Vray Physical Camera doesn't make sense

[cum. m+d]

Hey guys, I am a photographer that does 3D work as well.

These are my camera settings after i started messing with things like crazy trying to force the DOF.
https://www.screencast.com/t/0HdydlDrx

Here is the thinness of the DOF.
https://www.screencast.com/t/DtJztIR2wxd

I don't understand as everything is physically correct, including scale. This is a small object. The size of a mouse but I can't seem to widen the area of focus so it doesn't just become this thin line. Isit because it is a standard lens? Is a macro what I need and if so, How do I setup a macro lens to get a nice fall off into heavy DOF but we beautiful bokeh at the back.

This is my bokeh map. Is this the issue?
https://www.screencast.com/t/kYHCEDRBlGt

[vlado]

It would be best to post a scene with your setup.

Best regards,
Vlado

[cum. m+d]

Hello Vlado,

We signed NDAs for this project so is there a way I can share the file only with you?

Btw, congrats on winning the Academy award and thank you & your team for everything in our rendering world and your contributions. =)

[Morbid Angel]

iso of 25000? that does not sound right

However the F number is what controls the width of the DOF. I believe you adjust that you will get a wider DOF. However, there is no way (that I know of) to control the width of the area in focus.

[Komposer]

you have to switch on "Exposure color correction", only this enables the phys cam DOF, shutter and what ever things.
Then you can take a normal blendlist from real photogaphers and it will work realy correct.
Bad thing of exp controll, when you are too near to the objects, 20cm or so, the image will dimm dramaticaly.

[cum. m+d]

Yeah I ended up turning exposure control off.
I think due to the scene scale (small sized object) the DOF is probably realistic for a standard lens.

What pyhsical settings do I change in order to mimic a macro lens in the real work?

[francomanko]

you scene scale isn't in meters is it? If so change to cm.

[cum. m+d]

Oh!? is that what it might be?

Thing is, everything is to scale...I think based on meters but to scale still. So the object is probably 0.05 or something in world scale.

Does the scene scale affect physical camera? Wouldn't make sense though cause if everyone were to be working in real world scale but in cm instead of meters. They wouldn't think that is the issue cause everything is still "to scale"

[Komposer]

it´s basicaly recommended to work in cm and model in real scale. Then you can expect a proper DOF, close to real photograph settings.
...and you can use any common chart like this one.
The renderings shows, that it seem´s to work perfect, but I´m not a photographer

Startpoint was the 1meter group, with 5.6 f-numb and 500 shutter, that results in Row 14 in the EV-chart.
If you need more or less DOF, tweak the f.stop in real steps and look into row 14 how the shutter have to change, for the same brightness result...

...but you can also see, that vray physcam drifts heavy in brightness, when the scaling changes dramaticaly.
Is the focal dist, as example, 250cm it´s much brighter than at a dist of 25cm, and muchmuch darker at a dist of 2.5cm.
All 3 have the same lens settings - fNumber 5.6 and shutter 500
This should be the reason, that you at the end of the day switched off "Exp col cor" !?!
...perhaps your macro scene needs less than 2.5 cm?
Was for me again and again pure stress and time consuming to fight against that "reality feature"...
(discussed with forum/vlado and feedback was "has to be so, because it´s reality - nice)

What you can do is in macro case is...
...try to increas ISO until the brightness becomes ok (don´t think about reality
...plus/or lower the shutter speed
...or take your complete scene incl lights and cams into a group and scale it factor X up, until the brightness becomes nice values, while the DOF stay at what you want...

[Komposer]

here you can see, that DOF tweaking works perfect and like real, when you use cm and real object scales, with the help of the EV chart...
...with keeping the brightness at the same result...

[wizzackr]

it´s basicaly recommended to work in cm and model in real scale. Then you can expect a proper DOF, close to real photograph settings. (...)

Exactly, it only works if your model is at cm-scale.

It would, however, be really great if there was some sort of global multiplier to adjust the in-camera DOF to whatever scene scale Chosen by the artist/for the job - in lots of cases it is just not practical to model at a scale of cm as the scene will get so enormous that vray throws warnings with regards to the scene bbox being to big and that "raycasting errors might occur"

[francomanko]

Exactly, it only works if your model is at cm-scale.

scene units at cm, model to real world size. (sorry for being picky with wording)

[wizzackr]

ok, agree. vray's in-camera DOF seem to disregard maya's unit settings, too, or am I not getting something? Really late here so that's an honest question