Can you also do a relative compression test just to see if its noticeable on the scope image.

WPS is a vacuum/pressure transducer that members like james use for doing in cylinder running compression tests to great effect.

They can confirm many issues such as valve timing inaccuracies, valve leaking etc without to much dis-assembly of timing covers etc.

Just look through the scope forum section as I'm sure there is an example of it in use.

Well beyond me some of the diagnostics they do with it.