Time Lapse on a Budget: Calculating Intervals, Battery Life, and Card Space Before You Leave the House
The DP Who Arrived at Sunset With One Battery and No Card
A documentary filmmaker drives three hours to a cliff-top location to capture a sunset-to-night transition time lapse for an opening title sequence. She wants a 15-second sequence at 24fps. She sets up the camera, frames the shot, and sets a 10-second interval. Thirty minutes later, the camera battery dies. She has captured 180 frames. At 24fps playback, that's 7.5 seconds -- half the intended duration. She doesn't have a spare battery in the bag. She has no intervalometer-connected power bank. The drive back is three hours.
The time lapse is one of the most unforgiving production setups because it runs unattended for extended periods with no opportunity to intervene without disrupting the shot. Every resource -- battery, card, intervalometer interval -- must be calculated before the camera is placed. This post covers each calculation in sequence.
The Core Time Lapse Math
Three variables define any time lapse:
- Interval (seconds between frames)
- Shoot duration (how long the camera runs)
- Playback duration (how long the finished clip runs at 24fps)
The relationships:
Number of Frames = Shoot Duration (seconds) ÷ Interval (seconds)
Playback Duration (seconds) = Number of Frames ÷ Playback FPS
Interval (seconds) = Shoot Duration (seconds) ÷ (Playback Duration × Playback FPS)Example: To produce a 10-second clip at 24fps from a 2-hour sunset:
- Shoot duration: 2 hours = 7,200 seconds
- Required frames: 10 seconds × 24 fps = 240 frames
- Interval: 7,200 ÷ 240 = 30 seconds per frame
Use the Time Lapse Calculator to run this calculation for any combination of shoot duration, desired playback length, and frame rate. The calculator also handles hyperlapse intervals and high-frame-rate playback.
Interval Selection by Subject
The interval you choose determines how fluid the motion appears and which subjects work at all:
| Subject | Recommended Interval | Notes |
|---|---|---|
| Fast-moving clouds | 2-5 seconds | Faster intervals for dramatic cloud formations |
| Slow cloud cover | 5-10 seconds | Wide scenes with slow atmospheric change |
| Sunrise/sunset | 15-30 seconds | Standard interval for celestial transitions |
| Star trails (milky way) | 20-30 seconds | Minimise dark gaps between frames |
| Shadow movement | 30-60 seconds | Architectural and street scenes |
| Tide change | 60-120 seconds | Ocean scenes over 4-8 hours |
| Flower blooming | 10-30 minutes | Very long capture periods (1-3 days) |
| Construction progress | 1-24 hours | Multi-day or multi-week installations |
For sunset and star trail sequences, the 15-30 second range is the standard choice. Intervals shorter than 15 seconds on a mechanical shutter will accelerate shutter actuations significantly; at a 10-second interval over 8 hours, the shutter fires 2,880 times. On cameras with rated shutter lifespans of 100,000-300,000 actuations (Sony A7S III, Canon R5), this is insignificant. On cameras with lower-rated shutters, avoid very short intervals for long-duration shoots.
Battery Life Calculation
A camera's battery life during time lapse is different from its video recording battery life because the camera wakes, exposes, and processes between intervals. Power consumption depends on:
- How long the camera is active per cycle (shutter speed + processing)
- How long the camera is in standby between cycles
- Whether the LCD is on during the shoot (turn it off -- it doubles power consumption)
- Whether the camera is using IBIS, stabilization, or other active systems (disable these for static time lapse setups)
Practical rule of thumb: A Sony A7S III with the LCD off and a 20-second interval will typically capture 1,000-1,200 frames per battery charge (NP-FZ100). At 20-second intervals, 1,200 frames represents 24,000 seconds = 6.7 hours of shoot time. For a 2-hour sunset, one battery is adequate with margin.
For shoots exceeding 4 hours, an external power source is essential. Options:
- Dummy battery with power bank: A dummy battery adapter connects a USB-C power bank to the camera's battery compartment. A 20,000mAh power bank powers most mirrorless cameras for 10-15 hours.
- AC adapter with power cable: The cleanest solution for locations with power access. Most cinema cameras and many mirrorless cameras support AC power via a dummy battery or DC input.
- Solar panel with battery pack: For remote locations. A 60-100W foldable solar panel charges a power bank in 2-4 hours of direct sunlight and can power the camera directly with a stable charge controller.
Card Capacity Calculation
Each frame in a time lapse is a still image. RAW images from a modern full-frame camera are typically 20-50 MB per frame (Sony A7S III RAW: approximately 24 MB; Canon R5 RAW: approximately 45 MB). JPEG images are 5-15 MB per frame at medium-high quality.
For a 4-hour shoot at 15-second intervals:
- Frames captured: 4 hours × 3600 ÷ 15 = 960 frames
- At 24 MB per RAW frame: 960 × 24 MB = 23,040 MB = ~22.5 GB
- At 8 MB per JPEG frame: 960 × 8 MB = 7,680 MB = ~7.5 GB
A 64 GB card handles RAW time lapse comfortably for most single-day shoots. For multi-day installations or very short intervals, calculate the frame count before selecting card capacity.
For in-camera video time lapse modes (where the camera records an H.264/H.265 output directly rather than individual stills), the file sizes are much smaller. A 10-second in-camera time lapse clip at 4K H.265 is approximately 50-80 MB regardless of the shoot duration. The trade-off: in-camera video time lapse offers no post-processing flexibility per frame.
The Codec Storage Calculator handles video-mode time lapse calculations. For still-image time lapse, use the frame count method above.
