Rhino 6 bug - focal blur

OK, I didn’t see any specific language in that item to indicate that the option should be removed from the panel…

Windows 10 is worse than MacOS… :wink:

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Ah well, maybe the wording was a bit obtuse:

Highlight by me. The highlighted part was meant to express the ability to hide focal blur…

I did some testing, and maybe I should essentially divide the aperture value by ten (well, multiply by 0.1 really :wink: ) so that user doesn’t have to input such different values from Rhino Render.

I created https://mcneel.myjetbrains.com/youtrack/issue/RH-43998 for this. I’ll see if I can get it still into 6.1. Would be preferrable

(6.1.18030.17371, 30.01.2018)
Unknown command here:

Thanks, logged https://mcneel.myjetbrains.com/youtrack/issue/RH-44000

SetViewFocusDistance command is not mentioned in the online documentation.
The SetViewFocusDistance command does change the lens length, but the lens length displayed in the properties panel does not change.

The lense length is not changed. The focal point for depth of field is. Lense length is effectively the zoom.

The target location and the camera location do not change either. If the camera is stationary, and its target is stationary, and its length lens is stationary, it means that its focus is stationary.

Aperture as F-Stop. Setting an absolute value for aperture opening always feels odd, as lens length also affects amount of blur. F-Stop takes both lens length and aperture into account, and results in a more predictable amount of blur.

Sam

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Logged as RH-44003

I guess the camera doesn’t act completely as a real camera. The focal blur distance in our case is separate from the camera target. I can see how one could expect them to be related, but they currently aren’t.

@andy, any comments on this?

There is another problem with the aperture and the f-number (a.k.a. focal ratio, f-ratio, and f-stop). Both of them control the brightness of the image. The smaller the aperture, the dimmer the image. Worse yet, very small aperture blurs the image as much as very big aperture. In other words, both terms are very confusing. I would replace all variables with one variable called focal blur. (It would be nice to have linear motion blur and rotational motion blur.)

I will agree aperture affects exposure, I will have to disagree that aperture (and thus F-Stop on similar lens length) does not affect the depth of field. Personally, I don’t feel exposure is really of issue here as the raytraced mode is auto exposing for us. I don’t think it necessarily has to be F-Stop (although I feel there is a lot of familiarity with that concept), but it really should not be an absolute aperture value, which only takes input in model units when lens length is always mm. That in my opinion is not intuitive.

Sam

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The smaller the aperture, the longer the depth of field. Maximum angular resolution of any camera is limited by diffraction. For example, if wavelength of light is one micrometer and aperture diameter is also one micrometer, the maximum resolution of the camera is only one pixel. This is, of course, the most extreme example of a pinhole camera. Real-life medical microcameras have aperture diameter of about 1 mm and resolution of about 250x250 pixels. Camera resolution grows proportionately with the aperture diameter.

Note that aperture in Raytraced does not have any effect on exposure. And resolution is governed by the camera size, i.e. final image resolution.

The camera simulation isn’t that intricate.

RH-44000 is fixed in the latest Service Relase Candidate

Friendly reminder: The “autofocus” option is still in V6.4 RC1 ((6.4.18093.10341)

Aye, not sure if and how it is going to evolve.

I don’t know if it’s me or a new kind of bug.
For me the focal distance and aperture settings produce unpreditable and inconsitent results.

I hope we can agree that all other things equal, identical sets of values for focal distance and aperture should always result in the same visual result.

This is not the case in V6.4 RC1 in my experience. I fiddle around with (only these) two parameters. Upon hitting enter, the blur effect changes. Then, when I change these parameters back to the settings I had before (again all other thing equal) the image is completely different (like no blur vs blur-only). Feels buggy to me.

Can anyone confirm this kind of behavior?

UPDATE:
Seems like there is similar glitch in Cycles to the one in this thread :

Blur results are different before and after switching to shaded mode and back to Cycles.

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