20D On Camera Flash & External

[Mark_48]

I've had my 20D for a couple of weeks now and done quite a few outdoor shots I'm pleased with. I just started playing around with some indoor flash shots and now I'm not so pleased. Both with the on camera flash and an external 420EX shots are very under exposed. My 300D on the other hand, for the same shots is dead on where I think it should be with its on camera and the 420EX, both in Basic and Creative modes. To get a comparable exposure on the 20D I'm setting the FEC as much as 1 to 1 1/2 stops positive. And in Basic modes FEC isn't available, so those exposures are in the mud. I know there are alot of threads out concerning under exposure on the 20D, but is +2 stops typical to get a good exposure? I've checked my customs settings for anything I think might be related to flash exposure and it appears all settings are at default. I'm wondering at this point if the camera is somehow miscalibrated.

[tim]

I think that's just what the 20D does - mine does it, and so do a lot of other peoples. Have a read of this (http://www.robgalbraith.com/ubbthreads/showflat.php?Cat=&Number=303342&page=1&view=collapsed&sb=5&o=&fpart=1&vc=1).

I don't use basic mode, and the 550EX has control that seem to work better than FEC, so no problem for me.

[Leigh]

I haven't yet tried an external flash ( just got the camera a few weeks ago), but I got 2-3 stops under exposure, and a reddish / orange cast with the on-board flash.

Because the manual didn't indicate otherwise, I'd left the WB settings on AWB; When I changed the WB to the Flash setting, I got much better results.

Leigh

[tim]

2-3 stops, or 2-3 steps (1 stop)? By default on the 20D each click of the little wheel is 1/3 of a stop change.

[scottbergerphoto]

Before you jump to conclusions about the 20D's exposure, please read the section on ETTLII in the EOS Flash Sticky. In certain situations, you will get very different results depending on how CFn. 14 is set.
Scott

[freddycr]

I've had the 20D for a couple of weeks now, tried indoors & outdoors, both as main source of ligh and as fill.....never had a problem. I got some dark ones at the beginning , but found that the trick is let the cam measure properly the conditions (let the little scale you see on the viewfinder set in the middle), pressing the shutter buttom half-way before firing
I also increased the flash compensation 2 pts
Here as fill-up

http://img.photobucket.com/albums/v629/alcorjr2/sta-ana038Medium.jpg

[Mark_48]

On the 300D DRebel I have I seldom used Basic modes, but they did work well for the most part with the camera flash as well as external giving a reasonably proper exposure. I understand pretty well how the ETTL-II functions and it clearly should be better than its pedecessor as it takes into account more information. And yes, the FEC setting can tweak in the flash to give acceptable exposure for different flash units. I haven't tried any bounce or diffused flash yet so I don't know if maintaining the same FEC setting will work or not.
As I had mentioned I don't use Basic modes often, if ever. On the occasions my wife picks up the camera as she did with the 300D, that's where the problem lies. She's a Basic modes user and not much will change that. The 20D goes for a tidy chunk of change and my expectations would that it would easily out perform the DRebel on all counts, including Basic modes. It appears I can't get good flash exposure from the Basic modes as I could from the DRebel and there isn't a way to tweak anything to bring it in, not that DRebel could be tweaked, it just didn't need it.
The 20D is a significant step up from my DRebel in terms of functionality and control. It no doubt will serve me well for weddings and such. I just can't get a grip on the fact yet that the camera to me isn't functioning at least close to 100% due to the Basic mode and under exposing flash. And there seems to be an acceptance that this is OK ("Because I don't use Basic modes").

[Mark_48]

Well I thought I had a better understanding of E-TTL II, but I'm beginning to think I'm under exposed in my comprehension of it.

Scott if you don't mind me using a quote from another thread....

Everybody take a deep breath and repeat after me, "ETTLII has nothing to do with the active autofocus points." There is alot of useful information on this issue in the EOS Flash Sticky.
Scott

email from Canon support on question regarding under exposure of flash in Basic modes.....

Thank you for contacting Canon product support. I am sorry to hear you
are experiencing an issue with the flash exposure on your EOS 20D.

Please remember that metering is linked to the active AF point. If you
focus (meter) on a very light area of the subject, the camera will
expose for that area. As a result, darker areas of the same subject may
appear underexposed. Using the camera's AE Lock (or FE Lock, for flash
images) function should improve your results. Alternatively, you can
meter on a more moderately toned area of the image.

If you continue to experience an issue then please forward the camera to
our factory for evaluation. For factory service, forward your digital
camera (remove the CF card and battery) properly packaged and insured,
with a letter describing the difficulties. Be sure to include your name,
address, telephone number, and proof of warranty (if applicable). Send
to the Canon Factory Service Center at the following address:

Canon Factory Service Center
100 Jamesburg Rd
Jamesburg, NJ 08831
Tel.# (732)521-7007

[PacAce]

Well I thought I had a better understanding of E-TTL II, but I'm beginning to think I'm under exposed in my comprehension of it.

