List of Lenses Affected – Update 3

May 3, 2010

Campaigns, EOS 5D Mark II, EOS 7D, REPORTS, Special Info, Tech Info

Content:

List of Lenses Affected by Iris Issue – UPDATE 3
Comments – EOS 7D too?
Feedback
Contact Canon

LIST OF LENSES AFFECTED BY IRIS “JITTER”

Due readers requests, we collected all possible feedbacks to make a list of lenses that are affected and not affected by the “IRIS jitter” issue when mounted on a Canon EOS 5D Mark II with firmware 2.0.4.

Please keep in mind this list was made in part with the feedbacks from many readers. We did not test “all” these lenses by ourselves so we cannot guarantee 100% of accuracy, but the “affected” ones are 100% confirmed.

UPDATE # 3

We have detected that there are some zoom lenses with a non constant aperture design, that suffer “iris jitter” issue when zooming in or out.

It is not the change in light when the focal length changes (which is very easy to see on the LCD display). It is REAL “iris jitter” that can be seen and heard, also affecting the LCD image in Live View mode, and of course the video clip if you are recording.

UPDATE: After watching directly and very carefully the iris behavior during zooming in and out whilst testing zooms with “variable aperture” design, we saw there is no iris issue in those cases.

Question: What happens then, and why do we hear the iris changing while zooming in a non constant aperture zoom in Live View mode?

Answer: The camera “tries” to keep the original aperture value during the zooming process. Since the zoom has a “variable aperture” design, the camera changes the iris a bit (closing or opening it, usually in 1/3 steps) in order to keep the aperture value selected by the user.

We wish there was a function to disable that “aperture adjustment” when zooming in or out a “variable aperture” zoom lens, so the iris would remain in the exact same position, no matter the focal length change. Yes, we know it would result in an increase or decrease of light and exposure, but that is MUCH better than a “jump” of the iris or dropped frames in a footage…

NOTE: We must clarify that the “iris jitter” DOES exist when using the lenses listed below. In those cases there IS an abnormal behavior of the iris, as showed and explained in previous reports.

However, there are also few reports about constant aperture zooms suffering random iris jitter. We can’t still confirm it, but there is a video showing one case (check the comments by readers at bottom)

LIST UPDATE

– Lenses NOT affected by IRIS jitter:

Canon EF 14mm f/2.8L II USM
Canon EF 24mm f/1.4L II USM
Canon EF 28mm f/1.8 USM
Canon EF 35mm f/1.4L USM
Canon EF 35mm f/2.0
Canon EF 50mm f/1.8 II
Canon EF 50mm f/1.4 USM
Canon EF 85mm f/1.2L II USM
Canon EF 85mm f/1.8 USM
Canon EF 135mm f/2L USM
Canon EF 200mm f/2.8L II USM

Canon EF 16-35mm 2.8L II USM
Canon EF 24-70mm f/2.8L USM
Canon EF 24-105mm f/4.0 L IS USM (*)
Canon EF 70-200mm f/2.8L IS USM
Canon EF 70-200mm F4L IS USM

(*) UPDATE: According to a feedback (see comment posted by a reader on this topic) this lens may suffer some iris issue, but in a different way. Rather than whilst manually changing focus, the iris wrong behavior may occur randomly.

– Lenses AFFECTED by IRIS jitter:

Canon EF 100mm f/2.8 Macro USM Macro
Canon EF 100mm f/2.8L IS USM Macro
Canon EF 180mm f/3.5L USM Macro

Canon EF 300mm f/2.8L IS USM
Canon EF 300 f/2.8L IS USM + 1.4x TC
Canon EF 300mm f/4L IS USM

Sigma 150mm f/2.8 EX DG APO HSM Macro

Tamron SP 90mm f/2.8 Di Macro AF

COMMENTS – 7D too?

It is more than evident that there is an issue on the iris control in firmware 2.0.4 that affects the communication between camera and lens. It affects most (if not all) Macro lenses and some few non-Macro lenses when rotating the focus ring manually, but also might appear as a random iris wrong behavior in some few lenses.

There are also some users of Canon EOS 7D reporting similar iris issues with the latest firmware update (version 1.2.1). If you have a 7D and experience this issue feel free to post your comment here, as detailed as possible.

FEEDBACK

Feel free to report any lens that you find to be affected or not affected by the “Iris jitter” problem. We might include it in the list.

Be sure to follow the instructions detailed on this Report to reproduce the “iris jitter” issue. Also check the video posted here to see the iris behavior when directly watching it.

If you find another issue, please detail it as much as possible to discard any wrong camera setting.

Please keep in mind we need to be as precise as possible, so if there is any doubt or inconsistency, double check your lens and camera configuration, and repeat tests if necessary.