[MAC] New user to Photolab - underexposure issue


(George Tsoumelekas) #1

Hi all, i am a new Photolab user (30 days trial phase) and face the following issue: when importing photos, the software applies automatically some kind of preset (?) that underexposes severely and increases the contrast all photos. I can see that software applies automatically a preset as for the 1st second the photo appears to be exposed properly and then turns underexposed without any adjustment from my side. Is this normal? In the presets setting i use the “no correction” and sRGB as color space. My camera is a Canon 6d and i use Lightroom and DPP for many years but never seen this before. Thank you in advance.

(Svetlana G.) #2

Hello George,

1 - Could you, please, provide me with any of sample images to have a look?
2 - By default “DxO Standard” preset with auto corrections is applied. But you wrote you apply ‘No correction’ preset then Before/After images should be equal.
So waiting for your images for the investigation - you can upload them here upload.dxo.com under your name instead of ‘support ticket number’ and let me know when ready.

Thank you
Svetlana G.

(George Tsoumelekas) #3

Thanks for the prompt reply Svetlana. I am at work right now but i will upload them as soon as i get home.

(Sigi) #4

Hello George,

set the preset used to “DXO standard” in the settings and look what happens



(Platypus) #5

I get the same effect. Images start ok and then turn dark. This effect came in somewhere in the late OpticsPro versions.

In RawDigger and/or FastRawViewer, I see that my Canon files have an offset of about 4’000 for black and a linearity limit of about 10‘000 (according to exiftool), so maybe that DxO has other ideas of what black and white should be. Every raw developer has a different interpretation of what „no correction“ is too.

Just adjust the sliders until your result meets your expectation and after a while, you might be happy with the proposed presets or start creating your own.

If you decide to buy, go for the elite edition which offers better options. You‘ll want them if you get serious.

(George Tsoumelekas) #6

I recorded my screen and uploaded it - ticket number is my username. Let me know when you have a chance to check it.

(George Tsoumelekas) #7

Thanks for the reply. I am attaching 2 pictures before/after (again, I have selected “no correction” in the presets settings). As I captured the print screens, I noticed that in the first picture PL doesn’t read the histogram.



(Peter) #8

i got the same issue with auto mode. two raw applications which where different and DxO was around 1/2 EV darker. i think it expose to the middle instead of ETTR.

i use the Smart Lighting and the boxtool instead of auto exposure correction.
is much better.

edit: windows version. example:

i think its interpretation of the rawfile,
ive abandon the Auto Exposure Compensation (it’s sets to often in - xx.xEV wile +xx.xEV has a better result.) and go primary for Smartlighting and boxes plus manual correction in global exposure if heavily underexposed/overexposed)

(Svetlana G.) #9

Okay, thank you.

@LCDI could you, please, have a look?

Thank you
Svetlana G.

(Christian) #10

Which Picture Style do you use? Do you have Auto Lighting Optimizer enabled? Both will change the JPG preview in the RAW file which is most likely what DxO displays in the first instant.

I also suggest you try FastRawViewer as it will allow you to inspect the “RAW histogram” so you will see if you leave to much unused on the right side, in the lights.

(Christian) #11

Or do you have Highlight Tone Priority enabled? This will underexpose the RAW by one stop. DPP compensates this automatically, but DxO most likely not.

(LCDI) #12

So Well :slight_smile:

@tsoumi If you can provide us 1 of the picture you use in the Screen Cast it could be great.
Anyway, I’ll explain how the pipe of display a preview is done when a picture is discovered for the first time :

  • The picture is loaded
  • When it is loaded, we display first the screennail If we don’t have any cache file of this picture.
    :question: the Screennail is an embedded picture generated by the camera when writing RAW file. It is used for example to preview the picture on the camera’s LCD screen, in file managers.
    In some cases depends of the camera, if you choose some parameters like B&W the screennail could be B&W
  • We compute a first low res version of the picture with correction, when it is availalbe we display it in preview, (the blurry one)
  • We compute the final version and display it in preview.

In your case, I think that the stored picture in the screennail is “overexposed” compare to the Raw data that we retrieve.
You can use Exiftool to extract embedded pictures for example this command line :
exiftool -a -b -W %d%f_%t%-c.%s -preview:all YourFileOrDirectory

Hope I was clear :slight_smile:


(George Tsoumelekas) #13

Thanks for the detailed reply. I usually shot only Raw, never jpeg. Nevertheless, I tested some jpeg files and indeed there is no change in the exposure. I uploaded the raw file along with an export from the exiftool - I have used as ticket reference my username. Please let me know when you have a look.

(LesC) #14

I must say that I have been experiencing this issue for quite some time as well. So much, that I have created myself a preset DxO Standard +0.30 ev (and I often have to increase this exposure compensation even more). I apply this preset automatically upon opening my RAWs in DxO.
I have Highlight Tone Priority enabled on my EOS 7D, so indeed: that could be the cause! I’m now definitely going to do some tests with and without Highlight Tone Priority.
I never knew that this feasture would underexpose the RAW by one stop! Thanks for mentioning this. It might be the solution to my problem.