5dmk3 and 580exII Underexposure Issue

Hi there. I'm new here.

I searched this forum for some answers but did not come across any.

Anyone here experienced underexposure issues with 5dmk3 and 580exII set on bounced?

Never had this problem with the 5Dc. With the 5Dmk3 every shot is under by 1 stop.

Any help is appreciated. Thx

Welcome to POTN. If you could post examples with EXIF attached, it would help us to determine the nature of the problem. Otherwise it's just going to be a guessing game.

Welcome to POTN, Aswald.

A full-frame shot (down-sized, or course) with EXIF intact will help a lot. Is the flash exposure underexposed, or the ambient? Both? It would help to know the camera's mode and settings, as well as the setting on the flash (ETTL or manual). I am sure we can help you. We just need a bit more specific information. A shot showing the problem will help immensely.

The First 2 pics are taken with the 5D mk3 and 580ex2 set on bounce. I tried bumping up the flash compensation to max with little results.

The 3rd pic is taken with the 5Dc and 580ex2 set on bounce on same location and almost same settings. If I recall correctly, the difference was only in the shutter speed.

The last pic was taken with the G9 and 580ex2 set on bounce.

All pics are jpeg files straight off from camera and resized using DPP. No editing was done. Not too sure if exif is intact as I haven't linked pics to my flicker account for a long time.

Although the 5Dc + 580ex2 still looks a bit under but not as much as the 5Dmk3 + 580ex2. I never had any issues with the 580ex2 on the G9.

The 5Dmk3 meters excellently without the flash. Usually a bit underexposed but not much. Any opinions and help is greatly appreciated. The 5Dmk3 settings are all default and so are the 580ex2 settings which works great on the 5Dc and G9.

Pictures of friends with consent.

IMAGE LINK: http://www.flickr.com …24280281@N03/10​094774716/

IMAGE LINK: http://www.flickr.com …24280281@N03/10​094774856/

IMAGE LINK: http://www.flickr.com …24280281@N03/10​094758565/

IMAGE LINK: http://www.flickr.com …24280281@N03/10​094832693/

Thanks for the warm welcome guys. It's great to be here. Haven't really been on any forums for a long time, so this is a nice change for me.

Pretty awesome pics found on this forum. I'm a long term Canon user. I started with the Yashica FX3 Super with it's nice 50mm F1.7 lens. Then I upgraded to the Canon A1 with the beautiful 50mm F1.4 SSC after my Yashica got stolen. In between I used the fantastic Fujica ST705 and the Olympus Pen EE. Both were very good film cameras. The Fujica's lens was .....really nice on film. Nice and sharp and made skin tones looked really healthy! I miss the film days.

Hope to contribute, and learn some tips from folks with similar interest.

you are shooting at ETTL, try manual flash settings an adjust power,or stay on ettl say aperture or TV priority BUT set the iso high

I had problems with 5DIII focusing properly with the 580 II, but I think there is a firmware upgrade for that which I have yet to install. Maybe this is related and you should try the latest firmware upgrade. Otherwise if the only problem is a little consistent underexposure and focusing is good, I know it sounds simple but really just override by +1 or +2 on either the flash or the camera. Another thing to look for is to see if your ETTL setup on camera (or even on flash) is not at -1 or -2 by accident. Try setting all settings to factory defaults and try taking a few bounce pix to see if that goes away. I find that sometimes when I am experimenting with a lot of stuff, I end up forgetting to reset it back to normal.

tonyniev wrote in post #16347337
you are shooting at ETTL, try manual flash settings an adjust power,or stay on ettl say aperture or TV priority BUT set the iso high

Thanks for the suggestion. I tried switching to AV mode but same results. I can switch to manual flash and bump up the power but I was wondering why it was ok with my 5Dc and G9 but not on the 5Dmk3. Both 5Dc and 5Dmk3 uses E-TTL 2. I never had any flash under exposure issue on E-TTL before the 5Dmk3.

spear wrote in post #16347380
I had problems with 5DIII focusing properly with the 580 II, but I think there is a firmware upgrade for that which I have yet to install. Maybe this is related and you should try the latest firmware upgrade. Otherwise if the only problem is a little consistent underexposure and focusing is good, I know it sounds simple but really just override by +1 or +2 on either the flash or the camera. Another thing to look for is to see if your ETTL setup on camera (or even on flash) is not at -1 or -2 by accident. Try setting all settings to factory defaults and try taking a few bounce pix to see if that goes away. I find that sometimes when I am experimenting with a lot of stuff, I end up forgetting to reset it back to normal.

Thanks. No issue with focusing with the 580ex2 on. Firmware for the 5Dmk3 is the latest. Flash compensation is set at 0 on the 580ex2. I googled this issue on the net and it seems I'm not the only one. Quite a few posting of this phenomenon...but sadly not even Canon realizes there is an issue (or not).

One suggestion was to press FEL (Flash exposure lock) before taking the photo. While this may seem to be a solution, it'd be really troublesome, not to mention an added burden on battery power. Besides, I had the notion that E-TTL 2 emits a pre-flash to calculate the flash exposure needed.

tonyniev wrote in post #16347337
you are shooting at ETTL, try manual flash settings an adjust power,or stay on ettl say aperture or TV priority BUT set the iso high

That was my first thought, too. Theses shots are at f/4, ISO 640, 1/100 & 1/125. With bounce flash, I would expect them to look better than this.

YashicaFX2 wrote in post #16347494
That was my first thought, too. Theses shots are at f/4, ISO 640, 1/100 & 1/125. With bounce flash, I would expect them to look better than this.

the 5Dc shot was at 1/80, iso 640 and F4.

when I was shooting celebrities on red carpet, I cannot use ETTL with the 5D2 and 580 EXII, the shots were always underexposed, I normally shot on manual mode and flash on manual too at 1/4 power, the subjects are only from 10 to 20 feet away,

Hmmm...back when the 20D came out, it was routine for folks to have to dial in FEC +1EV routinely, in order to get the right tonal density in a scene shot with flash...regardless of direct flash or bounced flash it was the same. Then, when the 40D came out, that need for 'permanent FEC' disappeared...direct flash and bounced flash seemed accurate without FEC. Not sure what is the issue with your 5DIII, but offer that bit of historical insight.

The fact that you have already bumped up FEC with no better results might be a clue as to the nature of the problem. The shots you posted would not seem to have any corner case content that should fool ETTL metering; the white shirts in the first photo might result in a bit of underexposure, but certainly not the other shots.
The G9 shows you what you should get...my speculation is that the original Canon dSLR flash engineering team left Canon for a while, but have now come back to Canon.

tonyniev wrote in post #16347877
when I was shooting celebrities on red carpet, I cannot use ETTL with the 5D2 and 580 EXII, the shots were always underexposed, I normally shot on manual mode and flash on manual too at 1/4 power, the subjects are only from 10 to 20 feet away,

Tony, thanks for this tip. I tried it and it works and it makes good sense. Really appreciate it.

tonyniev wrote in post #16347867
the 5Dc shot was at 1/80, iso 640 and F4.

Previously, when I dial the shutter speed, the back ground would get either darker or lighter but the subject would remain lit in a somewhat consistent manner of equal brightness. It isn't the case here.