300D FEC Workaround

[drisley]

I just got my 300D and love it.
I do, however, miss the flash exposure compensation my ol' G3 had.
I've heard people say there are ways around this limitation.
Anyone care to share some ideas.

Oh, and I don't mean changing the flash exposure semi-permanently by hooking the 300D to your 'puter, and running a firmware hack.

I have a 420EX, and I really dont want to spend the money on the 550EX just for this reason (plus it's too big for my needs).

Thanks in advance!
:)

[dtrayers]

Welcome to 300D ownership!

The only FEC workaround is the hook to the 'puter method. Or a 550EX or the Sigma equivalent (you might consider that flash).

I've learned to use the Flash Exposure Lock and have learned that if I FEL on a tone a little darker than a caucasian face I get pretty good exposure. Just remember that E-TTL biases to the focus point and it happens AFTER you focus lock. So if you do the 'ol focus, recompose, shoot method, and the focus point moves to a lighter or darker tone, you'll get unexpected results.

Also, shoot in RAW mode and you'll get at least 1.5 stops extra exposure latitude. And if you have Photoshop CS, you can edit in 16-bit mode and use the Hightlight/Shadow adjustment tool to bring out more shadow detail.

You may have seen this site but if not here's all you need to know about E-TTL. It's required reading for EOS camera owners:

http://photonotes.org/articles/eos-flash/

[Man-Fai Wong]

I'm curious about this also since I'm a G3 owner (w/ 420ex) considering an upgrade to 300D.

Shouldn't applying some positive (regular) exposure comp be an ok workaround most of the time? I know the results won't be quite the same of course, but doesn't it just mean you can't control fill flash (separately from the rest of the exposure)? What else am I missing?

When I use a digital elph cam like the S230, which has no FEC, I just use exposure comp to prevent overexposure. In that case, it tends to make background exposure darker than if I could use FEC.

_Man_

[slin100]

I read about another FEC workaround that is a variation of using FEL on a brighter or darker-tone. You can also accomplish negative FEC by moving closer, doing FEL, moving back and taking the shot. Move back before doing FEL to achieve positive FEC.

I know, it's not a very elegant workaround compared to simply having a 550EX.

[jrm]

While I have used 35mm SLRs for years, I was never a flash user. Most of my shots were outdoors and I simply used available light. My indoor shots (many years ago) were primarily at concerts, where distance and stage lighting made flash useless. More recently, I was using a strobe setup with a handheld light meter.

Thus, despite some reading on the subject I remain pretty clueless about flash and TTL/E-TTL subjects.

Am using a 300D, and may consider adding a flash in the near future. I understand about FEL - at least as much as anyone else seems to. But the FEC concept evades me.

Could someone explain in general terms what FEC is and how it works?

Is it something that the flash automatically calculates? Is it basically a manual setting to raise/lower flash power - and if so, does the camera take this into account in the exposure settings?

Thanks in advance

[Sketcher]

http://revolution.cx/rcx/fecset.htm

:oops: And I've just read the rest of you post and berated my twitchy post finger. Sigh... I gotta quite doing that!!!

Cheers :)

.

[rick barclay]

Hello, everyone-my first post after lurking for a week or so.

I'd like a clarification on this FECSet 1.0/420EX issue for the Digital Rebel,
which I own. My understanding of the post is that your photos will
improve dramatically using FECSet on a 300D equipped with a 420EX flash, but if you have a 550EX, then you don't need the FECSet program.

Am I correct in this interpretation? I have no problem spending the extra $$$ for a better flash, but I would be pleased to know if it could also
help me avoid installing a program I really don't want. And I must say
those photos in the FECSet test look 1000% percent better using FECSet.

Another question I have: I recently took some photos of Delbert McClinton performing in Myrtle Beach, and while some of the exposures
using the on-board flash came out pretty good, others were very dark
and had to be touched up in Photoshop. Someone mentioned that using
a flash in a concert environment, with all the floodlighting and stuff, would
be useless. Is this true? I'm interested because I am wondering if had
I had a 550EX on my Digital Rebel that night the pipctures would have
come out much better than they did.

Thanks a lot for your replies. I'm new to photography but not forums, and
I must say I am very pleased with what I found here--a very congenial,
active site.

[drisley]

All FECset does is increases/decreases the flash output of the DRebel on a semi-permanent basis. If you increase the output by +2/3ev, then it stays that way permanently until you hook up to your computer and change it again.

With the 550EX, there are buttons on the back of the flash that let you change the flash output dynamically. This is much more convenient.

The 550EX does offer a more powerful flash than the 420EX, so it may help in concert situations. However, the reason why your pics were underexposed may not have anything to do with the flash power, but rather how the E-TTL metering decided to shoot the scene. Also, it could have been because your exposure time or aperture values werent suitable (you didnt say what mode you were shooting with).

[slin100]

Could someone explain in general terms what FEC is and how it works?

Is it something that the flash automatically calculates? Is it basically a manual setting to raise/lower flash power - and if so, does the camera take this into account in the exposure settings?
Flash exposure is usually based on properly exposing a mid-toned, foreground subject. Flash exposure calculation completely ignores the effect of flash on the background. The exposure of the background is determined by the shutter speed and aperature.

