hi my name is Joonas and next I'm going to show you how to use 32-bit float
workflow for your cgi images first I'll explain it in theory with some diagrams
and then I'll show it show an example how to do it in practice so okay let's
go to the computer now I'll try to explain this rather simple thing in a
simple way so let's imagine that you have a CGI scene with a very bright Sun
and some some very bright light source and some areas that are really really
dark so your scene has a very wide dynamic range and let's say that this
high histogram is representing that dear the whole dynamic range of your scene
and when you normally render out an image JPEG or gif 8 or 16 bit image you
basically have to choose which part of your scene is exposed correctly and you
kind of have to leave out something so part of the image is going to be
overexposed and part of the image is going to be underexposed or like totally
black so totally white or total black because these areas that fall below zero
or are above 100 those are going to be clipped and the information is gone it's
just total white no details and this is the year this is something that is
common to 8-bit images and 16-bit images so 58 jpg PNG and all those images but
if you use 32-bit float images and then you have the option to still bring back
information that is fallen above 100 or fallen below zero so basically you don't
see it when you when you look at image the white parts over over exposed parts
they look overexposed but the information is there so basically it
means kind of like I'm trying to explain by using this transform function so I
can kind of ugly lift stuff from total black and I can recover highlights
by compressing them inside the zero and 100 pounds and just to be clear when we
do this this basically decreases contrast but it increases dynamic range
when we're compressing the image it so when we compress the dynamic range to
fit into this zero and hundred space we lower contrast so I'm going to explain
by these two images and let's pop up the histogram just a second let's put it to
lumiose city okay it's the intagram here is a very low contrast image and as you
can see the histogram is like compressed it's only in the middle but if I show
you the high contrast version you can see the histogram is spreaded to left
and right so you're going to hear you can see that a contrast and dynamic
range are kind of like well opposite opposite things well kind of the same
thing but on the opposite side anyway so this is the theorem that if a scram and
when you take a picture you lose everything that falls below zero or is
above 100 if you use 8 or 16 bit images but if you use the dual bit load then
you can recover stuff because the information is still there so that's the
theory anyway mmm so in practice here we have this is
a 32 bit float image and as we can see here we have some issues like the
neighboring Wharf should not be white and there's another issue that sometimes
you have when you render out 32-bit float images is that the colors close to
zero that are close to black kind of start to go invert inverted so I'll fix
that and let's fix this window as well so
let's start with the window so in the fix the window will use the levels
adjustment layer most of the adjustment layers are not accessible in 32-bit
float but the levels is so let's use that and here and we're going to use
this down up a slider below the main one that we
normally use this but the this time we're gonna use this and this basically
decreases contrast and by decreasing contrast it will increase dynamic range
so let's see we slide it back we start to get detail like the bricks individual
bricks of the walls start to be visible so now we have the highlights recovered
next let's kind of fix the color issues here so I don't really know how what
causes this but I know that this weird coloring is because the hues are
inverted and we can do it by clicking this slider and bring it up in this case
about 30 the word 24 maybe so now it's very very very low contrast image but
again low contrast in is high means high dynamic range and the colors are kind of
straited out straight and well straightened out so it goes up what they
supposed to be they are not inverters so now this is basically the 32 bit float
part and now we just go mode 16-bit image mode 16-bit and yes we want to
merge the whole thing I'll choose exposure and gamma because this keeps
the the image visually identical and okay and then I'll bring back and now
you can see we have these adjustment layers back back on track so we're going
to use them as well as we want so I'll choose the exposure now though I'm in
the curves and I'll just bring it back blacks down and then I'll make nice kind
of like gamma adjustments all in like this something like this and now we
basically have well image that we have we have controlled we have what's the
word we have been mastering the dynamic range of the images correctly and next
I'm going to show you how to do after this like look after this global
assessment I'm going to show you how to do local adjustments I'll now show you
two techniques the first one is example the first one I'll I'll give a
nice pop to the floor so I'll make another curves adjustment layer then
I'll be tough I will be watching just the floor and I'll add a bit of contrast
to the floor so it looks good it'd be too much well I guess it could
be nice that's just it a bit more let's say that's that's good and into an - to
effect this only to the floor I'll make the mask inverted and then
I'll take the brush tool make the brush big and nice and add the flow about 20
somewhere there and then I start I will add white and I start painting in the
mask so painting white to the mass so it will wherever it's the wherever the mask
is white there it will say it will be applied the layer will be applied and
welds black the delay will not be applied so that's about it so now again
we now going to see that the floor got a quite nice remake and now I will show
you another one so this was this kind of like brute
force technique just by well adding white paint in white but next let me do
a bit more advanced and this time I want to bring more kind of like want to bring
more clarity I would say that they're highlights the window part I'll create
another contrast slider again and then I'll just bring down the exposure like
this and then I'll add em now I'm looking only at the window because we
can unmask it quickly and then I'll add this bit of vibrance and bit of
saturation and if we put this into a group you can see that they well the
outside looks bit better now so to to apply this layer only to the window
I'll use something called a luminance mask so I'm going to create a mask based
on the luminance values of the image and that is done easily with this free
plugin from Jimmy McIntyre and with this blocking I can just create a price mask
and now it created these extra channels where I can choose what I want to like
what part what part of the luminance I want to emphasize and let's say this
looks well let's use this this this looks quite nice on them so our ass
again and here I can chain of blue black parts are not affected and the white
parts are affected and everything in between
depending on the shade of the gray will will be gradually more and more affected
so let's create a Content a second here yep let's create a mask to this group
let's invert it so basically making it invisible then choosing this pride mask
one pressing command and then pressing click on this now we have this and we
have to click this RGB layer by the RGB channel back to have the correct colors
and now I'll start painting in just the part that I want to affect so let's make
a big nice brush a maybe not that big and I'll just paint in with the whole
flow is good well paint in what I where I wanted to
effect I'm just painting like this
okay now I'll command D to deselect the marching ants and here you can see that
I kind of give a slide well I brought the down the highlight part set a bit
and if we want to add the mask as you can see here this is a mask and all the
dark parts are not affected only the white parts but I still want to kind of
refine it and I'll just add a bit of black to this edges let's have the glow
bit lower there and I'll just add a bit of map black to restrict the effect of
the layer just do the parts that I wanted to effect so let's see maybe not
something like this okay let's see
not good yeah okay so he were here we had the two techniques of just brute
force painting the masking or then using this free blocking from Jim Jimmy
McIntyre to create this luminance mask and then do a bit more defined work okay
so here it is thank you and go ahead and practice bye
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