20D and 580EX - underexposures are the rule

[Confalone]

I find my 20D and the 580EX always underexpose by 1-2 stops when I shoot on the green rectangle. The ONLY solution to get properly exposed shots is to use P and set the Flash Exposure Compensation to 1 -1/2 stops. This gives fine exposures in general. My question is: Is this what others are finding tp be the case? My little DIgital Elph SD10 gives terrific exposures on point and shoot, so why doesn't the green rectangle on the 20D / 580 EX do as well? THX in advance.

[tim]

Can you post a couple of sample pictures? I can think of a couple of things but I want to see the pics first. Please post them resized from the camera but without any levels adjustments, and if you're using photoshop use "save as" rather than "save for web" so that exif information's embedded in the pics.

[Confalone]

OK Here are the examples. THe darker one is a point and shoot with the "Green Rectangle" I get a great exposure with the baby elph SD10 but not with the $ 2500 20D and 580 EX ! The brighter one uses the P setting with a FEC of + 1 1/3. Is the camera working correctly? Is there a better way? THX

[tim]

The first shot in green box with no FEC is correctly exposed, more or less, the one with P with FEC 1 1/3 is massively overexposed. The camera is exposing the foreground correctly (the flowers), which is what it's meant to do, it doesn't worry so much about the background. If you want the background lit up as well you might try a diffuser like the omnibounce, with some light bounced off the roof.

What is it you think it's doing wrong?

[Confalone]

Tim - If you think the darker image is the correct exposure, how would it show up as a print without adjustments in PS. The histogram of this darker image stops about halfway towrd white ! I agree about the overexposure in the lighter one. I guess less FEC would be about correct. I'm mostly interested in your belief that the green rectangle shot is proerly exposed. <aybe I'm not correctly calibrated as the observer. Pat

[tim]

I don't have photoshop here, so I can't look at the histogram, but in the 2nd shot the flower is clearly overexposed. In the first the flowers are well exposed, but the background is dark. What are you actually trying to take a photo of here? It's an artificial scene that doesn't represent real world photos very well. Like I said, the camera assumes the main subject is in the foreground and exposes it well, and doesn't worry about the background so much.

I don't think the shooting mode is relevant here, the FEC setting is more important. I shoot M when i'm using a flash, or Av if I just want fill flash.

What color is that thing in the background in real life, dark brown or light brown?

[Confalone]

I thought the shot would be a challenge since it has the flowers in the foreground and the fireplace in the background [about 7 feet away] The wood is bleached oak, so it's pretty light. I haven't figured out M for flash yet, but I'll give it a try. How does it differ from P? There also is an M setting on the 580 EX. I don't know what that's about! THX for your help. Pat

[tim]

I don't think you can do this shot with direct flash, and have both the flowers and the background exposed well. SLR cameras assume you know what you're doing, and how they work. I'd like to see the shot from the Elph, to see what it does.

Try pointing the 580EX towards the roof, angled forwards a little, and pull out the diffuser panel so it stands straight up - don't let it cover the flash head.

Shooting M is easy - just set it to M mode, whatever F stop you want, and 1/250th of a second. The exposure time determines how bright the backgrond is, nothing else, because the foreground's illuminated by the flash. You have to be a bit careful, if there's some ambient light on the foreground subject and you choose 1/10th of a second, the foreground object can appear blurry, because it's made from light from the flash and from ambient. I don't think i've described that very well, maybe someone else can help out.

[Curtis N]

Maybe this will help (maybe not). The green rectangle uses ALL of the AF points and generally assumes that the closest thing it sees is your subject. So it focused on the flowers in the foreground and metered the flash according to that distance. By switching to a mode that allows you to choose the AF point (such as the center one), the camera would focus on the fireplace and the flash metering system would use that distance in its calculations, correctly exposing the fireplace (but probably overexposing the flowers). A P&S camera with only center AF would do the same thing.

The other element at work here is flash fall-off with distance. It's hard to tell from the photo, but if the fireplace is twice as far from the flash as the flowers, it will receive only 1/4 as much light from the flash (the inverse square rule). Proper flash exposure is very distance-sensitive.

Both of Tim's suggestions were good: Either bounce the flash off the ceiling or use Av mode so the camera will properly expose the background with ambient light.

Hope this helps.

[tim]

Curtis, my understanding is that with ETTL-2 flash exposure is evaluative, not linked to the active focus point. This means it will put out enough power to just avoid blowing the highlights in any part of the picture, in this case, the flower. If you replace the flowers in the foreground with a dark object i'd bet that the whole scene would have a more even exposure.

[Curtis N]

my understanding is that with ETTL-2 flash exposure is evaluative, not linked to the active focus point. That can't possibly be true, because it would blow my whole theory!:lol:

Honestly, I forgot the 20D has a different TTL flash metering system than my DRebel, so I'll shutup and listen now.:o

[tim]

In case you didn't know, flash photography is HARD! Like Bloo said, practice, I think the basics can be taught, but in the end it comes down to experience. I'm starting to get a feel for flash photography, after 3-4 months with my 550EX. I strongly recommend people read this whole thing (http://photonotes.org/articles/eos-flash/), even though it's long, then experiment, then ask questions, then read it again, then experiment, etc.

