My Rebel XS AF System Sucks..

Hi,

I took some bird pictures yesterday in rather poor light with the 400 f/5.6L and had some ok pictures but also many many that were soft or oof.

I was shooting with a mix of One Shot and AI Servo, depending if the birds were moving or not.

I shot this at 1/640, ISO 800 f/5.6 on Av mode. I am very disappointed because it would have been a great picture but nothing seems to be in focus! This happened for the sequence of shots I did (1.5fps RAW) in total 3 shots for the flyby:

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Your camera should autofocus just fine. Was the lens you were using stabilized? What was your technique for taking the shots? Did you keep your finger pressed halfway on the shutter button as you followed the bird to keep the focus going?

Many years ago I shot a dolphin with a Rebel and the servo kept the moving target perfectly in focus.

How does it focus on stationary objects?

Jon_Doh wrote in post #15842463
Your camera should autofocus just fine. Was the lens you were using stabilized? What was your technique for taking the shots? Did you keep your finger pressed halfway on the shutter button as you followed the bird to keep the focus going?

Many years ago I shot a dolphin with a Rebel and the servo kept the moving target perfectly in focus.

How does it focus on stationary objects?

No the 400L isn't stabilized but I don't think that's the issue. I track the birds while pressing the really slow shutter. It doesn't AF sometimes on landscape either, or yesterday I was taking pictures of someone and the 70-200 just wouldn't focus at all with all possible settings..
I'm thinking of upgrading to a 1D3 soon.

Here is an example of a sharp pic I got yesterday.

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On the first two there are parts of the water that are clearly in focus. Looks like it was where the bird might have been when it was still in the water.

With a 400mm lens on a crop body and at a shutter speed of 1/640 you are unfortunately going to battle getting sharp pictures of a static subject nevermind the shots you attempted, both camera blur from your movements and movement blur from the subject itself is going to take it's toll.

A camera upgrade wouldn't be a bad idea. I used to have the XS. Great little starter camera but it certainly doesn't do action shots like a more capable body. The lens is obviously not the issue. Technique maybe, but it sounds like you had all the settings right. You've got a couple of lenses there that would shine with a better body.

It's not the speed issue, i've gotten sharper at lower speeds than 1/640.
I wouldn't think it would be technique as i've tried every possible setting on my camera and similar issues always occur at each outing.

Jan, looking at your Flickr page you have some really great BIF shots - but I did notice they seem to be all taken in good light. Based on them I don't think it's a technique issue. I can't comment on low-light AF performance on the Xs or the 400/5.6 as I've never used either.

But the only way to know for sure if the Xs is failing is to test with a different body in the same conditions.

I have a love-hate relationship with my 1000D (as it's called here). I have found AF to be incredibly inconsistent with large-aperture lenses where my 40D does just fine. It was completely atrocious with the 50mm f/1.8. For now I have just resolved to using smaller aperture lenses on it (which seems to work fine) and shoot it to the bones.

So yeah, I'm in the "get a new body"-camp.

joeblack2022 wrote in post #15842761
Jan, looking at your Flickr page you have some really great BIF shots - but I did notice they seem to be all taken in good light. Based on them I don't think it's a technique issue. I can't comment on low-light AF performance on the Xs or the 400/5.6 as I've never used either.

But the only way to know for sure if the Xs is failing is to test with a different body in the same conditions.

Thank you!
The most recent bif were taken with a friend's 7D, although all shot with AI Focus (my mistake) they were still pretty good and a lot better hit rate.

jackerin wrote in post #15842781
I have a love-hate relationship with my 1000D (as it's called here). I have found AF to be incredibly inconsistent with large-aperture lenses where my 40D does just fine. It was completely atrocious with the 50mm f/1.8. For now I have just resolved to using smaller aperture lenses on it (which seems to work fine) and shoot it to the bones.

So yeah, I'm in the "get a new body"-camp.

I'm pretty much fed up with it with all my lenses :P It just can't do the job...

Jan, get a 30d cheap Infact very cheap, and probably better focus than 1000d aswel, same centre focus as 40/50/60 so aslong as you are at f5.6 or larger with your lens then the focusing should'nt be a problem...

P.

Pagman wrote in post #15843081
Jan, get a 30d cheap Infact very cheap, and probably better focus than 1000d aswel, same centre focus as 40/50/60 so aslong as you are at f5.6 or larger with your lens then the focusing should'nt be a problem...

P.

Thanks for the suggestion, although I want something newer in technology. The 1D3 is a great body despite being fairly old. We'll see..

Jan Jasinski wrote in post #15843438
Thanks for the suggestion, although I want something newer in technology. The 1D3 is a great body despite being fairly old. We'll see..

Did you want to go full frame? I personaly would miss the crop factor giving us that slight zoom edge.

P.

The XS can take good shots.

those are good shots of the surfers.

outside of the 1/1250 vs 1/640 SS, one key difference is the angle of view of the lens and it's effect on DOF.

http://www.dofmaster.c​om/dofjs.html

same camera, 1000D, same f/#, 5.6, in both examples:

i'm a little surprised AI didn't keep up a little better. as already mentioned, the water behind the bird, and even the tail feathers are in focus.

looks like it's time to start thinking a about new body.

edit: well shucks, i read misread the exif data on the surf pics and thought they were shot at 200mm. either way i think the goose is approaching the camera faster than the surfers.