this might be a stupid question...

pearljamfan

does the light on the af assist actually do something?? will the af not work as well if i switch it off, because it annoys me when im taking a few photos at a time of something, was at the frames gig before xmas and it kept shining off some fellas hoody and it made me feel conspicuous.

... off topic, heres one i quite liked from the gig.

Prenderb

First of all - no such thing as a stupid question!

Secondly, yes, it helps the camera to make the focus. When it's dark, the camera can't see what it's focussing on so finds it harder to make a decision on when it's focussed or not. AF probably won't work as well without the assist light.

The alternative is to go to manual focus?

pixbyjohn

Usually the assist light helps the camera focus when in a dark situation. You can switch it off but then the autofocus might not be able to focus. Then manual focus may be better in that situation if you can pick something to focus on.
http://www.camerahacker.com/disable_AF_aid/index.php

Heebie

You could use a different flash that utilises an IR or near-IR focus assist light. (Mine is near-IR.. you can see it if you're looking at the flash unit, but you really can't see it shining on anything.)

pearljamfan

aha!! thanks a million.

i dont mind manual focus, its just on this new camera in mf when u start to focus ,the screen automatically zooms into a tiny area on the subject before you're even able to frame the shot and i dont like it!

magicbastarder

pearljamfan wrote: »

does the light on the af assist actually do something??

i suspect it won't do anything if you're too far from the subject.

ThOnda

From built-in flash, the assist light has at most the same range as the flash, so not much more than 5 meters. And really could be disturbing. Going manual for for flashgun with IR assist light would be my choices.

.Conor.

I've never really paid much attention to the little light on the af until you obviously brought it to my attention now. Really good question and its weird how the light was shining off the mans hoody I didnt think they were that "powerful." but I assume it's needed for the af.

pearljamfan

hey conor, it was off the guy in front of me, place was packed and i couldnt get anywhere near the stage to get a decent photo, i was annoyed cos i couldnt get the camera to focus at all on the stage , just on the guy in my way, lol. and it was bright orange too. so i was wondering if id switched it off would i have better or worse chance.

.Conor.

The only thing I can think of is if you try focusing with the light on and then try again with the light off in a room with very dim light.

5uspect

What kind of camera is it?

pixbyjohn

5uspect wrote: »

What kind of camera is it?

panasonic gf1

5uspect

Well it seems to be a capable camera.
From dpreview:

Aside from the viewfinder, our biggest worry about the viability of all non-reflex interchangeable lens cameras is the reliance on sensor-based contrast detect autofocus. Our experiences so far - with the live view modes on current DSLRs - haven't been promising; all are painfully slow and most are close to unusable for any non-static subject.

When we visited Panasonic in Osaka last year to talk about the development of Micro Four Thirds we were assured that our concerns would be unfounded; this is a system designed from first principles on the basis of live view only operation, and a lot of work has gone into the design of new contrast detect focus algorithms. This, we were told, along with the extra processing power of the new Venus HD engine, would mean contrast detect AF that was at least as fast as current entry-level digital SLRs using the traditional phase detect AF.

The good news is that Panasonic's engineers have kept true to their word; the focus is not only astonishingly fast for a contrast detect system; it's easily as fast as any conventional SLR in this class. And unlike even most mid-range SLRs you get 23 area auto AF and the ability to place a single AF point almost anywhere in the frame - and that's before you throw in Panasonic's remarkable subject tracking AF and Face Detection. Panasonic seems to have overcome the main problem currently associated with using live view on an SLR (focus speed) and in so doing produced a truly usable live view-only camera.

Focus speed is determined by a combination of the performance of both camera and lens, and the GF1 is fastest when used with one of the two kit lenses Panasonic currently sells for its Micro Four Thirds system (the 14-45 and 14-140mm); with the 20mm F1.7 it's a touch slower (there's a lot more glass to move). That said, comparing the GF1 with the 20mm to the E-P1 with the 17mm pancake is like chalk and cheese; the Panasonic combo feels easily twice as fast. We'll look at this in more detail later in this review.

All autofocus systems suffer in low light but it helps to know how your particular autofocus system works. The GF1 has a contrast based system that uses the imaging sensor. SLRs have a completely different sensor just to handle the autofocus tucked into the viewfinder.

Looking at your image above there is good contrast between Hansard and the dark background. I would turn the AF beam off and focus on this high contrast edge setting a manual focus point, if possible. The beam is only going to light up stuff in the foreground and confuse things.

With manual mode once you set it does it zoom back out? The performers aren't going to move too much and neither are you. You might get acceptable sharpness by just parking the focus in place and snapping away.

Mr. Grieves

I imagine at that subject distance and angle of view, setting the focus to infinity would have woked fine, even using a wide aperture. Infinity is easier to find on some lenses than on others (most let you focus beyond infinity but have a marker giving a rough indication where it is).