Alternately, shoot on manual flash, which is something I haven't tried yet, but is on my list for one day when i'm bored.

[blinking8s]

i find mine pretty darn accurate...but it still requires understanding of the flash and what it can do, how to bounce it ect..

[Titus213]

I too am battling with flash exposure, or rather underexposure. I took heart in this thread: http://photography-on-the.net/forum/showthread.php?t=80273

It can be done. I just hope it's not pure happenstance...It must be something that can be repeated..So far I like the LSII but haven't really played with it enough in all the different modes, most noteably M. But that is coming up this weekend.

[tim]

Those are great pics. The scene's good too, reasonably flat, more dark than light, and not too close to the camera. The 550 or 420 should do that in ETTL mode with no FEC, and it'd be even nicer with a lightsphere 2.

[PacAce]

I find my 20D and the 580EX always underexpose by 1-2 stops when I shoot on the green rectangle. The ONLY solution to get properly exposed shots is to use P and set the Flash Exposure Compensation to 1 -1/2 stops. This gives fine exposures in general. My question is: Is this what others are finding tp be the case? My little DIgital Elph SD10 gives terrific exposures on point and shoot, so why doesn't the green rectangle on the 20D / 580 EX do as well? THX in advance.
Try taking the picture again but this time, try not to get the flash light bouncing off the glass of the china cabinet. I'm sure if you took the same shot with your SD10, it would come out even darker. Of course, you can prove me wrong by posting a sample of a shot from the SD10 (of the same china cabinet and flowers) here, too. ;)

[J Rabin]

Well, good advice so far. Here's more to ponder. When I remember to do this, keeping camera in M (80% of time for flash) or Av (20%), flash exposures with Canon E-TTL II are best in my life. Don't shoot P with Canon flash photography. Old photojournalist taught me:

"Use shutter speed and/or ISO to properly expose the background and use f/stop and flash to expose the foreground."

First, get your camera out of P, where you are in control of nothing. Second, take that same scene and get a single focus point over foreground flowers. Then progressively modify shutter speed. Then progressively modify ISO. What you will find is that flash output stays the same(!) on foreground flower subject, as it should, while background at higher ISO or slower shutter will hit a setting where it is properly exposed. After a while, you get to geshtalt a scene with camera in M before the shot.
There is a famous series of tests to prove this works. I think they were called the Teddy Bear Tests at Nikon's site.

I do this all the time at work, taking pictures of people (foreground) giving public presentations with a LCD PowerPoint projector (background). I meter and hold flash off camera.

Lastly, P or Av will give different background exposure depending on how much ambient light a Canon camera meters before the shot. High moderate ambient light (above about 10EV) results in auto fill-flash reduction. Canon's engineers DESIGNED their flash system to reduce background exposure, because I suppose they feel many people like that look.
Another reason to put camera in M when doing flash.

Canon does not document it's flash features well, thus there is a big learning curve. Read Scott Bergers "sticky" at the top of this flash forum. Read Photonotes.org. and read Frary's web site on canon auto fill flash.

Hope that helps. J.

[OceanRider]

I am also very frustrated/confused with my 580EX and my 20D together. Its either over or under exposed every time either on Av P. I was mistaken to think that just marring the two would produce as good as pics as my older P&S S50, no way. My S-50 made perfects shot everytime..this new combo is brutal. Every shot needs to be FEC'd in some way. I unerstand that each pic is really two exposures when using flash (the abminent background and the flashed forground.) Adjusting our exposures and FEC to change each, but I thought this 20D combo would do a much better job.

Oh well.

[OceanRider]

this article was a GREAT help understand flash exposure. Amust read for the beginner. Pics included!




Here is a link I ran across that explains the use of fill-flash really well........easily understood and gives example pics which are worth a 1000 words!!

http://www.popphoto.com/assets/down...21200311318.pdf

oh yeah.......it's in PDF format so you need the Adobe reader installed on your computer.......

[Confalone]

OK - here are the two shots. The darker one is the $ 2500 D20 580 EX and the lighter one is the $ 300 SD10.

[tim]

Interesting. The shot from the baby camera is more even, but I think the shot from the real camera is better exposed. You might like to rotate pictures before you post them, it's annoying to look at them like that.

Have you tried my suggestion of using bounce flash with the catchlight up?

[Curtis N]

Which are you trying to expose correctly, the flowers or the fireplace? With direct flash at that distance, you're not going to get both. The SD10 overexposed the flowers - the white petals are completely blown. The 20D underexposed the fireplace.

