[OpenSPIM] About the cylindrical lens

[Johannes Schindelin]

Hi Dr Jan,

On Tue, 2 Jul 2013, Krieger, Jan wrote:

> not in an open SPIM, but in a standard setup, we use a non-achromatic
> lens with two different lasers (491nm and 561nm): Using the same beam
> expander I observed a shift of the thinnest portions of the two
> lightsheets (NA0.3 projection objective, 1.2µm and 1.3µm 1/e²-halfwidth,
> so also very small depth of field) of about 10-20µm. So we now use two
> beam-expanders (one for each laser) and that works perfectly as you can
> use the expanders to compensate for the cyl. lens.
> 
> About the focal length: The change should mainly be in the height of the
> LS, as its properties (width, depth of field) are determined by the
> projection objective only). So in the worst case you'll lose intensity,
> right?

Thanks for the information. Would you mind adding it to the Wiki? I could
imagine that the FAQ ("Does it matter whether the cylindrical lens is
color-corrected?") would be a good place...

Thanks!
Dscho