There is a serious risk of damage to objective lenses when you are using the motorised stage to move between more than one sample vessel in an adapter. Lenses with working distances of about 500 µm or less will hit the adapter when moving between the vessels. For example, if you were to try to move the 63x oil lens between two 35 mm dishes in the adapter below, the lens would hit the base of the adapter because its working distance is only 130 µm.

To avoid damaging lenses in this way, please do the following:

• Avoid imaging samples in different openings where possible, especially during time-lapse. Use multi-well vessels like Lab-Teks and multi-well plates instead.
• If you absolutely must use multiple openings then the 10x and 20x Plan Apo lenses have working distances of 1 mm or more and should be safe to use in most cases, but please check with a member of light microscopy staff before seeding your cells or mounting your specimen
• The 40x, 60x and 100x lenses have working distances of  less than 250 μm and therefore will be damaged unless you use the procedure below.

How to avoid damage when using lenses with short working distances

The microscope can be programmed to drop the focus drive to the Escape position after each capture, which will ensure the lens is out of danger while the stage moves. This involves automatically executing commands in the ND Acquisition window.

1. Click on the XY tab in ND Acquisition 
2. Click on the Advanced button near the bottom 
3. Tick the the Execute Command before Capture and Execute Command after Capture boxes
4. Click on the drop-down menu arrow next to the field and select Command List...
   
5. A new window will open with a long list of commands on the right.
6. To enter the correct command in the field next to Execute Command before Capture, scroll down the list and double-click StgZ_Refocus();
7. To enter the correct command in the field next to Execute Command after Capture, double-click StgZ_Escape();
   
8. To cancel the Escape/Refocus routine for future timelapses, uncheck the Execute Command boxes.
   

Integrating the above commands into a time-lapse will cause the focus to move to the bottom of its range after each position is captured and refocus immediately before the next capture. This will avoid damage to the lenses but will also significantly slow down the acquisition as the focus takes some time to move between the Escape and focus positions, and it must do this at every position.