Soft White vs. Clear

This will be a fairly short and simple comparison but worth to mention.  In the above image, the bulb on the left has a white coating inside the glass.  Sometimes the glass is "frosted".  The bulb on the right has clear glass.  If you choose to use standard light bulbs like these for your studio, its best to choose the frosted or soft white version.  

The above photographs were taken with a soft white bulb (left) and a clear bulb (right) from 4 feet away on a white wall.   You should be able to see the slightly uneven distribution of light on the right image.  If you don't see the difference right away, back off from your computer screen about 4 feet.   The reason the soft white bulb has a even illumination is because the coating inside the glass bulb diffuses the light and eliminates any brighter areas.  This unifies the emitted light by the lamp.  The appearance of a glowing filament in a clear glass incandescent bulb works well in home fixtures in bathrooms or dining room chandeliers, but if you need to evenly illuminate a flat surface, go for the soft white or frosted bulb.