DOF too deep(not blurry)

[lorenzo_spinola]

Hi guys,
I had this problem since a while now, but because I don't use DOF very often, and I never have time to breath, I'm here today asking for help.

I work in scale, I know how DOF works in real life, but here in vray to start seeing something I have to put a value of 1.2 in the Fstop.
in general, with that value, depth of field should be very narrow and very blurry, but as you can see in my render test, that is something I should expect from higher values

Is this happening to somebody else?
Lorenzo

[fixeighted]

If you switch the scene units to mm then you should get the correct result, as the Vray cam works with mm and doesn't (though it would be nice) do an 'auto-convert'

[Joelaff]

DOF also gets messed up if you somehow managed to scale your camera. In fact in this case there is what I would call a bug that displays the plane of focus in completely the wrong place.It's not normally good to scale your camera. However, if you have a camera parented to a null and scale the null it will happen.

[lorenzo_spinola]

If you switch the scene units to mm then you should get the correct result, as the Vray cam works with mm and doesn't (though it would be nice) do an 'auto-convert'

so for others (me) that are using cm?
it sounds a bit stupid though that working in a different scale system messes up everything in the vraycam.

anyway, could it work in this way?
cm/mm--->Fstop 1.2 equal fstop 12? and so on..

[fixeighted]

It is annoying to have to remember but that is the case. It does state that mm is necessary in the docs.

I don't think that conversion is correct...maybe there is an equation but that is way more hassle than switching units I'd say.
Also it throws out all the other settings of course.

[^Lele^]

If your f-stop is 1.4 with mm as units, it needs to be 0.14 with cm as units.
We should probably make this clear in the docs.

[lorenzo_spinola]

If your f-stop is 1.4 with mm as units, it needs to be 0.14 with cm as units.
We should probably make this clear in the docs.

Thanks for confirming

[Vizioen]

If your f-stop is 1.4 with mm as units, it needs to be 0.14 with cm as units.
We should probably make this clear in the docs.

No f-ing way. Seriously? After all this time, this explains why I had to "hack" myself to a more or less correct DOF. Does this also apply to the PhysicalCamera of 3dsMax? So the standard F-stop of 8 is actually 80 when working in cm..... This kind of should be fixed to work with all the scene units.

[^Lele^]

Does this also apply to the PhysicalCamera of 3dsMax?

Yes, it's identical in this respect.

This kind of should be fixed to work with all the scene units.

I'd agree, but there may be reasons as to why it's not the case.

[lorenzo_spinola]

No f-ing way. Seriously? After all this time, this explains why I had to "hack" myself to a more or less correct DOF. Does this also apply to the PhysicalCamera of 3dsMax? So the standard F-stop of 8 is actually 80 when working in cm..... This kind of should be fixed to work with all the scene units.

mmmm....standard fstop 8 shoulb actually 0.8 if you are working in cm

[fixeighted]

Interestingly, this 2013 post quoting Vlado specifically states that conversion is taken care of internally.
Maybe something changed over the years to invalidate this feature...
https://forums.cgsociety.org/t/vray-...nits/1573235/3

This is the Chaos forum thread https://forums.chaos.com/forum/v-ray...m-Units-again=

[^Lele^]

focal length isn't f-stops.

[fixeighted]

Apologies...it was an assumption that 'generally' the camera settings would be converted regardless of units setup.

Probably more difficult than it seems, but if it's just an internal conversion then why couldn't the F be the same, out of interest?

[fixeighted]

The framing is very different between the switched units, for whatever reason.
I noticed the target distance changes from 451.779 to 45.178, which seems like a negligible amount though the visual difference appears far greater.

[^Lele^]

Yes, in fact even dividing f-stops isn't a fix.
It could be due to the way the lens is modelled, or some other obscure reason.
I poked the devs and asked. I'll feed you guys back as i'll know more.