7 Sept 2018

A 20X N.A. 0.75 PlanApochromat lens has been added to the Zeiss 700.

Why was this added?

The old lens was left on the scope for users who insist on using it.

How do you know which lens is which?

On the touch pad, the old lens is the button in the upper left (position 1) and the new lens is the 20x in the lower right (position 6).

In the pull down menu for lenses in the Zen confocal software:
old lens: EC Plan-Neofluar 20x/0.50 M27
new lens: Fluar 20x/0.75

The label for the new lens is wrong as it is really a planapochromat, but to make the confocal operate correctly we used the closest lens we could find where the N.A. matched.

Direct comparison of lens.

Original images were collected at 1024 x 1024 pixels at scan speed 7. Only changes made to images is spatial rescaling 33%.
Laser, gain, pinhole settings exactly the same with both lenses.
The point is that the new N.A. 075 lens (left) is brighter than the old N.A. 0.50 lens (right).

A small cropped area viewed at the original spatial resolution (one pixel in image viewed on screen as one pixel) with linear contrast adjustments applied to both green and blue channels shows that
1. in right image blue is out of focus (by 3 um) with regard to green and
2. in the left image the green is slightly higher resolution.