(1dx) Best way to use flash in Av mode?

[keithop]

Hi

Apologies if this is a simple (atupid) question but it's confusing me at the moment.

1DX on Av mode. Aperture set to 1.4, fine, 580exII in ettl mode.

Just experimenting indoors to get familiar with the flash system and with the flash direct, all I get are hopelessly over exposed images.

I'd simply have expected the camera to work the shutter speed, iso and flash output to get the exposure reasonably ok but it seems to put the iso at 400, shutter speed not particularly fast (sometimes 1/25) and over expose :/

I've reset all camera settings to make sure I'm not doing something silly so I must be missing something ?

Thanks for any ideas

 

[phototeacher]

I don't know the 1Dx, but with the Mark 4, putting the camera in Av mode will allow it to adjust the shutter speed for the correct exposure at the aperture you have set. It does nothing for ISO.

I would propose that shooting at f/1.4 at ISO 400 (which I would say was set by the user, not automatically) would result in overexposure in the typical indoor setting, with you subject only a few feet away. Using Av mode the camera will try to balance ambient light exposure (your slow shutter speed) with flash exposure, and I think that f/1.4 is too wide for the situation. Try using either a smaller aperture,(f/4-5.6) and/or a slower ISO.(200)

You might also try putting the camera in M and using a shutter speed of 1/60-1/200, ISO 400, and f/5.6 and I think you will see some better results.

 

[keithop]

Hi there and thanks for the reply!

phototeacher wrote:

I would propose that shooting at f/1.4 at ISO 400 (which I would say was set by the user, not automatically)

Seems like as soon as I put the flash on, it defaults to iso 400 :/ although sure, I guess I could change it. It seems like a rather weird auto-choice

would result in overexposure in the typical indoor setting, with you subject only a few feet away.

yep for sure that's what's happening

Using Av mode the camera will try to balance ambient light exposure (your slow shutter speed) with flash exposure, and I think that f/1.4 is too wide for the situation. Try using either a smaller aperture,(f/4-5.6) and/or a slower ISO.(200)

I do a lot of wide aperture/small dof work and so this is really a test to see how the 1dx modes suit this. On other cameras, I'd choose Av, 1.4 for the small dof, ISO would be manual 100, and it would try and adjust the shutter speed to compensate but I guess what I'm saying is the 1DX at the moment is getting this horribly wrong with a higher iso than is needed AND a slower shutter speed. That's what's confusing me.

You might also try putting the camera in M and using a shutter speed of 1/60-1/200, ISO 400, and f/5.6 and I think you will see some better results.

For sure you're absolutely right and that's where I may well end up. I'm positive sticking it in M I can choose sensible values, it's just I'm confused at how bad Av seems

 

[phototeacher]

I am only familiar with the Mark 4 and the original version of the 580EX, but don't think either is that different from you equipment. I am not sure why it is setting ISO automatically; must be something I am missing.

Hopefully some others will join in. I understand about the shallow D of F, and it should be do-able at a slower ISO.

 

[Rexgig0]

Selecting f/1.4 is telling the camera to select a very fast shutter speed, faster than the flash sync speed. The camera responds by shooting at the maximum flash sync speed, but the Speedlight defaults to full-nuke. This is my non-technical way of understanding Syl Arena's answer to a nearly-identical question at a Speedliter's Intensive event.

The simple, quick solution is to set either the camera or flashgun to Manual. I almost always use the camera's Manual Mode when using a Speedlite. I am not an expert, and do not claim the title of "professional" photographer, but as my signature lines indicate, I have some practical experience with Canon Speedliting.

--
I wear a badge and pistol, and, primarily with 7D cameras, with 10-22mm and 100mm Macro L lenses, shoot evidentiary images at night, which incorporates elements of portrait, macro, still life, landscape, architecture, PJ, and occasional action.

 

[Zeee]

There is a real danger using Av mode indoors if you don't understand it. If your ISO is too low and you lock the aperture which is what Av is all about the shutter will adjust itself to keep the light meter centred. You can wind up at 1/15 or slower depending on the conditions.

There are a few options. Putting the camera to manual for indoor shooting is preferable. Here you can set your shutter and aperture independently regardless of ISO. The flashes job is to expose the subject.

If you shoot in Av pay attention to the shutter speeds and raise the ISO as needed to get the shutter speed up.

In both cases rule of thumb is to have the ambient exposure at least two stops underexposed - no less. This gives you a nice balance between flash and ambient. In other words your subjects don't look nuked. Of course this all depends on the light, how high you are wiling to go with the ISO and the speed of your lens. If you need to be more than 2 stops underexposed then you have to work with that.

