1.2 Mergin Dev

In this chapter we will merge the rendered panorama layers in Photoshop to one HDR file

Import and Merge

Exposure Brackets

We’ve rendered one Layer for each exposure in Autopano

Select Merge

Photoshop > File > Automate > Merge to HDR

Import the images

Browse to select the images

Disable Attempt to Automatically Align Source Images

Trap: If you’re prompted to set EV values manually, the layers weren’t rendered with EXIF metadata. Re-render as TIFF or JPEG, not PNG.

Merge step

One sentence here

Set 32 Bit Mode

Remove Ghosts: Usually leave disabled. Can improve result, but also create unwanted artifacts

Set White Point Preview: Set a preview exposure


Usually feels like missing saturation

Check the HDR

One sentence here why this is important

Eyedropper to 32-bit

Get the Info box

Click on the Eyedropper

Change display values to 32-bit

Checking Values

Hover over brightest highlight areas such as direct light sources

Values in highlight should be over 1, ideally much higher, here over 16, great!

Try different areas. If you can’t find values over 1, it’s not a true 32-bit HDR

32-bit Preview Options

View menu > 32-bit Preview Options

That’s the White Point Preview set earlier during merge

Preview Exposure

Lower the Exposure to the point that only the highlights stay bright. If the highlights darken linearly together with the image, the dynamic range is not good, or is not an HDR

Next: Find the exposure value closest to normal exposure. If that’s more than +/- 1, compensate later with a color correction.

Move slider to 0. We want to save and export with no Preview Exposure

Save and Export

If the Preview Exposure was within margin and is now set to 0, we can move on to export the HDR

Flip HDR

1. Save Photoshop file
Use a meaningful name, not just HDR_02.psd

2. Flip horizontally
Image menu > Image Rotation > Flip Canvas Horizontal

3. Save Radiance file
Use a meaningful name, not just HDR_02.hdr