Is 30D AF-system adequate to cover runway (in low light situation to track down models)?

[felix_ing]

Hi,

 

I've recently shot the L'oreal Fashion Week in Toronto using:

30D + 24-70mm on monopod (poor choice of lens = yes, but I needed to cover

some backstage so needed the wide end...and 24-105 wasn't available for rental

blah blah blah and I didn't want to rent 2 lenses; shot in M-mode, AI servo,

highspeed (5fps) mode, ISO 1000, 1/200 @ f/4-ish, portrait orientation, with

top AF point selected (in portrait orientation)--> should I have used "auto-AF

selection"?

 

I find that it was hard to track models at times and that images aren't as

sharp as I'd like them to be. So my question is, since the center AF point is

a cross-type and others are not (hence difficulities tracking models), can I

use center AF point to track models (will be aimed at crotch area of garment,

so garment will be in focus, hopefully), stopped down to around f/5.6 and get

their faces in focus?

In such distance am I safe to say that the models faces and their crotch are

at the same focus plane?

 

Anyone have shot runways care to share the setting that worked best for you?

Also, anyone used the extended ISO3200 in real life situation? How do you find

the noise?

 

Much appreciated.

 

Cheers

[dcheung]

Runway models walk pretty fast. Perhaps some of the softness in your images is due to the shutterspeed not being fast enough. At 1/200, it should be fast enough, but if you are staring at 100% crops and filling the frame with the model, then there just might be a bit of motion blur induced softness in the image.

[jean_marc_liotier]

Instead of paraphrasing Ken Rockwell I'll just cite him :<br>

<p style="margin-left: 40px;" align="left">"It's

more difficult for

the camera to track moving targets as they get closer. This is because

the focus system has to work harder and faster to change the focus as

targets approach. Pro cameras and lenses like the F6 and an AFS

telephoto rarely run out of steam. An amateur f/5.6 lens on an N75 may

not be able to track moving subjects if they get too close. No problem,

just know this and wait till subjects are further away if you have to.</p>

<p style="margin-left: 40px;" align="left">You can

see this with a

camera on a tripod tracking focus on moving cars. The focus ring moves

slowly when cars are far away and moves furiously as cars approach you.</p>

<p style="margin-left: 40px;" align="left">This has

nothing to do

with the absolute speed of the subject. It's trivial to hold focus on

an airplane doing 550 knots 10 miles away and very difficult to hold

focus on a 6 year old kid running towards you from five feet away.

Don't get frustrated if a soccer player is running towards you and the

camera can't hold focus as you're tackled; this is normal."</p>

<p align="left">Since you took a 24-70 you had to stand

close to those fast walking models, which may well explain the

difficulties with the AF.</p>

<p align="left">So get a longer lens and stand back,

you'll give your AF system an easier time.</p>

<p align="left">As a bonus, a longer lens will compress

the model's features, which is often a desirable side effect.</p>

<p align="left">I would use my 70-200/2.8 or rent a

300/2.8.</p>

[brian_coy]

I actually recommend prefocusing on a point in front of the model and then taking the pic when they get to that point.

[steve_dunn2]

<cite>should I have used "auto-AF selection"?</cite>

 

<p>Probably not. Assuming you were shooting from the floor and the model was on an elevated catwalk, geometry says that the model's lower extremities would be closer to you than the upper ones. The AF system tends to favour the AF point which covers the closest "subject" so it would probably focus on something other than the face. As well, a walking person's lower extremities tend to move around a lot more; arms swing back and forth and legs walk. The head may not necessarily move in a smooth, steady, straight line, but it's going to be much less erratic, so it makes a better target.</p>

[fernandocolon]

<p>I'm with Brian Coy on this, sometimes in low light the AF might be inconsistent. I manually focus on an area of the runway and wait for the models to reach it before getting my shot. I use an 80-200mm /2.8 and the distance helps with DOF. 3200 ISO is a bit too much noise for me, so I use 800-1600 ISO and reduce noise in post. Hope that helps</p>