A common error is that larger diameter of a lens would give better resolution. This is only true if all the aberrations have been taken care of. The reality is the larger the diameter, the higher its aberrations and it is more difficult to correct.
~George C, President of BC Photonics Technological Co., Richmond, Canada
To put eye glass in the pocket with out a case. The lens curvature vertex is always damaged and it becomes opaque.
~Debebe K., General Management, Addis abeba, Ethiopia
Do the math! Know what focal length you need. Also know how much chromatic aberration you can deal with.
~Faculty/Staff, Louisville, KY
Have a good discussion with the supplier about the requirements you are looking for.
~Engineering, Design, Venlo, Netherlands
Secure is common to buy the best and after do not work with them.
~Pere Pons Tomas, Photographer, Barcelona, SPAIN
Pay attention to number of elements, corrections, and coatings.
~Fred M, CNC Operator, Lawrenceburg, TN
Consider diffraction limit of lens vis a vis ccd/cmos size.
~V Raghavan R, Scientist, Jodhpur, India
Be precise in relating the primary use for the lenses.
~Normand M, Manufacturer, Sudbury, Canada
Use reputable labs and take advice from peers.
~Paul S, Loupe & light Specialist Optician, Northampton, UK
Model, model, mathematically model
~Jesse S, Student, Virginia, MN
~Paolo S, Faculty/Staff, Merate, Italy