Kari - Melissa you are AMAZING!! Thank you so much for putting this together; I just ordered my flashes and your concise explanation made this so easy to pick up :)

Elizabeth G - Thank you so much for this tutorial! It helped me so much. I was wondering if you have a second shooter also shooting off your 600ex-rapt slave unit. When I'm shooting with other photographers that also have a 600, I would love for us to both be able to use the same slave (with us each having a 600 master on camera). I just can't seem to figure out how to set this up. Do we both set our flashes up the same way as this tutorial, or is there another setting we need to adjust?

hectir rivera - Nicely done , I just got the 600 ex rt system I did a wedding and it was horrible I couldn't get the flashes to sync don't know what I was doing wrong ... I have my flash on top of camera on ettl and group A only the others I had in manual slave units. I think I was doing it wrong. So you're saying that you have to ve in GR mode your master correct ? And the other flashes on manual I'll try that ... I'm trying to keep my flash on top of camera and my others on manual mode slave correct ? Maybe It was my cabon 5d.mark 2 ? I was using or I have my flash on ETTL on top of camera ?

Sarah - Thank you so much for this walk-through. I know I could have eventually figured it out while re-reading through the manual but I'm pretty sure you saved me a lot of time and headache. Thrilled to finally have a second flash to start to play with.

Jamey Johnston - Wonderful and concise explanation of how to setup the flashes in a master slave mode. Thank you, Melissa! God Bless!

Gretchen - MJ you are the BEST. Seriously. I am so excited to use my new 600's now that I am all "set up".

Jenna - Rented three 600s for my wedding on Saturday. Thank you so much for writing up this guide that made setup so fast and easy for me!

Topher - Hi Melissa, thanks for the setup guide, it was very useful. I found myself shooting in a barn with high ceilings and the rafters were strung with christmas lights. So there was decent ambient light, but the flash setup was not great! I'm thinking because there was little bounce? I had this exact setup (one on camera ettl, one off camera manual) What camera setting do you use? Aperture priority? What ISO? I ended up going manual, but it still wasn't great. I had done weddings in regular ballrooms and the results were great, that's why I think it had to do with the space. Thanks for any insight as to camera settings

Shelley Hohe - THANK YOU SO MUCH MELISSA! I purchased 2 600 EX-RT's 6 months ago and I had such a hard time figuring these out. I am so thankful you shared this step by step tutorial on how to set up OCF….THANK YOU!!!

Sarah Neal - WOW - just got these babies hooked up. I'm so happy I could cry. I always found the pocket wizard system super unpredictable, complicated and ultimately something I didn't use a lot because it felt over my head. Your instructions coupled with manual are stellar. Can't wait to try out my next wedding. Thanks Melissa!

Melissa Jill - Hi Keif, No, unfortunately that can't work because the 580ex II doesn't have radio transmission built in. But sell your 580ex II used and get another 600 -- well worth it!

Keif - Can one set the on-camera 600exrt as a master and then an off-camera 580exii as a manual slave, but still be able to control the power output of the 580exii from the 600exrt?

Melissa Jill - Hi Abbey! My one tip is to not shoot with your off-camera flash in your composition when shooting with both on ETTL. For some reason, the 600s don't put out enough power when you do that. So best to shoot more from a side angle. Hope this helps!

Abbey Powers - Hi Melissa! Just read this and thought it was extremely helpful. I have a 5D Mark II and was wondering if you had any suggestions when using both in ETTL mode since I can't set my slave to manual. Basically, I upped the exposure compensation on the master by +1 like you suggested. I just wasn't sure if there were any suggested settings on the slave since it can't be set in manual... I'm very new to this, but this has helped me a lot! Thanks!

Cheri - Melissa-I just bought the 600's and am so grateful for your review and set-up post. I am still working with the 5dmkII but am super excited to use my new flashes and will eventually upgrade to the 5dmkIII and re-visit this post for set-up instructions.

Anna K. - I can't even begin to say thank you enough for this post! I've been struggling with my 600's for the longest time and now I FINALLY understand how to operate them perfectly! After a few hours of practice and reviewing your instructions I am SO excited for my reception tomorrow night! Thank you so much Melissa!Xoxo!

Courtney - Actually, you CAN use your second flash in manual mode on a 7D! Oddly enough, though, you must do it through your camera menu. Under the first camera menu, Select Flash control, then select External flash func. setting. Change flash mode to Manual flash, and change the flash output as desired.

Abby - Thanks a million for this great info! You saved me tons of time setting up my new flashes!

Rob ONeill - Much appreciate your efforts. The shear number of button-touch combinations for these lights is daunting. Probably near a hundred. Honestly, I don't think that my mind, at my age, is capable of remembering them all. I do wish that you would have posted the formulas complete without readers having to go back and forth to the manual. Maybe you could create a "Cheat Sheet," about 5 pages long with the boiled down instructions for all the settings and sell it. Many would buy it. I'd be first. All the best to you.

Emily Davis - Thank you so much for writing this Melissa! It would have taken me all day to figure out how to work my 600 ex-rts. I actually decided to buy them after reading your review and your explanation for how to work them! I knew I could use the steps you wrote out to get them set-up - - otherwise, I may not have bought them for the fear that I'd never learn to set them up correctly! You are appreciated! :) :)

Melissa Jill - Hi Tracy -- You have to use pocket wizards with the 580s. With the 600s you don't have to -- they have radio transmission built in. This post is really just instructions for setting up the 600s.

Tracy Dodson - Melissa, I am trying to get this to work with my 580EXii. I got it working before and now I can't figure out what I did. Maybe I used my pocket wizards! Can you let me know how to set the 600 and the 580 without pocket wizards? Or should I use the wizards?

Kellie Penn - I opened up my new 600s the other day & tonight I sat down with them and read your blog post. Oh my goodness. You made it so easy to understand and I am crazy excited for my wedding on Saturday to give them a try!

Damon Nash - This was an awesome article. I didn't know that group A defaulted to the on camera flash. I own 3 of these flashes and have been struggling with trying to balance the on camera light with my 2 externals. Thanks!

Shawna - Thanks for this review! I just ordered them :)

Carla - Awesome, awesome post. Thanks, Melissa!

Melissa Jill - Hi Melissa, No you can't because the 430 doesn't have radio transmission capability.

melissa - i'm wondering if you can use the 600 as a master and the 430 as a slave and achieve the same setup?? i have 2-430's and I know they can be set as slaves... hmmm... if anyone knows let me know! :)

Melissa Jill - Hmm...I haven't noticed that Karyne. It's possible I haven't shot a long enough event yet, but mine have fired every time.

Karyne - Have you changed up what battery packs you use? I use the same battery packs as you, and I don't feel like they're working as well with the 600s.

Melissa Jill :) - Hey Lindsay -- Before I got my 5D Mark III I shot one wedding reception with both units on ETTL and it seemed to yield a decent result. The images in this post were shot in this way: http://www.melissajill.com/blog.cfm?postID=1141&canon-ex-rt-review So that's what I would recommend.

Lindsay - I'm in the same situation as Christy, and can't afford the Mark III right now. What would you suggest with settings, both on ETTL or both on Manual? love this post!

Christy Tyler - I own these but have the 5D Mark II and am SO annoyed that I can't shoot with one on ETTL and one on manual! I can't get the results I want with both on ETTL, and manual becomes a pain for getting quick shots with the on-camera flash properly exposed... so I switched back to using my old flashes with pocket wizards for now. One more reason why I need to upgrade to the mark III.... Thanks for the tutorial! Can't wait to use this once I'm able to upgrade!

Cindy - Has anyone told you lately how incredibly awesome you are?