A Happy DOF accident that I don't quite understand - Thread one

McKinnanMcKinnan Posts: 0
edited January 2014 in New Users

First off, I hope I can post these in the order that I'm talking about so I'm breaking this up into 2 threads

Long story short, I wound up with an "accidental" DOF while transferring some models from another scene and I want to use it :-) However, it does not seem to be "obeying" the typical DOF settings I've learned about from you guys (i.e. Focal Length, dof, focal distance and f/stop)]. So I thought I would post 2 scenarios and maybe someone could explain.

First is the "accidental" - I'm posting Camera in Perspective view, Render and DOF settings.

See how the f/stop is all crammed together?

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Post edited by McKinnan on

Comments

  • McKinnanMcKinnan Posts: 0
    edited December 1969

    So in this second post, I'm trying to manipulate the DOF settings and cannot seem to come up with the same blurred result in the foreground character.

    Maybe someone could shed some light?

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  • XoechZXoechZ Posts: 1,102
    edited December 1969

    The "sharp box" is very narrow here, so everything outside will blur very quickly over distance. His head is much closer to the sharp area than her. So she is already blurring a lot more than he is.

  • XoechZXoechZ Posts: 1,102
    edited December 1969

    The "sharp box" is much broader here than in your first example. So blurring will not start so early. Thats why her head is still almost sharp.

    Generally said (not very technical but practical): the narrower the "sharp box" from the DOF setting is, the earlier and heavier the blurring outside of it. So it is not an accident, it is just showing its nature :-)

  • McKinnanMcKinnan Posts: 0
    edited December 1969

    Hi XoechZ - ok, but isn't the rule "things inside the box are clear and things outside the box are blurry"? I guess I don't understand why he is pretty clear and she is REALLY blurry. you're saying it's because she is much futher away from the "sharp box" as you call it?

  • SickleYieldSickleYield Posts: 7,639
    edited December 1969

    It's an interesting case, though - I'm glad to have seen it. I didn't know that the size of the sharp box had an effect on how far outside it the "hard blur" zone would start (I have only very limited experience with photography). There's a lot that can be done with that knowledge that can't be done without it.

    So thanks!

  • McKinnanMcKinnan Posts: 0
    edited December 1969

    so blurring starts before AND after the box and increases with distance?

  • XoechZXoechZ Posts: 1,102
    edited December 1969

    Yes, that is exactly what I wanted to say. He is soutside of the box, but still very close. She is far away compared to the size of the box and his distance to it.

  • XoechZXoechZ Posts: 1,102
    edited January 2014

    McKinnan said:
    so blurring starts before AND after the box and increases with distance?

    Yes, thats true!
    Everything inside the box is sharp, everything outside the box gets more blurry with distance. And the narrower the "box" is the more blur you get.

    I have also no experience in photography, so I cannot give you a technical explanation. It is just my experience with DOF in DAZ Studio, because I use it a lot.

    Edit: In fact, changing the size of the "box" is the only way to control the blur. More or less.

    Post edited by XoechZ on
  • McKinnanMcKinnan Posts: 0
    edited December 1969

    Awesome! I would have never thought of that! playing with that now (i always gotta see for myself, lol). Thank you XoechZ!!

  • McKinnanMcKinnan Posts: 0
    edited December 1969

    So I've been playing with this an cannot seem to find a way to keep her REALLY blurry as in Happy Accident and get him nice and sharp. I think I'm trying to break some law here, lol. A DOF policeman may be writing me a ticket as we speak!

  • XoechZXoechZ Posts: 1,102
    edited December 1969

    Try to move the center of the box to the middle of his head. But keep it narrow. Maybe that helps.

    I am also no expert with this. As I said in the other thread, these are just my experiences with the DOF effect. It takes me always a bit of trial and error and some test renders to get it as I want it.

  • McKinnanMcKinnan Posts: 0
    edited December 1969

    I think that idea is going to work! Again, never would have thought of that - way to get creative XeochZ. I think once I fix my lighting in this, I will be very happy. Thank again!

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  • XoechZXoechZ Posts: 1,102
    edited December 1969

    No problem. I am always glad when I can help :-)

    I think when you understand that "box" concept (something every photographer would kill me for) and its visual setup in the viewport, then it is easy to get any desired DOF effect. But it is still always a bit trial and error, especially with extreme settings like yours.

  • TjebTjeb Posts: 507
    edited December 1969

    @McKinnan

    I alway do what you do: create a new camera, click top-view to adjust the 'box'
    If you don't like that, there is another way to check the DOF area:
    You choose a color, (in my case blue) and switch on and off the near and far DOF plane visibility.
    Everything between those blue screens should be in focus.

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  • SzarkSzark Posts: 10,634
    edited December 1969

    but you can control the strength of blur via the F-Stop...lower is blurred and higher is less blurry

    Either side of the DOF planes (sharp box) will start at crisp and gradually get blurrier depending on the the F=Stop value.

  • Richard HaseltineRichard Haseltine Posts: 101,083
    edited December 1969

    Merged the two threads as they are pretty much covering the same ground.

  • XoechZXoechZ Posts: 1,102
    edited December 1969

    And the F-Stop value is the slider that controls the size of the box. Narrow or broad. So the same thing, just a different point of view :-)

  • McKinnanMcKinnan Posts: 0
    edited December 1969

    @tjeb & Szark - thank you both for the info! I will play with both of those insights as soon as I get back to my computer!

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