[J Rabin]

Confalone.
You're posting again. Did you read my post on previous page? You do not understand the SLR E-TTL II flash system and the relationship between shutter speed/ISO for background and f stop/flash exposure for foreground. There's nothing wrong with your camera; it's not a point and shoot.
J

[PacAce]

OK - here are the two shots. The darker one is the $ 2500 D20 580 EX and the lighter one is the $ 300 SD10.
If you were to ask me, I'd say that the 20D is exposing the picture just right and teh SD10 is over exposing the picture. I much prefer the 20D shot, but that's me. Maybe that's the reason I've never had any complaints about any of my flash pictures. I think they're spot one, personally. :)

Now, tell me, truthfully, is your living room (or whereever that shot was taken) really that bright as depicted by the SD10 shot? (If it were, then you wouldn't really have had the need to use the flash, I don't think. ;) )

[Confalone]

OK - I want to thank all of you for your helpful comments. I am concluding that my 20D is operating as Canon intended. I would have liked an idiot-proof point and shoot option [green rectangle] that gave acceptable flash pix. I now know that getting the correct exposures with flash is very difficult. The suggestions and links you have posted are a great help. THere are a lot of us out there that have found the 20D 580EX disappointing in this regard. I hope that I can learn to use the camera in P, M Av etc mode and get spot on exposures. All of my shots have been greatly improved by image processing in PS. I just didn't want to have to do this to all my picture, especially when I've taken a lot. The green rectangle should do better for routine, view once pictures. I'm not sending the camera back to Canon for evaluation. I have much to learn. I hope others will find this thread valuable. Pat Confalone

[tim]

Pat, I really think you should go back and read this entire thread again, and take note of the suggestions people made, and their explainations of why it's working as it is. Also, the link from the sticky thread that I linked to is also invaluable. By your last post it just doesn't sound to me like you've learned anything from this thread, which is a shame, because there's lots of good info here.

[Todd Jacobsen]

I thought the shot would be a challenge since it has the flowers in the foreground and the fireplace in the background [about 7 feet away] The wood is bleached oak, so it's pretty light. I haven't figured out M for flash yet, but I'll give it a try. How does it differ from P? There also is an M setting on the 580 EX. I don't know what that's about! THX for your help. Pat

Try the same shot, but utilize AV mode.

Utilizing Auto or P (without FEC), will, to the most part, only care about the foreground. The background will not be exposed to the appropriate shutter speed required. Particularly when utilizing P, if the background is dark, the shutter duration is probably at the minimum (1/60) for P mode. By evaluating the histogram, you'll know to switch over to Av to take the same shot.

Utilizing Av, the background will be correctly metered and your shutter speed will adjust accordingly. You may realize that you will need a tripod to keep the camera shake to a minimum *due to a slow shutter speed).

It's an easy test. Try the shot again in P and then Av and note the shutter speed difference when you utilize the same apeture in Av as the camera set in P. Also note if there is any change in the picture, you should see a difference - particularly in the background. You shouldn't see a difference with the foreground (flowers).

Now, if your subject isn't as willing (or static) as the flowers (like kids), you will probably want to use Tv instead of Av in order to inhibit subject (foreground) blur. Same game applies (except a mistake in P with moving subject can lose the "moment").

[Confalone]

wow - the same shot is Av had a 4 sec shutter. Thanks to IS it wasn't too bad hand held. THe exposure was bright and not overdone, but I would have to use a tripod on this shot.

[ska60te]

I usually shoot iso 200 125/sec. f5.6,f8.0 (manual mode!!!!) +2FEC try that as a "baseline" and tweak from there

[Todd Jacobsen]

I usually shoot iso 200 125/sec. f5.6,f8.0 (manual mode!!!!) +2FEC try that as a "baseline" and tweak from there

Good point, indoor shoots can (some people would use the word should) be set at iso400.

[steve547]

I just got my 20d last week and there's no question that all flash pictures are way under exposed and have to be edited. But has anyone tried the old fashion way of using the GUIDE NUMBER that alway works on film cameras. But you need a flash that can go to full manual and put out maximum for that. I think only the most expensive canon speedlites do that, mine dont. I'm still trying Av settings, and I'll try overexposing the flash next. I also think the default white balance is set wrong for flash, but that's another story. If we all keep trying, maybe we'll figure it out.

[tim]

I just got my 20d last week and there's no question that all flash pictures are way under exposed and have to be edited. But has anyone tried the old fashion way of using the GUIDE NUMBER that alway works on film cameras. But you need a flash that can go to full manual and put out maximum for that. I think only the most expensive canon speedlites do that, mine dont. I'm still trying Av settings, and I'll try overexposing the flash next. I also think the default white balance is set wrong for flash, but that's another story. If we all keep trying, maybe we'll figure it out.

Most of these issues come down to inexperience with ETTL flashes. Have a read around and see if you can learn something, and pay special attention to using FEC for light colored scenes. Film has a lot more exposure tolerance than digital, so I guess that unless you're good and fast at your sums, ETTL will do better, so long as you understand it. I can get reasonably consistent exposures with ETTL now, after some practice.

[Confalone]

Agrrh ! I think my 20D is going back to Canon. I bought the Canon SD500 Elph for my daughter and I took the same shot with each camera on full auto. The dark one if with the 20D [ $ 2,500 ] the better shot is with the SD500 [ $ 490 ]. This can't be right.

[tim]

The printer on the left is in the foreground, do it again without that. Remember how we said the flash exposes for the foreground? That's the key here. Also, ETTL exposure isn't linked to the active focus point. The reflection off the fireplace might also be making a difference, but the print is a more likely solution.

Again, i'm going to suggest you re-read this thread, because you don't seem to have taken in the information so far. I'm not having a go at you, just making a suggestion to help you learn :)

[tim]

I have read that calibration (or replacement) helps in some cases, but I still think the problem here is more likely to be technique than the equipment. I'd like to see the photo from the 20D taken again and posted, with the suggestion I made above - ie make sure the printer isn't in the frame.

