Search the CONFOCAL archive at
http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal

forget the better do signal/noise ratio. Actually because pixel dwell 
time is short, the pmts have less time to make a more statistically 
accurate measurement. What leica claims is that due to faster scanning, 
the number of molecules in the exited state and triples which get one 
more photon is decreased, consequently decreasing bleaching. As far as I 
remember, the resonant scanner operates at 8000 lps which makes a pixel 
occurring in the range of tens of ns. If you remember a typical 
relaxation half life time is <10ns, meaning that at some degree this can 
be true.

Apart from the numbers, we do realize that bleaching is in fact less but 
it is not linear (some time because you have to use more laser power its 
actually higher). This can be due to the lifetime of the fluophore, due 
to environment conditions, etc...

About speed I remember taking pictures at 3ms frame rate with a 16 pixel 
height, having the complete confocality.

I had never try it but I would say that the sp5x (fiber white laser) can 
have a laser power limitation when using the resonant head.

No commercial interest,
NM



Gurrie Dimitri wrote:
> Search the CONFOCAL archive at 
> http://listserv.acsu.buffalo.edu/cgi-bin/wa?S1=confocal
> Hello,
>  
> I'm looking for information about practical experiences with the SP5 
> resonant scanner.
>  
> Leica is claiming: resonant scanners have a much better signal/noise 
> when compared with normal scanning devices, but still offer true optical 
> sectioning at the diffraction limit.
>  
> Do you have any practical evidence on this?
>  
> Thanks for your help.
>  
> Dimitri
>  
> 
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-- 
Nuno Moreno
Cell Imaging Unit
Instituto Gulbenkian de Ciência
http://uic.igc.gulbekian.pt
http://www.igc.gulbekian.pt
phone +351 214464606
fax   +351 214407970