Tried 550 EX in store today...

[DocFrankenstein]

Went in and had 5 minutes to play with the rebel and 550 ex. It was in ETTL mode and the camera was in Av.

I look in the viewfinder and half press the shutter button. It meters 1/5 th of a second... which is what I would get without the flash.

I fire off the flash... the exif data still says 1.5th of a second. :?

Is this normal? how does the whole thing work?

[droosan]

Went in and had 5 minutes to play with the rebel and 550 ex. It was in ETTL mode and the camera was in Av.

I look in the viewfinder and half press the shutter button. It meters 1/5 th of a second... which is what I would get without the flash.

I fire off the flash... the exif data still says 1.5th of a second. :?

Is this normal? how does the whole thing work?

Yes, in Av mode that is what it does. Flash in Av mode is Fill-Flash, meant to fill in your subject, a face for example, but leave the background (Sky, Trees,... ) bright.

If I want the flash to compensate for darkness, I set the camera to M, choose my Aper. according to what DoF I want, choose my Shutter according to how much, or how little, blur I want, and let the 550ex do everything else. Works great in low light situations, gyms etc. Now with digital if you try this and get too much flash glare, you can increase the ISO. It's amazing to be able to review and fix on site.

[EXA1a]

Went in and had 5 minutes to play with the rebel and 550 ex. It was in ETTL mode and the camera was in Av.

I look in the viewfinder and half press the shutter button. It meters 1/5 th of a second... which is what I would get without the flash.

I fire off the flash... the exif data still says 1.5th of a second. :?

Is this normal? how does the whole thing work?

Yes, in Av mode that is what it does. Flash in Av mode is Fill-Flash, meant to fill in your subject, a face for example, but leave the background (Sky, Trees,... ) bright.

If I want the flash to compensate for darkness, I set the camera to M, choose my Aper. according to what DoF I want, choose my Shutter according to how much, or how little, blur I want, and let the 550ex do everything else. Works great in low light situations, gyms etc. Now with digital if you try this and get too much flash glare, you can increase the ISO. It's amazing to be able to review and fix on site.

You are right. One addition: With Wasia's modified firmware you have the custom function to set the synch speed in Av mode to either 1/200 or to ambient light (=default, fill-in flash). That's one big advantage of this firmware. Works w/o any problems for me.
--Jens--

[scottbergerphoto]

The camer meter measures ambient light only. It doesn't care if you have a flash on. It tells you the proper exposure for the ambient light. The only exception to this is P mode, where by default, the camera won't let the shutter speed drop below 1/60 of a second. In Av, Tv, and M modes you need to be careful in low light situations that you aren't using too slow a shutter speed for hand holding or you'll have a blurred background.

For Mark II and 1 Series body users, Av and Tv are programmed to use the flash in fill flash mode. There is an automatic reduction of the flash output by about 1 stop. To use the flash as your primary light source on a 1 series camera, use M mode.
Regards,
Scott

[JX]

What does everyone think aboutthe 580X Speedlite flash units From what I read it seems to be optimized for the D20 and the MarkII.

[Namagemo]

Brings up a question I've been meaning to find an answer to.
What is the correct way (if any) to use the dreb flash for fill flash outdoors?

[timmyquest]

Brings up a question I've been meaning to find an answer to.
What is the correct way (if any) to use the dreb flash for fill flash outdoors?

For fill flash i find it's best to just use AV mode

[dphoto]

Hey Rich,

Well, I'm still pretty new at this, but let me give it a try. If I'm holding the camera, then I'll probably use Tv mode so I can keep the shutter speed where I want. I pop the flash up and then I aim the focus point at my subject and press the shutter down halfway. From what I understand, the metering mode in this case should be evaluative, so an aperature will be set for the whole scene (remember, the camera does not keep the flash in mind when figuring this out). Then, when I take the picture (which is correctly exposed for the ambient light) the ETTL takes care of illuminating my subject based on the aperature value that has already been determined.

Am I missing anything here?

