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SIGMA's Garish Red Problem ...

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Banned
Hi all,

most SIGMA users already know, that pictures that contain large-scale and bright garish red picture elements often cause severe problems.

In these cases, the very sensitive red-channel overflows.

The best way to handle this problem is to "underexpose" these shots when shooting them. Later, when developing the image, one might correct exposure to the necessary extent .... then things are done with!

But ... what can be done, when such a (problem) shot was taken without exposure correction.

Coincidentally, I happened to find a solution to recover such shots ...:)

Let us have a look at the issue:

View attachment 276

Well, I took this photo with my SD14 with NO exposure-corrections (multi spot metering). As expected, the red channel strongly overflows ... as the histogramme clearly indicates ....:eek: All SPP sliders are in "0"-position.
The rose does not look nice ... somehow washed out ... no fine details in the rose's petals ....

View attachment 277

The only options to correct the histogramm are first to darken the image until the red cahannel performs correctly (let us forget this!) or to reduce colour-saturation to the necessary extent ... let us watch this option...

View attachment 278

Well, now we have detailed structures in all petals but ... the rose looks pale and flat now ... no real solution, I think.

View attachment 279

As I found out ... the X3F-RAW-file is not the problem! It contains the necessary image information ... In this case it is the SPP converter, which cannot handle this problem.
I took another converter ... namely RAW-PHOTO-STUDIO.
First the RAW with NO corrections ....

View attachment 280

The problems now are exactly the same compared to SPP! The red channel overflows absolutely .... as the histogramme indicates, too.

But, RPS provides the option, to adjust different colours differently and independently. So, you can adjust the red colour range independently as far as colour saturation and brightness are concerned. This is, what I just did in the next step ... a very small correction of the image contrast ... and ..

View attachment 281

Now watch the detailed structures of the petals, colour saturation and the histogramme.
Done, I would say.

View attachment 282

See you with nice pictures

Klaus
 

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I don't konw german then i download today ARCSOFT PHOTOSTUDIO DARKROOM (the same of your software but in english), because i've the same problem on develop saturated red channel on SPP and LIGHTROOM 2, but i don't find anything for view full red channel of my X3F than a normal control of RGB. If you are so gentle to tell me how do you do, because i think to change my SD14 with a SD9 or SD10 for this problem.
I'm waiting for your response.
regards
 
Hallo amaxgraph,

welcome in the Sigma User Forum! Unfortunately, I do not use ArcSoft software, so I can not help you with this question.

Klaus is on vacation until 9th of October as far as I know, so it will take some time until he can access internet again.

best wishes
 
I don't konw german then i download today ARCSOFT PHOTOSTUDIO DARKROOM (the same of your software but in english), because i've the same problem on develop saturated red channel on SPP and LIGHTROOM 2, but i don't find anything for view full red channel of my X3F than a normal control of RGB. If you are so gentle to tell me how do you do, because i think to change my SD14 with a SD9 or SD10 for this problem.
I'm waiting for your response.
regards

Hello Maxograph,

welcome to the forum!

In fact, there is a difference between Arcsoft Darcroom and RAW-Photo-Studio!

Both softwares are similar ... but not the same! Arcsoft Darkroom was first, before they sold there software to "IMAG MASTER". So, RAW PHOTO STUDIO is Darkroom's progression.

http://www.rytterfalk.com/2007/10/08/raw-photostudio-darkroom-159-high-iso-flash-movie/

Here, Carl Rytterfalk shows basic functions .... :)

The "Garish Red Problem" can only be solved with RAW-Photo-Studio ... as I showed above! Darkroom does not have the selective colour menue, which was added with the later RAW-Photo-Studio!

So ... get you RAW-Photo-Studio to replace Arcsoft Darkroom! :)
Follow the steps, I indicated above! Most probably, you will be successful!


See you with nive pictures

Klaus
 
thanks Kluas, i'm testing in this day RAW PHOTOSTUDIO (i have many problem with the german language), and i've viewed immediatly the benefit. this situation have create more problem (than resolve it) on my workflow. I'm explain that i would say, i'm using LIGHTROOM 2.1 with all my camera (EOS30D, LUMIX DMC-L1, NIKON D1), i've just calibrated this camera with a colorchart target (with significant improvement of colour in Canon and Panasonic camera), but my mode of shot (only RAW in every camera), can't combine with RAW PHOTOSTUDIO and LR21. I search to expplain better my problem, to export a photo with optimal colour developed by RAW PHOTOSTUDIO i colud convert this in TIF file (8/16 bit), but in LR21 i loose the info about colour temperature and other, then now for SIGMA file i take even the X3F and a copy (colour correct) of TIF. This as a significant improve in dimension of my catalog and i can't have only a program (because RAW PHOTOSTUDIO can't have the database capabilities) for do my work. If you have info about a new version of SPP or a method to export a DNG (the DNG convert in RAW PHOTOSTUDIO is with a camera raw of ADOBE then reply the problem of read my X3F in LR21) with read X3F of RAW PHOTOSTUDIO i can't sell my SD14, if aren't solution about i'm selling this ASAP.
 
