flash in daylight

Elaine

Pathfinder...I really like your colorful horsies! They are a nice example of what you explained about how to use flash effectively.

I was thinking about this very issue today and wondered how to maintain that nice blurred background in a bright light situation where your aperture has to be reduced in order to match a rather slow shutter speed (because of the limits of the flash)? I'm guessing putting quite a bit of space between your subject and background would be one way. Would using some sort of filter be appropriate (and if so, what sort), to darken things a bit, kinda tricking your camera into allowing you to use a wider f/stop? Am I even thinking about this correctly?

Antonio Correia

Elaine.
Look here:

http://www.dgrin.com/showthread.php?t=70330&highlight=fill+flash+pathfinder

Let me try some help:

1. Expose correctly a scene, a landscape for example.
2. Under-expose to (-) 1/3 or (-) 1/2 (EC = Exposure Compensation)
3. Place your human figure in the foreground.
4. Pop the flash or take your flash out of the camera
5. Shoot once with the flash.
6. How's that ?
7. If the person is too iluminated, turn the power of the flash down (making a FEC = Flash Exposure Compensation) or put it further away.

Remember:
A. The aperture controls the flash
B. The speed controls the background.

The longer the speed, more detail you get in the shadows.
Closing the aperture you get darker foreground.
Question of balance.

Please see here one of my modest experiences.
Hope to be of some help.

Is this OK Jim ?

pathfinder

You did great Antonio!! I could not have said it any better!!

Elaine,

The trick to control the exposure of the background is to shoot in Manual Mode on the camera. This allows you to underexpose the background however you choose. Look through your viewfinder in Manual Mode, and dial back the exposure with the light meter needle in the viewfinder. If you are shooting in bright sunlight with a large aperture, this means your shutter speed will be VERY short - maybe 1/2000th of a sec or faster.

The problem is that your flash will not synch, normally, at shutter speeds faster than 1/200th or 1/250th for most DSLRs.

For example, this shot



was shot at about ISO 100, f2.2 ( gives that nice shallow DOF and bokeh ) at 1/2000th of a second with the correct flash lighting for the foreground.

The flash was set up in ETTL and High Speed Synch was engaged on the flash to allow it to work with my camera at 1/2000th of a second. If I had not turned High Speed Synch on, the flash would not let me set my camera to 1/2000th even if I tried to manually adjust to 1/2000th. It would not permit a shutter speed faster than 1/200th with the flash turned on - this is built into the EOS flash system. If you use a PW to trigger an off camera studio strobe, it will fire, but not expose the sensor due to the narrow slit of a focal plane shutter at 1/2000th. Hence, the need for High Speed Synch which actually flashes your flash multiple times as the small slit of the focal plane shutter passes across your sensor. The downside to HSS, is that your strobe will not be quite as powerful - you give up about a stop of light or so, so if your shutter speed is less than 1/200th - you can turn HSS off.

It must have been overcast the day I shot the horse above, as a sunlit scene for ISO 100, at f2 requires a shutter speed of 1/8000th as per sunny 16

But overcast would require 3 stops more light, and 1/2000th would underexpose the street as it did - about 1 stop or so, and this looks like about 1 - 1 1/2 stops under in the background.



Part of the secret of the image is shooting with a 135 f2 on a full frame body, which maximizes the shallow DOF of the 135 telephoto, and creates that lovely L glass bokeh.

But you could get a similar effect with a 70-200 f2.8 zoom also.

Elaine,
I am glad you liked my horses, and the lighting I did with them, I kind of wondered if anyone really noticed the effect I was trying to achieve. You did - thanks again, for your kind words.

Read, Antonio's post again - he really gets fill flash and off camera flash and its cool possibilities.

When I shot these horses, I mounted a 550ex with its little plastic footmount that comes with it, on top of a cheap tripod, so that I could move the flash around to achieve the effect. I triggered it with an ST-E2, but this could have been done entirely with a totally manual flash triggered by a pc cord, or a set of PWs. You would have to move the flash fore and aft, or adjust the power output with a knob, but the images could have been just as nice. The ST-E2 and ETTL make it a little faster and easier to set up - that can be real important if you are shooting fidgity kids:D I was lucky, my little horsies never complained a bit about how slow I was

The blog at strobist.com has great stuff about off camera flash also.

Everyone always wants to buy that new lens or new camera that will shoot the great pictures, but simple, skilled, use of flash will create dramatic new images for a lot less money.

