Tutorial: How to Convert an image to HDR in Photoshop cc? This is to convert any image into an HDR image to use as Light Map for rendering Image Based Lighting in any 3d Software. Using a JPEG or any other format other than High Dynamic range won’t give a good result when rendering..
1. Launch Photoshop with the Image you want to convert into an HDR Map once loaded we then need to create 3 different Exposures for Merge HDR Pro to do it’s thing. The easiest and none destructive way to do this is to add an Adjustment Layer to the Image and save out each Exposure separately. Remember to save the images in TIFF file format;
-2 Exposure, Original Exposure, +2 Exposure, giving them each a corresponding name.
Once the 3 different Exposures have been saved out then the images can be imported into Photoshop’s Merge HDR Pro for the conversion to begin…
2. To Load the Images in Photoshop go to; File – Automate – Merge to HDR Pro BROWSE to the 3 Exposures that have been saved out and select all 3, OPEN those, then select OK. This will start the process for Photoshop to use all 3 Exposures and convert them to HDR, the images and result can be reviewed once the images are loaded.
There’s still an Add/Remove option later, it appears in the Merge to HDR dialog box with an Add/Remove button.
If there is a question about the exposure values of the images, Photoshop displays the Manually Set EV dialog box…
3. Scroll through each image to check the Exposure Values are correct you can Add or Remove more images depending on the desired result. If known then enter the correct camera parameters in the Exposure Time, f-Stop, and ISO boxes, or select EV and enter the value in the box. Use the “>” button to review each image.
Photoshop will then start the process of merging the files to create an HDR Image, depending on you PC spec this time can vary but only a matter of seconds.
When finished, the Merge to HDR dialog will appear in a large preview window and the images appear on the left…
4. Select – MODE 32 BIT – check box Complete Toning in Adobe Camera RAW Remember to select the dropdown in 32 BIT mode so Photoshop doesn’t compress the image loosing the High Dynamic range. Then Check through the Exposures to see if any are not needed, it may require all the images to get the best result, it will also give more freedom at later stages.
If Complete Toning in Adobe Camera RAW is selected this will grey out the Exposure slider, then select Tone in ACR.
This will then open to a Camera RAW dialogue box with some options on the right…
5. Scroll through the White Balance Drop down box for best result Sometimes leaving it set as default can be the best result but scrolling through will give an idea which setting should be used. Keep an eye on the Blacks, which should stay Black and Shadows shouldn’t be darkened too much loosing detail. The same goes for Highlights and Whites, the Highlights don’t want to bleed out as staring into the Sun.
Use the tools in the Top Left of the Dialogue box to Navigate around the image for review.
Exposure, Contrast, Highlights, Shadows, Whites, Blacks – should be adjusted one at a time to avoid confusion…
6. Select OK and the end result will be displayed in Photoshop At first glance there is no obvious indication from the image itself that this is an HDRI and not an ordinary photo. However, if you look at the image title bar, Photoshop includes HDR in the name, this is the difference between a good Image Based Light Map and something that’s substandard.
All the Extra information stored in the HDR will give much more Photorealistic results when rendering.
All that’s needed to do now in the last step is Save out the High Dynamic Range Image…
7. Selecting a HDR file type is a straight forward process Photoshop supports many different HDR file types, including the Standard Radiance RGBE and OpenEXR formats. There are other formats but to use this in a 3d aplication for Image Based Lighting then choosing HDR or OpenEXR is the way to go.
They both represent the same data, but with different file formats, EXR is becoming the industry standard for floating-point colour data. They’re smaller and more accurate than HDR files.
I hope this helps you out and if you have any questions or comments then don’t hesitate to drop me a message on twitter.