[steve547]

Tim, I think your not getting the point. You shouldn't have to worry about what's in the foreground before you take a picture. The ETTL system isn't worth losing the spontaniety of the shot. But I wouldn't send the camera back for that since I can correct the under exposure quickly by adjusting the level control in my editing program. I would try increasing the exposure control or even putting the flash on manual and using the guide number method. Pictures taken out door seem to be OK.

[tim]

Tim, I think your not getting the point. You shouldn't have to worry about what's in the foreground before you take a picture. The ETTL system isn't worth losing the spontaniety of the shot. But I wouldn't send the camera back for that since I can correct the under exposure quickly by adjusting the level control in my editing program. I would try increasing the exposure control or even putting the flash on manual and using the guide number method. Pictures taken out door seem to be OK.

I understand that some people want to treat a DSLR with external flash as a point and shoot, but that's not what they're for. They're tools that assume a reasonable amount of knowledge and experience from the user. If you don't want to bother with that use a point and shoot. I think I have the point just fine.

[steve547]

I understand that some people want to treat a DSLR with external flash as a point and shoot, but that's not what they're for. They're tools that assume a reasonable amount of knowledge and experience from the user. If you don't want to bother with that use a point and shoot. I think I have the point just fine.


All I'm saying Tim is that some people want to use a DSLR for the many advantages it has over point and shoot cameras. This under exposure problem can be managed easily without having to become an expert on the ETTL system. Which may not be the best thing Canon ever invented.

[tim]

All I'm saying Tim is that some people want to use a DSLR for the many advantages it has over point and shoot cameras. This under exposure problem can be managed easily without having to become an expert on the ETTL system. Which may not be the best thing Canon ever invented.

I agree that some people might want a "dummy mode" on a DSLR, but I (politely) disagree that's what should be provided. DSLRs are about giving power and control to the user, but that comes with a burden of knowledge. I don't want my camera making all the decisions for me, I want to have control. For example, maybe I want to expose the foreground and leave the background dark - that's my decision. If not I use Av mode with the flash as a fill.

Every problem on this thread so far can be worked around if the user knows that ETTL exposes the foreground with the flash. If you want the background exposed as well the solutions are:
- Shoot in Av mode, the longer shutter speed will exposure the background, but will be harder to hand hold.
- Bounce the flash (might work, might not).
- Use directed light or a 2nd flash.

If people don't want to understand and explore the options, then a high end point and shoot is probably a better, cheaper choice.

[steve547]

I don't want my camera making all the decisions for me, I want to have control. For example, maybe I want to expose the foreground and leave the background dark - that's my decision.

I agree with you in principle. The problem is that I want to have the control of exposing the background with my flash without having the camera force me to expose only the foreground. I might want to crop out the foreground and just use the background. I think Canon should have given us the option of firing the speedlite at maximum force and pemit us the option of choosing the proper f stop to expose the part of the scene we think is important. I think some of the speedlite models can do that, unfortunately my 220ex cant. I don't like automatic exposure, Tim. I prefer a spot meter for outdoors and a manual flash for indoors, but I still like the other aspects of using an SLR.

[tim]

My 550EX and the 580EX can be used in manual mode, that might suit you better.

[steve547]

Thanks for the info Tim.

[drisley]

I had a S30 and G3, and I can say that there was a definate improvement in flash performance going to the 300D.
Now, with the 20D, the flash improvement with ETTL-II is even BETTER.
Sure the pictures were brighter with the S30 and G3, which seems to look more pleasing to some, but at the same time they would blow the highlights, much like Confalone's second picture above.
This is technically incorrect, as you can not recover lost highlights, but you can recover detail in the shadows (although at the expense of some noise).

And Tim is correct, the 20D uses ETTL-II which is evaluative, and does not rely on the autofocus points. This is a TREMENDOUS improvement (for me atleast) over ETTL which the older cameras like the 300D use.

[PacAce]

Agrrh ! I think my 20D is going back to Canon. I bought the Canon SD500 Elph for my daughter and I took the same shot with each camera on full auto. The dark one if with the 20D [ $ 2,500 ] the better shot is with the SD500 [ $ 490 ]. This can't be right.
Before you send the camera back, you might want to check your C.Fn-14 setting and make sure it's not on 1 (Average).

[tim]

From the EOS Bible.


Normally E-TTL II uses evaluative algorithms for its flash metering, but the EOS 1D mark II has a new custom function (CF 14-1) that lets you use centre-weighted averaging rather than evaluative metering for flash metering if you prefer.


Sounds like averaging would be better for people who want a point-and-shoot style flash to me, but i've not played with it at all.

[Confalone]

C.Fn-14 is set on 0 [all the Fns are set to 0]. I believe the Canon 20D does have a point and shoot mode - the green rectangle and P. I've learned from this thread how to get better flash exposures using Tv Av and M and/or post processing. However, I don't always want or have the time to run the photos thru PS or deal with multiple settings while I take the pictures, hence the Point & Shoot option is desireable in these cases. I shot random pix at CompUsa tongiht using a number of cameras, including the Nikon D50/D70 and a host of others. I found they all gave great exposures in fully auto mode. Why shouldn't my 20D with all its fire power? Does anyone out there get reliable exposures with the 20D on auto or P without using FEC of + 1-2 ??

