Why doesn’t the VFB save the VFB color adjustments? It get’s me every time and it kind of defeats saving all the elements together from the VFB.
Great question…i am here to ask the same question today 
Hoping anyone or chaos group could answer this, thank you.
OpenEXR files are by definition intended to be in linear space without any color corrections.
Best regards,
Vlado
Okay, good to know. What would the best way to save the VFB color grading in 32 bit, with all the elements?
This might not always make sense. Many color corrections (highlight burn, LUT etc) clamp the result or otherwise modify it in a way that makes 32-bit output somewhat pointless. A better approach would be to export a LUT file with the color corrections and apply it on the exported linear EXR output.
Best regards,
Vlado
Gotcha, thank you!
@Vldao AFAIK using the current V-Ray LUT export (.cube files) will not produce the same result as the VFB for color values that go beyond the 0 to 1.0 range, because the cube file is written for the default domain 0..1.
Daniel
Hm, I have to check that.
Best regards,
Vlado
If vray can save out all the correction into EXR like corona is great right?
Nope. EXR files are supposed to represent the raw render without color corrections. We will enable the writing of the color corrections when saving to 8-bit files (JPG, PNG etc) but not for EXR files.
Best regards,
Vlado
Now i understand why vray turn off the option. but it is hard to explain to those who using corona in my company 
What is HDR format mean? do vray got this option now?
yes please, and also would be really really handy to enable writing LUT in 8-16 bit files directly from VFB. Any previews we make in VFB, atm we have to print screen instead of proper save when using LUTs
Right or wrong, I save a jpg version and copy/paste it over my EXR versions top layer (all in Photoshop), changing the jpg exposure to .4545. I then drag things I want above that jpg version, like reflection and specular. This way I get my bloom/glare, compressed highlights and all VFB setting with access to the linear information from the EXR.
why are you not saving vrimg file during render? saves your ass in so many situations. even if something crashes you have half of the frame. and most important thing - raw full backup of your render to use if you need it.
that is why this is the best way of saving renders. its a perfect copy you can resave as many times you need to as many formats you require. load it back to VFB and rerender a region to speed things up. backup in an event of a crash is just minor bonus.
and this is just a checkbox. no additional clicking needed.