On Feb 10,  5:43pm, Rui Malho wrote:

> > signal ? Furthermore, and under exactly the same settings, "accumulate to
> > peak" with new PMT1 needed 6 frames while old PMT1 needed only 2 frames. Why
> > this difference ? Finally, if one has a pair of enhanced PMTs with a RSI=2
> > (or more) can we really expect to obtain a similar signal if the gain
> > settings are decreased by a similar factor ?

On Tue, 11 Feb 1997, Aryeh M Weiss wrote:

> Concerning accumulate to peak, the number of frames required depends a lot on
> the kind of noise you have. Are the images obtained after 2 passes with the old
> PMT are as good as the images obtained after 6 passes with the new PMT?

I agree, one noisy pixel could stop the accumulation, while the rest of the
image is significantly dimmer.. In order to be more quantitative, one can
check the pixel average variance (or standard deviation) over selected
parts of the two images.

Regrads,

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Stamatis Pagakis Ph.D.                                    [log in to unmask]
University Laboratory of Physiology          [log in to unmask]
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