[tim]

C.Fn-14 is set on 0 [all the Fns are set to 0]. I believe the Canon 20D does have a point and shoot mode - the green rectangle and P. I've learned from this thread how to get better flash exposures using Tv Av and M and/or post processing. However, I don't always want or have the time to run the photos thru PS or deal with multiple settings while I take the pictures, hence the Point & Shoot option is desireable in these cases. I shot random pix at CompUsa tongiht using a number of cameras, including the Nikon D50/D70 and a host of others. I found they all gave great exposures in fully auto mode. Why shouldn't my 20D with all its fire power? Does anyone out there get reliable exposures with the 20D on auto or P without using FEC of + 1-2 ??

Both of the photos you've taken with the 20D and post so far have an object in the foreground. Have you compared a Nikon or other good brand in those circumstances? I doubt you could in a store. Like i've already said, reshoot that last shot you did with the 20D but make sure you don't put the printer in the bottom left of the screen, or have anything else much closer than the background. The photos above isn't a fair comparison because of the way you framed it.

Maybe I should do a few shots at home myself to demonstrate.

[jrsforums]

With CF14=0, ETTL-II will be "subject based" and can use anywhere from 1 to x metering segments depending on the camera's analysis of the pre-flash information.

With CF14=1, the E-TTL II flash metering algorithm equally (a.k.a. "averaged")to all flash metering segments....

See Westfall's post at: http://photography-on-the.net/forum/showthread.php?t=46311

The "averaged" approach is probably what you are looking for to approach P&S flash "performance".

John

[drisley]

That sounds right to me jrsforums.

[Wazza]

And do you have an example without the white, just to see how much it increases exposure?

[tim]

I've deleted my previous post, after a little more thinking, Wazza was replying to my now deleted post.

Look at the differences in these images between having a white plastic bag in the frame, and not. The flash is exposing for the foreground, as expected. It's not a perfectly fair test, as I also recomposed, but I don't think it's to significant - if anyone else wants to give it a go, that'd be interesting.

The evaluative/averaging made very little difference, as did the bounce flash. Let's let the pictures speak for themselves.

http://mrwild.co.nz/unprotected/potn/550ex-20d-test2.jpg

[Wazza]

Yeah ok.

:p

[drisley]

Tim, I think you are right.
If this last scene had been any brighter, the white bag would have been lost in overexposure.
And, in that last picture by Confalone, not only is the white printer in the way, there is a huge glare coming off the fireplace in the 20D shot, and not in the p&s shot, probably due to a small change in angle of the camera. That glare alone would throw any metering system out of whack.

[Confalone]

OK - I"ve retaken the shot with the 20D on full auto [green rectangle] WITHOUT either the printer in the foreground or the strong reflection on the right side of the wall. I've included the previous shot taken by the sd500 elph point and shoot. Your comments, please...

[drisley]

That looks better.
You can see the brightest item, the white painting on the wall, is the same on both.
The rest of the image is slightly darker probably because it was taken at night and the p&s was taken during the day (judging by the windows).
Personally, if I knew somebody who was only going to be shooting in the auto modes, I would probably not recommend an SLR, but rather a p&s digicam.

[steve547]

They both look good, but both have to be edited before you can print them. So no advantage for the sd500 (except that it can fit in your shirt pocket and the 20d can barely fit through the front door). The 20d will give you better results when you edit both though.

[tim]

The pic on the left looks much nicer to me - better contrast and saturation - I presume that's the one done with the 20D. One thing I notice is that the angle between the fireplace and the chair looks different with each camera - I presume because of perspective, the place the photo was taken from, or the lens used.

I hope this thread has been helpful Confalone :)

[Lotto]

I found my 20D is hypersensitive to metal or glass reflection. I had a chance to shoot some 'female stage dancers', half my flash photos were badly exposed, all of them have that brass bar in the middle.

This test shot is for tim, I like his wood panel:lol:

[tim]

I found my 20D is hypersensitive to metal or glass reflection. I had a chance to shoot some 'female stage dancers', half my flash photos were badly exposed, all of them have that brass bar in the middle.

This test shot is for tim, I like his wood panel:lol:

That wood panel's off my Mums wall, my girlfriend got it to do jigsaws on!

ETTL-II is meant to know when one sector of the photo is over-bright, and weight it down accordingly. Apparently it doesn't so well, I find it always exposes the brightest/whitest thing well, and leaves everything else dark. I guess times like that you need to switch to manual flash - which I think requires a fair bit more knowledge - which I personally don't posess.... yet!

[tweatherred]

This has been an interesting thread. Like Confalone, when I recently switched from p&s to my 20D the flash exposure was not always what I expected/ was trying for. This is more true with the built-in flash than the 580EX. One factor that has not been mentioned above is that the camera is very quick and the flash will fire at reduced power even if it has not had time to fully cycle; waiting a little between shots might help in some instances. More importantly, experimenting and reading will allow you to take full advantage of the 20Ds capabilities. Based on your pics I think things are working as they should, and trying some different techniques (especially bouncing and or diffusers) may get you the results you want. Don't get to hung up on using the point and shoot modes; part of the power of a camera like the 20D is that you can tweak the settings to get just what you want for a given set of conditions, then leave the camera set that way for p&s simplicity.

