Canon 20D AF ?

illuminati919

I was looking to purchase 20D sometime in the near future, I have one question ?

1. How fast is the autofocus in darkness ?

Thanks alot guy, any other info would helpful as well.

Red Bull

It really depends on what lens you are using. One with a 2.8 or faster aperture will focus faster than one with an aperture of 4 or 5.6.

Other than that it focuses pretty darn fast.:D

binghott

illuminati919 wrote:

1. How fast is the autofocus in darkness ?

12 miles per hour

Justiceiro

In my experience, this is completely dependent on the lens. My 50mm 1.8 is pretty slow. The 35-135 USM is very fast. If you need a fast AF, buy a USM lens.

gus

How dark ?

What lens ?

Mate thats a really open question.

Red Baron

Faster lens = faster focus. In the Canon lineup, L lenses focus faster than non-L. I have the 20D and I've never had a problem focusing in what I consider low light. If you're talking virtual darkness then any camera will struggle focusing. Also, don't forget that mounting an EX flash will allow you to focus in lower light situations by using an IR beam from the flash.

pathfinder

None of the Canon cameras will auto-focus in darkness. Low-light yes, depending on lens, but darkness NO, Nada, Never!! Even the f1.2 85mm requires some light to work with.

I think some of the Sony camera's use IR lamps to focus in the dark - not sure about this - Andy may know the anwser.

illuminati919

I'm not talking about super dark situations, I shoot alot of BMX photography at night so that would be the situation.

Whats a good over all canon lens that would focus fast, preferably a wide angle, around $400 ?

wxwax

binghott wrote:

12 miles per hour

illuminati919

12 mph aint fast enough.

pathfinder

The solution for fast shooting in very dim light is to prefocus manually in advance, and shoot with flash

binghott

if you're shooting bmx at night, it can't be that dark because you'll need enough light to get a shutter speed fast enough to stop the action. i've shot in some very dark nyc clubs with my 20d and have had some trouble focusing at times. i'm not annoyed at all about it, it's expected. i was shooting at iso 3200, 1/30sec, f/2.8 and still getting dark shots. when i needed focus help i just used my 420ex flash's autofocus and was able to get it. 1/30sec would be far too slow to catch bmx action, so you hopefully won't be shooting in conditions as dark as i was.

my recomendation: use car headlights to light the area. i think it could give a very good, moody atmosphere to your bmx shots.

illuminati919

I normally do prefocus and do use a flash, but prefocusing sometimes doesn't do it, especially if I am shooting at a contest. The thing that I am getting out of this is probably a faster lens instead of dishing out the $800 for the new body.

Any suggestions for wide angle Canon lenses that can focus fast in the dark under 400$ ? Im using a D60 body right now as well. Thanks alot guys ?

binghott

illuminati919 wrote:

The thing that I am getting out of this is probably a faster lens instead of dishing out the $800 for the new body.

$800 for a 20d?! on what planet?!

i think a 20d would change your life over a d60.

illuminati919

20ds on ebay sell for like 900 sometimes maybe even lower, thats for only the body.

Red Bull

Dang! If I could get my hands on a 20D body for that cheap, I'd jump on it! (Unless it was damaged) I already have a 20D though.

You could do a search on B&H. Just go under lenses and select wide angle and sort by price. Maybe the Sigma 20mm f/1.8 EX or the Canon 28mm f/1.8?

Justiceiro

Illuminati, you have to be a little clearer in your terms.

When you say "how fast does it focus" what exactly do you mean? Do you mean how fast it can focus multiple times on a moving target? Are you asking how quickly the lens can reacquire an AF lock? This is a lens issue.

If your lens is just zooming back and forth, and not aquiring anything, that's a different issue. Then you have a body problem, or you are too close to your subject for a non-macro lens, or its simply pitch black.

Technically speaking, you can't take pictures in the dark. Or else you get a black triangle. If you are doing BMX, then you probably need a lens and body that can focus repeatedly on moving subject at relatively high shutter speeds even in low-light conditions.

So you need three things; USM (for the continuous drive reacquirment of AF lock on moving subjects), a wide aperture (to let more of that low light in) and a high ISO rating (to make the sensor capture more of an image with less light).

The 20d is going to work a lot better than the 350d or the d70 in terms of ISO. It goes to 3200 by activating the custom option. This is equal to a stop wider than the 350d or d70 at 1600. Also, canon's sensors seem to be better at lower noise at high ISO.

The lens I would recommend would be the 28mm 1.8 USM prime, for about $400, or if you have $1000 or so to drop on glass, the 24mm f1.4 L (way out of my range.)

The 3200 ISO is probably worth the $400 more than the 350d costs. Given that it will allow you to raise the shutter speed a bit, which will freeze motion better than the 350d.

pathfinder

You really need to try shooting with a 1DMkII -

There is a real magnitude difference in focus speed with the 1DMKII and a 20D. I shoot with both and many times prefer the 20D, but for sports it is no contest. The 1DMkII wins hands down on focus speed.