数字化出现严重的偏色 - Severe color cast appears during digitization

[黄海钦]

数字化出现严重的偏色。提供了相机翻拍后相片和captureone导出的相片。使用colorperfect出现严重的偏色

A severe color cast appears during digitization. The camera-reproduced photo and the photo exported from Capture One were provided. When using ColorPerfect, a severe color cast appears.

[C.Oldendorf]

我没有写过任何包含 Capture One 的工作流程说明。相机 RAW 文件应使用 colorperfect.com 上的 MakeTiff 辅助程序转换为 TIFF 文件；这个程序已包含在你的许可证中。

如果实际翻拍画面中的周围区域没有被识别为胶片片基/色罩，请把图像裁切到实际负片画面区域。或者，如果你不想裁切，也可以先画一个选区来标明彩色负片所在的区域，然后按住 SHIFT 键启动 ColorPerfect。

我感觉可能有一些杂散光照到了你的负片上，或者在负片表面附近发生了反射。也许你的翻拍装置还需要再调整一下，以消除这种影响。

另外，你也可以增加 1EV 的曝光量，这样可以得到更好的数字化质量。

---

I have not written any workflow instructions that include Capture One. Camera RAW files should be converted to TIFF files using the MakeTiff auxiliary program from colorperfect.com; this program is included in your license.

If the surrounding area in the actual camera capture is not recognized as the film base/mask, please crop the image to the actual negative image area. Or, if you do not want to crop, you can first draw a selection to indicate the area where the color negative is located, and then start ColorPerfect while holding down the SHIFT key.

I am under the impression that some stray light may be reaching your negative, or that light is being reflected near the surface of the negative. Perhaps your camera-scanning setup still needs some adjustment to remove this effect.

Also, you can increase the exposure by 1 EV to obtain better digitization quality.

[Full image link - opens in new tab]

[Full image link - opens in new tab]

[C.Oldendorf]

也许我还应该解释一下，为什么在 Photoshop 的预览中图像看起来噪点那么多。Adobe 在把预览图传给插件时使用的是跳像素的方式，也就是并不是按正常缩小图像的方式来生成预览。因此，噪点会被以一种不自然的方式放大；如果之后用正常方式把图像缩小到类似尺寸，就不会出现同样程度的噪点。在 PhotoLine 中，这一点是不一样的。

---

Perhaps I should also explain why the image looks so noisy in the Photoshop preview. When Adobe passes the preview image to the plug-in, it uses pixel skipping, meaning it does not generate the preview by downsampling the image in a normal way. Therefore, the noise is amplified in an unnatural way; if the image is later downsampled normally to a comparable size, the noise will not appear to the same degree. In PhotoLine, this is different.

[黄海钦]

我被一开始的偏色吓到了，所以我没去调参数。后来我调了一下就好很多。图片是我大概调了一下

At first I was frightened by the severe color cast, so I didn’t try adjusting the parameters. Later I adjusted them a bit and it became much better. The image is roughly adjusted by me.

[C.Oldendorf]

虽然你一开始展示的、与黑点有关的问题现在看起来似乎已经消失了，但从色彩上说，我对目前看到的结果还不能完全信服。请非常谨慎对待那些没有按预期方式使用 MakeTiff 和 ColorNeg DC 的流程。它们有时可能看起来能用，但也很可能会对结果造成不利影响。我给你看一下我最初发出的那张图像，在几乎没有做太多调整之后的 100% 局部裁切。

Although the black-point-related problem you initially showed now seems to have disappeared, I am not fully convinced by what I am seeing in terms of color. Please be very careful with workflows that do not use MakeTiff and ColorNeg DC in the intended way. They may sometimes appear to work, but they may also very well be detrimental to the result. Let me show you a 100% crop from the image I originally posted, after not having done very much to it.

[Full image link - opens in new tab]

既然现在只是一个局部裁切，我们也可以稍微把它提亮一些：在 ColorPerfect 中去掉一些 Black，并去掉一些 Graded White，从而更好地穿透画面中的雾霾。请注意船体本身很明确的颜色。也就是说，这个场景里其实有一些视觉线索，可以帮助你判断正确的方向。

Since it is now only a crop, we can also brighten it a little: by removing some Black and removing some Graded White in ColorPerfect, so that we can cut through the haze in the image more effectively. Please note the distinct color of the ship itself. In other words, there are visual cues in this scene that can help guide you toward the correct direction.

[Full image link - opens in new tab]

[robyferrero]

I tried processing it myself, and it came out like this. We can always argue about whether the tone is too warm or too cold, but that's beside the point. The image comes out well, but because of the more underexposed lower area, I preferred to lower the BPTails completely. However, I'm not sure I handled the more underexposed lower area well. So I also tried working without BPTails. You can see how with BP turned off, the more underexposed area remains more balanced, but at the expense of a softer overall contrast. I've also attached the two processed TIFF files and the dust-free TIFF negative so the author can do all the experiments he wants on a ready-made file.

[Lucc]

[Full image link - opens in new tab]

Hi,
I've tested your file.
Very nice shot.