Differnces in 550 EX and 580 EX

[Zamora3]

What are the main differences between the 550 Ex and the 580 EX?

I mainly want to use the lens for shooting indoor sporting events such as basketball.

If I use my 75-300mm IS 75-300m f/4-5.6 @ f4 and then set the iso to 400 or even 800, will that make indoor basketball pictures relatively brighter.

I have a Dreb right now but am plannig in the near future to purchase a 1D Mk II. WIll the flash make much of a difference on the Dreb?

[timmyquest]

On the rebel it will not.

On the MKII it can take advantage of its ability to adjust for the crop factor
Communicate for white balance

And then of course it is slightly brighter (not enough to matter in my opinion)
Smaller
Quicker recharge

[Zamora3]

so its pretty much a waste of money to buy the flash and have a dreb? What about the dreb with the hack ?

[Hellashot]

The 580 is slightly more powerful than then 550 and the 580 also has half the recycle time for flash charge. Plus it takes into account for the 1.6x factor to make the flash go farther than the 550 would by using automatic settings.

I'm not sure what the 580 would do on a non 1.6x factor camera. Maybe it would over-flash and wash out your images?

[DaveG]

I'm not sure what the 580 would do on a non 1.6x factor camera. Maybe it would over-flash and wash out your images?

No, part of what the 580 does is senses what crop factor your specific camera has and adjusts the width of the light beam based on that camera. It would adjust differently for a 1D Mark II and a 1DS Mark II; as well as for the 20D sized cameras.

The zoom head in the flash doesn't control output, it controls the width of the beam coming out of the flash. If I use a 50mm lens on the 20D it is effectively an 80mm lens. My 550EX flash sees that I'm using a 50 but always assumes that it's on a full frame camera, so the width of the light beam is wider than needed.

Now this could be a problem but only if the flash was used at close to its maximum distance. Say I'm focused on something ten meters away and the full power manual flash output is f16. I can't get MORE than f16 out of the flash at this point. But if the light beam was wider - which would diffuse the light - then I could get less light on to the subject.

I made up those numbers by the way, but my point is that this is rarely going to be a problem. The flash output IS going to be slightly more efficient so recycle time and power consumption should be better, since the flash/camera are outputting as efficiently as possible. But the flash/camera will adjust if the beam is "too wide" (which means slightly weaker) in the 550.

As far as that goes you can always use a manual zoom selection on the 550 to widen or narrow the beam. The flash on this setting will no longer recognise any zooming that you might do to the lens but it will not over or under expose - at least any more than normal. ;-)

[dphoto]

Wow, this is a helpful thread.

David, let me get this straight... let's say that I'm using my 550EX with a 50mm prime lens. There's almost no reason not to manually adjust the zoom on the flash to 80mm, correct? I mean, except for reasons of laziness or not wanting to put the flash in a manual mode that I might later forget about... I do stuff like that all the time when I flip this or that into manual mode.

Thanks again!
-Deva

[robertwgross]

This is not a large factor, but every time you zoom a flash head in or out, whether it is manually or automatically, you are using a little extra battery power. I find it easiest not to screw around with it much.

---Bob Gross---

[DaveG]

Wow, this is a helpful thread.

David, let me get this straight... let's say that I'm using my 550EX with a 50mm prime lens. There's almost no reason not to manually adjust the zoom on the flash to 80mm, correct? I mean, except for reasons of laziness or not wanting to put the flash in a manual mode that I might later forget about... I do stuff like that all the time when I flip this or that into manual mode.

Thanks again!
-Deva

Normally there is no reason not to use the manual flash zoom feature, if you feel a need for it. However when you flip the flash head into a bounce position - or use it as a Master flash - then the flash head will default to its widest setting no matter what lens is aboard. This is to create the widest light possible for bounce and to give as broad an "informational" pulse as possible on Master. If you'd manually selected the zoom setting it may not be wide enough to cover in bounce, or to get the instructions to a slaved flash. This isn't a big deal but remember to turn it back to auto zoom.

The power required to automatically zoom the internal flash head is something that I've never considered. I use NiMH batteries and have a spare set available if needed, which has never happened.

I use the 550 almost always on a Stroboframe Pro-T bracket with the camera connected to the flash with the Off Camera Shoe Cord 2. Zooming a lens forces a change in the flash that you can hear and see if you look. I kind of use this as an indication that I have a good contact between the camera and flash and that they are happily speaking to each other. If it takes some power then that's the way it goes. I should add that when the flash head is in the bounce position it won't zoom and it'll freak you out until you understand what happened!

[dphoto]

If you'd manually selected the zoom setting it may not be wide enough to cover in bounce, or to get the instructions to a slaved flash. This isn't a big deal but remember to turn it back to auto zoom.

Ahhhh... thank you, I would have missed that! So that's why I hear the flash head zooming whenever I flip it back up... it's moving to the widest position for the bounce.

Thanks!
-Deva