550EX / 420EX AF Assist Lamp Behavior Across Camera Bodies?

[scottbergerphoto]

I did some testing this morning comparing the behavior of the 1DMII, 20D, and 10D with two different 550EX's and a 420EX. Many people including myself have complained that the 1DMII + 550EX combination has unacceptably slow AF performance compared to the 20D and 10D. I was surprised at the results.

1.If you look how long it takes for the AF Assist Light on the speedlight to turn on after the * button is pushed on the three cameras (CFn. 4-1), there is a noticeable delay on the 1DMII from pushing the * button and the AF Assist Light coming on, and on the 20D and 10D, the delay is greatly reduced to almost instantaneous.

2. The 20D and 10D use different parts of the AF Assist lamp of the 550EX then does the 1DMII. The 20D and 10D activate a large round lamp under the bottom 1/2 of the AF Assist Lamp wheras the 1DMII activates 2 smaller lamps on the top 1/2 of the AF Assist Lamp.

3. When using a 420EX, the 20D and 10D light up only the right side of the AF Assist Lamp, and the 1DMII lights up both sides of the 420EX AF Assist Lamp.

I can only come up with two possibilities to explain this. Either the communication between the flash and the camera is different on the 1DMII from the 20D and 10D or my 1DMII is in need of repair. This might explain the lag people are seeing with the 1DMII and AF Assist Lamp.

Has anyone else looked at the behavior of the AF Assist Lamp across camera bodies? It would be great if someone could replicate my findings at least on the 1DMII, so I don't have to pack it off to Canon.
Regards,
Scott

[PacAce]

I did some testing this morning comparing the behavior of the 1DMII, 20D, and 10D with two different 550EX's and a 420EX. Many people including myself have complained that the 1DMII + 550EX combination has unacceptably slow AF performance compared to the 20D and 10D. I was surprised at the results.

1.If you look how long it takes for the AF Assist Light on the speedlight to turn on after the * button is pushed on the three cameras (CFn. 4-1), there is a noticeable delay on the 1DMII from pushing the * button and the AF Assist Light coming on, and on the 20D and 10D, the delay is greatly reduced to almost instantaneous.

2. The 20D and 10D use different parts of the AF Assist lamp of the 550EX then does the 1DMII. The 20D and 10D activate a large round lamp under the bottom 1/2 of the AF Assist Lamp wheras the 1DMII activates 2 smaller lamps on the top 1/2 of the AF Assist Lamp.

3. When using a 420EX, the 20D and 10D light up only the right side of the AF Assist Lamp, and the 1DMII lights up both sides of the 420EX AF Assist Lamp.

I can only come up with two possibilities to explain this. Either the communication between the flash and the camera is different on the 1DMII from the 20D and 10D or my 1DMII is in need of repair. This might explain the lag people are seeing with the 1DMII and AF Assist Lamp.

Has anyone else looked at the behavior of the AF Assist Lamp across camera bodies? It would be great if someone could replicate my findings at least on the 1DMII, so I don't have to pack it off to Canon.
Regards,
Scott

Scott, my comments:

1. I thought the same thing until today. Today, what I noticed was that the way the AF points blink are different between the 10D and the 1DmkII. With the 10D, it blinks as soon as you hit focus button, making it seem that it is responding instantaneously. On the 1DmkII, the first AF blink takes a little longer. However, if you just listen for the AF acknowledge beep and time it, it seems like they both beep after about the same length of delay.

2. The 1DmkII seems to only use the two upper lamps (the top two horizontal pattern lamps) no matter what AF point you select. However, the 10d uses the bigger, single vertical pattern lamps for the center AF point. For the other horizontal AF points, the 10D uses the two upper horizontal pattern lamps. And if you enable all the AF points on the 10D, all 3 lamps will be used by the 10D.

3. As with the 550EX, the 10D will use different lamps depending on which AF point is selected. If all are selected, the both are used simulataneously.

[PacAce]

BTW, I can understand why the 1DmkII would only be using the horizontal line patterns on the 550EX. That's because all the AF points are horizontal-lline sensitive. However, if you put on an f/2.8 or brighter lens, the 1DmkII will use the vertical line pattern (the bigger lamp) when the center AF is selected. That's because with a faster lens (> f/2.8), the center AF point (and all those in a vertical line to it) are also vertical-lline sensitive (which begs the question, "then why don't those AF points also use the vertical line pattern with fast lenses?"). :confused:

[scottbergerphoto]

Thanks for replying Leo.
I did some further testing with a 50 f/1.4. On the 10D and 20D, the Vertical AF Assist Lamp(single lower one) will light up whenever the Center AF Point is used. If the Center AF point is activated with others in automatic AF point selection, then all 3 assist lamps on the 550 light up.

