Aperture Value flashing - With Speedlite

[cliff46]

20D
420EX
TV (Creative Zone setting)

The manual states that when looking through the vewfinder and the shutter speed or aperture value flashes your exposure will not be correct.

When I use the 420 at any with a shutter speed of 250 the aperture value flashes. No matter what speed it set the shutter to it continues to flash.

Am I doing something wrong, like forgetting to mash one of those buttons or turn one of those wheels, or not combing my hair correctly?

Help please --- Thanks,

Cliff L :confused: ?

[tim]

Shoot in M mode, or ignore the flashing value. The camera doesn't know you have a big flash on it.

[Fills]

Av, Tv do not recognize the flash... like Tim said you can use M or the dreaded AUTO.

[RJSorensen]

Is there not a little 'flash' button on the top left that clues in the 20D to work? Seems like I have had to push it to get it to work in AV . . .

[robertwgross]

As you view the scene through the viewfinder, the camera really does not know that there is a Speedlite present, and it doesn't really care. You need to set the camera into the right exposure mode for the kind of flash photography you are trying to do.

At the last instant, as the shutter button goes down, the camera will find the flash unit and have it do a pre-flash for metering, the metering solution is put to the lens and shutter, and then an instant later the main flash pop happens.

So, right up to the last instant, the camera may be trying to warn you about low light, but then that goes away as soon as the flash illuminates the scene. For a beginner, it is a little scary. After you've done it a few thousand times at weddings, the scare goes away.

---Bob Gross---

[PacAce]

Actually, when the Speedlite is mounted, turned on and ready to fire, the camera does, indeed, know that there's a flash in use. And you can tell that the camera knows that if there's a lightning symbol at the bottom of the viewfinder. Now, if you had the flash on and you didn't see the lightning symbol (meaning the camera doesn't know about the flash) then you'd have cause for concern. :)

But everybody's right, though. In Tv and Av mode, the camera doesn't really care if you have the flash on or not. It'll ignore the flash if it's on and still calculate exposure for the ambient light.

[EricKonieczny]

wow I was wondering this same thing. I have been shooting in Manual mode becauseI though i was doing soemthing something wrong when i wasin AV and TV.

[cliff46]

BTW 3 hours before I ax'ed the question I called Canon and got the answer of all answers -- "The camera will not work properly if the aperture is blinking." They had the same info I gave you all.

Thank goodness for this forum.

THANKS A BUNCH FOR YOUR ANSWERS AND QUICK REPLY!!!!!

Cliff :) :) THANKS AGAIN:) :)

[robertwgross]

Actually, when the Speedlite is mounted, turned on and ready to fire, the camera does, indeed, know that there's a flash in use. And you can tell that the camera knows that if there's a lightning symbol at the bottom of the viewfinder.

Yes, it shows the lightning symbol for the flash, but the exposure values don't seem to change for what is about to happen.

---Bob Gross---

[scottbergerphoto]

The reason the Aperture Value Is Flashing is because at the shuttter speed you selected in Tv (shutter priority), even with the lens at maximum aperture, the Ambient Light Exposure is inadequate for proper exposure of the ambient light.
Since you are using flash, that may not matter to you. The meter doesn't take into account that you have a flash attached. In Tv, Av, and M the camera doesn't care if you have a flash on except that it won't let you increase the shutter speed above the max sync speed without some kind of warning. In P mode, the prescence of a flash, limits the lowest shutter speed to 1/60.
Scott

[robertwgross]

BTW 3 hours before I ax'ed the question I called Canon and got the answer of all answers -- "The camera will not work properly if the aperture is blinking." They had the same info I gave you all.

It sounds like they heard half of your question.

What is more fun is to call them at three different times and see how you get three different answers.

---Bob Gross---

[PacAce]

Yes, it shows the lightning symbol for the flash, but the exposure values don't seem to change for what is about to happen.

---Bob Gross---
Yes, Bob, that is correct, as I have already stated:


But everybody's right, though. In Tv and Av mode, the camera doesn't really care if you have the flash on or not. It'll ignore the flash if it's on and still calculate exposure for the ambient light.

[Eric DeCastro]

I shoot in "m" (i don't know how to use the other settings) and match my apreture of my lens (ie f/5.6) and put my flash at 5.6 If I need more light, i go to 6.0 if I need less light. go to 4.5 and I shoot in raw all the time to correct if I happened to mess up.

[R1 Kid]

I shoot in "m" (i don't know how to use the other settings) and match my apreture of my lens (ie f/5.6) and put my flash at 5.6 If I need more light, i go to 6.0 if I need less light. go to 4.5 and I shoot in raw all the time to correct if I happened to mess up.

Does anyone else use this method of manually setting their flash with their aperture?

