20D Underexposed / 420EX Issues

[AXENA]

OK.... I am begging the pros on this forum to offer up some friendly advice. The 20D I used for a wedding over the weekend performed relatively well. However, I did notice some strange occurrences which I am sure can easily be answered by the "regulars" of this forum. If y'all could be so kind to throw in your two-cents, I would humbly appreciate it:

1. 20D seems to underexpose images: At times the exposures are right on the money. At other times, in identical lighting, the images are well underexposed. I checked my EXIF info, and in fact, quite often I was compensating a full stop or more for the underexposure, and still had dark images. Before I go further, yes, I have the crappy "Kit" lense (18-55) on, however, that will be a thing of the past after this weekend (already learned which lenses are good/better to have in the arsenal... but recommendations always welcomed).

2. 420EX was used as primary flash (again, won't be an issue after tomorrow when the 420 will be moved to the slave spot and a 580 will replace it), and it worked fairly well, however, I keep reading over and over that it is supposed to work with the 20D to pre-fire a "test flash" and then "fire". That never happened once. I was able to do it manually with the * button on the camera, however, it didn't do it automatically like the built-in flash (which I didn't use). In the end, some exposures came out great, while others, primarily when used as fill or in dark situations, came out well overexposed or underexposed. Everything was shot manually (I learned on a Pentax k1000) and I am comfortable with manual everything. Is the flash/camera overriding my settings somehow... do I need to shut off a custom function somewhere? Or simply use a different evaluating system (i.e. center weight, etc).

3. With the 18-55 lens..... noticed that the camera would appear to have "focus-locked" on an image and it would look good to me through the viewfinder. However, post-shoot, noticed that about 30% of the images came out "soft-focused" even when the indicators seemed to have locked in where I wanted them to (i.e. subject's eyes, etc)... the area of attention came out soft-focused and a tree well in the background was sharper. Is this simply a problem with the lense and this camera, or have I lost touch with my focusing techniques? I understand the 9-point system will lock onto the closest point, but then why would a background item be more in focus than the subject where it appears to have locked-on-target? Anyone else with this issue?

I know that this camera is awesome.... too many people have raved about it, so I know that at least in some respects, I am not understanding something about it's operations. However, I don't recall having this issue with my film SLR's or my G5 in "manual mode" (don't laugh... it still kicks out great images, just lacks the ability to change lenses and therefore will remain with me until it, or me, dies).

Any help would be greatly appreciated.

Oh yeah... as a post-script... I know there are plenty of EX Speedlight threads out there, but I am looking for one for indoor portrait setups, and wedding setups. Are others out there using Lumiquest 80/20 bouncers or other items? Currently I have the Omni Bounce and the UniBounce (both are not the best image makers). HELP!

I turn it over to the experts out here at this point..... thank you! :-)
-Gary Latimer

[robertwgross]

1. 20D seems to underexpose images: At times the exposures are right on the money. At other times, in identical lighting, the images are well underexposed. I checked my EXIF info, and in fact, quite often I was compensating a full stop or more for the underexposure, and still had dark images. ...

2. 420EX was used as primary flash (again, won't be an issue after tomorrow when the 420 will be moved to the slave spot and a 580 will replace it), and it worked fairly well, however, I keep reading over and over that it is supposed to work with the 20D to pre-fire a "test flash" and then "fire". That never happened once. I was able to do it manually with the * button on the camera, however, it didn't do it automatically like the built-in flash (which I didn't use). In the end, some exposures came out great, while others, primarily when used as fill or in dark situations, came out well overexposed or underexposed. Everything was shot manually (I learned on a Pentax k1000) and I am comfortable with manual everything. Is the flash/camera overriding my settings somehow... do I need to shut off a custom function somewhere? Or simply use a different evaluating system (i.e. center weight, etc).

3. With the 18-55 lens..... noticed that the camera would appear to have "focus-locked" on an image and it would look good to me through the viewfinder. However, post-shoot, noticed that about 30% of the images came out "soft-focused" even when the indicators seemed to have locked in where I wanted them to (i.e. subject's eyes, etc)... the area of attention came out soft-focused and a tree well in the background was sharper. Is this simply a problem with the lense and this camera, or have I lost touch with my focusing techniques? I understand the 9-point system will lock onto the closest point, but then why would a background item be more in focus than the subject where it appears to have locked-on-target?

Flash underexposure is a common problem for some users. Describe your subject and settings better. For example, were you shooting at a white bridal gown at ten feet? Exactly how were you approaching exposure compensation? I have to ask that since exposure compensation does not work in M mode.

Pre-flash can be inhibited in some modes. Describe your settings at the camera and at the flash. Otherwise, sometimes the pre-flash is actually there and you don't see it.

For focus, there are several different things that will cause this. Describe your settings. For example, which autofocus mode? Which autofocus point was selected (or all?).

If background has higher contrast than the subject, and especially if the lighting conditions are tricky, the camera can select something slightly away from the main subject. This problem is improved by using the center point.

---Bob Gross---

[Icecamp]

This site will tell you all you need to know about Canon flash. In each mode the flash will behave differently. The most consistent results will be acheived when using Manual mode.
http://photonotes.org/articles/eos-flash/

[tim]

I'm not a pro, but I have a few thoughts:

1) The 20D exposes for the highlights. Check to see if the darker frames have a light source in them, that's what usually makes my frames too dark. The 20D is known to underexpose rather than overexpose, I did a shoot on the weekend with a model, maybe 50% of them needed to be brightened up, 10% darkened, and the rest were ok. It's much easier to make photos brighter than to fix overxeposure, especially using RAW.