I then tested my 1DMII with a 50 f/1.4, Center AF Point only. You are saying the larger center beam on the 550EX should light? Mine doesn't light the Center(vertical) AF beam except occasionally. For some reason, even with the Center AF Point manually selected, the Vertical AF assist lamp doesn't light. The low light AF is terrible.

Why does the AF Assist Lamp on the 550 or 420 takes longer to activate on a 1D MarkII then on a 10D or 20D? There is a noticeable difference in AF time between the 1DMII and the 10D/20D when using an AF Assist Light, with the 1DMII being slower. The delay seems to be the time it takes the camera to activate the AF Assist Beam. In the 10D/20D, it is almost instantaneous, while on the 1DMII it takes about 1/2 sec.

It looks like my 1D Mark II has to go to canon to starighten this out.
Regards,
Scott

[PacAce]

Thanks for replying Leo.
I tested my 1DMII with a 50 f/1.4, Center AF Point. You are saying the larger center beam on the 550EX should light? Mine doesn't.

Why does the AF Assist Lamp on the 550 or 420 takes longer to activate on a 1D MarkII then on a 10D or 20D? There is a noticeable difference in AF time between the 1DMII and the 10D/20D when using an AF Assist Light, with the 1DMII being slower. The delay seems to be the time it takes the camera to activate the AF Assist Beam. In the 10D/20D, it is almost instantaneous, while on the 1DMII it takes about 1/2 sec.
Regards,
Scott

Interesting, Scott. You saying that with your f/1.4 lens and using the center AF point, the bigger, single lamp of the 550EX does not light up? It still uses the two smaller ones? Hmmm, don't know what to tell you. With my f/2.8 lens, it does although if I used slower lens, it doesn't.

Re the AF light on time, I specifically tested that and in both my 10D and my 1DmkII, there's is an equal delay before the pattern lights up. However, the AF point of the 10D does blink as soon as the shutter (or "*") button is pressed but that doesn't mean anything since focus still hasn't been acquired. On my, they both beep at about the same time.

Just so we're comparing apples to apples, are you on the latest available firmware for both cameras?

[scottbergerphoto]

Interesting, Scott. You saying that with your f/1.4 lens and using the center AF point, the bigger, single lamp of the 550EX does not light up? It still uses the two smaller ones? Hmmm, don't know what to tell you. With my f/2.8 lens, it does although if I used slower lens, it doesn't.

Re the AF light on time, I specifically tested that and in both my 10D and my 1DmkII, there's is an equal delay before the pattern lights up. However, the AF point of the 10D does blink as soon as the shutter (or "*") button is pressed but that doesn't mean anything since focus still hasn't been acquired. On my, they both beep at about the same time.

Just so we're comparing apples to apples, are you on the latest available firmware for both cameras?
Leo,
See my edited post above. You responded before I finished editing it. Yes, all three cameras have the latest firmware.
Regards,
Scott

[PacAce]

On my 10D, the focus assist pattern from the flash doesn't come on instantaneously either. There's is delay of about half a second, just like your 1DmkII. If you're saying that on your 10D, the assist light comes on instantly, then there may be something wrong with my 10D, too. Since the delay for both my cameras are about just under a second before I get a focus lock, I guess i can live with that.

BTW, are you doing your tests in a really dim room. I am. Without the flash I can't even get a lock on my target.

[PacAce]

Scott, something you might want to check is whether C.Fn-17 has been set to expand AF point activation area and you're using AI Servo AF. My tests were done with Single Shot AF and no AF point expansion.

[scottbergerphoto]

Yes it is very dim. What I have found is that the Center AF point on my 1DMII, when activated, is erratically activating the Vertical Af Assist beam of my 550EX. Sometimes the vertical AF beam is emitted, but most of the time, just the two horizontal ones are.

On the 10D and 20D, activating the Center AF point, consistently causes the Vertical AF assist to be emitted.
Scott

[PacAce]

Did you see my previous post about the AI Servo?

[scottbergerphoto]

Did you see my previous post about the AI Servo?
Leo,
You are a freakin genius! :D I wasn't in AI Servo, but I was using CFN.17-1. I switched it back to 17-0 and the now the vertical AF assist beam lights consistently when I use Center AF point only. It reduced my AF delay.

Now the remaining question is, why doesn't the vertical AF beam come on when I use the Automatic AF point selection and the Center AF point is one of the active ones?
Thanks,
Scott

[PacAce]

Leo,
You are a freakin genius! :D I wasn't in AI Servo, but I was using CFN.17-1. I switched it back to 17-0 and the now the vertical AF assist beam lights consistently when I use Center AF point only. It reduced my AF delay.

