What is the significance of the different glass types listed for the lenses that you carry?

Each glass type has its own set of specific characteristics. We have selected the best glass types available to produce optimal results for each individual lens design. This is the most significant in the design of achromat lenses since they use two different glasses together to help reduce optical errors (aberrations). Different glasses also have different transmission ranges. For applications dealing with the UV spectrum, special glass types such as Fused Silica or Quartz need to be used. For the visible spectrum many glass types can be used such as N-BK7, B270 and others. Many of these same glass types are used in the near IR region of the spectrum, but their transmissions vary greatly. Finally, the glass types have an impact on manufacturing capabilities, which directly relate to cost. For more information on our different glass types, please view Optical Glass. Note that even though a glass may transmit a specific wavelength, if this wavelength is significantly different from the lens' design wavelength then a lens made of that glass can have noticeable performance changes, such as the resulting back focal length.