About this calculator
HDR (High Dynamic Range) photography captures the same scene at several different exposures and blends them together, recovering both bright highlights and dark shadows that a single exposure can't hold at once. This calculator starts from a baseline exposure (aperture, shutter speed, ISO) and builds a bracket of frames by shifting one of those three parameters up and down by your chosen stop interval.
How the bracket list is built
The calculator puts your baseline exposure in the middle (0 EV) and adds frames above and below it, spaced by the step size you choose. Frame counts are limited to the odd numbers 3, 5, 7 and 9 so there is always a baseline frame, and step sizes are 1/3, 1/2, 1 or 2 stops.
Only one of aperture, shutter speed or ISO changes; the other two stay at their baseline values. Shutter speed and ISO double with every stop, while the f-number changes by about 1.41 times (√2) per stop but in the opposite direction. A brighter (+EV) frame uses a wider aperture, which means a smaller f-number.
Worked examples
- Baseline 1/125 s, f/8, ISO 100 with shutter-speed bracketing, 5 frames at ±1 stop: the frames are about 1/500 s, 1/250 s, 1/125 s, 1/62 s and 1/31 s. The total brightness range is 4 stops, and with 1.5 s of overhead per shot the estimated total shooting time is about 7.6 s.
- For a night scene with a 4 s baseline, the same 5-frame bracket gives 1 s, 2 s, 4 s, 8 s and 16 s. The exposures alone add up to 31 s, and with overhead the tripod has to stay still for about 38.5 s.
- If you bracket aperture instead, starting from f/8, the +1 stop frame is about f/5.7 and the -1 stop frame is about f/11.
How to read the dynamic range guide
A total brightness range under 4 stops is labeled "standard": most scenes fit in a single exposure, so bracketing is optional. From 4 up to 8 stops it is "high contrast", the range where HDR blending helps with a bright sky over a shaded foreground. At 8 stops or more it is "very wide", for scenes like backlit silhouettes or a bright window in a dark room, where more frames are worth considering.
These categories are rules of thumb. How much a single frame can actually hold depends on your camera sensor and whether you shoot RAW.
Limits and common mistakes
- For still scenes such as landscapes, shutter-speed bracketing is the safest choice. Changing aperture changes depth of field between frames, and changing ISO changes noise.
- Even on a tripod, leaves in the wind or moving people can leave ghosting when you merge the frames. The more frames you shoot, the bigger the risk.
- Your camera's automatic exposure bracketing (AEB) supports different frame counts and step sizes depending on the model. Treat the results as a reference and check the real settings range.
- For long exposures, the longest frame may exceed your camera's maximum shutter speed. In that case consider bulb mode or a smaller step.
- The default overhead of 1.5 s per shot is a typical estimate. If your camera clears its buffer slowly, raise the value yourself.
Guides that pair well with this calculator
The number of frames and step sizes your camera's actual auto-exposure bracketing (AEB) feature supports varies by model. Treat these values as a reference and check your camera's real settings range before shooting.
Frequently Asked Questions
How many frames and what step size should I bracket with?+
Three frames at ±1 stop is often enough for an ordinary scene. For high-contrast scenes like backlighting or sunsets, widen the step (±2 stops) or add more frames (7 or 9) to cover a wider brightness range.
Should I bracket aperture, shutter speed, or ISO?+
For static scenes on a tripod (like landscapes), shutter-speed bracketing is most common, since depth of field stays identical across frames. For handheld shots or scenes with movement, ISO bracketing can be worth considering instead.
Why does this show an estimated total shooting time?+
Long-exposure bracketing (for example, night landscapes) stretches each frame's exposure time, so a full bracket can take much longer than expected. This helps you plan around how long a tripod needs to stay in position, or how much a scene's light might shift during the sequence.