[PacAce]

Does anyone else use this method of manually setting their flash with their aperture?
Since he is setting the aperture to match the aperture setting on the flash I can only assume that he is using a thyristor-controlled flash in AUTO mode. None of the EX Speedlite flashes that I am aware of works by setting the flash to a particular aperture.

However, what does confuse me is his statement, "If I need more light, i go to 6.0 if I need less light. go to 4.5". I'm assuming that when he says he goes to 6.0 or 4.5 he is referring to the aperture on the camera. However, to get more light into the camera he should be setting the aperture to a bigger opening, not smaller, and vice versa for less light. Maybe he meant to say it the other way around. Or his flash can be set for apertures in a fraction of a stop increments although I don't know of any flash that actually does that.

At any rate, none of this applies in your case with the Speedlite flash. But if you have the 550EX or teh 580EX flash, you can set them to manual mode and adjust the aperture based on your flash to subject distance and the output power you have set the flash to.

[scottbergerphoto]

You are correct as usual Leo. Nice new Avatar.
Scott

[robertwgross]

Is that Leo's new avatar, or an actual likeness?

---Bob Gross---

[PacAce]

You are correct as usual Leo. Nice new Avatar.
Scott
Thanks, Scott. I just got my 85 f/1.8 lens today and I was testing it out on my very cooperative model. While I was processing it, it occurred to me that he might make a very good avatar for me since I was due for a change anyway. Glad you like it. :)

[PacAce]

Is that Leo's new avatar, or an actual likeness?

---Bob Gross---
I am very proud to say that it is a very close likeness of me except that I only have 2 arms insead of 4 that this little fellow has. :mrgreen:

And, oh yes, my ears aren't as big.

[Andy_T]

Cliff,

welcome to the forum :D

I also was not too happy with the flash handling of my 20D when I first got it. Main reason was that with the flash activated (internal or external) I was getting very slow shutterspeeds... too slow for my liking and ability.

1/60 for 75 mm focal length (effective focal length of 120 mm) with the flash activated is too slow for my handholding abilities to get sharp pictures. There is also no need to go that slow, if the flash is active. My first thought was 'Stupid camera ... doesn't know the 1/focal length rule of thumb. P mode on my G2 was better :confused: '

However, all was not lost.
There is a very helpful custom function, CF 03-1, that sets the shutter speed to 1/250 in AV mode (not in P mode, and most logically also not in T mode). Allows you to adjust the aperture, while fixing the shutter speed (basically similar to using 'M' mode, but a bit more convenient to me).
Also, as was already pointed out, the camera *does* know if your flash is present and ready. When the flash has just fired and is recycling, I will see a slow shutter speed (e.g. 1/20) in the viewfinder display, and as soon as the flash is ready, this changes back to 1/250. So I also know if the flash is ready without taking my eye from the viewfinder.

How do you set exposure?

If you use an EX or compatible flash,
...then the flash should take care of getting the exposure right based on your selection.
If you want to have your images darker or lighter, you can use FEC. I very strongly assume this, as I don't have an EX compatible flash to try it out.

On any other flash,
...you will have to set the flash manually to match aperture and shutter speed. I use a 10 year old Metz MZ-40 with a Canon adapter. I can select the power of the flash by setting the EV value from 1 (full power) to 64 (1/64 of the power) in steps of multiples of 2 (1,2,4,8,16,...). By using trial and error, I have established that when I bounce the flash from my living room ceiling, for ISO 100, 50 mm focal length, 1/250 and f/4, an EV value of 4 gives me good exposition for shots over a normal portrait distance (2-3 meters). This relation of f/4 and EV=4 is something I manage to memorize :wink:

If I want to use f/2.8 instead, I set the EV value to 8, if I have to cover a greater distance, I would set it to 2. If the flash power is not sufficient for the aperture selected, I can increase the ISO number. When I shoot at a different location (different ceiling height or colour), I make some test shots and check the histogram before the main venue and adjust my settings accordingly.

This has been working
fairly well for me so far. Still an EX compatible flash is high up on my list of things to get next.

Best regards,
Andy

[Kiernan]

I just got my 420EX today and was fooling with it a bit ago on my Digital Rebel. Have a bit of learning to do with it. I was trying to take a closeup and all the images were underexposed. I could see the flash firing through the viewfinder, but it wasn't syncing with the shutter.

Also, when I remove the speedlight, my camera refuses to pop up the built-in flash. I was trying to compare shots between the on-camera and the speedlight. No matter how many times I turned off the camera, hit the flash button, or held my tongue to the left at the roof of my mouth, it wouldn't work. Then, after about 5 mins of fiddling, it finally popped up. Something I'm going to have to research, it appears.

Oh, and the DReb is the same as the 20D with the value flashing in Tv mode.