The thing about Av if handled properly gives you almost enough light for an exposure so the flash just tops it off, kinda like a fill. You get nicely lit backgrounds that make the subjects even look better.

I use Av outdoors and M indoors. I have a 5D3 and and a 7D. I have no issues shooting 6400 with my 5D and will go up to 3200 with my 7D but prefer 1600.

Here is a link to a forum I posted when I had a 5D2. Todays high ISO capable cameras have change the playing field.

http://photography-on-the.net/forum/showthread.php?t=1108954&highlight=5D2+iso

 

[WalterSrChat]

keithop wrote:

Hi

Apologies if this is a simple (atupid) question but it's confusing me at the moment.

1DX on Av mode. Aperture set to 1.4, fine, 580exII in ettl mode.

Just experimenting indoors to get familiar with the flash system and with the flash direct, all I get are hopelessly over exposed images.

I'd simply have expected the camera to work the shutter speed, iso and flash output to get the exposure reasonably ok but it seems to put the iso at 400, shutter speed not particularly fast (sometimes 1/25) and over expose :/

I've reset all camera settings to make sure I'm not doing something silly so I must be missing something ?

Thanks for any ideas

Hi Keithop

With the 1Dx set to AV mode, the ISO should only change when you change it, unless you are in ISO (A) mode.

Shutter speed is linked to the aperture setting, in AV mode.

When you add a Canon flash, and decrease the aperture setting in AV mode, the shutter speed will increase until it reaches the maximum allow by the flash, and go no further.

What you are described is happening with the ISO in AV Mode should not be possible with the 1Dx.

Suggest you send the 1Dx in for evaluation/repair.



Walter Sr

 

[rbarta]

keithop wrote:

Hi

Apologies if this is a simple (atupid) question but it's confusing me at the moment.

1DX on Av mode. Aperture set to 1.4, fine, 580exII in ettl mode.

Just experimenting indoors to get familiar with the flash system and with the flash direct, all I get are hopelessly over exposed images.

I'd simply have expected the camera to work the shutter speed, iso and flash output to get the exposure reasonably ok but it seems to put the iso at 400, shutter speed not particularly fast (sometimes 1/25) and over expose :/

I've reset all camera settings to make sure I'm not doing something silly so I must be missing something ?

Thanks for any ideas

RTM.

Actually you have 2 problems.

p.125 You have Auto-ISO set. With Flash it goes to 400 (unless that will cause overexposure, then it will be set lower). BTW, it sets it to this because it will prob be able to pick up some background and won't use tons of flash energy, it is a general setting for people who are not in manual.

I highly suggest you don't use Av for flash as it will set exposure to normal and use flash for fill only. This is why the overexposure is happening. It sets exposure to normal because you are making the depth of field as the #1 priority.

Time to step up to Manual mode and set your ISO manually too. With a flash you actually are dealing with 2 exposures, one for the scene and one for what the flash is illuminating. This might help

 

[jimi_astroman]

When I use flash with my 1DX I often use the P mode then dial in compensation on the back of the flashgun. I also don't have auto iso set but use somewhere between 200 & 800 depending on the circumstances and I use the built in reflector of the flasgun to soften the light a bit or an Opteka flash reflector which attaches to the gun. It works for me.

 

[pete zeugma]

auto everything rules ok..

I love how people buy expensive toys and dont read the manuals.. It took me over a month of reading and experimenting before I was back to the same level of instinctive knowledge I have with my 1Ds mk2&3, same with the flash gun upgrades too.

 

[keithop]

pete zeugma wrote:

auto everything rules ok..

I love how people buy expensive toys and dont read the manuals..

Please keep your pejorative, and incorrect, assumptions to yourself. If you can't add anything useful to a thread, why bother replying?

It took me over a month of reading and experimenting before I was back to the same level of instinctive knowledge I have with my 1Ds mk2&3, same with the flash gun upgrades too.

..and I am observing a behaviour during my reading and experimenting that didn't seem to tie up to my (mis)understanding of the manual. Hence I decided to ask here. If you feel that the simplicity of the question is beneath you, that's fine, but I've no idea why you feel the need to let us all know.

Thanks to everyone else for the useful replies, very much appreciated!

 

[keithop]

rbarta wrote:

Time to step up to Manual mode and set your ISO manually too. With a flash you actually are dealing with 2 exposures, one for the scene and one for what the flash is illuminating. This might help

Thanks for that!

Back to M it is

 

[Ludvig]

Why don't you use High Speed Sync for the flash? I guess the shutter is flashing in the viewfinder because the shutter speed is too low. Press the third button on the flash until you see the flash symbol and a H next to it.

I just tried, and a shutter of 1/5000 sec. at f/1.2 works fine. Also 1/60 sec. at f/1.2 gave a good result with the flash (AV mode, ISO100).

