I just double-checked, and you are absolutely right. I must have been too immersed in the storytelling to have noticed. I was viewing strictly for entertainment and not with a reviewer's eye.I've seen at least 1 review of the Blu-ray that states the two IMAX sequences open up to 1.90:1 .
In addition to our esteemed reviewer Neil, Someone named RAH disagrees with you.Was not impressed by the picture quality on this movie, looked soft, and didn't look like a typical 4k scan to me.
There is nothing like having a minority opinion.Unimpressed by this film, not as good as the previous two. Script and action sequences very derivative and with an ending we have seen many times before, not least in one of Moore's Bonds. I found the cinematography to be 'muddy' and not as crisp as the previous two films. Cruise should have stuck to his previous policy and used a different director.