New T4i owner - please help

[crotonmark]

I have a canon 50mm 1.8 lens and a canon 35/105 3.5/4.5 lens.
I want to use the t4i for video but my lenses really focus slowly.
Is this the nature of video on a DSLR or is it my lenses?

Also I would ideally like both a longer and a shorter lens.
Is there a set of lenses that a general photographer should have? Mark




M

 

[KmH]

I have moved your question to the DSLR Video Discussion forum in the hopes you'll get more replies to your video focusing issue.

From dpreview.com - Canon EOS 650D/Rebel T4i In-Depth Review: Digital Photography Review

In our EOS 600D review, we noted that focusing in video mode was that camera's Achilles heel. Canon has sought to address that with its introduction of a completely new 'hybrid AF' system in the EOS 650D that makes use of phase detection in combination with contrast detection AF methods. One of the more obvious benefits of this hybrid approach is that phase detection AF will ensure (for objects in the central area of the frame) that the lens begins its initial focus search in the correct direction, rather than racking all the way through its focus range before 'locating' the subject. This obviously makes for more pleasant-looking video footage. The 650D also breaks ground by offering continuous AF in video mode - dubbed 'Movie Servo"

Servo'.

 

[John27]

It's a little of both as I understand it. I shot a little video with a friends 5D II and USM L lens (I don't recall what focal length or aperture, but one of the larger white-bodied telefotos). It focused incredibly fast! That is in part due to the very fast focusing of L lenses (And I believe the USM feature as well) AND the variety of auto-focus sensors the 5D II has along with it's fast processor.

FWIW, I read an article a while back on Canon DSLR's used in the video world. (House M.D.'s producer liked to use 5D MK II's for certain shots, and if he used it for one shot he used it for the entire episode for consistency!) It seems like most of them prefer to either, A) Not focus in the shot (use complicated rigs and stage the actors so that they always remain at the correct 'distance' to remain in focus. Needing only very minor adjustments. Except of course when focusing drastically for 'drama', like focusing in between two actors in the middle of an intense scene!) or B) Modify lenses or use big lens-grip-things in order to make them easy to quickly manually focus. Which I imagine takes a bit of skill.

DSLR's take great videos in certain situations and the lenses can create incredibly sharp video with a neat 'cinema film camera' look. But there are some compromises! Remember your DSLR's JOB is to shoot still images, and the video is just a 'feature'. If your primary goal is shooting video but with occasional photos, then a video camera whose JOB is to shoot video, but can snap stills as a 'feature' is a better solution!

(But I do love the take video on my T1i!)

 

[KmH]

Yep! Canon's USM (UltraSonic Motor) focuses faster than their consumer grade lens auto focus motor. Technical Room - USM

 

[brunerww]

Hi Mark - I did a touchscreen autofocus 'shootout' between the T4i and my Panasonic GH2, and the T4i did a pretty good job of fast autofocus with the new $149 40mm STM "pancake" lens. The 40mm and 18-135 STM lenses were purpose-built for the new autofocusing T4i and EOS-M cameras. And it was pretty quiet too, for a Canon lens (please watch in 1080p - and note what happens to the green screen as the lens shifts focus):

T4i Touchscreen Autofocus Test - YouTube

As you've discovered, your non-STM lenses will work for autofocus in video mode, but they will be slower and noisier than STMs.

By way of comparison, here is the same touchscreen autofocus test - this time with the Panasonic GH2 and a 14-140 lens (again, please watch in 1080p - and note the lack of moire in the green screen):

GH2 Touchscreen Autofocus Test - YouTube

STM lenses are pretty good for video autofocus - but Panasonic video optimized lenses are faster and quieter.

Cheers, and hope this is helpful,

Bill