<div dir="auto">Dear all,<div dir="auto"><br></div><div dir="auto">This is a constant discussion topic between the users of microscopes. It always used to take one complete session of my classes to discuss about the significance of "magnification".</div><div dir="auto"><br></div><div dir="auto">The magnification is a real measure but it does not have any numerical significance for us. It is like asking how much is the current inside a lens!</div><div dir="auto"><br></div><div dir="auto">Let's consider the magnification as a name, i.e. a string type value, for a certain optical configuration of the projection system. Let's name 100000x james and 50000x jones. Nothing happens.</div><div dir="auto"><br></div><div dir="auto">The important measure is the pixel size for the digital image recording systems and the image dimension (real image width for example) in the analog formats. </div><div dir="auto"><br></div><div dir="auto">Historically it was a place of debate in the Philips EO (later fei and nowadays TF) microscopes. The magnification was changing depending on the viewing plane: lower for camera rolls and higher for sheet films. But in older Zeiss EMs we never had this consideration.</div><div dir="auto"><br></div><div dir="auto">Hereby, I also draw your attention to the following standard:</div><div dir="auto"><br></div><div dir="auto">ISO 29301:2017, Microbeam analysis — Analytical electron microscopy — Methods for calibrating image magnification by using reference materials with periodic structures<br></div><div dir="auto"><br></div><div dir="auto">It is a precise method for calibrating the magnification in TEMs, however it may not be very easy to implement. The previous version was not practical at all, especially for lower magnifications and I hope they have addressed the issues with the previous version in the newer one.</div><div dir="auto"><br></div><div dir="auto">So in general, the term magnification is just for internal use. It is just for describing a lens configuration, and finally it changes from the sensor to your printer to your monitor.</div><div dir="auto"><br></div><div dir="auto">Best Regards,</div><div dir="auto"><br></div><div dir="auto">Farzad Hamdi,</div><div dir="auto"><br></div><div dir="auto">University of Halle</div><div dir="auto"><br></div><div dir="auto"><br></div></div><br><div class="gmail_quote"><div dir="ltr" class="gmail_attr">On Tue, Jun 23, 2020, 19:50 Morgan, David Gene <<a href="mailto:dagmorga@indiana.edu">dagmorga@indiana.edu</a>> wrote:<br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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<p>Hi,</p>
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<p> Does anyone happen to know whether the magnifications reported by a Talos Artica are supposed to be "mag on the viewing screen" or "mag at the film plane"? We clearly have a serious issue with the calibrated magnifications on our microscope, but I just
recalibrated it and got more or less the same lousy magnifications. I'm trying to understand our issues, and knowing what the microscope thinks it is reporting would be helpful. Thanks in advance.<br>
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