It's extremely important to know which exposure mode the camera is using because the mode determines whether or not the camera will select a shutter speed/aperature combination that will properly expose the background. In low-light situations, Av and Tv mode will result in a properly exposed background, P mode will not. Things get a little tricker in bright light (EV 10 or brighter), because auto-fill-flash takes over and the camera will attempt to expose the background properly in all three modes, including P.

FEC is used to adjust the flash power which, in effect, affects only the exposure of the foreground. It is manually set. I suppose auto-fill-flash is considered a form of automatic FEC but it is seldom referred to as such. FEC does not alter camera's exposure settings. This is, in fact, a feature because it allows you to independently control the exposure of the foreground and background. For example, you could dial in +1 FEC and -1 EC and the foreground would be 1 stop overexposed and the background would be 1 stop underexposed. Well, the exposure of the background may not be exactly 1 stop underexposed because the flash may affect the background.

For more information consult http://photonotes.org/articles/eos-flash/.

[jrm]

drisley,

So if I understand this correctly, FEC is basically a manual override to change power of the flash.

The "meter" says everything will be perfectly exposed, but we know better so use FEC to crank up the flash power a bit. The "meter" will now indicate overexposure, but the shot will come out the way we want.

And this cannot be done with the on-board or 440EX flash (forgetting hacks, or external computer control for the moment), but can be done easily with the 550EX (or Sigma equivalent).

Is this right?

[rick barclay]

All FECset does is increases/decreases the flash output of the DRebel on a semi-permanent basis. If you increase the output by +2/3ev, then it stays that way permanently until you hook up to your computer and change it again.

With the 550EX, there are buttons on the back of the flash that let you change the flash output dynamically. This is much more convenient.

The 550EX does offer a more powerful flash than the 420EX, so it may help in concert situations. However, the reason why your pics were underexposed may not have anything to do with the flash power, but rather how the E-TTL metering decided to shoot the scene. Also, it could have been because your exposure time or aperture values werent suitable (you didnt say what mode you were shooting with).


Ahhhh, thanks, drisley. Being the rank amateur that I am, I shot everything in auto that night :oops: . ISO was 100. This Digital Rebel is my first camera. I'm trying to learn as much and as fast as I can. I know
I should have used a higher ISO and wider aperture setting, but I didn't
know squat two weeks ago, when I took the photos.

[Man-Fai Wong]

For example, you could dial in +1 FEC and -1 EC and the foreground would be 1 stop overexposed and the background would be 1 stop underexposed. Well, the exposure of the background may not be exactly 1 stop underexposed because the flash may affect the background.

I could be wrong (since I haven't thoroughly tested it w/ my G3 + 420ex), but wouldn't those settings yield "correct" exposure for foreground/subject w/ underexposure for background?

As I understand it, the +1 FEC and -1 EC would basically cancel each other out for exposing the subject. If I'm really wrong on this, please let me know.

For more information consult http://photonotes.org/articles/eos-flash/.

Yes, that is a very interesting read although a bit long and somewhat convoluted. I read it a long while ago before buying the 420ex for my G3.

_Man_

[Man-Fai Wong]

http://revolution.cx/rcx/fecset.htm

:oops: And I've just read the rest of you post and berated my twitchy post finger. Sigh... I gotta quite doing that!!!

Cheers :)

.

Seems like a good workaround. Guess that's what I'd do (w/ +2/3EV for FEC) if I get the 300D.

With a DSLR, I don't expect to use the flash too often since I can pump up the ISO. And even on my G3, I tend to stick w/ the same FEC most of the time. Interestingly, I find -2/3EV to yield good results for FEC on my G3 most of the time.

_Man_

[dtrayers]

As I understand it, the +1 FEC and -1 EC would basically cancel each other out for exposing the subject. If I'm really wrong on this, please let me know.



Think of the FEC contolling the flash and the EC controlling the aperture and shutter speed. If you dial up -1 EC and have the flash off the entire scene will under expose. If you then turn on the flash (no FEC yet), then E-TTL will adjust the power of the flash such that the subject being metered is properly exposed. The background will still be underexposed (maybe not as much as 1 stop as there will be some spill from the flash), but the metering is taken from the subject under the active focus point(s).

Now add +1 FEC and the calculated flash to properly expose the subject will be increased by one stop. In theory, you can have an over-exposed subject and under-exposed background.

So why use FEC? Because if your subject is already above neutral tone, then you'll want to compensate with a little extra flash to compensate (just like adding EC on a snowy scene).

E-TTL will meter for the active focus point and try to properly expose. If you want to compensate, use FEC. Just using EC will have no effect on the subject.

Notwithstanding the above, a lot of people have found (myself included) that in general adding +2/3 FEC yields a lot more properly exposed flash shots (with a small percentage over-exposed).

And notwithstanding that, I don't typically use FEC and shoot in RAW mode and I can usually compensate for any under-exposure in the conversion.