Please help me understand my settings

[CanadaJen]

Please forgive me if this is a really dumb question but I am extremely new to all this and can't quite figure this out! And it's driving me nuts tonight so I turn to you ;)

My husband is in a wedding party tomorrow so I was taking some pictures of his lovely rented tux. I'm using the 27-70 L lens I borrowed, had standard bedroom lighting and my 580 ex flash. I had it in Av mode and started at f/2.8, ISO 800. For the life of me I could not get a shutter speed fast enough to produce a clear image even after adjusting to f/3, f/4 etc and bumping ISO to 1600 (silly I know but I was trying everything). Every shot was still blurry! I put it in P mode - the camera selected f/4 and gave me a shutter speed of 1/60! Perfect pic. Why could i only get, at most, 1/25 in Av mode when I set f/4? What am I doing wrong?
I hope that made sense...I know I've got so much to learn and I hope someone can help! Perhaps I should go read the manual again...:o
Thanks!

[Deckham]

Aperture works the exact opposite to how you think it does :)

I'm am going to point you to a little thing I wrote up in reply to someone's question - it may help a little.

Link: http://www.redbubble.com/people/deckham/journal/884910-exposure-for-beginners-intermediate-photographers

[eddarr]

If you are shooting with flash it becomes even more important to shoot in Manual. Try setting the camera to F/8.0, 1/200 and ISO200. Set the flash to TTL. I'll bet the picture will be just about perfect every time.

I look at it like I'm setting the camera to the correct exposure for when the flash is firing. Rather than without the additional light. Then set the flash to either use TTL metering or to a manual power output.

[Wilt]

Something is quite odd, and there are no clues as to the root cause of the oddity!
In P mode, camera set 1/60 f/4 and exposure was perfect and not shakey...yet when you set Av mode f/4, the camera chose slow shutter speeds.
In the same light, the same resultant shutter speed should have been set by the camera in Av mode...1/60 ! And by setting ISO 1600, it should have used 1/250 in the same light!

[Wilt]

Aha, you used the FLASH and that changes the camera's behavior. With a flash, P mode sets 1/60 and f/4, but Av mode behaves differently...with the f/4 set, the camera reads the ambient light (which was probably fairly low) and sets a shutter speed which will allow it to grab a shot with ambient light in the background while using the flash for the foreground subject...and Canon has set up the programming so that it often chooses stupidly slow shutter speeds when doing this! That is why we advise to never use flash in Av mode ordinarily.

[Deckham]

and Canon has set up the programming so that it often chooses stupidly slow shutter speeds when doing this!

Don't forget about the existence of tripods ;)

[Wilt]

Don't forget about the existence of tripods ;)


Ha, ha, setting up a tripod in the middle of a dance floor at a wedding reception! :lol:

[Deckham]

Ha, ha, setting up a tripod in the middle of a dance floor at a wedding reception! :lol:

Read my quote of your statement, then my response again...

[Wilt]

Read my quote of your statement, then my response again...


But that is why I mocked that (not your statement of it)...that Canon was stupid enough to think that in all cases someone using Av has the camera on a tripod. They should have set a CFn that lets the photographer determine the minimal acceptable shutter speed, to suit the situation at hand.

[Deckham]

But that is why I mocked that (not your statement of it)...that Canon was stupid enough to think that in all cases someone using Av has the camera on a tripod. They should have set a CFn that lets the photographer determine the minimal acceptable shutter speed, to suit the situation at hand.

I have always wondered why they haven't, actually - and that goes for the full 3-suite of settings. Setting outside bracketing parameters could have many applications. When I shoot street, I would love to be able to program in ISO 400-800 / Ap f/4-f/8 / SS 1/150th - 1/8000th, with priority depending on Tv/Av mode, or using the setting as a 'cage' in manual.

Then again, I just shoot in manual in that case :)

[Tixeon]

My husband is in a wedding party tomorrow so I was taking some pictures of his lovely rented tux.

Maybe you should have your husband wear the tux for the photos...:confused::):) Just kidding... I know what you meant but was just having some fun with the way it's worded.;)

eddarr & others have given you some good advise above. I have very good results with Manual & ETTL. Good luck

[René Damkot]

Canon was stupid enough to think that in all cases someone using Av has the camera on a tripod. They should have set a CFn that lets the photographer determine the minimal acceptable shutter speed, to suit the situation at hand.

There is a (silly IMO) menu setting for that on the x0D series (forces sync speed in Av, resulting in "Bat in a cave" images.)

IMO Av does exactly what it's supposed to do (and what setting "slow sync" on Nikon does).
Just keep an eye on the shutter speed, and use -EC (and maybe some FEC) to get what you want or, better yet, set the camera on M.

The only stupid thing Canon did (let's not start on ETTL), is to make it impossible to use the camera in Av (or whatever mode except M), with the flash on M....

[Wilt]

There is a (silly IMO) menu setting for that on the x0D series (forces sync speed in Av, resulting in "Bat in a cave" images.)

IMO Av does exactly what it's supposed to do (and what setting "slow sync" on Nikon does).
Just keep an eye on the shutter speed, and use -EC (and maybe some FEC) to get what you want or, better yet, set the camera on M.

Yes, it does what it is supposed to do, but it would do it so much better if there was the shutter speed floor that could be set. I find that in covering weddings in their hectic paced moments, that the background lighting in the scene changes so rapidly as you shoot at different camera angles and therefore you all too easily find yourself suddenly with the camera trying to use 4 second exposures -- just when you have a rapid fire sequence you want to capture!

The only stupid thing Canon did (let's not start on ETTL), is to make it impossible to use the camera in Av (or whatever mode except M), with the flash on M....

Yeah, it seems a bit odd that you cannot treat the Canon flash as a source of a fixed intensity momentary light, set the lens aperture where you want it, and then let the camera set a slow shutter speed for the ambient.