If a light-painting result shows a small gap or dark stripe where the trail briefly disappears, that is not a Virtual.ink bug. It is a normal limitation of video capture.

Why photos behave differently

A long-exposure photo keeps the sensor collecting light continuously for the whole exposure. A moving light source can draw one uninterrupted trail.

Video does not work that way. At 25 fps the camera records 25 separate frames per second. Between frames the sensor has to reset before it can expose the next frame. During that reset window the light source can keep moving, but nothing is being recorded.

Virtual.ink can only stack the frames the camera actually sends. The positions that were never captured during those reset moments do not exist in the input, so the final trail can show a gap.

This is a sensor limitation, not a software fix

This behavior comes from the camera capture process itself. A capture card does not cause it, and Virtual.ink cannot reconstruct light positions that never reached any frame.

Video light-painting is a trade-off: you gain live feedback and instant playback, but you accept that a faint gap can still exist between captured frames.

How to make the gap smaller

The most effective control is shutter speed.

• At 25 fps, a shutter speed around 1/25 s keeps the sensor open for most of each frame period, so the gap becomes as small as the camera allows.
• At 1/50 s, the gap is larger.
• Faster shutter speeds make the gap more obvious.

If your camera and capture path support 50 or 60 fps, those higher frame rates can also help because each frame period is shorter.

Why some gaps look much worse

When the shutter speed is too fast, for example 1/100 s or 1/200 s, the sensor stays closed for most of each frame period. The light can travel a long distance before the next exposure starts, so the missing segment looks much wider.

If the gap looks extreme, check shutter speed before assuming there is a wiring or software issue.

If the gap is still visible

Even with the slowest usable shutter speed, a small reset interval still exists. The gap may remain faintly visible depending on the movement, the background, and how much the light source blooms into the surrounding pixels.

What helps:

• Move more slowly so the light covers less distance during the reset interval.
• Use 1/25 s at 25 fps as the default starting point.
• If needed, retouch the gap afterward in a photo editor.