Is depth of field working in the new beta?


#1

Hi all. busy playing with the new Beta. I am finding the depth of field is blurring the entire scene, even with a DOF object defined. My F-stop is 0.3 and blades 6.


#2

Hi @fxgogo,
thanks for testing!

Do you use blenderseed or any of the other plugins?
F# 0.3 is a very low one and the depth of field accordingly very shallow, means most of the scene will be blurred.
Some things to try:

  • You could try with F# 1.4 -2.8 and your scene should be sharp around the target region.
  • You could toggle autofocus and see if it makes a difference to specifying the target
  • Check your scene units, this affects focal distance and therefore F#

If it does not improve then it is indeed a bug.

Just to show a simple example scene with appleseed-Max: The target is the knot, F# = 1.4


#3

Note that F-stop values are linked to two things:

  1. The scale of your scene, i.e. how much real world physical distance 1 unit of distance represents.
  2. The dimensions of the camera’s film.

If 1 unit of distance represents anything else than 1 meter, or if the camera’s film dimensions aren’t realistic, then F-stop values will stop matching those from the real world.


#4

Thanks for the tips guys. I will look at the scene again and see what is up. Oh, I am using Blenderseed @Mango3


#5

The reason why I ask which plug-in is used when an issue with appleseed appears is that it helps us to drill down and find the cause of it. Bugs can be related to the

  • DCC application (Blender, Max, Maya, Gaffer)
  • plug-in
  • appleseed render core
  • or a combination of the above mentioned.

For instance, each application has their own camera types and the plug-in needs to map the properties of built-in cameras to the appleseed camera for rendering. So a bug in the DOF controls in blenderseed would not automatically mean that also appleseed for Max & Maya or appleseed core would be affected.


#6

Alright, thought I would dig into this a bit.

I started a new scene in Blender and used the default camera and cube. The only changes I made to the scene setting were to use the metric system and 1 unit is 1 meter. Unit scale stayed at 1. I added in more cubes and a floor to be able to see the DOF effect easily. The red cube is the focal point.

The default camera has a focal length of 35mm and a sensor size of 32. I enabled the DOF and set the blades to 6. these are the results I got:


This is the scene with 2.8 at the f-stop (or rather the f-Number to be exact).


The scene with a 0.3 f-stop


The scene with a 0.15 f-stop. We are seeing some of the DOF effect now.


I tried one of the camera presets here, in this case the Canon 1100D.

So I think there might be an issue. I could also be doing things terribly wrong, so I am uploading the Blender file as well for others to check my work.
Appleseed DOF test.zip (88.0 KB)

Loving the interactive rendered viewport by the way. Makes tweaking the lighting so much easier.


#7

Thanks a lot for the detailed analysis and the test scene, this will help! We’ll be looking into it shortly.


#8

Hi fxgogo,
I checked out your file and the depth of field does work, your scene just isn’t set up in a way to show it off. There are three things that determine the plane of focus on a camera: film size, focal length and focus distance. Your camera has a 28mm focal length, which is fairly wide angle, and that increases the focal region. Also you have the focal point at a fair distance from the camera, which also increases the focal region. Finally your film size is smaller than a 35mm frame, and that also increases the focal region. So it’s going to be very difficult to see much of any blur with this setup even if you do lower the F-stop significantly.

image

Here’s what it looks like with a 35mm film size, 90mm focal length and the cube in the front as the focal point.

Hope this helps.


#9

That is some good information Jonathan. Thanks for that. I think what I need to do more than anything, is become more photographic in my 3D work. I think I have spent too many years with old school renderers, that I am used to cheating these effects.

Good to see the effect works. Right, let me test this on my original scene. Back shortly.


#10

I must admit that appleseed is rather unforviging when it comes to setting up DOF or other spatially-sensitive effects such as SSS…


#11

Yeah that’s one of the benefits and drawbacks of path tracing: it behaves more like the real world.

There are some handy phone apps out there that take in those three main specs and will actually tell you what the range of focus will be.