Tokina 11-16 Cine distance mark problem

The place for questions about shooting with Blackmagic Cameras.
  • Author
  • Message
Offline

Krishna Pada

  • Posts: 86
  • Joined: Tue May 17, 2016 5:55 pm

Tokina 11-16 Cine distance mark problem

PostSat Aug 18, 2018 7:00 am

Got a Tokina 11-16 Cine with EF mount. Exfellent lens, but the distance marks are not at all accurate. For some of us who still go by the old school method of measuring the distance by tape, find it difficult to effectively use the lens.

Any idea how to adjust the lens to distance markings? I can't find any suitable shim set for this lens. Tokina also doesn't sell one it seems.
Offline

Anatoly Mashanov

  • Posts: 503
  • Joined: Sun Sep 28, 2014 11:36 am
  • Location: Russia

Re: Tokina 11-16 Cine distance mark problem

PostSat Aug 18, 2018 12:30 pm

I never disassembled Tokinas. But I have disassembled a lot of other lenses and even assembled some of them back. And they mostly have some mechanics that allow the distance ring to be fine tuned. For instance, Fujinon C6x17.5 and Canon V6x16 rotate the front lens block after you weaken the plugs. And Promaster Spectrum 7 28-210mm has a fine tuning mechanism under a front rubber grip.

I believe that shims are for tuning the lens to parfocality ONLY.
Online

Denny Smith

  • Posts: 8813
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: Tokina 11-16 Cine distance mark problem

PostSat Aug 18, 2018 5:03 pm

Auto EF lenses are normally not shimable, and due to the difference in the EF mount tolerance from one ca era to the next, most EF lenses do not have accurate witness distance marks. I have the excellent Duclos mod Tokina 11-16 and the focus throw is short, so it would be hard to get many witness marks on the focus ring scale. That said, at 11mm the DoF is so wide, you just set the distance or focus to the main area you want in focus, and you will have a large in focus area in front and behind thst setting. Witness makes on UWA lenses are not that useuable due to the short focus throw anyway.
Cheers
Last edited by Denny Smith on Sun Aug 19, 2018 5:14 pm, edited 1 time in total.
Denny Smith
SHA Productions
Offline

Krishna Pada

  • Posts: 86
  • Joined: Tue May 17, 2016 5:55 pm

Re: Tokina 11-16 Cine distance mark problem

PostSun Aug 19, 2018 5:07 pm

Denny Smith wrote:EF lenses are normally not shimable, and due to the difference in the EF mount tolerance from one ca era to the next, most EF lenses do not have accurate witness distance marks.
Cheers


I don't know about other lenses, but Zeiss CP.3s, SPs, CZs and LWZs are perfectly shimmable to accurate witness marks in EF mounts. Zeiss sell the shim sets, and the focus chart too. I have calibrated all my Zeiss lenses (all EF) myself.

Most of us think EF is an electronic mount, but manual lenses are also very much there. And they follow the same shimming principle as any PL mount lens. Unfortunately, I can't find a shim set for Tokina 11-16. Their Cine Primes have the shim sets for sale.
Online

Denny Smith

  • Posts: 8813
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: Tokina 11-16 Cine distance mark problem

PostSun Aug 19, 2018 5:27 pm

Yes, manual EF Cinemorimes can be shimmied, no electron contexts to worry about.
But on shorter focal length UWA lenses like the Tokina Mk1 Cine (and Duclos Mod version) which only has less that a 180-degree total focus throw, with witness marks for closer focus distances that are really useable, you have several 1.x then you get 2, 2.6 and 3-feet. After that, you only have and Inf. On the Duclos you go from 4, to 7, then Inf. So for anything close to normal shooting distances of 10- to 20 feet, no witness marks after 10-feet.

With the lack of an available shim kit for the Tokina 11-16, tells me the lens is not user shimable.
That said, perhaps the new Mk2 version currently in process of being released, will have a shim kit.

Shim the inexpensive Cine-like Zoom lens to be Parfocal, then use an EVF to set the focus. With the Duclos Mod, I can zoom in to 16mm, use the EVF zoom and get an accurate focus, then zoom back to the focal length you want. With the zoom Parfocal, focus will be set correctly and very accurately.

You are not going to find many Cine type, or other zooms, that are going to give you a parfocal Zoom and accurate witness marks, unless you spend more than $10K for the lens.
Cheers
Denny Smith
SHA Productions
Offline
User avatar

rick.lang

  • Posts: 8678
  • Joined: Wed Aug 22, 2012 5:41 pm
  • Location: Victoria BC Canada

Re: Tokina 11-16 Cine distance mark problem

PostSun Aug 19, 2018 5:48 pm

I’m hopeful the future Tokina 11-20mm CineATX T3 parfocal zoom will solve the need for accurate witness marks. There’s quite a premium price over the stills photo version of the Tokina 11-16 and 11-20 lenses. My think is they’ll have that new Ciné lens at Photokina in September.


Sent from my iPhone using Tapatalk
Rick Lang
Offline
User avatar

Valery Axenov

  • Posts: 24
  • Joined: Mon Mar 26, 2018 9:49 am
  • Real Name: Valery Axenov

Re: Tokina 11-16 Cine distance mark problem

PostFri Aug 24, 2018 10:00 am

What camera did you use? Did you check this lens on Camera with (factory) EF mount (no any let say EF-4/3 adapter(!)). That's the first point. Second are critical points of focuse - are you sure that you have correct infinity (or close focuse) at the end of the scale? May be lens to film distance is correct (and it's necessary only to move the scale ring (it may be lose or fixed in not correct position). (Normally screws that fix the scale ring are under the rubber focusing ring of the lens (Canon FD and classic mechanical lenses)) And last point every thing (mount) that one man was able to assemble, any other are able to fix. ps I fixed all my cine lenses Angenieux, Zeiss, Russian OKS first many years ago to my 16mm camera, now to BMPCC - corectly to scale of classic measuring roulette with toleranses within 1cm. In my case old pro cine lenses (out of factory) were 100% correct. (And in all cases I corrected 4/3 mount (or C mount) adapters only. All third adapters are out of specification now a days.) Aluminum foil/35mm film or abrasive paper are good materials to correct any mount to specification. (Better to have also clock micrometer with 0,01mm scale.)
Online

Denny Smith

  • Posts: 8813
  • Joined: Thu Aug 01, 2013 4:19 pm
  • Location: USA, Northern Calif.

Re: Tokina 11-16 Cine distance mark problem

PostFri Aug 24, 2018 4:49 pm

But what is The Point? You can not use the distance scale to focusmthe lens, you only have marks for 2, 3, and 7 feet then inf. or 2, 3, 5 feet and inf. How are you going to focus it at 10-feet using the focus scale?
It is an EVF lens, forget the scale, not really useable anyway, and just focus thenlens using the EVF or monitor with a zoom in to focus.
Cheers
Denny Smith
SHA Productions

Return to Cinematography

Who is online

Users browsing this forum: Adam Silver, Bryce Guinan, Chris Leutger, Denny Smith, giuseppeflandoli, Robert Niessner and 12 guests