Determining the actual scale factor ...

Mitko Veta mitko.veta at
Thu Dec 2 09:36:27 EST 2010

As far as I can tell, the spatial sampling resolution is independent
of the magnification. For example, you can use a 40x lens, and for
some reason, decide to sample with a very coarse grid, which will
produce large pixel spacing. Or am I wrong?

Mitko Veta

On Thu, Dec 2, 2010 at 3:29 PM, Hauke Heibel
<hauke.heibel at> wrote:
> After looking at the CMU-1 dataset I am wondering how reliable the
> OBJECTIVE_MAGNIFICATION values are. At level 0 the dataset has a pixel
> spacing of ~0.23 microns and according to a whole bunch of references
> from the web this is typically corresponding to a 40x objective
> whereas the objective magnification is stored as 20x in the CMU-1
> dataset.
> So, either the assumption that 0.23 microns always correspond to 40x
> objectives is wrong or the file entry is not reliable. Maybe somebody
> can confirm or disprove the first assumption?
> Regards,
> Hauke
> p.s. I started a feature branch for the objective power implementation
> on my github fork.
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