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Enhance contrast in render

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  • Enhance contrast in render

    I know I can do tweaks in post, but I'm asking this as an educational exercise.

    The first image is the raw render, using DMC + DMC - Colour Mapping Reinhard with Burn set to 1.0.


    It's rather flat.


    This other one is the same image, except with a curve adjustment from the VFB.



    Quite a big difference.
    Is there a way to approximate my desired result in the raw render?
    Would it be colour mapping?
    Camera settings?
    Post Processing section under Indirect Illumination?


    Please mention what V-Ray and SketchUp version you are using when posting questions.

  • #2
    Re: Enhance contrast in render

    Well you can certainly adjust your contrast and saturation in the post processing tab you mentioned. Its better for a more permanent solution.
    John Harvey<br />Intern Architect<br />Digital Design and Fabrication<br />http://jrharveyarchportfolio.blogspot.com/

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    • #3
      Re: Enhance contrast in render

      I just realised how big difference there is between my work monitor and my home monitor. Thought I had them both calibrated... Looks so dark on my work monitor.
      Please mention what V-Ray and SketchUp version you are using when posting questions.

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      • #4
        Re: Enhance contrast in render

        Its next to imposible to get any two monitors from different manufacturers to be the same. Even worse is trying to get and image converted from the monitor to the printer. Since every monitor looks different you have to calibrate it even crazier to go to print and even then, every printer is different. It can be one heck of a headache.
        John Harvey<br />Intern Architect<br />Digital Design and Fabrication<br />http://jrharveyarchportfolio.blogspot.com/

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        • #5
          Re: Enhance contrast in render

          I found this site invaluable for monitor calibration:

          http://www.normankoren.com/makingfineprints1A.html

          Badly calibrated printers are the bane of my working life- I did some visualizations a while back and the client complained that when the professional printers printed test pages for the glossy brochure the images were too dark and rather green. After a lot of back and forth photoshop adjustments and testing they were finally happy with the printed images (which now looked awful on my calibrated screen, very overexposed and pink). I happened upon a copy of the final brochure a few months later- my images looked about right.... and every other photograph (which probably cost more per photo than all my images put together as they were taken by a professional photographer, set up on location with props and models) looked............ too dark and rather green.: Presumably the photographer had quite rightly refused to ruin his perfectly good photographs just to try to accomodate a printer firm who didn't know (or care) how to calibrate their equipment. It just astonishes me how unprofessional some "professional" printer firms are.... and they're always happy to blame others, even when all the evidence points to them.

          Sorry, this has gone a bit off-topic. :-[
          SU 2018 + VfSU 4.0

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          • #6
            Re: Enhance contrast in render

            Most of the reason why these renders tend to "lack contrast" is that by default we are gamma correcting the image. Gamma Correcting completely changes how the mid tones of the image reacts and although a gamma corrected workflow is something that is widely used in CG, its not something that's really expected by default.

            Assuming that you have the default gamma correction settings, just change the output gamma to 2.2 and disable Correct RGB and Correct LDR. Render. The result will have a completely different level of contrast and a completely different. Does that get you part of the way towards what you are expecting?
            Damien Alomar<br />Generally Cool Dude

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            • #7
              Re: Enhance contrast in render

              Originally posted by John H
              Its next to imposible to get any two monitors from different manufacturers to be the same. Even worse is trying to get and image converted from the monitor to the printer. Since every monitor looks different you have to calibrate it even crazier to go to print and even then, every printer is different. It can be one heck of a headache.
              Yea, I know you can't get them identical. But the difference between my home and work monitor was very distinct.
              Please mention what V-Ray and SketchUp version you are using when posting questions.

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              • #8
                Re: Enhance contrast in render

                Originally posted by dalomar
                Most of the reason why these renders tend to "lack contrast" is that by default we are gamma correcting the image. Gamma Correcting completely changes how the mid tones of the image reacts and although a gamma corrected workflow is something that is widely used in CG, its not something that's really expected by default.

                Assuming that you have the default gamma correction settings, just change the output gamma to 2.2 and disable Correct RGB and Correct LDR. Render. The result will have a completely different level of contrast and a completely different. Does that get you part of the way towards what you are expecting?
                The Output was already set to 2.2, with the Input linked to match. (That's the default, right?)
                I unticked the Correct RGB and Correct LDR Textures and rendered with DMC+DMC as I did with the two previous examples;


                I really don't know what to make of this...
                Please mention what V-Ray and SketchUp version you are using when posting questions.

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                • #9
                  Re: Enhance contrast in render

                  I changed the Gamma Input/Output to 1.0 and reduced the GI HDRI multiplier. Then I got some colour back with IR+LC. But when I switched to DMC+DMC I got a big lack of colours again. Here's a example where the right half is the IR+LC test while the left half is the DMC+DMC:
                  Please mention what V-Ray and SketchUp version you are using when posting questions.

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                  • #10
                    Re: Enhance contrast in render

                    Full IR+LC Test:



                    Still can't get the DMC+DMC with proper colours. (Not really sure if Gamma I/O of 1.0 is what I should use. But the 2.2 didn't look right either...)
                    Please mention what V-Ray and SketchUp version you are using when posting questions.

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                    • #11
                      Re: Enhance contrast in render

                      I'm not sure, but maybe we find a simple solution for the problem - did you use "store with IrrMap" at the "sun" light? If you don't use the IM, than all lights with this option on are off. I run in this problem some years befor and your DMC images are looking like without sun.
                      www.simulacrum.de - visualization for designer and architects

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                      • #12
                        Re: Enhance contrast in render

                        The only light source is the HDRI GI map.
                        Please mention what V-Ray and SketchUp version you are using when posting questions.

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                        • #13
                          Re: Enhance contrast in render

                          Hi guys,..

                          What do you think is the best software that can edit images like this .,? I use lot of editor but I think I did not yet found the best.,Can you tell what you think is better.,?


                          _________________
                          Rapid Prototyping

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