Flash for Canon 5d Mark III

Recently purchased camera and am looking into getting a flash. What are the advantages of the 600 vs the 580? Have watched a few videos where the photographer has used flash and a secondary light source in an outdoor setting. Just don't want to get into a situation (as I learn) where I wish I would of purchased something else. Or wondering why I bought this when the other would have worked.

thanks

The 600 has a built in radio transceiver for wireless communications. The 580exII uses a series of light pulses to communicate wirelessly. For on camera use the 580 is a great flash and can be ada9ted to radio triggers via 3rd party systems. But if you are starti g from scratch the 600 is a great system going forward.

Since you have a 5D Mark III, you have the ability to shoot in Group Mode. For example, this allows you to shoot one flash in ETTL Mode and the other in Manual Mode. This may not be a concern for you now. However once you learn one flash, you will want to build from there.
I would not even consider purchasing the 580 EXII. The Canon 600 EX -RT allows you to shoot wireless Radio, not optical like the 580 has. Optical must have line of site to communicate. Radio does not need line of site. You can shoot through walls. Much more reliable. Menu navigation is much easier on the 600 system as well. With the 600, No need for additional triggers to shoot wirelessly, thus eliminating failure.
Three years ago I needed another flash to go along with my 580 EXII and 430 EX. With the newly intruded 600 EX RT and the ST-E3 Transmitter, I knew this was the wave of the future. Within a month, I unloaded my old 589 and 430 towards an aditional 600. Best move I made. Yes the 600's do multiply quickly.

The 600EX-RT may have RF wireless control and triggering, but the 5D3 does not have RF triggering built-in. You would need to spend an additional ~$265 on a Canon ST-E3-RT to use the 600EX-RT wirelessly off-camera, in addition to the ~$550 for the 600EX-RT itself.

You can get used 580EX II's in great shape for ~$300 used, then add a ~$70 set of Yongnou YN-622C RF triggers if you want wireless off-camera flash. But there are so many good third-party options it is hard to recommend the 580EX II or the 600EX-RT unless you're philosophically opposed to considering anything but Canon gear.

For example, the Yongnuo YN600-EX-RT is functionally equivalent to the Canon 600EX-RT but costs only $125, while the Yongnuo YN-E3-RT is equivalent to the Canon ST-E3-RT transmitter but costs only $90. You could buy four YN600-E3-RT flashes plus a YN-E3-RT transmitter for LESS than the cost of one Canon 600EX-RT.

The Cheetahstand/Godox/Fla​shpoint AD360 is a high-powered, bare bulb flash powerful enough to overpower the Sun when shooting outdoors and costs around the same as a Canon 600EX-RT. However, this is a manual-only flash so you need to set the power settings and camera exposure values manually using a flash meter, or calculate/estimate and test to get the proper exposure.

The Cheetahstand/Godox/Fla​shpoint V860C is a traditional form factor flash that provides full ETTL (automatic exposure control) but uses a LiON rechargeable battery pack offering quick recycle and longer battery life than AA primary or rechargeable batteries, and also can be integrated with RF triggers compatible with those used by the AD360. So if you think you might want to add one or more AD360's in the future but want ETTL as well, this is a good choice at around $180 each.

Finally, if you are okay with manually-controlled flashes only you can't beat the value of the Yongnuo YN560-III or -IV with the YN-560-TX transmitter. The flashes cost around $70 each and the transmitter only $45, so you can put together a 4-light setup for around $325.

drifter106 wrote in post #17604016
What are the advantages of the 600 vs the 580?...

• Radio communication for off-camera lighting (if you also get a master unit (another 600 or the ST-E3-RT or Yongnuo clones) to be on the camera hotshoe), rather than optical. That generally means you don't have the same range or line-of-sight restrictions that optical has. This tends to make much more difference in reliability if you are shooting in non-studio conditions, say outside on location in bright sunlight.
  
  
• Has a dot-matrix LCD display, which means the button labels are "soft" and the UI is much more intuitive than with the slightly more cryptic each-button-does-two-or-three-things on the 580EXII.
  
  
• Has a recycle beep to let you know audibly when the flash has finished recycling and is ready to fire.
  
  
• Can be used (if you have another RT unit on the camera's hotshoe) as a remote shutter release for your camera.
  
  
• Gr mode, which allows you to mix eTTL, Manual, and MULTI modes among different group of remote flashes and to turn remote flashes on and off.
  
  
• Can use four-digit ID codes x 15 RF channels, which basically means there are 150,000 channels to choose from and far less chance of interference than if you use the mere four channels that the 580EX/II's optical allows for.
  
  
• Can change the color of the light on the LCD to green, orange, or red to indicate different states of the flash (e.g., master or slave), etc.
  
  

All great points. One that hasn't been mentioned yet is that 580II's AF assist isn't compatible with the 61-point AF grid of the 5D3. When I went from a 7 to 5D3, I noticed that my 580II sometimes struggled with the outermost AF points, especially if the subject was very close to the min focusing distance of the lens. 600 doesn't do that.