction to the baseline style you use.

Doug Peterson (e-mail Me)
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[Doug Peterson]

--was wrong--

[Dragomir Spassov]

Thank you, Bart!
Yes I suspect pixel pitch of the back, but I have a lot samples from a Sinar 54M back with same rez, sensor size, pixel pitch.. and its captures don't shows any artifacts. I cant remember has this back an AA filter, witch will be a good explanation for its artifact free captures.

There's a moire removal tool under the "details" tab in Capture One.

Thanks for remaining, amsp! I know where it is. But unfortunately it can't help. I have few more variants to gain a clear exit from this situation, but nothing can deliver the pure detail, when it is not in the picture.

Hard to tell without having been there with the subject matter, lighting conditions etcbut it looks to me like you use Adobe Camera Raw or Lightroom rather than Capture One. Can you confirm this?

It was a Capture One 5.1.2 Pro without use of moire tool.

[Christopher Sanderson]

Warning: Commercial Pitch! 

This type of moiré removal is covered in detail in the Lu-La Guide to Capture One.

Once you have tried that tool in C15 Pro, I believe you will realize how simple this is to remove.

[Dragomir Spassov]

Posted by: dougpetersonci
That's minor color moire. Minor meaning that the tool in Capture One should handle it quite nicely with minimal negative impact on the image. If you shoot this type of subject as your mainstay then you could add 20-30 points of moire reduction to the baseline style you use.

No Doug. 20-30 points are helpless. If I want some improvement, should use about a 65-75 depend of the case.. Of course such amount leads to others artifacts and only thing which going better is the color moire. I have more acceptable variants to handle with the color, but have no idea how to handle the lack of detail?

[Dragomir Spassov]

Warning: Commercial Pitch! 

This type of moiré removal is covered in detail in the Lu-La Guide to Capture One.

Once you have tried that tool in C15 Pro, I believe you will realize how simple this is to remove.

Thanks, Chris! I can provide a raw file to you. If you be able to successful develop the missing details, based on this video lesson, then ok - I will buy it.

[Steve Hendrix]

No Doug. 20-30 points are helpless. If I want some improvement, should use about a 65-75 depend of the case.. Of course such amount leads to others artifacts and only thing which going better is the color moire. I have more acceptable variants to handle with the color, but the lack of detail?

Dragomar:

You might also modestly try the color slider in the NR tool. This may produce less peripheral damage than the color moire tool.


Steve Hendrix

[Dragomir Spassov]

Yes Steve, I know. I'm not bothered with the color issue. The problem is something brake the hairs. They are not smooth but broken by some kind of horizontal lines, and aliasing. The final look of the zoomed image at 100% is a thing that I can't call a photographic aesthetic. Things going worst when the image reach a postproduction. If I want a smooth hairs or other thin lines, I have to loose a detail, or start a very time consuming restoration.

[tho_mas]

Yes Steve, I know. I'm not bothered with the color issue. The problem is something brake the hairs. They are not smooth but broken by some kind of horizontal lines, and aliasing. The final look of the zoomed image at 100% is a thing that I can't call a photographic aesthetic. Things going worst when the image reach a postproduction. If I want a smooth hairs or other thin lines, I have to loose a detail, or start a very time consuming restoration.

not exactly time consuming (still annoying... mabye).
- edit your file in C1
- clone variant
on the variant:
- correct the color moiré with the moire tool or, in this case probably better, color noise reduction
- correct the little aliasing artifacts with luminance noise reduction (you can also play around with the "long exposure" slider and/or the "surface" slider)
[you can store these settings as "presets" for the resp. tools so that you can easily use them for other captures as well]
- process both the images, open them in Photoshop
- set the "softer" image as background layer and the "sharper" image on the upper layer
- erase the artifacts with a soft brush on the upper layer