To apply the same settings to several graphics, you can create a graphics group by assigning a common group name to the GraphicIDs (base file names) of the graphics in question. For example:
[GraphGroup] ; Graphic ID = graphic group name, any name you want ab01f853=schematic ab012c13=schematic aa568433=screenshot ab00b5d3=screenshot
Once you have assigned a group name to one or more graphics, in any of the other [Graph*] sections you can assign properties to the group name instead of to an individual graphic file. The values you assign affect all graphics defined as belonging to the named group, except any graphics to which you explicitly assign a different value.
For example, to avoid scaling screenshots, but reduce schematics in size:
[GraphScale] ; Do not scale images in the screenshot group: screenshot= ; Scale schematics to 25% of their original size: schematic=25
Another way to assign a graphic to a group is to insert an HTMConfig PI marker in text just before the graphic in your DITA document, with content as follows:
HTMConfig="[GraphGroup]=graphicgroupname"