face
Ben Esler
VFX Artist
Environment Map:
Exposure:

Going out to take HDRI photos always has been a laborious and expensive task. With new 360 cameras on the market it is becoming easier and cheaper to shoot these photos. Ricoh's Theta 360 camera line allows for manual shooting modes. Allowing for bracketing over several exposures.

Capture

Not needing a DSLR, chrome ball, and larger tripods means that a single person can easily carry all the gear needed. The time to shoot including setup and tear down is less than 10 minutes.

Gear

The total cost for my setup is under $450 new. The Theta S saves equirectangular images at 5376x2688 resolution. A monopod is heavily suggested with 360 cameras. It reduces how much of the feet of the tripod is showing from the final image. The one I use extends from 44cm to 135cm and light weight. X-Rite ColorChecker Passport is helpful for color correction after shooting.

Brackets

To shoot manual in the Theta App takes a long time for multiple exposures. Jianming Guo made 360 HDR Bracket Tool to automate this process. After setting the number of brackets and the exposure range, the camera takes a photo on auto. The values from this photo are used as a proper exposure for the other brackets. Majority of my shoots are 7 brackets of ±3 EV, shoot multiple times for post process.

7 brackets ±3 EV

White Balance

The Theta S does not shoot in a RAW format and saves a jpeg. This means that the number of colors and information in the file is severally reduced. Making a proper white balance during shooting even more important. If the photos are taken either too cool or warm there will be a loss of data to correct during post-process.

As Shot

White Balanced

Post Process

There is little difference to how you would create an HDRI with a DSLR vs the Theta S. Most notably there is no need to align photos, since the images are saved as an equirectangular at the time of capture.

Bracket Cleanup

Each bracket is imported into Photoshop with all other images of the same bracket. They are checked for alignment or any issues that could create errors. A layer mask is used on each image of the bracket to remove myself and others. Then all layers are combined into a Smart Object with a Median stack mode. This reduces noise and will not stack anything that was masked earlier. The file is exported as a copy, so it doesn't contain the smart object.

HDRI Creation

Each bracket from Photoshop is imported into Lightroom. These are merged into an .dng file which is 16-bit, this makes working with the file faster and allows for more features in Adobes software. Photoshop can create 32-bit images, but if you use their Camera Raw adjustment it will be converted to 16-bit.

Color Correction

The photo taken with the X-Rite Color Passport with proper exposure is exported as a .dng and read into X-Rite's software. It will create a correct color profile based off the image. This can then be applied to the HDR file to color correct the image. Though since the original images were .jpeg it won’t be perfect, but closer.

As Shot

Color Corrected

Unreal Engine 4

Take the final .dng and export it as an .hdr file, then import into UE4. The file will be at 5376x2688 and is well above the max in game texture size. Mips will be made automatically to account for this. However, if you do plan on making adjustments in the editor to the texture, consider exporting the file at a lower resolution. This will speed up the time it takes to make the changes.

Conclusion

Using the Theta S does not replace a DSLR for a proper HDRI. The Theta shoots 8-bit making the original files not be able to be assigned a camera/color profile properly. Using two extreme fished eye lenses make the resolution of the final HDRI lower than if shot multiple times with a 15mm lens. However, it does allow for quick and light weight captures.

Pro
  • 8 min capture
  • Equirectangular
  • Little post work
Con
  • Lower resolution
  • Non-RAW files

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