There's no such thing as a "1080i master" for a film. Films are not interlaced and people often misunderstand what interlacing actually means. Video is only interlaced if there is temporal displacement between fields. For films, this is what happens (in 50 Hz countries):No, he's right. They're 1080i. I know, because I still have the HDTV MPEG-2 Transport Streams for I-IV, VI & VIII. In virtually every respect they look much better than the Blu-rays (sans II) because they don't have DNR applied and their grain structure is intact. You can see glimpses of these original 1080i masters at the beginning of the Captain's Summit interview on the last disc of the set.
I'm assuming your transport streams came from OTA, Cable or Satellite? I would have to ask how you know that they truly originated from 1080i masters? I question it because there have been numerous times where 720p HDTV broadcasts that are upconverted to 1080i. Here in Canada, back in February, the Canadian broadcasters of the Super Bowl were airing it in 1080i, ven though their originating feed was from Fox's 720p non-branded feed. Also, I believe ABC broadcasts 720p, but here Canadian Channels upconvert the 720p feeds/tapes to 1080i. So just to say that you have a HDTV 1080i feed raises some questions.
So the movies may've been transferred in 720p, but the current masters are just upressed versions, and the Blu-Ray producers decided to apply noise filters to make the movies look more like 2. We know that Paramount was going to release the theatrical version with Robert Wise's approve color-timing (as Darren Dochterman noted on the 2009 audio commentary), but for whatever reason Paramount went back after the commentary had been recorded and released the 1979 Color timing. So Paramount is known for not using the best masters for whatever reason.
1080p/25 video ---> broadcast as 1080i/25 ---> TV notices 2:2 cadence in signal and applies weave deinterlacing to display 1080p/25
It works in a similar way in 60 Hz countries:
1080p/24 video ---> broadcast as 1080i/30 ---> TV notices 2:3 cadence in signal and applies 2:3 pulldown deinterlacing to display 1080p/24
Those Star Trek 1080i streams contain 1080p video with no interlacing artefacts if they're played back properly.
Of course the source could be 1080i with interlacing artefacts but I don't even see how that's possible with a film, even in the hands of someone incompetent.
By "1080i master" I was referring to the videotape format. 1080/59.94i is absolutely a real tape format that a film can be telecined to. Yes, the film itself is composed of progressive frames, but the 1080i master is interlaced with pulldown just as you describe. So, yes, there is such a thing as a 1080i master and it is completely valid terminology. For example, here is film preservationist Robert A. Harris using it in reference to an old 2001 HD master that existed (circa 2010) for "Singin' in the Rain":
http://www.hometheaterforum.com/top...out™-spartacus-in-blu-ray/page-3#entry3580974
And he referred to the 1080i master again in in 2012 when the Blu-ray (based on a new 4K scan) came out and he reviewed it:
http://www.hometheaterforum.com/topic/315845-a-few-words-about™-singin-in-the-rain-in-blu-ray/