The 3ds Max Bitmap shader is fully implemented as a special wrapper shader around the Arnold image shader. The wrapper shader takes care of all the coordinate system transforms (before using image) as well as all the color modification features on the Output rollout (after using image). 


The Arnold implementation has the following limitations

Unless you need to take advantage of the Bitmap's advanced parameters, it is strongly suggested that you avoid its usage, and prefer the Arnold image node. In addition to the above limitations, the wrapper can add many auxiliary nodes to support the Bitmap parameters that do not have an equivalent in the Arnold node, which can have a severe impact on the rendering time.


Consult the 3ds Max manual, for details on how all of the parameters work.