Maybe i don't explain well my problem (or we don't know that i'll ask you), the gear for ADOBE Product (DNG converter, Camera Raw, LightRoom that i call LR21 - LightRoom 2.1 candidate version) it's the same, then if i can't covert well my X3F with LR21, nothing of other software product by ADOBE that work different (final result it's same). If you know (but know really), a method to convert in digital format (every format but not TIF - tag informed file format or JPEG) that have inside every info generate by EXIF of my SD14, i'll thank you, if you haven't this knowledge don't respond to this question.
regards
 
Dear Amaxgraph . The most advanced degree of control over RAW conversion can only be found with dcRAW .

This little gem of software will allow you to convert to any Image file format ,with or without Gamma Encoding , to any Color Space with or without Color Balance and a lot more and it is free.

Output Options
0 Raw color (unique to each camera)
1 sRGB D65 (default)
2 Adobe RGB (1998) D65
3 Wide Gamut RGB D65
4 Kodak ProPhoto RGB D65
5 XYZ

This image for example is an SD9 X3F file processed in dcRAW-X , the Mac version , as a LINEAR CONVERSION . That is without Gamma encoding and Tone Mapped in Adobe Photoshop CS4.

View attachment 782




Luis
 

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Sunset with overly Strong Red

Yesterday, I was trying to shoot the Sunset. The Sun was already below the horizon, so all the red was the glow reflecting off the clouds.To boost the color saturation and contrast, I tried Uncompensated as well as both -1EV and -2EV settings. The photos were far from perfect, but the most striking difference between the SD14 photos and how I saw the sky was the intensity of reds captured. I saw subdued pastels, my SD14 captured intense and vivid crimson.

These images have not been adjusted. I converted them from X3F to 16 bit TIF with SPP, and then resized and saved as JPG with IrfanView.

ISO: 100, White Balance: Sunlight, Shutter: 1/10, f: 8

View attachment 879

ISO: 100, White Balance: Sunlight, Shutter: 1/10, f: 11 ( -1EV )

View attachment 880

ISO: 100, White Balance: Sunlight, Shutter: 1/10, f: 14 ( -2EV )

View attachment 881

Apart from a slight need to shift the color balance away from Magenta, the high red sensitivity brought results which were not visible to the eye.
 

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Yesterday, I was trying to shoot the Sunset. The Sun was already below the horizon, so all the red was the glow reflecting off the clouds.To boost the color saturation and contrast, I tried Uncompensated as well as both -1EV and -2EV settings. The photos were far from perfect, but the most striking difference between the SD14 photos and how I saw the sky was the intensity of reds captured. I saw subdued pastels, my SD14 captured intense and vivid crimson.

These images have not been adjusted. I converted them from X3F to 16 bit TIF with SPP, and then resized and saved as JPG with IrfanView.

ISO: 100, White Balance: Sunlight, Shutter: 1/10, f: 8

View attachment 941

ISO: 100, White Balance: Sunlight, Shutter: 1/10, f: 11 ( -1EV )

View attachment 942

ISO: 100, White Balance: Sunlight, Shutter: 1/10, f: 14 ( -2EV )

View attachment 943

Apart from a slight need to shift the color balance away from Magenta, the high red sensitivity brought results which were not visible to the eye.

Very nice shots Steaphany , and thanks for a very interesting and valuable posting about the peculiarities of digital sensors that have prompted many to say that , particularly Foveon sensors, behave more like Transparency Film , where slight underexposure brings out Increased Saturation.

Your keen observation :

.......... the high red sensitivity brought results which were not visible to the eye.

also points to another interesting fact , this time about the high sensitivity of the Foveon sensor to Infra Red , and the , somewhat insufficient Infrared Cutoff Filter.

Hope that somebody picks up on this , perhaps Tony C or Kakou.

Luis
 
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