I believe the correct way to test is to zoom to the max telephoto position, then focus on your subject, then go wide to see if focus holds. That is how professional video zoom lenses work.

The 70-180 micro is said to be parfocal.

El_Pickerel said:
The first 70-200mm VR lens is parfocal.

Nope - been playing with it and it certainly is not. It is close, but not a true parfocal.

At the hyperfocal distance all of those lenses may be (due to the natural optics), but anything closer (<15ft) the focus moves just a bit. Many Cinematic lenses will zoom with zero focus movement at all lengths.

There seems to be a lot of confusion over it or at least incorrect assumptions. Parfocal lenses have internal elements that move to zoom and focus. Or easier to understand, the lens does not expand or contract to zoom. The key is, not all lenses that internally zoom and focus are NOT parfocal.

My Tokina AT-X PRO 28-70 f2.6-2.8 (Angenieux design) is parfocal.

24~70 2.8 seems to be. 70 -200 VRII is not.

One of the rental houses told me that the Nikon 17-35 f/2.8, 24-70 f/2.8 AF-S , 70-200/2.8 VR Mark I are all Parfocal. I expect that they are not the only ones. That was why I was asking.

In Canons line up these are there Parfocal lenses:

EF 16-35mm f/2.8L USM
EF 17-40mm f/4L USM
EF 24-70mm f/2.8L USM
EF 70-200mm f/2.8L USM
EF 70-200mm f/2.8L IS USM
EF 70-200mm f/4L USM

Discontinued lenses that are Parfocal include:

EF 17-35mm f/2.8L USM
EF 20-35mm f/2.8L
EF 28-70mm f/2.8L USM
EF 70-210mm f/4
EF 80-200mm f/2.8L
EF 100-300mm f/5.6L
EF 100-300mm f/5.6

The first 70-200mm VR lens is parfocal.

SkintBrit said:
OK, you've got me thinking, so what is it about modern lens construction the makes the focus shift when zooming? I've always accepted that it happens and never knew that anything else was possible.

I would assume the technology would be like the autofocusing binoculars. They stay focused even when you zoom in and out.

OK, you've got me thinking, so what is it about modern lens construction that makes the focus shift when zooming? I've always accepted that it happens and never knew that anything else was possible.

thanks for the insight! so there comes the next technology, the manufacturers will make us want to own...sigh

parfocal lenses must have been common in the pre-AF-era. i remeber reading in old "learning photography"-books, that you should zoom to max to fineadjust your focus, then zoom back to your desired focal length and take the shot. this ofc only works with parfocal lenses.

another reason for the good ol MF-horses, they have better focusing-gears anyway.

Thanks for the definition Tao.

In that case then, I don't think any modern Nikon lens is a parfocal zoom lens.

For those who knew but probably forgot, A parfocal lens is a lens that stays in focus when focal length is changed.

I do not believe there are any in the current or in any recent history that had a place in Nikon's line-up. The only parfocal lens I have heard of lately being released is one from Sony (16-50mm). I know Minolta used that design back in the day.

Parfocal is obviously a desire for video but as all modern lenses were not made for video by any company, this will become one of the questions companies may choose to address.

Does anyone have a list of which Nikkor Zoom Lenses are Parfocal Lenses?