Suitable lenses for matt box

[tj williams]

In shopping around for a wide zoom a mid zoom and a tele zoom I've run across a number of seemingly usable zooms. They don't push pull to zoom, but rotate.
When you actually get your hands on them though you find that the length of the lens changes by 15 to 20 mm when you zoom. (Canon 17/50mm 2.8) Often there is a little ridge near the front containing the front element which moves outward changing the length of the lens. Probably this is not considered a big deal in still photography but how will I get this to sit behind my matt box???

Another one as you focus the ring moves up and down the barrel by the width of your finger. I haven't seen any focus gears wide enough to cover this???

People out there with stills experience or zoom owners. What zooms are available in 2.8 all the way thru the range, where the focus doesnt move on the barrell and the length of the lens does not change???

I'm open to Sigma Tokina Canon Nikon may go with Canon if I can finde the lenses because of Birger.

[M Olsen]

TJ,

The earlier Angenieux 25 - 250's breathed like that. There is a cog for the ARRI F\Focus that covers that sort of travel.
Also if the rubber "donut's" available for the Matt Boxes do not suit, then get a piece of heavy black cloth sewn into a sleeve with elastic front and back, that works every time. I have one left over from my focus pulling days.. it still comes out the meter box when encountering the odd sized lenses with non standard front element size.
I am sure that a couple of things will happen as momentum gathers which will include a third party rehousing Canon and Nikkors to a common fit and also manufacturing interface odds and sods like "Donuts" focus gears etc to suit.

[Evin Grant]

The 17-35mm f2.8 Nikkor of course. And the 80-200 f2.8 AF (two ring version) doesn't change size either. The 28-70 f2.8 does extend out but an adapter that connected to the hood bayonet could easily be constructed to solve this issue.

[Moir]

Sigma 120-300mm f2.8. Canon mount version should work with Birger adapter?