 

[qianp2k]

keithop wrote:

Hi

Apologies if this is a simple (atupid) question but it's confusing me at the moment.

1DX on Av mode. Aperture set to 1.4, fine, 580exII in ettl mode.

Be aware of Av mode indoor or low light as you need to watch shutter speed if flash works in fill-flash mode when there is strong ambient light indoor for example. Better to shoot in M mode indoor to set specific aperture and shutter. ETTL flash will automatically complement to ambient light to get correct exposure.

Just experimenting indoors to get familiar with the flash system and with the flash direct, all I get are hopelessly over exposed images.

Two possibilities here.

a) Your 580EX II is in TTL not eTTL mode at the moment that you can see on LCD, a common issue involves with 580EX II that happened to me many times. Use more powerful batteries, clean hotshoe connector but FEC (flash exposure compensation) always will fix ETTL->TTL issue at the moment (that used to drive me crazy when it happened). That will cause over-flashing.

b) There are strong indoor light. At F1.4 you shutter is beyond 1DX's X-Sync speed (1/250?) However by default, HSS is not turned on 580EX II (that is stupid as should be other way around that turn on by default, press button to turn off). You need to press the button to turn it on that will stay until you take battery out. So your 1DX will be set at 1/250 sec that also will cause overexposure.

I'd simply have expected the camera to work the shutter speed, iso and flash output to get the exposure reasonably ok but it seems to put the iso at 400, shutter speed not particularly fast (sometimes 1/25) and over expose :/

The reason camera set ISO to 400 automatically is because you use Auto ISO. If you shutter is only 1/25 and aperture is f/1.4, it sounds 580EX II is on TTL mode.

I've reset all camera settings to make sure I'm not doing something silly so I must be missing something ?

If it's TTL issue as I suggested to use more powerful battery (such as 2500 mAh or above), clean hotshoe interface, and use FEC (change to a different value and then change back) that always will fix the issue then.

Thanks for any ideas

 

[Glenn Haley]

Good response for a good discussion. One of the drawbacks of forums is everyone can express their opinion no matter how ignorant they are.

As for using AV with flash, I think most of us have tried it and have similar results and switched to other modes. I use Manual at 160th, F/5.6 or F/7.2 and ISO 400 or 800 for most flash shots. My C1 and C2 modes are set for that. "P" also works but I lose control of the DF.

I have had good results using AV as a flash fill outdoors with high ambient light.

 

[Zeee]

rbarta wrote:

keithop wrote:

Hi

Apologies if this is a simple (atupid) question but it's confusing me at the moment.

1DX on Av mode. Aperture set to 1.4, fine, 580exII in ettl mode.

Just experimenting indoors to get familiar with the flash system and with the flash direct, all I get are hopelessly over exposed images.

I'd simply have expected the camera to work the shutter speed, iso and flash output to get the exposure reasonably ok but it seems to put the iso at 400, shutter speed not particularly fast (sometimes 1/25) and over expose :/

I've reset all camera settings to make sure I'm not doing something silly so I must be missing something ?

Thanks for any ideas

RTM.

Actually you have 2 problems.

p.125 You have Auto-ISO set. With Flash it goes to 400 (unless that will cause overexposure, then it will be set lower). BTW, it sets it to this because it will prob be able to pick up some background and won't use tons of flash energy, it is a general setting for people who are not in manual.

I highly suggest you don't use Av for flash as it will set exposure to normal and use flash for fill only. This is why the overexposure is happening. It sets exposure to normal because you are making the depth of field as the #1 priority.

Agreed. However if handled correctly AV can work very well. There is pro photog at the POTN forums that strictly shoots AV and gets outstanding results. Again since the ambient exposure is normal the flash just gives the final touch to the subject/s with fill. The image looks more natural, the way your eyes saw it. A nice balance between ambient and the flash. As you know our eyes take several seconds to adjust to a scene while the camera cannot. On camera flash guru Neil van Niekerk has commented on his work several times. That does not happen very often. More than one way to skin at cat. Still I prefer M for indoors but would shoot AV if I had to.

If I can find that thread I'll post it. Been a while.

Time to step up to Manual mode and set your ISO manually too. With a flash you actually are dealing with 2 exposures, one for the scene and one for what the flash is illuminating. This might help

 

[Zeee]

qianp2k wrote:

keithop wrote:

Hi

Apologies if this is a simple (atupid) question but it's confusing me at the moment.

1DX on Av mode. Aperture set to 1.4, fine, 580exII in ettl mode.

Be aware of Av mode indoor or low light as you need to watch shutter speed if flash works in fill-flash mode when there is strong ambient light indoor for example. Better to shoot in M mode indoor to set specific aperture and shutter. ETTL flash will automatically complement to ambient light to get correct exposure.