I think the teddy bear test mentioned above is here:
http://www.nikonians.org/html/resources/guides/teddy/teddy-bear-1.html

[chillpons]

The pic on the left looks much nicer to me - better contrast and saturation - I presume that's the one done with the 20D. One thing I notice is that the angle between the fireplace and the chair looks different with each camera - I presume because of perspective, the place the photo was taken from, or the lens used.

I hope this thread has been helpful Confalone :)


Tim yours and many others posting here were useful to me. I took a print of all your suggestions and tested my new flash(Sigma EF500 DG Super) with EOS300D at home with different Shutter and ISO speeds in Av mode. I believe this was Curits' suggestion. I was amazed to see the foreground's exposure remains same and the background's exposure varied everytime i changed the shutter speed, Aperture and so on..

I may not have done or followed the instructions exactly as they meant but i did realise and am happy that i am bit more familiar with flash photography.

Thanks a lot confalone for posting this thread it sure did help me :).

[Confalone]

I found the info in this thread to be very informative - thanks to all who contributed. I eventualy did send the 20D to Canon and they "adjusted exposure". It's amazing - it's like a different camera. I now believe that my 20D needed this fix. I can hit ON THE BUTTON exposures every time. Amazing.

[steve547]

I found the info in this thread to be very informative - thanks to all who contributed. I eventualy did send the 20D to Canon and they "adjusted exposure".

How did they adjust the exposure. Is it something we can do without sending it to Canon like increasing the exposure settings or is it factory adjusted (with all your exposure/sharpness setting still in the default position)?

[Ronald S. Jr.]

OK Here are the examples. THe darker one is a point and shoot with the "Green Rectangle" I get a great exposure with the baby elph SD10 but not with the $ 2500 20D and 580 EX ! The brighter one uses the P setting with a FEC of + 1 1/3. Is the camera working correctly? Is there a better way? THX

I'm not sure what part of the world you're from, but where I'm from, a 20D body and a 580EX flash together aren't more than 1700 or so. Maybe I'm just weird. :D

[drisley]

That's about right.
I think the 20D and 580EX retail for about $2500 here.

[dwterry]

Okay, I admit to not having read the entire thread... but a real quick skimming of the messages posted I think might have missed this very significant point.

In the pictures done by the 20D where the images are dark, the flash itself is being REFLECTED back to the camera by a surface within the picture (shiny walls, mirror, etc).

E-TTL will always underexpose an image in which the flash is reflected back at the camera.

There is one picture where you showed the 20D version as being dark, but the P&S version being lighter... did you notice there was no flash reflection in the P&S version? That means you took the P&S version at a different angle. Fixing the angle in the same manner and reshooting with the 20D would have solved the problem nicely.

E-TTL is smart. But it can be easily fooled by objects in the foreground (already mentioned) or highly reflective objects within the frame.

I love my 20D. :-)

[Confalone]

1. The $ 2500 included the LENS and the 580EX
2. When Canon returned the 20D they said they "adjusted the exposure, adjusted the focus, and installed the latest firmware version 2.02". The camrea performs MUCH better after Canon worked on it.

My conclusion is that my particular 20D needed recalibration. This is no way invalidates any of the great advice and learnings given in this very informative thread. Pat Confalone

[drisley]

That's good news Pat.
Luckily you got Canon to look at it.
I wonder how many people out there have "miscalibrated" cameras and don't know about it?

My 20D has been awesome, other than the crappy BG-E2 grip. And it is almost 1 year old to the day!

[dwterry]

My 20D has been awesome, other than the crappy BG-E2 grip.

Just curious... what don't you like about the grip? (I ask because I've been thinking of getting one)

[drisley]

Well, the grip is great, except the 20D grip has quite a few issues.
First is the well-known "flex/power loss" issue. The 20D grip doesn't fit snugly onto the camera like the grips for Canon's other cameras and often when you have an external flash mounted, or heavy lens, the grip will pull away far enough from the camera to cause a brief power interruption.
I sent back 4 grips because of this, and each new one did the same. I know of many others in the same boat. Also, there is the well-known "battery indicator" issues, and AA battery problems. These last two canon is supposed to have fixed in the latest batch, but many are still reporting the same problems. Do a search in this forum or on google and you will find thousands of complaints about the 20D grip.

[geokuf]

I found this thread very informative. Thank you guys for sharing your knowledge.

[fstop11.net]

What 20D users tend to forget is how easy it is to spin the dial that effects exposure bracketing. make sure you have it set central.

[tim]

What 20D users tend to forget is how easy it is to spin the dial that effects exposure bracketing. make sure you have it set central.

Exposure bracketing is controlled from within a menu. You're referring to exposure compensation, which is controlled by the thumb wheel when the camera is in "photo taking" mode. You do have to be careful to set the EC how you want it, you get used to it after a while, the display in the viewfinder helps.

You should also know that exposure compensation isn't as important as flash exposure compensation when you're using a flash. EC controls the background exposure, FEC controls the main subject exposure. I tend to leave the EC at 0 when i'm using a flash, or more often I shoot in M where EC is ignored.

