This is a 4X PLAN infinite microscope objective. It has NA of 0.1 and requires 180mm tube lens. Effective working distance is 19mm. It is an excellent choice to start doing extreme macro using an objective.
Because it is an infinite objective, magnification can be varied by using different focal length tube lens. For example, when a 70-300 zoom lens is used as tube lens, when zoom is set at 300mm, magnification is 4x300/180 = 6.67x, when zoom is set at 100mm, magnification is 2.22X (with some vignetting)
This item comes with RMS to selected filter thread adapter so that it can mounted in front of a tube lens. Other size filter thread needs additional ring adapter. It is ready to be used upon arrival if a tube lens with selected filter thread size is available.
IMPORTANT NOTE: IT HAS BEEN TESTED WITH FULL FRAME TUBE LENS WITH APS FRAME CAMERA. IT HAS NOT BEEN TESTED ON A FULL FRAME CAMERA YET, BUT TESTING IS UNDER WAY