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There are AFAIK no true parfocal photo zooms - true parfocality requires complex optical constructions which are too expensive to make sense in a photo camera.

On top of that, even parfocal cine zoom lenses need manual shimming adjustment because of mechanical tolerances of camera mounts. This isn't possible with photo zoom lenses either.

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The Sony 28-70 FE (kit lens for the A7) is surprisingly close to being parfocal (it is for my purposes).      On my A7s, I use it as a constant 5.6 lens for the most part.

 

EDIT This might help too.  

  https://www.lensrentals.com/blog/2016/03/mythbusting-parfocal-photo-zooms/

 

I actually only read it after posting.        I think shorter range zooms may give greater consistency for those that are close to being parfocal.

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5 hours ago, cantsin said:

Well, only zooms can be parfocal...

Primes can be (sort of).

With cameras that have a variable digital zoom you can use that.      May have its uses for video though.     Sony cameras can use Clearzoom (which is virtually lossless variable to 2x.    For 2x to 4x digital zoom is not so good and obviously lossy).

For the most part though, you are right.

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28 minutes ago, noone said:

Primes can be (sort of).

With cameras that have a variable digital zoom you can use that.      May have its uses for video though.     Sony cameras can use Clearzoom (which is virtually lossless variable to 2x.    For 2x to 4x digital zoom is not so good and obviously lossy).

For the most part though, you are right.

But then every prime is parfocal, since its plane of focus isn't involved in the digital crop process at all...

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9 minutes ago, TheRenaissanceMan said:

But then every prime is parfocal, since its plane of focus isn't involved in the digital crop process at all...

Agreed.     So long as you have variable digital zoom available.     Not something for stills really unless focal length challenged (though it has its uses- but not needed to be parfocal) but for video, if I did anything other than record bands or had any actual ability to do it properly, I would certainly be using clearzoom with my A7s and 24 1.4/85 1.2 FD L lenses when I thought it would work.

I posted a very lame demonstration of clearzoom on YouTube a couple of years ago  (with a Nikon 50 at 5.6) but there are some better demos of it there.

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Another quick (and lame) demo of Clearzoom with A7s and 55 1.8 Sony Zeiss and short extension tube.      I think it would come in handy for short quick takes.    Maybe a lens like a 24 1.4 would be useful.    

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