Three Production Scenarios
Scenario 1: Sunset-to-Night Transition for a Feature Film
Target: 12-second opening title sequence at 24fps. Capture window: 1.5 hours (6pm to 7:30pm). Calculation: 12 seconds × 24fps = 288 frames. Interval: 5400 seconds ÷ 288 = 18.75 seconds, rounded to 19 seconds. Battery: one charge with LCD off is sufficient for 1.5 hours. Card: 288 frames × 25 MB (RAW) = 7.2 GB. A 32 GB card has ample margin. Tripod: mandatory. Wind deflector for the camera head if the location is exposed. The calculation is done at home; the equipment list is confirmed before leaving.
Scenario 2: Multi-Day Construction Progress Time Lapse
A commercial client wants a 60-second progress time lapse over a 90-day building construction. Target playback: 60 seconds at 24fps = 1,440 frames. Shoot duration: 90 days. Interval: 90 days × 86,400 seconds/day ÷ 1,440 frames = 5,400 seconds per frame = one frame every 90 minutes. Camera: a dedicated time lapse camera (Brinno TLC2020 or GardePro A3S) on AC power with weather protection housing. At one frame per 90 minutes, card consumption is negligible (high-resolution JPEG at roughly 2 MB/frame × 1,440 frames = approximately 2.9 GB for the entire 90-day project).
Scenario 3: Night Sky Star Trails
Target: 20-second clip of star movement at 24fps. Shoot window: 5 hours on a clear night. Calculation: 20 seconds × 24fps = 480 frames. Interval: 18,000 seconds ÷ 480 = 37.5 seconds, rounded to 38 seconds. At 38 seconds, use a shutter speed of 25-30 seconds to capture individual star trails per frame and minimize the dark gap between frames (38 - 30 = 8 second gap). Battery: 5 hours × (38-second interval) = approximately 474 frames per charge. Most mirrorless cameras manage this on a single charge with LCD off; bring a spare battery as insurance. Card: 474 frames × 25 MB = ~11.5 GB. A 32 GB card is sufficient. The overcranking vs. undercranking guide covers how star trail time lapse relates to the broader concept of frame rate manipulation.
Pro Tips
Tip 1: Arrive early. A time lapse setup requires precise framing, a perfectly level camera (use a bubble level), and a confirmed focus lock (switch lens to manual focus after locking). For a sunset shoot starting at 7pm, arrive by 5:30pm to allow time for setup, focus confirmation, and a test sequence of 5-10 frames before the main event begins.
Tip 2: Lock exposure manually before the time lapse begins. If the camera is in auto exposure, it will adjust exposure as the sky darkens, creating flickering between frames -- each frame slightly brighter or darker than the last. The solution is to either shoot in manual exposure (and accept a slight underexposure in the darkest portion of the sunset) or use deflickering software in post (LRTimelapse). Manual exposure is simpler and produces cleaner results when planned correctly.
Tip 3: For moving-camera time lapse (hyperlapse), the interval calculation is the same but the motion between frames must be consistent. Use a motorized slider or mark physical positions on the ground at measured intervals. An inconsistent step distance between frames produces jerky motion in the finished clip that is very difficult to correct in post.
Frequently Asked Questions
What is the difference between in-camera time lapse and shooting individual stills?
In-camera time lapse mode produces a finished H.264 or H.265 video file directly from the camera. It is convenient but offers no per-frame post-processing capability -- exposure, white balance, and noise reduction are applied globally in-camera and cannot be adjusted per frame in post. Individual still (RAW or JPEG) capture requires assembly in post using software like After Effects, Premiere Pro, or LRTimelapse, but gives full control over each frame's exposure, color, and noise reduction. For professional work, individual RAW capture is the preferred method. For run-and-gun documentary or casual use, in-camera video mode is adequate.
How do I eliminate flicker in sunset time lapse footage?
Flicker is caused by small variation in shutter speed, aperture, or exposure between frames. Three causes: auto exposure mode, mechanical aperture blades (stopped down lenses flicker due to small variations in blade position at small apertures), and automatic white balance. Fix: shoot in fully manual mode, use a lens without electronic aperture control or step the aperture to f/8 where blade variation is minimal, and lock white balance. For existing flickering footage, LRTimelapse and the deflicker plugin in After Effects both correct moderate flicker in post.
Can I use a smartphone for a professional time lapse?
Modern flagship phones (iPhone 16 Pro, Samsung S25 Ultra) produce usable time lapse footage for lower-end applications. The limitations are: no RAW per-frame capture in most apps, limited long-term power management, no intervalometer integration, and exposure control that is less consistent than dedicated cameras. For broadcast, commercial, or theatrical use, a dedicated camera with manual control is required.
What is the recommended software for assembling RAW still time lapses?
LRTimelapse (Windows/Mac, $99-$149) is the professional standard for deflickering and assembling RAW time lapses, with a Lightroom and Photoshop integration workflow. Adobe After Effects assembles image sequences natively and handles the export to ProRes or H.264 for delivery. DaVinci Resolve also imports image sequences and handles color grade across the entire time lapse non-destructively.
Related Tools
The Time Lapse Calculator calculates interval, frame count, and playback duration for any time lapse setup. The Codec Storage Calculator handles video-mode time lapse storage estimation. The Battery Runtime Calculator models battery life for extended time lapse setups with specific camera power draw figures.
Conclusion
A time lapse that fails because the battery died or the card filled is not a bad luck event -- it's a planning failure. The interval, battery life, and card capacity calculations take under 5 minutes with the Time Lapse Calculator. Do them at home the night before, not in the field after setup. Every resource is consumed at a predictable rate. Know the rates, bring the resources, and the shot completes. What is the longest continuous time lapse you've captured, and what resource came closest to running out before it finished?
