If your Excel link changes aspect after being updated despite no changes being made to the source file, it could be caused by a change of scale in your Office applications.
When using Excel, and especially the export feature, it is important to note that the size of cells/texts/charts in Excel changes depending on the computer. It depends mainly on:
- The zoom level in Excel,
- The DPI (Dots Per Inch) scaling in Windows.
Impact of zoom level
The rendered size of a cell in Excel obviously looks different depending on the zoom level, but the actual size is different too.
A 99 pixels wide cell at a 100% zoom level should appear twice as small at a 50% zoom level. We could expect the actual width of the cell to remain 99 pixels when being copy-pasted in another application.
This is not the case, as shown in the example below.
Things are much worse when taking into account the variations in font size. Font sizes are typically much smaller integers than the width of a column in pixel, rounding can have very drastic effects on the aspect in Excel (more details in the "Impact of fonts' size" section).
Once again, we cannot stress enough how important to understand that there is not a single definitive way an Excel document will look on any machine. What you see on your screen will be sometimes slightly, sometimes glaringly different from what your co-workers will see. This is before even taking into consideration exporting to PowerPoint or printing to physical paper, which are also lossy data conversions. We are only talking about Excel here.
In PowerPoint and Word
When updating a chart in PowerPoint, the height can change slightly, and when exporting with the 'Resize Chart Height' option enabled, the resulting image might not exactly match the shape.
This happens simply because the size of an Excel chart is linked to the zoom setting in the workbook view. In the example below, you can see how the scaling setting (and ultimate chart size) in Excel varies when moving the Excel workbook zoom from 100% to 80%.
100% Zoom - Height = 10,6cm 80% Zoom - Height = 10,8cm
Impact of font size
When you change the zoom level, Excel tries to render the size of the cells and text accordingly. In order to keep the appearance of the cell and the text crisp, it rounds to an integer value.
Since the font size is typically quite small, there is a big risk of deviation when rounding. Thus, the text might look too small or too big for its cell, which will have a blank space at the end of it, or overlap on/under the next column. This is especially true when working with a wide cell and/or a small font size.
Example scenario: suppose your zoom level in Excel is 100%, and let's consider a 100 pixels wide cell filled with text, using a font size of 10 pixels. When you change your zoom level to 85%, the cell is rendered on your screen as an 85 pixels wide cell, and the font is rendered in size 8 (instead of the theoretical 8.5). This will cause the text to appear less wide than the cell. N.B. the way Excel calculate the different sizes is more complicated, but the reasoning holds.
100% Zoom - normal 66% Zoom - the text overlaps
Impact of Windows scaling
All of these issues can also be caused by the screen resolution. You can access these settings by right-clicking on the desktop and choosing Display settings.
Windows addressed this issue in a very detailed article.
Fix for these issues
To minimize these issues and ensure there aren't any further disturbances when coworking on a document, all UpSlide users in the same team should follow these recommendations:
- Keep the zoom level in Excel/PowerPoint/Word at 100%
- Set the scaling of Windows to 100%
If you still notice some differences when exporting from Excel, read this article to know why you might be seeing this.