Shades are unnecessary. In bright sunlight, too much light gets in, but that can be fixed by narrowing the slot that light enters through. EDIT ( I mean front to back narrowed - not side to side.) A little electricians tape might do it, but I put the Chrony inside an old plastic power tool box with glass lenses covering the holes where the light enters the box ( cut to match chrony). I did this to protect it from weather, but have never needed shades - a large wood screw at each end of the plastic box aid in aiming it correctly. It sits outside year around - I just take the little information box - whatever they call it - to the house to record readings.
One more tip for them - in winter, the battery is always going to be low of voltage - I just wired in a 12 volt atv battery. Most electronic stuff has a built in regulator so the extra few volts is no problem and a charge may last for a year or more while it too stays sitting out at the bench - under cover.
With those two fixes, my Master Chrony is very dependable - very seldom missing a reading. It will read with a half inch of snow laying over the light pickups.
One strange problem was mice eating the little cable which comes from the sensor box to the brain box - I think that it must be plastic made from vegetable oil or something - the little boogers cut my wire into little pieces and carried it away - so the new one is in a steel tube, and hockey tape covering the ends so they won't eat it.