Forum: Photography


Subject: HELP!!! slow auto-focus

TheSecond opened this issue on May 09, 2006 · 5 posts


TheSecond posted Tue, 09 May 2006 at 2:37 PM

Attached Link: Nightvisions-UA.com

Dear photographers,

I havent been around for quite a while due to my venturing in the field of working as a photographer. More detailed as Party Photographer.

But now I have come across a problem with my OLYMPUS E-300. Light at these events is often very bad and in the last time it gives my auto-focus real trouble to get focused, even when in not so difficult environment with little strobe-light. I am doing this now for 5 weeks (about 10/11 nights) and I thought that the "tiredness" of my auto-focus might be related to the battery of the camera.

My question to you is now if the slow auto-focus might be related to the slow failure of my camera battery or rather the batteries of my external flash and the support light?

Thanx for your help, if you are interested in what I do, link below (or above, never exactly recall).

Ulf

 


Valerie-Ducom posted Tue, 09 May 2006 at 2:52 PM

Attached Link: http://www.steves-digicams.com/2004_reviews/e300.html

Hi The Second,

f the camera has multiple focussing points then it will have multiple zones; what Canon call their AIM system. The number of flash metering zones depends on the camera model. For instance, the EOS 10/10s has three focussing points and three flash metering zones, and flash metering uses whichever corresponding autofocussing point or points are active. However, the EOS 5/A2 uses the same sensor as the 10/10s so it too has 3 flash metering zones even though it has 5 autofocus points. The Elan II/EOS 50 has 3 AF focussing points and a 4 segment/3 zone flash sensor. (this latter means that the flash sensor has 4 segments but it chooses two consecutive segments, yielding 3 possible zones)

These multiple zone flash sensors let the camera bias the flash exposure to the currently selected AF point. When you focus manually the camera does not bias any flash zone but chooses the central zone instead.

Note that the A2/5 is somewhat different from other multiple AF point cameras in that it will only bias flash exposure correctly to the nearest AF point if that point was manually selected. In automatic and ECF modes it apparently always chooses the centre zone.

Well, If you see more information looking my links

Hugs



Onslow posted Wed, 10 May 2006 at 12:08 PM

I don't have experience of that particular cam but as a general rule the lower the light the slower the focus, it will be nothing to do with your battery.

Having spoken to people who do such photography they tend use fast short lenses where possible eg 50mm F1.4 seems to be popular on a Canon.

Perhaps if Donald gets a chance to return to the forum he might be able to enlighten more on what set up he used for the gig shots he recently posted.

And every one said, 'If we only live,
We too will go to sea in a Sieve,---
To the hills of the Chankly Bore!'
Far and few, far and few, Are the lands where the Jumblies live;
Their heads are green, and their hands are blue, And they went to sea in a Sieve.

Edward Lear
http://www.nonsenselit.org/Lear/ns/jumblies.html


TheSecond posted Wed, 10 May 2006 at 12:54 PM

Thanx you two, the lens was also a guess of mine. Need to get a faster lens, I am still working with the kit-lens, which is nothing special. Just wonderd, as it was better in the beginning and lets me down more and more in the last time.


Valerie-Ducom posted Wed, 10 May 2006 at 1:58 PM

I'm enjoy to help you 😄

Good day and Hugs