[myself62]

i would have thought that if your subject is exposed well but your back ground is to dark you would need to adjust your shutter speed down.
example, if you are shooting in TV priority and its set to say 200, dropping it to 125 or lower will give you a longer exposure for your background brightening it up while the flash keeps main subject lit properly.
am i wrong???

ive had the same problem, thought about it but havent tested it.

[René Damkot]

You're right. That's exactely what Tim is saying ;)

[myself62]

tim was saying to shoot in AV priority, would that give the same result? i thought it would be easier to adjust your exposure in TV priority

[René Damkot]

In both cases you adjust your exposure by dialing in an Exposure Compensation. Changing Aperture in Av or shuttertime in Tv, will only mean the camera adjusts time or aperture accordingly.... Exposure of the ambient stays the same then. (Off course, when ambient is low, changing shuttertime in Tv from, say 1/200 to 1/20 will have an effect, just as changing from f/22 to f/2 will ;) It's all within limits)
Frankly, I never use Tv, I even disabled it on my 1D2 :p

[tim]

You can achieve the same thing in any mode if you understand what's going on. I used Tv once, don't see any point, I use Av and adjust things until they're how I like. It's all about the shutter speed/aperture/ISO, exposure modes just make life easier.

[steve547]

I'm learning the hard way that there's no good way of second guessing what the ETTL will do. So my next plan is to use the 20d on Manual and setting the shutter to 1/250 to force the ETTl to use the flash as the main light source(to avoid blurring and fix the color balance to flash), and setting the f stop high enough to get a good depth of field. And hoping the flash is strong enough for that f stop setting. I noticed that the ETTL always uses the widest f stop, the slowest shutter speed and prefers to cut down the flash duration. I tried taking a family picture at 1/250 TV and was surprised to see the ETTL use an f stop of 4 (my widest) and only 2 of the 5 people in my photo were in focus at that depth of field. My next attempt at a family photo will be on Manual with f 11 and 1/250. I hope that will put everyone in focus. What do you guys think?

[myself62]

ok guys, i tried AV priority but my aperature opened much to long, i tried differant f stops but still my aperature was open to long. (low ambient light in room)
i went back to TV priority, dialed in 200, back ground was a little to dark. dialed in 60 and the back ground came out well lit.
i just cant see how AV priority would work as far as giving you the right background lighting if the ambient light is very low. how do you who shoot in AV priority overcome that?
maybe ive missed something in these threads.

[René Damkot]

Use high iso, open up the aperture, and try to freeze the subject with the flash. (This usually works when the ambient light is mostly on the background, not the subject)
Good explanation here (http://www.dg28.com/example.1.html)
Example: http://www.atak.nl/inc/img.inc.php?pic=plaatjes/actpics/051013bg_%20kowalski_voorn/rhd20051013BGKV087.jpg&s=fotos:%20Ren%E9%20Damkot

[Jon]

ok guys, i tried AV priority but my aperature opened much to long, i tried differant f stops but still my aperature was open to long. (low ambient light in room)
i went back to TV priority, dialed in 200, back ground was a little to dark. dialed in 60 and the back ground came out well lit.
i just cant see how AV priority would work as far as giving you the right background lighting if the ambient light is very low. how do you who shoot in AV priority overcome that?
maybe ive missed something in these threads.
Remember, the camera meters for available light, always. The flash metering is separate. If you're in Av mode, the camera will try to set an exposure (which may be long) for the ambient light. If you don't want this, there's a custom function which allows you to "force" shutter speed in Av with flash to the sync speed. When the flash is off or not ready it reverts to normal operation. Of course, the 300D doesn't support this (with the hack? Anyone?)

[burchy]

I’ve recently been taking portraits of my 9 month year old daughter using an EOS 300D + 28-80mm ultrasonic zoom with 550ex. I’ve been getting mixed results with the exposure so I’ve been shooting in RAW in order to mitigate any under exposure. Incidentally in processing the RAW images I’ve had to add approx 2 stops. The under exposure isn’t just the background, it’s the main subject as well. I’ve mainly been using the Av mode with the camera set to a fixed 1/200th second shutter, with the aperture wide open and the focal point fixed to the centre spot. The reason for this was the little madam moves about far too much and a fairly high shutter seems necessary.

The focal length has been set to between 60-80mm, so on the 300D that gives me 100 – 130mm ish.

It suddenly dawned on me because I’m using a 550ex that the zoom head in the flash isn’t compensating enough for the x1.6 multiplication factor of the camera, so I’ve upped the FEC on the 300D by 2/3rds. This seems to have made a vast improvement to the exposures. Has anybody else had similar experiences? Does anybody think this could really be the problem or if I’ve just masked an inadequacy in my photography? I’m suspecting the later is the case as ETTL should cover the fact the head isn’t zooming enough shouldn’t it?

[tim]

It suddenly dawned on me because I’m using a 550ex that the zoom head in the flash isn’t compensating enough for the x1.6 multiplication factor of the camera, so I’ve upped the FEC on the 300D by 2/3rds. This seems to have made a vast improvement to the exposures. Has anybody else had similar experiences? Does anybody think this could really be the problem or if I’ve just masked an inadequacy in my photography? I’m suspecting the later is the case as ETTL should cover the fact the head isn’t zooming enough shouldn’t it?

