Exposure settings



  • 0_1516803134805_lion-hd-wallpaper_015820727_22.jpg

    0_1516803451588_flash.jpg



  • Photons may have infinite travel, but they don't have the same effect at all distances. I already acknowledged that I WAS using inverse square fall off. The body builder image shows the concept I am trying to achieve - a very well lit foreground subject with parts not far away in near darkness. This is accomplished here with a flash and a fast shutter speed. What is the mechanism in Poser that you would use to accomplish this?


  • Poser Ambassadors

    @matb
    The lion image is clearly postworked and not at all the result of any lighting phenomenon.

    The bodybuilder is not flash from the camera. There is a spot light above and to the left - you can see the specular reflections from that light on everything and the shadow on the chair to the right.

    Your presumption that the background is lit by that light but somehow diminished is incorrect. The background equipment is actually in relative darkness.


  • Poser Ambassadors

    You should read the text that goes with the Marc Schultz image.

    http://marcschultz.com/blog/pros-cons-of-speedlight-photography/

    The whole article is about placing additional lights. Yes these are flash, but not pointed at the background.


  • Poser Ambassadors

    Marc wrote:

    "Despite all the pros and cons, all the photos you see in this post I shot very recently using only a group of three speedlights triggered remotely within a very dimly lit weightlifting gym in order to capture these images of a Thai bodybuilder."

    See? The background is dimly lit, not at all by the bright speedlight (flash) we see pointing at the person.


  • Poser Ambassadors

    0_1516812997896_Limited Range Light.png



  • Poser doesn't support the physical camera aspects of Cycles, much like it doesn't have an equivalent of Filmic to give a more realistic range of light and dark. If you want to work with exposure, I'd suggest downloading the latest Blender, the Real Camera add-on, and setting the Color Management (in the Properties: Scene panel) to View > Filmic. Blender's Cycles also has denoising, so you can us a lot fewer samples. Oh, and it has a Physical node to make setting up most non-procedural materials pretty easy.



  • To further BB's comments, if you want to emulate a flash, use a spot rather than a point light. It better represents the focused beam. Flash units are rarely isotropic.

    To Kobaltkween, Blender has filmic response as standard since 2.79. No need for the camera add on anymore.



  • @piersyf They're two different things. The physical camera add-on allows you set the scene's camera using real world camera settings, including f-stop and ISO/exposure. Sort of like you can do in DS/Iray.



  • I know, I have it. But your comment only mentioned filmic response, nothing about recreating a DSLR. Just addressing filmic response, default Blender has it. If you want extra emulation capabilities, get the add on.



  • @piersyf That is what it means to "work with exposure." It's only something relevant to cameras- how long the film or sensor is exposed to light. In other words, shutter speed, or ISO. And I was well aware of the inclusion in 2.79, which is why my instructions said how to turn it on, not how to download it.



  • I know the lion is post worked, I said that in my second post, and I'm not surprised that the bodybuilder image was lit with overhead lights - these were illustrative. I really appreciate you chipping in to educate me, but I am CERTAIN that I read in a digital photography magazine a few years ago, a technique for accomplishing the same LOOK using a combination of ultrafast shutter speeds and other settings. I don't know what those other setting were but low iso and wide aperture seem plausible candidates.

    I'm simply unsure how to accomplish this effect in Poser. You gents have pointed out how my vocabulary is wrong, and my understanding of the physics of light is wrong, but still nobody has offered a suggestion how TO achieve what I know is achievable.


  • Poser Ambassadors

    @matb said in Exposure settings:

    but still nobody has offered a suggestion how TO achieve what I know is achievable

    I really don't know what to do to move forward now. We've said in several different ways that you need to use spot lights to throw light on your subject but not on the background, and further that the rendered effect of dim vs. bright lighting can be enhanced through postwork with Poser. A suggestion was offered that you perhaps can get more what you want by NOT using Poser.


  • Poser Ambassadors

    @bagginsbill said in Exposure settings:

    0_1516812997896_Limited Range Light.png

    I also showed you this which shows a pointlight in a can prop, thus physically making the light NOT REACH the background objects.


  • Poser Ambassadors

    Trivial post processing gives me this:

    0_1516895014071_Limited Range Light.png.jpg


  • Poser Ambassadors

    No matter how you imagine exposure works, the fact is that exposure is a linear operator applied to all levels of the scene.

    The term linear operator is a mathematical definition. Perhaps it doesn't mean anything to you but your belief system is that exposure is non-linear. Thus - what you want can't be done unless you stop using the words you use, i.e. exposure control is not what you seek.

    In postwork we can do all sorts of non-linear things. And with different film(ic) models we can do non-linear things. Film is non-linear.

    SuperFly is strictly linear.



  • When using a flash and natural light with a camera, one can use the shutter speed to balance the two - faster shutters reduce the natural light contribution. Maybe that's what he's referring to.


  • Poser Ambassadors

    In which case you simply put more light on the subject. How you manipulate that light ratio with a camera is indeed by adjusting the exposure so as to influence the brightness of the flash. This is motivated by the fact that you can't tell the sun to be darker.

    In Poser we simply turn the main spot light up and the other, ambient lighting down. Nothing more to it.


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