micro converter HDMI>SDI

If we connect a laptop (with a powerpoint presentation) to the microconverter via HDMI, the SDI signal is sent to the Braoadcast PIC.
In the preview of the Broadcast Pic we can already see that the quality of the image is worse than on the laptop.
How can we improve this?

Make sure the HDMI output of the laptop is set to a TV resolution, preferably 1920 x 1080 (or UHD of the converter supports it).