I didn’t know before but both Tarkan and Leia were obviously CGI to me. CGI Leia looked worse to me.
I didn’t know that Cushing’s Tarkin was making an appearance going in, I thought they’d write their way around him - maybe have him hologram in or something. Putting him in-scene purportedly as a person was a brave call to make.
The lighting of his face and (oversmooth) texture of his uniform really didn’t mesh with the others in the background. He stands out like a hologram and initially I thought that that was what they were going for.
It was really well done, either way, but I’d have put him further into shadow and darkened it all a bit. As it was it fell into the uncanny valley for me, animation wise, but the voice actor was brilliant and it didn’t affect my enjoyment of the movie.
I knew they were CGI before seeing the movie so it doesn’t count.
My wife didn’t know however. She didn’t notice anything wrong with Tarkin but said that the special effect was obvious as soon as Leia appeared. For the record, she’s not a fan of Star Wars. I think she saw the orginal trilogy only twice, three times at most, so perhaps she didn’t remember Tarkin.
I am a CGI aficionado, and also knew Peter Cushing was dead, so was well aware that Tarkin was artificial. But I felt that it was 95% amazing work. The difficulty is the shooting style and lighting were different enough to make him look a bit off too. If it had really been him (somehow looking exactly the same forty years later) he would’ve looked a bit unusual anyway.
For me there was a subtle problem in the eyes, including the way he blinked, and the motion tracking was also a bit slavish. It needed to loosen up a bit as it made his head bob in a funny way.
Leia was less successful. Her face looked a bit long, kind of chalky and artificial, and her eyes also were slightly off. But this was cutting edge, envelope-pushing work, and knowing how difficult some of this can be, I am extremely impressed by what they managed to achieve.