Playing with photos and Photomatrix Pro:
Ok so I take several photos at different shutter speeds and fstops, it seems like when you open the RAW file in Photomatrix Pro it exposes/view all of the images at some set value which is correct!!!
So for example these two:
Look the same, but they were taken are very different exposure settings, this is revealed by reducing the exposure on thei mage in post revealing that the one imagecaptured details in the lighter areas where the other didnt:
Same two images but with the exposure reduced in post. This is how image programs should behave!
Now for example lets open the same 2 images in photoshop and you will see my issue:
The one appears much brighter as photoshop views then relatively not absolutely. Which makes sense for the majority of things.
The problem is when assembling several exposures into 1 HDR image, at some genius point it shifts all the image brightness values to a centre point, an image preview white point or something, effectively turning the values into relative opposed to absolute.
Relative is nice for viewing images as you don't have to worry about exposing it properly in the viewer, however it makes HDR images USELESS! for rendering/image based lighting. It should be down to the viewer/reader to expose the image correctly but instead it appears to physically move light values around in order to bring it to a centre point for viewing.
I'm still not sure what's going on, I'm now getting the feeling that the image data recorded is kept accurate in linear pixel values and It's just the viewer converting it... It's hard to tell as I have found NO software that lets you sample a pixel and tell you It's real inear luminance value, they all tell you the relative value I think.
What I want to be able to do is take a 3D render and take a photograph and sample the actual surface luminance and check they are correct, check the sun is the right luminance, check the wall is the right luminance value for the size of room and the provided lighting.
Ok so I take several photos at different shutter speeds and fstops, it seems like when you open the RAW file in Photomatrix Pro it exposes/view all of the images at some set value which is correct!!!
So for example these two:
Look the same, but they were taken are very different exposure settings, this is revealed by reducing the exposure on thei mage in post revealing that the one imagecaptured details in the lighter areas where the other didnt:
Same two images but with the exposure reduced in post. This is how image programs should behave!
Now for example lets open the same 2 images in photoshop and you will see my issue:
The one appears much brighter as photoshop views then relatively not absolutely. Which makes sense for the majority of things.
The problem is when assembling several exposures into 1 HDR image, at some genius point it shifts all the image brightness values to a centre point, an image preview white point or something, effectively turning the values into relative opposed to absolute.
Relative is nice for viewing images as you don't have to worry about exposing it properly in the viewer, however it makes HDR images USELESS! for rendering/image based lighting. It should be down to the viewer/reader to expose the image correctly but instead it appears to physically move light values around in order to bring it to a centre point for viewing.
I'm still not sure what's going on, I'm now getting the feeling that the image data recorded is kept accurate in linear pixel values and It's just the viewer converting it... It's hard to tell as I have found NO software that lets you sample a pixel and tell you It's real inear luminance value, they all tell you the relative value I think.
What I want to be able to do is take a 3D render and take a photograph and sample the actual surface luminance and check they are correct, check the sun is the right luminance, check the wall is the right luminance value for the size of room and the provided lighting.
Just been tweaking and materializing a sofa I got from Evermotion:
