[OpenLayers-Users] UTM scales mismatch with Max/MinScaleDenomination

[Christopher Schmidt]

On Sun, Dec 02, 2007 at 05:52:59PM +0100, Andrea Aime wrote:
> Hi Chris,
> about this scale inconsistency, you're right in saying it's due to the
> DPI. The WMS standard suggests a DPI of approximately 90 (well, a 
> multiplication factor of 0.28 in fact), and that's what GeoServer is 
> using to compute the scale.
> To be exactly true to the WMS standard (as far as I understand it) the 
> setting would have to be:
> 
> OpenLayers.DOTS_PER_INCH = 25.4 / 0.28;

I'm not sure where the 25.4 comes from, but I do agree that in order for
OpenLayers to match the WMS Spec by default, it would need to have that
as a value. 

> Wondering if OL should default to it too (or is MapServer defaulting to 
> 75dpi instead?).

The default for MapServer is 72 DPI, yes. And at this point, there's
enough people using scale having this default that I wouldn't want to
change it in OpenLayers.

Regards,
-- 
Christopher Schmidt
MetaCarta