Camera RAW to linear exr?

gnoop

Do somebody know a program where It's possible to export full range of pixel brightness from a typical RAW camera makes to a linear exr file?   Maybe linear 16 bit tiff or something  without typical clipping?     Not in Adobe Lightroom it seems.   Maybe in some alternatives?

GlowingPotato

You can convert it in photoshop, but i don't know how much information you gonna loose or if its gonna be correct. but you can always adjust the scale later...
You can also work with linear mode in substance designer, but it won't read your camera RAW file. you need to convert it first.

gnoop

GlowingPotato said:

You can convert it in photoshop,

You mean by placing raw as a smart object in 32 bit psd file?   Seems it clips the range to 0-1 nevertheless.    "Camera raw" outputs only 16 bit clipped images too.   At least from what I see.

Does it have any hidden extra option?

Oh, you probably mean by stacking same images exported with different exposure and then combining  them into HDR one.      Wonder could it all be done by an action somehow?

Noors

Camera bit depth is usually 12-14 so i'm not sure why it would be clipped ? Real question, not expert in the field.

gnoop

Noors said:

Camera bit depth is usually 12-14 so i'm not sure why it would be clipped ? Real question, not expert in the field.

Camera 14 bit is not the same as with an image.   Usually camera raw contains pretty good range of brightness  beyond 0-1 , thus we could fix overexposure  in RAW pretty much like in exr files.    But for some uncertain reason every RAW processing soft output  just clipped 8 or 16 bit file where you already couldn't squeeze anything from overexposed areas

Noors

Not sure to get you. 14 bit camera has definitly to do with image bit depth. A RAW picture contains less data than a 16bit, not even saying 32bit, file format can handle. I don't remember having issues making HDRI from (bracketed) Lightroom 16bit tiffs. So i wonder if your issue isnt the raw limitation itself.

You can't get very far in (true) exposure correction with a single raw photo, you'd need exposure bracketed pictures for a full light range hdr (something like 5-7 pictures with 2EV's space for exterior lighting)

You can open a raw in photoshop directly without using a smart object and save as whatever. Tho i don't really get photoshop color management so i don't use it to deal with hdr.

gnoop

See here https://photo.stackexchange.com/questions/97065/raw-to-tiff-or-psd-16bit-loses-color-depth

The pictures explain it all.     Raw files might contain not as much of true HDR range as stacked result  but still essentially  more than  what your 16 bit tiff or psd export does.      So why bother with bracketed series if it's all already there 

BTW,  from what I see when trying to import exr from Photoshop  to 3d max  Phtotshop saves 16 bit per channel anyway, not 32 really

Noors

You are right, 16bit image doesnt handle dynamic range but does it clip data like 8bit ?

Apparently not, it's just not displayed the same way (which is on a 8bit screen at the end of the day anyway). I'm not sure i stand correct, but i get that 16bit displays the full range tonemapped to 8bit, while 32bit or raw displays only a portion to full range tonemapped to 8bit, depending of chosen options.

Obviously, from what i read everywhere, the way to make a 32bit image is to merge differently exposed 16bit pictures with photoshop hdr pro for instance. So i guess hdr pro does interpret the 16bit data "correctly". But i'm not sure tbh

gnoop

I think regular 16 bit image does clip the range based by  some white  and black points you set as 0 and 1 during Raw processing  and any values outside are just cut off.  The difference wit 8 bit is just a number a gradations in between those 0 and 1, no extra  brightness stored anywhere.  

And 16 bit inside  Photoshop saved exr  files are linear floating point values,  so called "Half Float"  and do store a range outside 0-1 , just not as big as in true "Full float" 32 bit probably.     

 

 I just wonder why we couldn't export  that  un-clipped half float from Raw  directly since RAW files obviously contain more illumination range. Bet it would be enough in some cases without all the hassle with bracketing , stacking, crispness loss etc.

Prime8

I did a quick test and opened a Canon Raw (cr2) file in Krita, it was opened as a 16bit integer, and saved it as exr.
Opening the exr in Krita and changing exposure on both images showed the same result, clipping at the same points.
The exr was created as a float, though converting it back to integer didn't make any obvious difference.

I'm by far no expert, but maybe you wanna give it a try with Krita.

gnoop

I tried with Nikon NEF  files and looks like Krita does just exactly same Photoshop does . It seems like clipping what raw file may contain into a certain exposure range/setting you do in open dialog .   So once it's opened  it's already clipped and  no advantages   at all anymore to turn it into floating HDR, EXR or Tiff.   

I just wonder would it be really necessary to take tripod and use bracketing  with a new generation of cameras  having all their mysterious D modes with extended dynamic range in RAW files doing only one time quick shutter opening.  Like recent Fuji cameras for example

Why 16 bit  in half float exr is enough to store dynamic range     but 14 bit camera RAW is not enough.  Imo  it should be there already to certain extent  . Maybe noisy but still there   

Prime8

Too bad. The dynamic range of the image I tested with is probably not wide enough to test it correctly and I don't have any other viewer to see if Krita already clips it during opening.