We have often had the discussion about "what blend filtering the ISI should be in while working on HEPI tilt decoupling".

The first plot compares the response from "HEPI IPS" motion to "ISI GS13 motion" for two different configurations: "ISI damped" and "ISI isolated". The low frequency part of the transfer functions don't change, indicating that the tilt coupling ratio is unchanged.

The second plot compares tilt decoupling results for several blend configurations. The black line is the reference (no tilt correction). The exact same tilt-correction factor was used for all other measurements (for the records, the decoupling factor used was 7.0%, calculated from the measurement shown in the first plot).

This second plot shows that the tilt correction implemented works just as well for all blend configuration, which is really good news.