Scott if you don't mind me using a quote from another thread....



email from Canon support on question regarding under exposure of flash in Basic modes.....

I think that fellow at Canon support has his ETTL and ETTL-II all mixed up. Or rather, he doesn't seem to know that there's a difference between the two. That or he doesn't know that the 20D is using ETTL-II. In any case, he's wrong and Scott is right. :D

[robertwgross]

The Canon quote does not mention ETTL or ETTLII.

Also, we don't know what question the Canon quote was attempting to answer.

---Bob Gross---

[Mark_48]

I think that fellow at Canon support has his ETTL and ETTL-II all mixed up. Or rather, he doesn't seem to know that there's a difference between the two. That or he doesn't know that the 20D is using ETTL-II. In any case, he's wrong and Scott is right. :D

From the response I got from Canon, it seemed like a generic answer, particularly as my question had related to flash in the Basic modes and his suggestions for AE or FE lock aren't applicable to the basic modes.

I do recall reading something Chuck Westfall authored around here which concurs with what Scott had stated.

[PacAce]

The Canon quote does not mention ETTL or ETTLII.

Also, we don't know what question the Canon quote was attempting to answer.

---Bob Gross---

Check the last two words in the first paragraph. He specifically acknowledges the EOS 20D as the camera the owner is having problems with. And the 20D incorporates ETTL_II and not ETTL.

[robertwgross]

Check the last two words in the first paragraph. He specifically acknowledges the EOS 20D as the camera the owner is having problems with. And the 20D incorporates ETTL_II and not ETTL.

Sure, the 20D is named, but we don't know what the original question was that the quote was supposed to answer. In other words, it is out of context.

---Bob Gross---

[PacAce]

Sure, the 20D is named, but we don't know what the original question was that the quote was supposed to answer. In other words, it is out of context.

---Bob Gross---
Thank you for contacting Canon product support. I am sorry to hear you
are experiencing an issue with the flash exposure on your EOS 20D.
Let's see. We know the Canon rep knows about Mark's flash exposure problem with his 20D because he acknowledges that in the very first paragarph. Then he goes on to the 2nd paragraph and talks about the meterng. Now, unless he just decided to just out of the blue talk about something totally unrelated and irrelevant to Mark's flash problem just for the sake of making conversation, I think we can be pretty safe in assuming that the 2nd paragraph is supposed have some bearing on Mark's flash problem, can we not? His "stock" answer may have been used out of context but it was still used nevertheless.

[robertwgross]

Leo, we do not know what the original question to Canon was.

We know it had something to do with flash, and something on a 20D. Otherwise, we know nothing. I agree that the Canon quote sounds a little fishy, but without knowing the original inquiry, we're just fishing.

---Bob Gross---

[IainB]

It's interesting that others have experienced some 'teething' troubles with the 20D and external flash. I am still in the early stages of discovering my way around the 420ex and the 20D. My first attempts recently produced some underexposed images which I put down to inexperience and poor choice of bounce flash. I aim to take on board all the tips and learn from the experience of you all and see how I can improve. What I am not clear about is how the flash is being used. For example, is it being used in bounce or direct mode? And should that in fact make any difference? I guess it comes down to bracketing shots and evaluating the outcomes.
Still a bit green!

[scottbergerphoto]

The above posted message from Canon Service is incorrect and you should tell them to read their own technical information.Please read the ETTLII document from Chuck Westfall, Director of Technical Information, Canon USA. in the EOS Flash Sticky. This is the main reason for being of ETTLII.
Here is Chuck Westfall of Canon's post:
"E-TTL II is never linked to the active focusing point. In fact, that is one of the main differences between E-TTL II and the original version of E-TTL. There's a brief description of E-TTL II with sample images on Canon Inc.'s EOS-1D Mark II web site here.

Here's what we published in the EOS-1D Mark II White Paper document:

ADVANCED E-TTL II
New algorithm gives greater flash exposure control

For improved flash control using Canon EX series Speedlites, a new algorithm has been developed which enables superior E-TTL flash accuracy and reliability. In previous cameras, evaluative flash metering was based on the assumption that an autofocus point would cover the subject. When this is not the case, inaccurate flash exposures result. The EOS-1D Mark II’s evaluative flash metering is not dependent on the active AF point.

In the new algorithm, ambient light is measured when the shutter button is pressed. Next, a pre-flash is fired and the metering sensor takes readings at the central 17 metering zones. The ambient and pre-flash readings are compared. The metering areas having a small difference are selected as the flash exposure metering areas. (Areas with very big differences between ambient and pre-flash readings are excluded or down weighted because they are assumed to contain a highly reflective object or that the subject is not in that part of the frame. The algorithm avoids chronic underexposure problems in such situations.) These readings are weighted, averaged and compared with the ambient light reading, and the main flash output is then set and stored in memory. E-TTL II weights and averages the flash metering for the subject and all other objects at the same distance as the subject. Even if the subject’s position, reflectance or size changes, the flash output will not change radically. The flash exposure will be highly accurate and stable.