One other thing, you can use a neutral density filter to allow you to underexpose the background, without using such a high shutter speed. This will also filter the flash from your flash, so you MAY run out of flash power with a heavy ND filter. I have never done this, but there is no reason that you could not do it if the flash is strong enough, hence close enough. I am sure that under 5 or 6 feet, that a 2x ND filter would not be any problem for a 580ex at ISO 200 or so. If you want to flash a subject at 20 feet, it will not work then.

Elaine

Thank you, Antonio and Pathfinder!!

I have read through your posts twice and will do it again, I'm sure. I do understand shooting manually and exposing (or slightly underexposing) for the background and letting the flash take care of the foreground. I still don't have an external flash (of any type), so I've just been practicing these principles with my built-in flash. When my camera's anti-shake is turned on, the highest shutter sync speed I can get is 1/125. That's not very helpful in well lit conditions! Anyway, I had to stop down to f/9 in order to expose the background properly, but that produced a deeper depth of field than I preferred (thus, my original question). And then there is the issue with a built-in flash that I can't move it "fore and aft" and may end up blowing out my subject, even with FEC turned way down.

For posed family photos, I think I could make use of a manual flash. I'm hoping to switch camera systems to Canon in the next 6 months or so, but if I could get an inexpensive flash to mess around with now, I could probably learn a lot in the next 6 months. I really have no idea what I'm looking for though. Would you be so kind as to point me in the right direction?

Thanks again!

LiquidAir

High speed sync is a system feature and I don't believe it works with any third party flashes. I know that Canon flashes support high speed sync on Canon bodies, but beyond that you will need to investigate the particular body/flash combination to be sure you can do it. As a side note, when using high speed sync, you lose some power (it seems like 1/2-1 stop), so using it in full sun requires a powerful flash.

ziggy53

LiquidAir wrote:

High speed sync is a system feature and I don't believe it works with any third party flashes. ...

The Sigma EF-500 DG Super E-TTL does indeed support HSS/FP mode and Canon E-TTL II functionality, as does the new EF-530. The interface is not nearly as nice as the Canon EX flashes, but the price makes up for some of that clumsiness.

Elaine

ziggy53 wrote:

The Sigma EF-500 DG Super E-TTL does indeed support HSS/FP mode and Canon E-TTL II functionality, as does the new EF-530. The interface is not nearly as nice as the Canon EX flashes, but the price makes up for some of that clumsiness.

But it does not HSS with my Minolta 5D. :cry

pathfinder

Elaine, you can balance ambient versus flash with most manual flashes that allow dialing up and down their ouptut ( power ) like the Vivitar 285HV does. Or you can move the flash fore and aft ( closer or farther away ) from the subject.

What you cannot do, without access to HSS, is have the ability to use the very wide apertures out of doors in bright light that require shutter speeds > 1/500th or more.

After sundown, or during twilight, this is not a problem because of the lower light levels.

The built in flash in the body is of rather little use. I use it on a 20D or a 40D for fill flash in shade, but an off camera flash, triggered by a pc cord, Pocket Wizard, radio trigger ( pick your choice ) offers so many more opportunities.

I cannot really advise you about flash for cameras other than Canon or Nikon due to lack of familiarity on my part.

jeffreaux2

Couldn't she get the effect with her built in flash and a neutral density filter? Maybe?

And....am I wrong in thinking that the sony flash system is interchangeable with minolta? Might be worth a call to Sony to find out.

Elaine

I can indeed use a Sony flash...just being stubborn and not wanting to put $250 into a system that I'm hoping to set aside. That could nearly buy me a Canon 50 f/1.4!

I'm guessing the ND filter may help in some situations but not necessarily all. I mean, with an HSS speed of 1/125, there's potentially a large gap between that and proper background exposure on a sunny day with an aperture of 5.6 or so. But I'm glad to know my thinking was not completely off here.

Thanks for all the help, folks!

LiquidAir

jeffreaux2 wrote:

Couldn't she get the effect with her built in flash and a neutral density filter? Maybe?

Yes. In fact, if you have good quality ND filters that is the better way to go because keeping the shutter speed under the sync speed gives you more effective power to compete with daylight.

jeffreaux2

Elaine wrote:

I can indeed use a Sony flash...just being stubborn and not wanting to put $250 into a system that I'm hoping to set aside. That could nearly buy me a Canon 50 f/1.4!

I'm guessing the ND filter may help in some situations but not necessarily all. I mean, with an HSS speed of 1/125, there's potentially a large gap between that and proper background exposure on a sunny day with an aperture of 5.6 or so. But I'm glad to know my thinking was not completely off here.

Thanks for all the help, folks!

