Lens recommender · physical model

Predicted clay–background contrast through each lens class

Describe the scene. The model computes what each cone class receives from the clay and from the background through each lens, and ranks the lenses by a motion-weighted detectability index. Every assumption it makes is shown beneath the result.

The scene

Clay colour Background the clay crosses

Light on the clay

The largest single term. Either state it, or let the model work it out from where and when you shoot.

Lighting

Compute from place, time and the direction you shoot

Latitude Longitude Date and time (local) Compass bearing toward the target (°)

Observer

Luminance threshold (Weber) Red–green threshold (L−M) Blue–yellow threshold (S)

Leave blank for the standard observer. If you have run the study, enter your thresholds from its results page; a red–green-weak observer, for instance, gets less from the chromatic difference and more from a lens that creates a luminance difference.