Canon 50mm 1.4 focusing on xxD vs Rebel

I have a Canon 50mm 1.4 that has given me some terrific pictures over the past few months on my XSi, but I feel that its focusing is not as good as it should be. I know that it is not ring USM, but I don't think that it's any better than my kit lens. It takes longer for the 50mm to focus from a far wall to a closer subject than the kit lens. And sometimes, in average light, it will take 2-3 seconds for the focus to lock onto my subjects eyes. This is too slow for trying to capture quick expressions of my 7 month old daughter.

I am saving for a 50D (or 60D?) right now and I'm wondering if the lens will focus noticeably better on this camera or if I will always live with this. If so, should I just sell it to save for a 17-55mm? I do take many of my pictures at f2.2 and lower, but I think 2.8 will be fine. Thanks for any advice.

Welcome to the forum! Focusing on a blank wall is a tough task. How about a real test?The 50D is a great camera for many reasons. Forget dreaming about a 60D or other rumors.

My 50mm 1.4 focuses better on my 40D than on my T1i or XT, from my experience. I get a higher rate of keepers with the 40D. It's definitely noticeable at wider apertures.

It's not slow at focusing though and it's faster than 2-3 sec for any focusing. I wouldn't say its any faster on the 40D.

I have never found the 50mm 1.4 to be particularly slow at focusing, neither on my old XT nor on my 40D. With the XT, it was often hunting in low light, but I think this was caused by the body rather than by the lens. It's much better now with the 40D.
But noticeably faster, no. I haven't noticed any focus speed improvement

The camera body can significantly determine lens focus speed? That's new to me.

I'd've thought that any difference in the actual focus CMOS sensor or the algorithm employed would be a matter of micro-seconds?

My 1.4 makes frequent moves between my 5D Classic and my 20D and I never noticed any difference in the time taken to achieve focus. Sure it's noisy but, of my three primes, it is at least as fast as my 200 2.8 and significantly faster than the 85 1.2. Those differences and similarities apply across the two bodies.

Thanks for the advice. Is there a better way to test if the lens is focusing too slow or if I just need to work on my technique? For the distance test I focused on some objects on a wall 20 feet away and it locked focus. Then it took what seemed like almost a second to focus on my subject 3-4 feet away. All of my other lenses would snap to this focus much quicker.

Sometimes it will take 2-3 seconds to focus in a different situation. Like when a person is moving a bit and I'm trying to focus on their eyes. Maybe this is the focus "hunting" that I read about, but it only happens with this lens and it happens in all types of light.

BTW, dreaming about a 60D is just my way of not putting another big dent in the credit card immediately.

Smthrz wrote in post #8444861
Thanks for the advice. Is there a better way to test if the lens is focusing too slow or if I just need to work on my technique? For the distance test I focused on some objects on a wall 20 feet away and it locked focus. Then it took what seemed like almost a second to focus on my subject 3-4 feet away. All of my other lenses would snap to this focus much quicker.

Sometimes it will take 2-3 seconds to focus in a different situation. Like when a person is moving a bit and I'm trying to focus on their eyes. Maybe this is the focus "hunting" that I read about, but it only happens with this lens and it happens in all types of light.

BTW, dreaming about a 60D is just my way of not putting another big dent in the credit card immediately.

I've never experienced similar issues with mine. While it doesn't focus as fast as, say my 24-70, it is no slouch either. Never felt like it takes ages.
You could try to clean the electronic contacs on the lens mount with a swab and some alcohol.
Does it hunt or is it a linear move from close to far and vice versa?

It certainly shouldn't take 2-3 seconds. The difference between my 50 1.4 and the 85 1.2 is "ker-chink" versus a leisurely 0.5 second at most. But then, the 85 has a lot of glass to move . . .

Is your delay a slow progression to the focus point, or does the lens 'hunt' - a back-and-forth overshoot process before it finally locks on? Remember, the autofocus process relies on contrast, so blank, low-contrast surfaces or low light might have it struggling.

Once or twice, in 3200 extremis, I've switched off AF and gone manual. But, as others have observed, digital viewfinders are generally less bright, opening yet another can of worms.

edit - oops, parallel posting with Krapo

Well, I spent more time this morning with the 1.4 and I think really it's just my user error. If I really try to do a good test it does not take a full second to focus in or out. But, in real world shooting it still seems to take this lens longer to focus. I tried to replicate the 2-3 seconds to focus issue and it only happens when the light is pretty low or the subject keeps moving. Even then it doesn't happen more than once every 10 shots or so.

You guys answered my question. Basically, if I'm not happy with the lens now, it sounds like getting a 50D may help a little, but not enough to change my mind about it.

So I like the lens for objects that aren't moving. And I'm happy with how sharp it is, even at 1.4. But when I'm in an event situation where something is moving and I need to get the shot, I don't feel that I can trust the focus.

I think my distrust is because of the following factors
1) The autofocus motor is kinda loud
2) When I'm at apertures around 2.0 it still has a thin DOF
3) I know that I shouldn't, but I typically use center focus and focus then recompose and I suppose this is enough to throw it out of focus

Are there people that use the 50mm 1.4 for events or is it more used just for portraits where you can ask the person to stay still? I'm considering selling it to help fund a 17-55mm, Sigma 30mm 1.4 or 60mm macro. Any suggestions?

i think it is user error, try not to use f1.4 ~ 2, just use f2.8 and try to focus. Most of the time the lens cannot lock its focus due to its thin DOF (below f2)

Smthrz wrote in post #8446425
Well, I spent more time this morning with the 1.4 and I think really it's just my user error. If I really try to do a good test it does not take a full second to focus in or out. But, in real world shooting it still seems to take this lens longer to focus. I tried to replicate the 2-3 seconds to focus issue and it only happens when the light is pretty low or the subject keeps moving. Even then it doesn't happen more than once every 10 shots or so.

You guys answered my question. Basically, if I'm not happy with the lens now, it sounds like getting a 50D may help a little, but not enough to change my mind about it.

So I like the lens for objects that aren't moving. And I'm happy with how sharp it is, even at 1.4. But when I'm in an event situation where something is moving and I need to get the shot, I don't feel that I can trust the focus. Another lens to consider is the 85/1.8 if focusing if focusing speed is your main concern.

I think my distrust is because of the following factors
1) The autofocus motor is kinda loud
2) When I'm at apertures around 2.0 it still has a thin DOF
3) I know that I shouldn't, but I typically use center focus and focus then recompose and I suppose this is enough to throw it out of focus

Are there people that use the 50mm 1.4 for events or is it more used just for portraits where you can ask the person to stay still? I'm considering selling it to help fund a 17-55mm, Sigma 30mm 1.4 or 60mm macro. Any suggestions?

I find my 50/1.4 focuses faster and more accurately on my 50D than on my XTi. The main problem is thin DOF for moving subjects, but the thin depth of field is the reason why I have this lens.

I think the 50/1.4 could be used at events, although I am not sure what is your definition of event and you may be better off with the flexibility of a zoom. The 85/1.8 is another lens to consider if focus speed is your main concern.

I guess this is why the 50mm 1.4 is so perplexing for many people, including me. If your recommendation is to shoot it at 2.8 and above, then I'll get a 17-50mm or 17-55mm. I didn't realize that it would take longer to lock focus if I'm between f1.4 and f2.0. Is this true?

I may try taking it to a camera shop and trying it on a 50D. That may help me decide to keep it or not. Thanks for the help.