I think you can get a ND filter up to 3 stops density.....and they can be stacked.....AND......they can be used with any camera system. On a couple of occasions I could have used one for natural light portraits. My Canon(400D) has a maximum shutter speed of 1/4000 which on the surface seems plenty fast, but is not fast enough in bright conditions when trying to use a wide aperature to control depth of focus. This is nearly an identical situation you are combatting

---

too slow max shutter speed to use the aperature you desire. A ND filter would definately have baled me out. As it was, I had to take a pass on the photograph. Granted this has happened maybe twice, but........still a limit I have bumped into. The 30d and 40d( coming soon!!!- I hope) both go up to 1/8000. If I were going to try it though, I would absolutely NOT get the thread on filters, but instead go with a cokin holder and square filters that is capable of working on all of the lenses in my bag and on my wish list. They are also usefull on landscape photos.......especially nice for waterfalls!!!

I don't blame you a bit on the flash purchase. But hey!!!! Santa is coming soon.....you better be a good girl!!

Scott_Quier

jeffreaux2 wrote:

I think you can get a ND filter up to 3 stops density

Actually, they are commercially available to at least 10 stop. Here's a simple search I did at B&H to show (linkie)

Not cheap, but they're there.

jeffreaux2

Scott_Quier wrote:

Actually, they are commercially available to at least 10 stop. Here's a simple search I did at B&H to show (linkie)

Not cheap, but they're there.

WEll....there ya go!! Thanks for the info Scott. I know landscape photographers use them tons, so that makes sense that so many choices are available. Have you ever used one for portrait work? I have seriously thought about getting one because of the limitations of my camera. If all goes well, this camera will be a back up soon....and I won't have to worry about that anymore!!!

Scott_Quier

jeffreaux2 wrote:

WEll....there ya go!! Thanks for the info Scott. I know landscape photographers use them tons, so that makes sense that so many choices are available. Have you ever used one for portrait work? I have seriously thought about getting one because of the limitations of my camera. If all goes well, this camera will be a back up soon....and I won't have to worry about that anymore!!!

No, I've not used one. I did learn at the Glacier Shootout that Andy Williams swears by his 10-stop ND. I think I overheard him to say that it's the only ND he has - but I could be mistaken on that point.

jeffreaux2

Scott_Quier wrote:

No, I've not used one. I did learn at the Glacier Shootout that Andy Williams swears by his 10-stop ND. I think I overheard him to say that it's the only ND he has - but I could be mistaken on that point.

Youch!!!:D

Can you weld or view an eclipse through that?

I serious have thought about trying it with portraits, but I am hunting light more often than trying to chase it away!

pathfinder

10 stop NDs can be hard to focus through in anything less than very bright sunlight.....

SloYerRoll

pathfinder wrote:

10 stop NDs can be hard to focus through in anything less than very bright sunlight.....

I know PF already know this..
Leave your ND filter off when composing and getting your focus lock. Then switch to MF.

Put your ND filter on right before your about to press the shutter. Saves on the eye strain!

pathfinder

Be an interesting workflow for portrait shooting won't it?:D

Antonio Correia

This can be of some use for this thread !


Quoting from strobist
"Controlling Your Light from the Camera
Assuming just one flash and ambient light, there are only three combinations with which to control the two variables.

1. To alter flash and ambient levels together:
Remember, flash cares about the aperture and ambient cares about both the aperture and the shutter speed. So to lighten or darken both at once, we adjust the aperture.
If, for instance, our whole scene (flash and ambient) is too dark at f/8, we could move to f/5.6. This would lighten everything by a stop -- flash and ambient alike. Conversely, we could darken the entire scene by going from f/8 to f/11.

2. To alter the ambient level but not the flash:
As we said, flash cares about aperture and ambient cares about both aperture and shutter. So to control the ambient only, we will adjust the shutter but leave the aperture as is. Assuming you are within your sync speed, this will alter only the ambient-lit portions of your photo, as in our coffee table camera shots.

3. To alter the flash-lit area but not the ambient:
This is the most complicated of the three, but only as much as "chocolate/vanilla twist" ice cream is more complicated than either of its components.

Flash cares about aperture, and ambient cares about both aperture and shutter speed. So to alter flash only, we are going to adjust the aperture (which alters both) and compensate for the ambient by adjusting the shutter the other way."


My photo was shot by isolano

jeffreaux2

pathfinder wrote:

Be an interesting workflow for portrait shooting won't it?:D

Funny-
More like impossible!! But I think that only a few stops at most would be needed to bring SS within range.

SloYerRoll

Ya, I goofed on the post. I somehow thought this was a landscape thread.. Don't ask, cuz I don't have an answer...

Cheers,
-Jon