A curved dark area at the bottom of a close flash photo can be the shadow of the lens or lens hood blocking the flash. It is a physical illumination obstruction, not necessarily a shutter-sync band. Compare a capture without the hood and, when practical, one made from farther away before trying to brighten the dark patch in an editor.
Look at the lighting path
With a small on-camera flash, a long lens or hood may sit between the light and the nearby subject. Sony documents this situation and suggests removing an attached hood or increasing shooting distance. Wide-angle shooting with some high-magnification zooms can make the obstruction more noticeable. The advice depends on camera and lens arrangement, so inspect the actual setup.
Do not assume that every lower shadow has this cause. The table could be shaded by a real object, and a straight band can have a synchronization explanation. Record whether the shadow changes with the accessory and distance while exposure settings remain comparable. That is a more useful distinction than judging only how black the region looks.
Use an ordinary tabletop as a diagnostic subject
This is a reader test plan, not a completed studio test. Set a textured neutral object on a tabletop, away from reflective hazards, and keep the camera steady. Record camera, lens, focal length, shutter speed, aperture, ISO, and whether the hood is fitted. Make a reference frame using an allowed flash-sync setting from the camera manual.
Remove only the detachable hood when its instructions permit, then take another frame. Restore the original arrangement and take a third from farther away if space allows. Keep a note of the framing change rather than silently comparing differently cropped images. Inspect the boundary of the shadow and the object's actual surface texture in all frames.
Fix the capture before reconstructing the product
If the shadow changes with the hood or distance, improve the setup and retake the required composition. A more suitable flash position or lighting arrangement may be needed, but choose it according to your equipment rather than a universal menu recipe. Brightening a severely blocked region can reveal noise without providing a genuinely illuminated view of the material.
For a product listing, preserve what can be verified. If the dark patch hides a texture, seam, or wear mark, an AI fill can create a plausible surface that differs from the object. Capture another clear view instead of treating a clean reconstruction as evidence of the product's condition. Keep real contact shadows that communicate its shape and placement.
Choose the properly lit photograph as the Imagild reference when a style transformation is wanted. Retain the obstructed original for comparison and check that the final artwork preserves the object's boundary and markings. Removing an equipment shadow is a preparation decision; changing the object's actual design is a separate brief requiring review.