Photography Lighting Tips

rT ut or ia l Up ! M ax w el lR Category: Lighting Autor: Next Limit Technologies en de Studio Lighting tips Many principles of photography can be applied to Maxwell Render and these tips will try and show you some common lighting techniques in a studio environment, and things to consider when lighting transparent and reflective objects like glass and metal. Regarding the emitters, it can be useful in many cases to avoid the evenly lit area of the emitter surface by making a gradient texture in any image editing application and converting that texture into an mxi using MXCL, then applying the mxi to an emitter material. The mxi emitter used in all these renders looks like this: Sk ill With glass being very transparent, it can be difficult to light it in a way that brings out it’s shape, and creates a contrast with it’s background. The following two studio setups will show you two approaches which you can build upon to render attractive looking glass objects. In the following render four emitters where used, placed in such a way as to light up the contours of the glass to bring out it’s shape but without making the reflections too harsh or obtrusive. Sharp side reflections of the lights was avoided using an mxi texture applied to the emitters, and the emitters strength was adjusted during rendering using Maxwells multi light feature. The next page shows the scene and emitter placement. Sk ill Up ! M ax w el lR en de rT ut or ia l Left emitter was set pretty low to only give a hint of the shape and keep the reflection of the emitter nice and smooth. Same thing with the emitter on the right. Sk ill Up ! M ax w el lR en de rT ut or ia l The top emitter was tilted forward a bit to properly light up the rim of the glass. The backdrop has a hole in it, a bit smaller than the foot of the glass. A small emitter was placed beneath the hole to light up just the foot of the glass. This way the emitter doesn’t cast any big disturbing reflections on the rest of the glass. Sk ill Up ! M ax w el lR en de rT ut or ia l With a light grey or white backdrop, the same studio setup as for the black back drop might not work too well, since everything in the scene will look white including the edges of the glass making it blend into the background. To avoid that just make sure you have something of a darker color in the scene for the glass to reflect. In this case since the environment is already black, the emitters where simply moved farther away from the backdrop so there’s a bigger area of black around the glass. It is important to note that moving the emitters farther away will not make the specular reflections lose their strength. Specular reflections will be just as bright, no matter how far the emitter is. This is good to keep in mind because if in some cases you find an emitter is casting too strong light on your background, instead of dimming it using the multi light slider (which would also dim the specular reflections on the object), you can simply move the emitter farther away. The left emitter was also scaled in Y to give a longer reflection in the glass. The hole and small emitter wouldn’t be necessary if you’re rendering on a light background, but in this case it was kept because it made some interesting strong reflections in the foot of the glass. Metallic objects can also pose a problem because of their high specular reflectiveness. Lets say in this render, the metal blade looks just like you want, but the background is too dark. Increasing the emitter strength would make the metall turn fully white, and moving the emitter closer is not possible. In this case you can take advantage of the fact that highly specular reflective surfaces will bounce the light rays at the rT ut or ia l same angle at which they hit it. In more precise terms: the angle of incidence equals the angle of reflectance. In practice this means that the emitter must be placed at a certain angle relative to the camera, if you want that emitter to be reflected by the metal. If we place another emitter outside of this angle of incidence relative to the camera, it’s rays will not reach the camera, and so that emitter will not contribute anything to alter the brightness of the metal. The image on the left illustrates this. You can see that this second emitter does not influence the metal at all, while it helps to brighten up the background. The light rays reflected in a specular way from the object, do not reach the camera, thus the camera is “blind” to this emitter. Sk ill Up ! M ax w el lR en de The result is, the knife blade has the exact same intensity but the background is brightened up by the second emitter, while also adding a nice highlight on the knife handle.