Jens, I read your post and I'm trying to grasp the concept here... Does the Wasia custom function have 2 options? And this only kicks in if you are using Av mode with the flash popped up, right? OK, if I'm on track so far, let me keep going. So, in one mode, the time value will always get set to 1/200, no matter what? And in the other, the Av works just like it normally does, trying to do an evaluative metering, correct? I see... you would use the 1/200 value if everything you are shooting is going to get hit by the flash, correct? Hmmm... that's interesting, because without even realizing it, I find myself using the Tv mode with a time of 1/200 when I use the flash indoors a lot. Is this any different than using the Av mode that will sync to 1/200? Hey, actaully, what's the difference between this and just using Manual mode with 1/200 and the aperature value of your choice? Can someone expand upon these 3 differences for me. I think I'm on the verge of getting this... just need a little help, that's all. :D

I love talking flash and lighting... just when you think you have it, someone points out a small detail that really gets you thinking! :D

Thanks,
-Deva

[scottbergerphoto]

Brings up a question I've been meaning to find an answer to.
What is the correct way (if any) to use the dreb flash for fill flash outdoors?
True Fill Flash usually requires that the flash be dialed down about 1-1 2/3 stops. You are just trying to fill in some shadows for what would otherwise be acceptable ambient lighting. It doesn't matter which mode the camera is in. Since the 300D doesn't have FEC on the body without the Russian firmware hack, use a 550EX with -1 to -1 2/3 FEC dialed in on the flash.
Regards,
scott

[dphoto]

Hey Scott,

Why would the flash need to be dialed down like that? Let's say that f/4 1/100 is being used to capture the ambient scene, and I want to fill flash my subject. The flash is going to account for the f/4 aperature. Are you saying that that additional 1/100 sec of ambient light will slightly overexpose the subject?

This brings up an interesting question concerning "painting with light". Is light "additive" in that manner? In other words, let's say I have a perfectly exposed subject at f/4 1/60 (no fill light needed). Then let's say I use the flash on that subject. Now, the scene would have been properly exposed with just the ambient light, and it would have been properly exposed with just the flash, so what happens when you use both? Is it going to have twice as much light as it needed, so it's now 1-stop over exposed? My brain hurts... :D

-Deva

[Jesper]

What does everyone think aboutthe 580X Speedlite flash units From what I read it seems to be optimized for the D20 and the MarkII.

Here is a thread from a few days back about the 580 EX: http://photography-on-the.net/forum/showthread.php?t=40497

[scottbergerphoto]

Hey Scott,

Why would the flash need to be dialed down like that? Let's say that f/4 1/100 is being used to capture the ambient scene, and I want to fill flash my subject. The flash is going to account for the f/4 aperature. Are you saying that that additional 1/100 sec of ambient light will slightly overexpose the subject?

This brings up an interesting question concerning "painting with light". Is light "additive" in that manner? In other words, let's say I have a perfectly exposed subject at f/4 1/60 (no fill light needed). Then let's say I use the flash on that subject. Now, the scene would have been properly exposed with just the ambient light, and it would have been properly exposed with just the flash, so what happens when you use both? Is it going to have twice as much light as it needed, so it's now 1-stop over exposed? My brain hurts... :D

-Deva
The flash exposure is not affected/controlled by the settings for aperture and shutter speed as long as you stay within the distance limitation as specified by Distance=GuideNumber / f stop at Iso 100. For Iso 200 mulitpy by 1.4 and for Iso 400 multiply by 2.
The flash exposure is controlled only by the duration of the flash burst, which is about 1/10,000 of a second. The camera fires a preflash, and based on the amount of light reflected back, it determines how long the flash burst will be. The camera doesn't know if the flash is the primary light source or a fill light. In Program Mode, it tries to figure it out and adjust accordingly. If you don't use -FEC, you will get a standard flash picture with headlights in the eyes flash. In Fill Flash, you want to only lighten shadows, such as under someones eyes.

Flash painting is usually associated with dark rooms, and manually using successive flash bursts and a long exposure. The camera doesn't differentiate one flash from ten. The light is additive. In the scenario you describe, the flash and ambient light are additive. One note, on the 10D, there is a feature called Automatic Reduction of Fill Flash, which automatically reduces the flash in bright ambient light. I keep that turned off in the custom functions and set my own -FEC.
Regards,
Scott

[dphoto]

Thanks for the info Scott.