The 1.6X multipication factor is irrelevant, a red herring. You'll find that you're using a white or light colored background, or there's something reflective in the photo. Please post an unaltered JPG conversion at 800px wide for us to take a look at.

[burchy]

I thought it might be a red herring Tim. There definitely isn't a white or reflective background in the shots I’m talking about. I will post a couple of examples when I get home (at work at the moment) of the straight JPEG conversion and the post processed image.

[Wilt]

Burchy, Your finding of need for FEC when flash is main source of light is not unusual at all...after all, we ARE talking about Canon ETTL here! ETTL notorious for underexposure, ETTL-II not much better for that. You will find that many users, including pros, shoot routinely camera in Manual and with FEC +1 1/3 and don't blink an eye "That's the way it is!".
Canon engineering terrific fill flash, but their main light flash sucks rotten eggs.

[burchy]

Okay the first image is the JPEG, extracted directly from the RAW:

http://img231.imageshack.us/img231/7153/crw2026rj2se.jpg

This is the image after a bit of post processing in PS:

http://img231.imageshack.us/img231/7063/crw20263an.jpg


The image was shot as follows:
300D, ISO 100, 80mm Focal length (128mm x 1.6), Av mode, 1/200 second, f5.6, auto white balance with external 550ex speedlite set in automatic ETTL. NO FEC compensation.

Incidentally I didn't spend much time on the 2nd image, I just increased the expsoure in PS by +1.8.

I didn't have a comparable example of FEC set to +2/3 but trust me when I tell you they come out much more like the second image. When I get some time over the weekend I'll post two consecutive shots one normal, one with FEC +2/3.

[burchy]

I suspected that might be the case Wilt. In the short experience I've gained with ETTL using the 550EX it does seem to struggle when the flash is the main light source. I've no worries compensating with FEC, in fact I've had some great results setting the flash to manual and controlling it that way. I originally posted as a sanity check really, I think you've helped to confirm that ETTL isn't perfect and a degree of compensation is to be expected.

[tim]

Burchy, that scene is very white, so I would expect you'd need to use positive FEC for that picture - at least +1, maybe more. Have you read this whole thread? It explains why.

[burchy]

Yes I've read the thread throughout and all the information on photonotes. This is a general problem I have when taking shots of this nature, regardless of white or not. The only successful "untweaked" flash shots I've ever managed are fill-in outdoors or indoor photo's where the focal point is in the distance. Anything else is badly underexposed and needs between 2/3 to a stop of positive FEC, regardless of what the camera mode is set to. It sounds like from Wilts comments this is not an unusual experience with ETTL users and in fact I'm getting more used to just setting the FEC every time I use the flash. I think it's just something you have to accept and get used to, not really a massive problem. Thanks for the clarification guys.

[tim]

Practice makes perfect :) Flash photography is hard, unfortunately. My 20D/580 works fine, it's only very light scenes (wedding dresses) or very dark scenes (tux) that makes me alter the FEC.

[burchy]

Agreed Tim, flash photography is hard and it's made even harder when you're getting used to a new system, lol! Once again thanks for the clarification, every now and then you need a sanity check.

[Curtis N]

there's a custom function which allows you to "force" shutter speed in Av with flash to the sync speed. When the flash is off or not ready it reverts to normal operation. Of course, the 300D doesn't support this (with the hack? Anyone?)The 300D has a custom function for this, too. It's called "Manual mode with shutter speed set at 1/200."

[tim]

Once again thanks for the clarification, every now and then you need a sanity check.

I'm sorry sir, but you are clearly

http://cb.nowan.net/artwork/insane.jpg


:p ;)

[burchy]

Yes I was afraid of that as well Tim. In response to Jon's post and more recently Curtis, I've got the alternative hacked firmware on my 300D that allows certain custom functions. One of which is forced 1/200 shutter speed in Av mode. Is this what Jon was referring to?

[Jon]

Yes I was afraid of that as well Tim. In response to Jon's post and more recently Curtis, I've got the alternative hacked firmware on my 300D that allows certain custom functions. One of which is forced 1/200 shutter speed in Av mode. Is this what Jon was referring to?
Yep.

[burchy]

Well it works for me! It doesn't give you all the custom functions that the EOS10D/20D provide, but the key stuff is: Forced max flash synch speed in Av mode, FEC control from the camera, Auto Focus mode control, shortcut buttons to alter shooting quality (JPEG formats & RAW) and some other stuff I can't remember. It's worthwhile mentioning in this thread for the FEC control & max synch speed alone. May help 300D owners struggling a bit with ETTL like myself.

[canon shooter]

OK - here are the two shots. The darker one is the $ 2500 D20 580 EX and the lighter one is the $ 300 SD10.Actually I think I like the 20D shot better.

Maybe you could try flash bracketing by 1/3 each

[canon shooter]

OK - here are the two shots. The darker one is the $ 2500 D20 580 EX and the lighter one is the $ 300 SD10.I actually like the 20D shot better.

You might try flash bracketing with 1/3 increase on each shot.