topic Re: EOS 600D Flash Problem in EOS DSLR & Mirrorless Cameras

EOS 600D Flash Problem

Dipankar — Sun, 04 Jan 2015 06:29:53 GMT

i ve EOS 600D. when capturing with flash it is pope up but image is still dark

Re: EOS 600D Flash Problem

ebiggs1 — Sun, 04 Jan 2015 08:17:51 GMT

Does the flash actually fire? Are you using the green square? A little more info would be helpful.

Re: EOS 600D Flash Problem

Dipankar — Sun, 04 Jan 2015 08:33:57 GMT

ya. flash fires but image is dark, sometime flash is not firing then the image is exactly as right apparture or sutter speed. what is the problem i m confused. i ve cleared all setting, flash setting but problem not solved

Re: EOS 600D Flash Problem

ebiggs1 — Sun, 04 Jan 2015 16:14:59 GMT

You didn't answer, are you using the "green square"? Or, are you using another mode setting?

Re: EOS 600D Flash Problem

TCampbell — Sun, 04 Jan 2015 20:39:27 GMT

We need to know what mode you are using on the mode dial.

Also... how far away is your subject? Pop-up flashes are not intended for distant subjects.

The pop-up flash on your camera has a "guide number" of 13 meters (43 feet). This is a "baseline" value which is NOT how far a subject can be under typical conditions... the value indicates how far a subject can be if the camera is using ISO 100 and the lens if f/1.0. Of course, your lens is NOT f/1.0, but the reason the value is used as a baseline is because it makes the math easy.

All we do is divide the guide number by the f-stop value that the camera lens is ACTUALLY using and that gives us the distance at which the flash can adequately light a subject.

Assuming you are using the kit lens (a variable f/3.5-5.6 lens) then the best the lens might be able to do is f/5.6.

Divide 43 feet by 5.6 and we get: 43 ÷ 5.6 = 7.67 feet. That's it... not even 10' away. BTW, this is VERY typical of pop-up flashes on any camera. Those tiny little pop-up flashes just can't emit much light.

The camera can improve this somewhat by increasing the ISO. At ISO 400, the pop-up flash can illuminate a subject 15' away. But we don't know what ISO your camera used because you haven't supplied us with that information. Your camera could push up to ISO 1600 and get that distance improved to about 30' but this has the downside of showing more "noise" in the image as you keep increasing the ISO sensitivity.

Fortunately your DSLR has a "hot shoe" on top which allows you to connect an external flash which can provide considerably more power. The Canon Speedlite 430EX II, for example, has a guide number of about 141' (43 meters). Using that flash with an f/5.6 focal ratio gives us: 141 ÷ 5.6 = 25.17 feet (a little better than 25 feet away). That's MUCH better and that's why Canon provides that hot-shoe for external flash.

Re: EOS 600D Flash Problem

Dipankar — Tue, 06 Jan 2015 17:05:25 GMT

i am in M mode, when using flash sometime it is firing sometimes not. but when flash firing there is no change in image lighting and i think it more darker than normal (without flash). it i done in ISO 400 (auto).

in protrait mode flash pop up, sometime not firing if firing no efect in image, it is dark

Re: EOS 600D Flash Problem

RobertTheFat — Tue, 06 Jan 2015 17:50:56 GMT

@Dipankar wrote:
i am in M mode, when using flash sometime it is firing sometimes not. but when flash firing there is no change in image lighting and i think it more darker than normal (without flash). it i done in ISO 400 (auto).
in protrait mode flash pop up, sometime not firing if firing no efect in image, it is dark

You should see at least the highlights of the scene properly lit. But the E-TTL algorithm is extremely averse to blown highlights and effectively treats all direct (non-bounce) flash as "fill". This usually works pretty well, but it means that you need to expose for the rest of the scene (other than the highlights) almost as though the flash were not present. If the scene is too dark for that to be an option, you probably need to set your flash to manual mode. Note, however, that setting the exposure to "M" does not put the flash in manual mode. The latter is an entirely separate setting.

Canon has never (to my knowledge) done a good job of explaining this, but some third-party commentators have. Gisle Hannemyr of Norway, for example, wrote quite a good paper on the subject a few years ago. You might be able to find it by googling.

Re: EOS 600D Flash Problem

ebiggs1 — Wed, 07 Jan 2015 14:05:49 GMT

"i am in M mode, when using flash ..." "i done in ISO 400 (auto). "

If your ISO is on "auto" you are not in complete manual?!?

Re: EOS 600D Flash Problem

RobertTheFat — Wed, 07 Jan 2015 14:44:10 GMT

@ebiggs1 wrote:
"i am in M mode, when using flash ..." "i done in ISO 400 (auto). "

If your ISO is on "auto" you are not in complete manual?!?

Well, M mode and Auto ISO can be simultaneously used with flash, but exactly what happens when you do so is rather vaguely explained (at least in the 7D and 5D3 manuals).

Re: EOS 600D Flash Problem

ebiggs1 — Wed, 07 Jan 2015 14:47:40 GMT

Exactly! M should mean manual.

Re: EOS 600D Flash Problem

RobertTheFat — Wed, 07 Jan 2015 15:01:19 GMT

@ebiggs1 wrote:
Exactly! M should mean manual.

Yeah, but at the risk of putting words in Canon's mouth, I think their argument would be that "M" refers only to the manual setting of lens aperture and shutter speed and is not intended to be inconsistent with auto-ISO. Note that it also doesn't imply manual setting of the flash, if flash is being used.

Re: EOS 600D Flash Problem

Skirball — Wed, 07 Jan 2015 16:17:37 GMT

@ebiggs1 wrote:
Exactly! M should mean manual.

This is probably the most asinine, petty, and completely irrelevant bit of semantics that some photographers like to debate. Manual purists.

Who cares what it's called? Do you seriously brag to your friends that you shoot in full manual? Is there a hierarchy to shooting modes> How does M with Auto-ISO stack up, is it higher or lower than shooting in Av?

If it's a functional shooting mode that helps me get the shots I want, I'll use it. I happen to use M with Auto-ISO quite a bit now, I find it to be very useful with the exception of not having exposure compensation. I also use M with eTTL flash on occasion, does that invalidate my admission to the manual-only club?

If you convince Canon to add a new shooting mode with M, auto-ISO, and exposure compensation and call it Wannabe Manual Pansy "WiMP", I'll shoot in it. I really don't care what the names are, just the results it gets me.

Re: EOS 600D Flash Problem

Dipankar — Wed, 07 Jan 2015 16:36:58 GMT

it is fully manual or fully auto i dont think it is problem. my problem is flash firing but image is dark that means camera is not consedering flash fire. clear ???????????

it was the problem of two days ago. from today i m facing new problem, i.e flash pop up but not firing 😞