What should Shadow Blur Radius be for a bright, sunny day?



  • Firefly, Poser 11

    Okay, I have an outdoor scene with one directional light and BB's envirosphere. I want to have a bright, sunny day. Should the Shadow Blur Radius be 2.0 or like 20.0 ?? I still don't understand when to properly set a high blur radius or a low one depending on the scene. Can someone give examples of proper use of shadow blur radius values?

    It's a backyard scene, a bright and sunny day for a barbecue. No clouds in the sky. What should the Shadow Blur Radius be?



  • @zazop As I understand it, and I'm sure someone will either confirm or deny, All the shadow blur radius does is determine how distinct, or indistinct, the edges of a shadow is in a scene. That said, I don't think there is any correct setting for it. It is, after all, art. Just set it until it looks right to you, which means you may actually have to render the scene a few times. Now as to specifics, the HIGHER you set the radius number, the blurrier the edges become. A setting of 20 on a bright sunny day outside isn't just ridiculous, it's ludicrous. Also remember that Nature simply isn't that precise, so there will always be SOME blurriness to a shadow. My suggestion is to start at a setting of one, render it and see how you like it, then go from there.



  • @zazop As a helpful tip to add to the advice above, when trying to determine what value you want to put the Shadow Blur at, instead of rendering the whole scene, select a small portion of the shadow edge you are interested in and do an Area render.



  • @zazop I have the SBR set to 2.0 for the sun light in my free light set.

    http://www.sharecg.com/v/86639/browse/11/Poser/Studio-Portrait-Lights-for-Poser-11-Poser-11-Pro

    0_1525791044844_Girl on the Beach.jpg



  • For some reason (maybe I read it somewhere?) I believe that the value of shadow blur radius is actually in degrees- but I may well be wrong. Since the sun subtends an angle of around half a degree (if I recall correctly a finger's width at arm's length is about a degree?) a value of 0.5 would seem about right, although I usually use 1.0 or 2.0. And don't forget that you can also fiddle with Shadow Intensity for the light: by default that's set to 1.0 giving dark black shadows, but if you reduce it you can lessen the strength of the shadows - personally I often use 0.8.
    (P.S. That's all for PP2014, but I think it'll be true for Poser 11 too)



  • @3dcheapskate Here's what the Poser Reference Manual says which is where I tried to take my answer from:

    The Shadow Blur Radius parameter specifies the radius of this blurry region. By default, this dial is set to a low value. Raising the blur radius increases the soft shadow edge effect.

    So generally, in math, Radius is a measure of distance or length, not angles.


  • Poser Ambassadors

    Light is a strange thing. In 3D we have to fake it. That was where the "old style AO faking" came from.

    => => It depends to a very large extend on your light setup. Wanna be true to life or cheat?

    If :

    • You render with GC ON at 2.2 and IDL enabled
    • You render in a IDL dome
    • If you have only a single infinite light "playing Sun".
      So sorry, but planet earth has only ONE Sun shining on dust particles polluted air bringing us the IDL.

    Your best bet would be a SBR between 10 and 15.

    But everything changes the second you add a second light, because the moment you added that second light, you started "cheating" again.

    So, For outside renders => Render inside an IDL Dome + a Single Infinite light to "play sun" + GC and an SBR of around 10-15 to start with.


  • Poser Ambassadors

    I'll second 0.5; that's what I use because I remember @bagginsbill recommending that as appropriate for full sunlight with an infinite light some time ago (possibly on the Rendo forums). Using a larger number will soften the shadows & is useful for approximating more overcast conditions.



  • @vilters You should never use a second light in an out door daytime render. It'll look off. Skydome and 1 infinite is all you need. If the HDRI you are using is of a very overcast day you can just use the skydome.


  • Poser Ambassadors

    @ghostship
    That is what I said : A good IDL dome and a single Infinite light.



  • Many times I add fill lights to outdoor scenes.
    Basically to add to the reflected light in the scene
    Simply because nothing in an hdri is close to the figure like it would be in real life, or in many hrdi photos



  • @vilters said in What should Shadow Blur Radius be for a bright, sunny day?:

    Light is a strange thing. In 3D we have to fake it. That was where the "old style AO faking" came from.