Just experimenting indoors to get familiar with the flash system and with the flash direct, all I get are hopelessly over exposed images.

Two possibilities here.

a) Your 580EX II is in TTL not eTTL mode at the moment that you can see on LCD, a common issue involves with 580EX II that happened to me many times. Use more powerful batteries, clean hotshoe connector but FEC (flash exposure compensation) always will fix ETTL->TTL issue at the moment (that used to drive me crazy when it happened). That will cause over-flashing.

That is due to the foot design of the 580II. If it is slighly loose and breaks contact it will revert to TTL which is for film. Canon re-desinged the foot and you can get it for about $50. Very easy to change. The original foot can also be adjusted for a tighter fit.

b) There are strong indoor light. At F1.4 you shutter is beyond 1DX's X-Sync speed (1/250?) However by default, HSS is not turned on 580EX II (that is stupid as should be other way around that turn on by default, press button to turn off). You need to press the button to turn it on that will stay until you take battery out. So your 1DX will be set at 1/250 sec that also will cause overexposure.

I'd simply have expected the camera to work the shutter speed, iso and flash output to get the exposure reasonably ok but it seems to put the iso at 400, shutter speed not particularly fast (sometimes 1/25) and over expose :/

The reason camera set ISO to 400 automatically is because you use Auto ISO. If you shutter is only 1/25 and aperture is f/1.4, it sounds 580EX II is on TTL mode.

I've reset all camera settings to make sure I'm not doing something silly so I must be missing something ?

If it's TTL issue as I suggested to use more powerful battery (such as 2500 mAh or above), clean hotshoe interface, and use FEC (change to a different value and then change back) that always will fix the issue then.

Thanks for any ideas

--
http://qianp2k.zenfolio.com/

 

[Zeee]

Zee Char wrote:

rbarta wrote:

keithop wrote:

Hi

Apologies if this is a simple (atupid) question but it's confusing me at the moment.

1DX on Av mode. Aperture set to 1.4, fine, 580exII in ettl mode.

Just experimenting indoors to get familiar with the flash system and with the flash direct, all I get are hopelessly over exposed images.

I'd simply have expected the camera to work the shutter speed, iso and flash output to get the exposure reasonably ok but it seems to put the iso at 400, shutter speed not particularly fast (sometimes 1/25) and over expose :/

I've reset all camera settings to make sure I'm not doing something silly so I must be missing something ?

Thanks for any ideas

RTM.

Actually you have 2 problems.

p.125 You have Auto-ISO set. With Flash it goes to 400 (unless that will cause overexposure, then it will be set lower). BTW, it sets it to this because it will prob be able to pick up some background and won't use tons of flash energy, it is a general setting for people who are not in manual.

I highly suggest you don't use Av for flash as it will set exposure to normal and use flash for fill only. This is why the overexposure is happening. It sets exposure to normal because you are making the depth of field as the #1 priority.

Agreed. However if handled correctly AV can work very well. There is pro photog at the POTN forums that strictly shoots AV and gets outstanding results. Again since the ambient exposure is normal the flash just gives the final touch to the subject/s with fill. The image looks more natural, the way your eyes saw it. A nice balance between ambient and the flash. As you know our eyes take several seconds to adjust to a scene while the camera cannot. On camera flash guru Neil van Niekerk has commented on his work several times. That does not happen very often. More than one way to skin at cat. Still I prefer M for indoors but would shoot AV if I had to.

If I can find that thread I'll post it. Been a while.

Here it is. Indoor using Av mode. Post #24 Neil makes a comment on it. Posts #22 and #23 show the reverse ceiling bounce this photographer uses. One of my favourite methods.

http://photography-on-the.net/forum/showthread.php?p=11566550

Time to step up to Manual mode and set your ISO manually too. With a flash you actually are dealing with 2 exposures, one for the scene and one for what the flash is illuminating. This might help

 

[AlanPezz]

I have a 6D. There is a menu setting to controlol the speedlight attached to the hot show. There are three options for shutter speed when in Av mode. The default is automatic. Option 2 is the limit the shutter speed between 1/60 and sync speed (1/180 on the 6D). The third option is the shoot at sync speed. You should have the same choice in your camera.

 

[Zeee]

AlanPezz wrote:

I have a 6D. There is a menu setting to controlol the speedlight attached to the hot show. There are three options for shutter speed when in Av mode. The default is automatic. Option 2 is the limit the shutter speed between 1/60 and sync speed (1/180 on the 6D). The third option is the shoot at sync speed. You should have the same choice in your camera.

I'm not having any problems shooting in any mode. Just adding a little info to the thread.