Glad you got it squared away. Would have been a bummer if you had to send it back and go without you camera for a week or two, huh? :D



Now the remaining question is, why doesn't the vertical AF beam come on when I use the Automatic AF point selection and the Center AF point is one of the active ones?
Thanks,
Scott

I was wondering about that myself (it happens on mine, too) but I'm not going to worry about it since it doesn't seem to be a problem. I heard that too much concentrated thinking can wear out the brain prematurely and I surely don't want that to happen to mine. I'm expeciting to live for another good many years and I want to make sure my brain lasts as long in good working order. :mrgreen: :lol:

[scottbergerphoto]

Thanks for all your help. This was driving me nuts. It's interesting that 17-1 is a reccommended setting by Sport's Illustrated but no one mentions that while improving sports shooting, it diminishes low light AF with flash AF assist.
Scott

[PacAce]

Thanks for all your help. This was driving me nuts. It's interesting that 17-1 is a reccommended setting by Sport's Illustrated but no one mentions that while improving sports shooting, it diminishes low light AF with flash AF assist.
Scott

I wonder if this is the same problem that's afflicting Dan Honeman which he posted about in the Rob Galbraith forum? I don't think he ever got it resolved, did he, that you know of?

[scottbergerphoto]

I posted today's travails and your solution over there in a thread he was participating in. He hasn't responded yet.
Regards,
Scott

[PacAce]

I posted today's travails and your solution over there in a thread he was participating in. He hasn't responded yet.
Regards,
Scott

Scott, the last post I see for the Galbraith forum thread relating to this problem is the one you posted at 3:00 this afternoon. However, when I looked in the index earlier this evening I saw that there was one from another person after 4:00 and when I just looked again a minute ago, I saw that you had also updated it but I can't get to those posts the normal way. I had to do a "Show All" and wade through all 6 pages of posts to see your last set of posts. Did you also experience this problem viewing the last posts? Since I noticed that you had made two similar posts and deleted the last one, I'm assuming that you were having problems with the last set of posts, too. Just curious.

[scottbergerphoto]

I have been having problems with that thread, Sometimes my browser shows 7 pages with my update and sometimes 6 pages without it. It must be a server issue(like I have any idea about servers :lol: ). I also posted it in the thread on AF assist behavior. I am somewhat surprised about the lack of responses.
Regards,
Scott

[deltaimages]

As a night time pap we have scrached our heads silly to solve the slow af on the 1dmkii using the 550 ex
This is better
note :af illuminator only works on one shot !
the centre point shoots the tiny af light which has a delay, much to dim and stalls af and you miss the shot
on all 45 points the beam fires the two brighter bulbs but the af is still as slow as it can not make its mind up which to use in low light.
What we do is change to one focus point next to centre, which on the 1dmkii is hardly nothing away from the middle point, now on comes the two red lamps without delay which are twice as bright as the small one and AF is instantanious and solves the problem.
hope this helps

[PacAce]

As a night time pap we have scrached our heads silly to solve the slow af on the 1dmkii using the 550 ex
This is better
note :af illuminator only works on one shot !
the centre point shoots the tiny af light which has a delay, much to dim and stalls af and you miss the shot
on all 45 points the beam fires the two brighter bulbs but the af is still as slow as it can not make its mind up which to use in low light.
What we do is change to one focus point next to centre, which on the 1dmkii is hardly nothing away from the middle point, now on comes the two red lamps without delay which are twice as bright as the small one and AF is instantanious and solves the problem.
hope this helps
I just gave your suggestion a try and, to be honest, it didn't make any difference which AF point I used. The focusing was still slower than on my 10D with the same lens (35 f/1.4) and flash (580EX). However, although the 10D focused a tad faster, the 1DmkII wasn't that far off. Not as bad as what Scott was initially experiencing. But then, his problem was due to a custom setting which when turned off made his 1DmkII focus much faster.

BTW, I see that was your first post. Welcome to the forum. :)

[deltaimages]

I have to agree with the 10 d aspect, my apprentice has a 10d and a 18-55 lefs lens which he cleverly adapted to fit his 10d using some expoxy and a hacksaw, his 10d never fails to focus using his 380ex, first time eveytime.
I think canon need a firmware update that gives the option of selecting speedlight assist lights manualy and cuts down the delays turning on the lamp.
Most just grin and bare it, many just sell up and buy the new nikon d2x.
Come on canon a pro spec camera that can not focus in the dark, its a firmware fault, sort it out !