    => => It depends to a very large extend on your light setup. Wanna be true to life or cheat?

    If :

    • You render with GC ON at 2.2 and IDL enabled
    • You render in a IDL dome
    • If you have only a single infinite light "playing Sun".
      So sorry, but planet earth has only ONE Sun shining on dust particles polluted air bringing us the IDL.

    Your best bet would be a SBR between 10 and 15.

    But everything changes the second you add a second light, because the moment you added that second light, you started "cheating" again.

    So, For outside renders => Render inside an IDL Dome + a Single Infinite light to "play sun" + GC and an SBR of around 10-15 to start with.

    I still say 10-15 is rather high. According to the manual.



  • @shvrdavid I suppose on indoor shots maybe with colored mesh lights??? Out door scenes work just fine without that as long as you light the skydome properly. Here the sun in behind the subject so most of the light is from the skydome.

    0_1525816477612_Camping.jpg


  • Poser Ambassadors

    If there are absolutely no clouds or haze in the atmosphere, the correct SBR is .5. And it is degrees.

    It's not wrong to use more (like up to 1) if the sun is passing through a lot of water vapor.



  • @bagginsbill said in What should Shadow Blur Radius be for a bright, sunny day?:

    If there are absolutely no clouds or haze in the atmosphere, the correct SBR is .5. And it is degrees.

    All right then. I obviously don't know what I'm talking about. So forget everything I said.



  • @caisson said in What should Shadow Blur Radius be for a bright, sunny day?:

    I'll second 0.5; that's what I use because I remember @bagginsbill recommending that as appropriate for full sunlight with an infinite light some time ago (possibly on the Rendo forums). Using a larger number will soften the shadows & is useful for approximating more overcast conditions.

    Found that one (or at least one of them) - 22 Apr 2015:

    https://www.renderosity.com/mod/forumpro/?thread_id=2889971&page_number=2#msg4200771

    (just spotted bagginsbill's post above which reconfirms)



  • @eclark1849 said in What should Shadow Blur Radius be for a bright, sunny day?:

    @3dcheapskate Here's what the Poser Reference Manual says which is where I tried to take my answer from:

    The Shadow Blur Radius parameter specifies the radius of this blurry region. By default, this dial is set to a low value. Raising the blur radius increases the soft shadow edge effect.

    So generally, in math, Radius is a measure of distance or length, not angles.

    Ah yes, in maths (or math if you prefer) radius is distance, but in Poser Manual speak it could be anything - time, weight, Jessis, etc... ;o)

    ( You don't actually believe that the manual speaks the truth, do you ? )



  • @bagginsbill said in What should Shadow Blur Radius be for a bright, sunny day?:

    It's not wrong to use more (like up to 1) if the sun is passing through a lot of water vapor.

    Phew, imagine the steam created by that !



  • @ghostship "Called fourex and spelt 'XXXX' 'cause Queenslanders can't spell 'Beer'" ;-)

    I can't count the number of times I have seen "behind the scenes" footage of photoshoots where crew members are holding up a big reflector. Absolutely zero difference from an area light used for fill, especially if the primary (Sun) illumination is somewhat behind the model and therefore casting shadow in the direction of the camera. If the real world professionals aren't afraid to augment inconvenient daylight when outside, then Poser artists certainly shouldn't be.


  • Poser Ambassadors

    @anomalaus

    Totally agree; But the same "thing" goes for make-up.

    Make-up, eyeliner, nailpolish, plastic boobs, and the list goes on and on.
    The lot is also to , tja, how to put it without stepping on toes. . . . . . make something not so perfect, "look" perfect. LOL.

    It is like so many things in life.
    We "fake" to look better, stronger, more appealing to the other side of the hormones. LOL.

    For years people have been complaining that I hang my Poser boobs too low.
    Tja, I live in a continent where we still have something called "gravity". (even with a Poser bra) LOL.

    So, in my Poser scenes, there is only ONE Infinite light inside an IDL dome.