Technical
How to make photos bright
What is Adaptive HDR photograph
01 / Modern screens
A JPEG has limited capabilities to describe brightness. The brightest color it can encode is white.
Modern technology (such as OLED) made it possible for the screens to display colors that are brigher than regular white. A recent phone panel runs several times brighter than the white. Thanks to that, the photos taken on your iPhone have a much increased brightness and contrast. Most mirrorless cameras and DSLRs don't add this information into the out-of-camera RAWs and JPEGs.
02 / Adaptive HDR
An ISO 21496-1 file contains the ordinary photograph and another grey image called a gain map. The map contains numbers for each pixel of the photograph which tell how bright the underlying pixel should be. Gain = 1.0 means "ordinary" brightness. Pixels with gain over 1.0 are displayed brighter, and under 1.0 — darker.
03 / Glowplume
Glowplume allows you to add a gain map to any photo and provides ample controls to adjust the brightness to your liking. You can select between Range (if you want to make most of the photo brighter, but leave shadows dark), Rising (brighter regions get much brighter), Even (all pixels get brighter, highlights, midtones and shadows)
Adjust Glow to set the maximum brightness for the photo and Depth to set the "maximum darkness.". On overly sharp photos adding a gain map can exaggerate the sharp edges, use Blur control to blur them downl.
Each of the modes has its own set of controls
| Every mode | |
|---|---|
| Glow | How bright is the brightest part of the picture. |
| Depth | How dark is the darkest part. |
| Blur | Softens the light's edges. Off by default, because it costs sharpness in the regions the map exists to light. Earns its place at high ISO. |
| Range — use to light up a range of tones | |
| Balance | Use to move the band up and down the range. Moving to the left will make more of the picture brighter |
| Width | How strong is the contrast between the dark and bright tones is. |
| Reach | Adjust to set brightness for the most brightest of tones. |
| Rising — brightens the brightest the most | |
| Steepness | Adjust the separation between bright and dark tones. |
| Even — uniform brightness for the entire picture | |
| Use to light up the entire picture. Best used for non-photographic images. | |
| Source — only for the files that already have a gain map (e.g. photos from an iPhone) | |
| Shadows | Adjusts brightness for the dark parts |
| Midtones | Brightness for midtones |
| Highlights | Brightness for the brightest parts of the image |
Glowplume also provides the regular "Develop" controls. Use those to edit the picture. They are standard, look and see for yourself what they do.