on.raw.photography

In case there is a problem I must fix it, I would not be aware of one but you can send the Tiff by Wetransfer or similar and I'll see it gets in here

It might also make sense to disable the feature when using the "make selection and open CP while holding down the Shift key" method you suggested earlier in the thread.
It always has been that way. That is the whole point of that feature :D The selection gets heeded no matter what.

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A ...

I have sent a new build to everyone active on this. It tackles the false-positive cases presented here while still working reasonably well on actual negatives. Furthermore, it no longer has any impact on modes outside of ColorNeg.

From here, I think there are two possible paths. If it holds up well ...

Start here: https://on.raw.photography/viewtopic.php?t=942


A short summary of the longer thread I linked above:

Yes, this can be expected. PerfectRAW is not trying to hide the raw sensor noise from you. In a dark, smooth blue gradient, chroma noise may therefore become more visible than it ...

In more general terms, I'm just trying to find images that tricks the algorithm so Christoph can use them to improve it. I imagine building a foolproof algorithm that always knows what's part of the image content and what isn't is a pretty hard problem. There are probably a lot of edge cases ...

Then some Fuji Xtra 400 frames.

Wonderful, thank you. I already have a bunch of qualifiers to assess if a geometry is a frame or may be a window in the photo for example only I lacked a feeling for what values to use as thresholds. I suppose I'll fine tune this some more tomorrow, make a binary ...

Scandiscanner wrote: Tue Jun 02, 2026 3:17 pm But I found some other files that did cause problems. Will post them shortly.

Nice, maybe something can be learned from them.

An update on this.

I have spent considerably more time on the frame-detection question over the last couple of days than I originally intended. The extended test set has made one thing fairly clear: the comparatively simple sensitometric, or density-/brightness-based, approach I had hoped might be ...

First:
Thank you for posting this example,
It is precisely the example that is helping me see where I need to do better still in terms of detecting a potentially harmful outside.
I won't go into it, I'll just try to fix it.

Second:
You do not need to crop anything:

One simply needs to know ...

Being able to work with the edge of the negative without it affecting the curve calculation is a useful option for many.


I should add that we have always had this ability in CP3; one simply needs to know what to do. If you draw a rough selection over the negative area, making sure not to ...

I found that the underlying reason for the observed difference I mentioned was in the fairly new frame detection.

Perhaps it was not the best idea to introduce that so late in the process, but the idea had enough merit, since for some reason it seems unintuitive to new users to crop to the negative ...

Addendum: I think this is a bug after all.

When I started working on the above, I assigned sRGB, called CP, and it came up in PerfectRAW because of my previous use on Roberto's cliff image with the two gulls and my rose example. I switched to ColorNeg and did what I did without any bumps in the ...

I'm back from my short trip and have looked at this briefly.
For now, I'll just post what I saved while doing so.
Film_054_Bild_024.jpg
I did make screenshots to revisit later. This is the sRGB thought. If the gut feeling that wide profiles are involved in what you saw holds up, I will need to ...

Roberto, howdy,

thank you for this illustrative image post. I enjoyed looking at its hidden details.
I think I can explain what is happening here, and in this particular image the explanation is actually rather simple.

The darkest meaningful parts of the scene are probably the black feathers of ...

The second thing to try is a two-phase process for Adobe RGB.

Set the image roughly as you like it in ColorNeg mode. Perhaps lower the overall FilmGamma for Advantix 200 by pressing the FilmType button and then scrolling Film Gamma. I would try something in the vicinity of 1.5 for the higher ones ...

I think the CP2/CP3 difference will come down to working spaces. This used to be the state of things:
https://www.colorperfect.com/working_spaces.html?lang=en

However, folks insisted on assigning ProPhoto RGB, etc., to color negatives prior to conversion. Long story short: for narrow working ...

Regarding CP2 and CP3 : If you are sure that you have the same FilmType and G/L setup, I will look at this next week.

Regarding Roberto’s image:
There is basically film base in the shadow under the car. Look at this page: https://www.colorperfect.com/noise.html?lang=en It explains what we see ...

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 ...

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。

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Perhaps I should also explain why the image looks so noisy in the Photoshop preview. When Adobe passes the preview image to the ...

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 ...

When I opened the TIFF file, it opened in CameraRaw.
That has always been a configuration choice in Adobe Camera Raw, like here in PS CS5: ACR-Tiff.jpg
I'm just showing where it is; what it localizes to will of course differ across languages.

Either turn TIFF processing off in Adobe Camera Raw ...

As promised I made a video of the basic steps today, added Chinese captions, to the attached version.
If the service is available you can also look at it on YouTube:

Thank you very much for posting your raw sample images, as well as examples of where you ran into trouble with them.
I have now looked at the material and processed the examples myself. The important point is that I do not see a general problem with ColorPerfect when the expected workflows are used ...

In a longer perspective, perhaps (like in DSLRs etc.) a given area (typically in the middle of the frame) could be defined, as an alternative to the "whole frame" approach?

No, too messy. The idea of an enforced center-weighted algorithm falls short of what should really be done: implementing ...

Quick Update - i watched the youTube Tutorial and i realsied that i had not switched from ColorPos to perfect raw... now it looks good regading slides..

Yes PerfectRAW makes slides pretty straigt forward I suppose, actually more so than ColorPos at times.

Regarding the digitization of negative ...