Most EF lenses provide distance information, and this data is also considered in determining if there is a highly reflective object, once again lessening the chance of underexposure.
************************************************** ***

Additional info on E-TTL II:

In essence, distance information is not required for E-TTL II. But when it is available and the flash is direct, then it can be used as a reference to modify the flash exposure if necessary.

Additionally, the EOS-1D Mark II is provided with a new Custom Function (C.Fn 14-1) that allows photographers to select between evaluative and averaged flash metering in E-TTL II. Averaged flash metering may be preferable when using direct flash with lenses that don't have a built-in distance encoder, but we encourage Mark II owners to try both settings on C.Fn 14 to see which metering method they prefer.

E-TTL II is functional with all EF lenses, not just the ones with distance data. If you use a lens without distance data, the only thing you lose is the Mark II's ability to modify the flash exposure based on distance data. Everything else works the same. The Mark II *never* falls back to E-TTL.

There's never any "full-frame" flash metering in E-TTL or E-TTL II. In both cases, with EOS cameras that use a 45-point focusing system/21-zone metering sensor, all flash metering is carried out by the 17 metering segments within the Area AF ellipse shown in the viewfinder. Subject matter outside the ellipse is completely ignored in terms of flash exposure control.

C.Fn 14-0 on a Mark II allows E-TTL II flash metering to be subject-based, so it can use anywhere from 1 to 17 metering segments depending on the camera's analysis of the pre-flash information. This is not a spot meter reading, unless the camera determines that the subject is so small that it occupies only one of the 17 metering segments. Most subjects will cover a larger area than that. The big improvement here over the original E-TTL algorithm is that the size and location of the primary flash metering area can change dynamically according to the size and location of the subject. In the original E-TTL algorithm, the size, location and weighting of the primary flash metering area was linked to the active focusing point.
C.Fn 14-1 on a Mark II applies the E-TTL II flash metering algorithm equally to all 17 metering segments within the Area AF ellipse, so in comparison to 14-0, 14-1 is not subject-based.

As I've mentioned in previous posts, the setting of the focus mode switch on the lens has no bearing on E-TTL II flash metering, so C.Fn 14-0 and 14-1 are effective whether the lens is set for AF or manual focus.

***

There are two differences between original E-TTL and E-TTL II in this particular comparison:

1. E-TTL II will factor in distance information when it is available during direct flash operation, regardless of the C.Fn 14 or C.Fn 4 setting. Standard E-TTL does not use distance info.

2. When C.Fn 14-1 is active on the Mark II, E-TTL II flashmetering is averaged for all 17 metering segments regardless of the C.Fn 4 setting or the focus mode set on the lens. This gives the photographer more flexibility in setting up the camera according to their personal preferences. Original E-TTL can't average its flashmetering unless specific camera settings are used."

--------------------
Chuck Westfall
Director/Technical Marketing Dept.
Camera Division/Canon U.S.A., Inc.
Scott

[Mark_48]

Yup, I should have included my original inquiry to Canon.....as follows:

Upgraded from 300D DRebel to a Canon 20D. With the DRebel in the Basic
modes I could get consistent exposures with the on camera flash as well
as a 420EX. The 20D with the on camera flash and the 420EX are
consistently underexposed in Basic modes.
Why doesn't flash work with the Basic modes on the 20D and is there a
solution.
I know I can use the Creative modes and compensate with FEC. The point
is that the camera should function by design in its Basic mode as
equally well as it does in the Creative mode, particularly with its own
built in flash.
And I think I will follow up with another email to Canon regarding their misinformation. Has anyone dealt with their telephone support? Is there the typical 15-20 minutes on hold waiting for first available support person?

Thanks Scott, that was the white paper I recall reading. I refound it and printed it out.

[scottbergerphoto]

Canon Support doesn't have a clue about many of the EOS Features. I spent an hour on the phone with them 6 months ago and I wound up teaching them wireless ETTLII.
Scott

[PacAce]

Canon Support doesn't have a clue about many of the EOS Features. I spent an hour on the phone with them 6 months ago and I wound up teaching them wireless ETTLII.
Scott
Unfortunately, that's basically how a lot of the level 1 support people are. They're basically the "answer the phone and see if you can find a quick anwer from the book" types.

If you really want to get your problem resolved or wish to talk to someone who knows what he's talking about, you'd have to have your problem escalated to the next level or two and that in itself can be a challenge sometimes.

But you really can't fault the level one people because they don't alway get the training they should have. (Due to the stressful position of a level 1 person, the turnover rate can be high in some companies so you can see why these companies don't want to have to keep training new people all the time.) Yes, it can be frustrating for the customers to have to deal with them but it's much more nerve wracking for them being in the front line, so to speak, and taking on a barrage of calls, some from irate and abusive customers. Being a level 2 and 3 support person myself and having had to fill in for level 1 people on occasion in the past for about an hour or so, I can tell you that it's no picnic being "out there".

But the bottom line is, that still doesn't excuse them from giving out false information. If they don't know or are not sure, they have the responsibility of escalating the problem to the people who can properly answer the question or address the issue at hand.