# 600ex-RT AF assist power



## pwp (Jun 3, 2012)

With the weak low light AF performance of the 1D4, I depend on the AF Assist on the 580ex & 580 exII when shooting functions, often held in low/mood lit venues. Last night I had a lot of lost shots where the 1D4/70-200 f/2.8is just couldn't get a lock, even with the 580exII assist. The 5D3/24-105 f/4 was a whole lot better which is to be expected, but still delivered a few _l o n g_ moments while it got it's lock.

Does the 600ex-RT have a more powerful AF Assist than the 580's? If so, this could become a core reason for updating.

PW


----------



## neuroanatomist (Jun 3, 2012)

It's not more powerful, at least by distance specification in the manual (same spec for 430, 580, 600, and ST-E2). What is different is the coverage area - the 580 isn't quite wide enough for the lateral points of the full 61-pt AF on the 5DIII and 1D X, whereas the 600 provides full coverage. That's the main reason I recently picked up a 600EX-RT. The head zoom to 200mm is also a great feature of the 600, IMO.


----------



## Daniel Flather (Jun 12, 2012)

The patten from the 600rt changes when you go from landscape to portrait orientation. I don't recall my 580 doing that, or maybe I never noticed. I sold my 580 so I can't try that out now. My 5d3 and 600rt's af assist works very well in low light; I've shot mostly close range stuff though.


----------



## MarkWebbPhoto (Jun 16, 2012)

The 600EX-RT doesn't seem any better from my testing with the AF assist over the 580EX II. I tested with my 1D MK IV, 5D MK II, and even the 5D MK III and a variety of lenses. I still works ok but I would like a little better range with the assist as well. The 600EX-RT is worth the mulah for all the feature upgrades and once I finish writing my review you will probably want a few of them! Tested high-speed sync in full daylight at 1/8000 sec, ISO 100, and f/2.8-4.5 which gave me some gorgeous shots. I'll post them soon enough.


----------



## wickidwombat (Jun 17, 2012)

tried a yongnuo ST-E2 copy? the AF assist is pretty stong
i dont have a 1Dmk4 but i can do some testing on my 1Dmk3
it definatley boosts the 5Dmk3 AF speed


----------



## MarkWebbPhoto (Jun 17, 2012)

I worked an outdoor reception last night. The only lights around were tiki torches and the DJ's party lights or whatever you call those. This was of course a perfect time for the AF assist light and the 600EX-RT performed just as good as the 580EX II. It is hard to compare the two without being side by side but I was quite happy with my results. I didn't get perfect focus every time but I definitely got 80% keepers (focus wise anyways). I don't feel like I need more range, I just wish I could focus faster using AF assist!


----------



## pwp (Jun 18, 2012)

wickidwombat said:


> tried a yongnuo ST-E2 copy? the AF assist is pretty stong
> i dont have a 1Dmk4 but i can do some testing on my 1Dmk3
> it definatley boosts the 5Dmk3 AF speed



Yes the ST-E2 makes a big difference with AF on my 1D4 & 5D3 . But they're kind of impossible to use with a flash on the hotshoe. All I was wondering was if the 600EX-RT had gutsier AF Assist than 580's. It would seem it's much the same, but does have compatibility benefits with the 5D3 & presumably the 1DX too.

PW


----------



## Gino (Aug 10, 2012)

I'm an amateur hobby photographer with no flash photography experience. I just purchased the 5D Mark III, and I'm looking at purchasing either a used speedlite 580II or a new 600ex for the camera.

I can get a used 580II in mint condition for about $380 on ebay, or get a new 600ex for around $550. If I'm just going to use the speedlite as a single on camera flash, is it worth it to spend an extra $200 for the 600ex....in particular are the extra AF coverage points that the 600ex offers for the 5D Mark III going to make a noticeable difference in the IQ of my photos?

The lenses I own are:
24-105L f/4 IS
70-200 L f/2.8 IS II
50 f/1.4
I'm planning on purchasing a 16-35L f/2.8 II

thanks


----------



## neuroanatomist (Aug 10, 2012)

If you plan to use the outer (lateral) AF points when shooting with a wide angle lens, in very dim light, then the wider area coverage of the 600 will make a difference. Also, if you plan to use it with the 70-200 lens, the 600 has a zoom head that goes out to 200mm, well the 580 stops at 105mm. The two flashes actually have the same power, but the longer zoom setting means a slightly higher guide number, thus 600 (60m) instead of 580 (58m).


----------



## mjcphoto (Sep 21, 2012)

Am I the only one who doesn't appreciate the 600EX-RT flash? Sure it's nice, and the build quality and extras are great. But for someone who documents weddings and uses the Canon on camera flash as a fill light / Qflash off camera as main, the extra features are kind of useless. Sure, for portraits or other shoots having two of these flashes or even three would be killer.

However, like the 580EXII before it, the 600 is just too slow when it comes to recycle times. I know the whole thermal protection stuff that's built in. I guess I've just grown accustom to firing away my 580's and not missing a frame. The 600 sits in my bag unused after a couple of trials  Much like the 580EXII before it. I found that even shooting a procession and trying to grap three nice shots of each wedding party member coming down the aisle (at this point it's my main and only light) can be risky. The flash will tell me it's getting too warm then shut down if I have to push it just in time for the bride! Then I'm forced to kick it up to 10000ISO which is doable but not always ideal.

And yes, I'm using the Canon battery pack as my source of power for the flash.


----------

