6 – Interfaces
A6000 and A8500 Series User’s Manual
72
6.4.2 Warm Filter (A670x and A675x Only)
The FPO Manual Focus lenses accept a filter holder that threads into the back of the lens. Here is an
example of an ND1 filter installed on the back of a 1X microscope lens. ND2 and ND3 filters are
available as well. These filters are used in conjunction with high-temperature radiometric calibrations,
but they can also be used without a calibration to reduce signal levels. ND1 reduces signals by a
factor of 10, ND2 and ND3 by factors of 100 and 1000 respectively.
Figure 6-9: HDC lens with ND1 filter screwed into the back
6.4.3 Warm Filter Holder (A626x Only)
The C-mount interface has a provision for holding a 1-inch warm filter behind the lens. To access the
holder, remove the four screws holding the interface to the camera. On the back side of the lens
mount there is a removable screw-on cap (FLIR P/N 4133832). Unscrew the cap and place the warm
filter in the holder. Because warm filters can come in different thicknesses, be careful when screwing
the cap back on. Do not overtighten or you could crack the filter. The filter holder recess is designed
for a 1mm thick filter.
Figure 6-10. Removable lens C-mount and filter retainer cap