Arshvista — Architectural visualisation: render | arshvista.com
How light is measured before it is rendered — photometric files, stops of exposure, and the hybrid setup that keeps windows from clipping.
Exposure is measured in stops, and one stop halves or doubles scene brightness. A correctly exposed daylit interior typically lands between −0.7 and −0.3 EV after white balance: inside that window the view through the glass keeps detail and the corners keep colour.
Real luminaires arrive as data. An IES LM-63 photometric file records luminous intensity on a 1-degree vertical grid (up to 100 angles) and a 10-degree horizontal grid (up to 10 angles) — the candela distribution that gives a rendered downlight its real-world throw instead of a generic cone.
On narrow screens, swipe or scroll the plate sideways.
For daylight, the standard setup is the HDRI-interior hybrid: a background exterior plate at about 0.2–0.5 scene strength blended with interior area lights. The plate supplies the view and the soft sky; the area lights do the heavy lifting, so window light stays soft instead of clipping.
The view transform is the final link between measurement and display. AgX replaced Filmic as Blender's default in version 4.0 (2023); Filmic had been the default since 2.80 (2018). Scenes lit by eye under Filmic can reopen under AgX with shifted contrast, which is why a render sometimes looks too contrasty after a version upgrade.
Diagnosis follows the measurement chain: if windows blow out, lower the plate strength before touching exposure; if the whole frame is flat, check the transform before blaming the lights. The sample and bounce side of the same preset is in the Cycles Render Settings Checklist for Interiors.
Further reading