I guess when I was thinking of fill flash, I was thinking of a dark subject against a bright background. It sounds like you are stating that fill flash can also mean brightening the darker areas of a subject. That makes sense. So the only way to do that is with FEC dialed down about a stop or so. It's like trying to learn how to cook... just use a stop or so of FEC to taste, and you've got it! :D

Thanks agian,
-Deva

[Namagemo]

scottbergerphoto wrote:
True Fill Flash usually requires that the flash be dialed down about 1-1 2/3 stops. You are just trying to fill in some shadows for what would otherwise be acceptable ambient lighting.


Yes. That is exactly what I want to do. And it has to be 550EX because manual operation is needed for this, or other less expensive ETTL compatible flash with manual control. Or the firmware hack. Does that about sum it up for my Dreb? Thanks to all...

[Headcase650]

I use the Digital Rebel with the 550EX. If your flash is in ETTL mode and the camera is in AV or TV mode it should Automatically reduce the amount of flash to fill in the shadows with out having to adjust the FEC on the 550EX itself. At least thats the way I understand it, Ive never had any problems. Someone correct me if Im wrong.

[Jesper]

You can find all you want to know about Canon's E-TTL flash system here: Flash Photography with Canon EOS Cameras (http://photonotes.org/articles/eos-flash/).

[scottbergerphoto]

I use the Digital Rebel with the 550EX. If your flash is in ETTL mode and the camera is in AV or TV mode it should Automatically reduce the amount of flash to fill in the shadows with out having to adjust the FEC on the 550EX itself. At least thats the way I understand it, Ive never had any problems. Someone correct me if Im wrong.
It is true that in ETTL the camera automatically reduces the flash output by about 1 and 1/2 stops in bright light in certain camera bodies under certain conditions and shooting modes. The camera computer calculates how bright the ambient light is and reduces the flash output. The problem is that the camera can be fooled by dark backgrounds, bright white clothing, etc. You will get more consistent results if you disable the automatic reduction of fill flash(10D) or use Manual metering mode(No auto reduction of fill flash on 1 Series bodies) and dial in -FEC on your own, either on the flash or the camera body.
One of the problems in deciding how to approach this is that Canon has made each body different in how they handle FEC and fill flash. The documentation is not clear as well. The 10D has a Cfn to turn off the Auto Reduction of Fill Flash. The 1 D Mark II has no such Cfn, so you have to use M mode to avoid it. I have no idea how the 300D handles it. The Photonotes article, while very detailed and informative is silent on this issue. It doesn't speak to the differences in Fill Flash between camera bodies.
If what you want to do is classic fill flash, just lightening up some shadows, then I advise you to find out how to turn off the Automatic Reduction of Fill Flash for your particular camera and dial it in yourself.
Regards,
Scott

[DocFrankenstein]

If what you want to do is classic fill flash, just lightening up some shadows, then I advise you to find out how to turn off the Automatic Reduction of Fill Flash for your particular camera and dial it in yourself.

YES! This is what I wanted to hear. Coming from you, I beleive it.

So maybe I could go with a fully manual flash? (which is much cheaper) I mean... the one that's manual only. If you recommend using the manual as the best way to do this stuff?

[dphoto]

Wow,

Thanks Scott. Does anyone know, is there any way to turn off Automatic Reduction of Fill flash for the 300D? I suppose if you are using the 550EX in manual mode, then it's off, but then you are having to try to figure out how much flash you need to use on your own. ETTL with FEC would be so much easier!

Thanks again for the great explanation!
-Deva

[scottbergerphoto]

Wow,

Thanks Scott. Does anyone know, is there any way to turn off Automatic Reduction of Fill flash for the 300D? I suppose if you are using the 550EX in manual mode, then it's off, but then you are having to try to figure out how much flash you need to use on your own. ETTL with FEC would be so much easier!

Thanks again for the great explanation!
-Deva
I believe a work around for Manual flash would work as follows:
1. 550EX on Manual, Camera on Manual or Av.
2. Set camera f stop for correct subject distance on Flash LCD readout, or use Distance = GN / f stop at ISO 100.
3. Close down the camera aperture 1 - 1 2/3 stops from #2.
4. Set the shutter speed to properly expose ambient light.
Regards,
Scott

[robertwgross]

Scott, we are going to rent you out as a flash consultant to the Canon Speedlite design department.

---Bob Gross---