Instructions:

• Determine length of lens from mount to end of lens in inches (IN) or millimeters (MM). This can be obtained by measurement, lens specifications or other manufacturers data.
• Identify Mount type: PL, Canon EF, or Nikon F
• Type lens length into appropriate box.
• The calclulator will return a Port Extender or Port Ring recommendation for use with Flat and Dome ports.

Notes on PE / PR Recommendations

• Image quality testing is necessary for any lens when used with either a Flat or Dome Port.
• "Best Image Quality" PE / PR recommendation is based on experience and user feedback regarding dome placement with respect to lens entrance pupil.
• "Compact Size" recommendation is based on experience with dome placement using a shorter PE / PR that results in smaller overall housing size yet retains image quality
• "LENS TOO LONG" means the lens length is too long for any single PE or PR. Contact Gates for other options.