2) You shot on manual? There's no preflash on manual, only on ETTL. The preflash is very fast, if you were on ETTL it probably fired and you didn't notice it - it's very fast.

3) I've noticed that with the 50mm F1.8 lens, but not with the kit lens. Were you focusing on auto or manual? If you're on manual check your diopter. If you're on auto your lens/body might need to be calibrated by Canon. Check it with another lens if possible, it's more likely to be a lens problem than a camera problem IMHO. You should be using the single centre focus point and a tripod when you test this.

4) The 580EX is best, but the most expensive. I'd wonder if the 420EX is powerful enough. The 550EX or Sigma Super whatever is probably a good midrange. If you expect to use a multi-flash setup in the future i'd go with the Canon. I use an Omnibounce or a LightSphere II on my camera, depending on the situation and what i'm trying to do.

[AXENA]

I tried to get the 420EX to pre-fire and in none of the modes was there a pre-flash. I had others as witnesses.... we tried it inside, outside, all sorts of ISO's, shutter speeds, etc. The built in flash does do the stobe-like pre-flash.... just not the external EX Speedlight. And yes, I am only using Canon off-the-shoe cords.... that might be the next question. In anycase... moving up to the 580 series this week... so this may be a non-issue... we'll have to see.

As far as the underexposure goes, I'll attach a photo, and the EXIF info, and maybe someone can give me some advice as to what went wrong. I have to sort through a bunch to find a good example of what I mean, so it will be in the next post in a few minutes....

Thanks for the input!
-Gary

[tim]

Gary - just because you can't see the preflash it doesn't mean it's not happening - it's very quick, seperated from the main flash by milliseconds. If you're in ETTL mode it will be happening.

If you're having problems post a pic or two, or write a thousand words... ;)

[AXENA]

Attached are two images that sort of show what I am describing above. The first (file aaa2.jpg) has EXIF info as follows (according to the meter in the viewfinder, this photo should have been OVEREXPOSED if anything... it was a hazy day, but bright, and the shutter was set +1 over "O":
File Name
IMG_1078.JPG
Camera Model Name
Canon EOS 20D
Shooting Date/Time
5/8/2005 2:14:45 AM
Shooting Mode
Manual
Photo Effect Mode
Off
Tv( Shutter Speed )
1/640
Av( Aperture Value )
5.6
Metering Mode
Evaluative
ISO Speed
100
Lens
18.0 - 55.0mm
Focal Length
55.0mm
Image Size
3504x2336
Image Quality
Fine
Flash
Off
White Balance
Cloudy
AF Mode
Single AF
Parameters
Tone Curve Standard
Sharpness level 0
Color tone Normal
Color Space
sRGB
Noise reduction
Off
File Size
2558KB
Custom Function
C.Fn:00-0
C.Fn:01-0
C.Fn:02-0
C.Fn:03-0
C.Fn:04-0
C.Fn:05-0
C.Fn:06-0
C.Fn:07-1
C.Fn:08-0
C.Fn:09-0
C.Fn:10-0
C.Fn:11-0
C.Fn:12-0
C.Fn:13-0
C.Fn:14-0
C.Fn:15-0
C.Fn:16-0
C.Fn:17-0
Drive Mode
Single-frame shooting

Disregard second shot.... I shot the image by hand at 1/60th... my error.... other photo below is a better example....

ANY HELP IS APPRECIATED.... I never had these issues with the G5 or old film SLR's..... not sure what the issue is here with 20D. Some shots are "right on the money" while others just aren't at all.....

[AXENA]

Gary - just because you can't see the preflash it doesn't mean it's not happening - it's very quick, seperated from the main flash by milliseconds. If you're in ETTL mode it will be happening.

If you're having problems post a pic or two, or write a thousand words... ;)


GOTCHA! OK then... maybe it's happening... I wasn't personally staring into the flash myself, however, I am used to other flashes that give you that "strobelike" preflash... even if it's quick, you know it's happening. If the Speedlights are different, then great... no problem. In general, I like the SPLight, maybe it is just a learning curve with the equipment. I'm trying not to write tons.... even though it seems like I am.... just nervous that the money I poured into the new EOS system could have been used elsewhere (nah..... who am I kidding.... I still would have bought it... I just need to know what it is I am doing wrong with it). I am scouring throughout this message board and have found some good info... just nothing specific yet similar to what I am experiencing. If the problems occured consistently, then I would say "yes... I am definitely messing this up myself." However, since it occurs in similar conditions, in what seems to be a random pattern, I need to question whether it is me, or the 20D. I am sure that someone will read this and say "Nope, it's YOU dude... read the manual." The manual stinks. That's why I am looking for other EOS users that may have had this happen. Or, I really have no idea what I am doing. Whew.... there... done. Pics are posted.

Thanks again!
-Gary L.

[tim]

Can you put the full, unaltered image on a web server and link to them? If you can do that i'll take a look when I get home in a few hours, it's a lot easier there as my software's all set up there.

[AXENA]

sure..... I will put the full photos at http://www.garylatimer.com/eos.htm
Thanks again for putting up with my issues here....
Gary

[tim]

No problem, I often learn something myself when I help people out. Post again when the shot's are up, i'll look at it sometime this evening (NZ time).

[AXENA]

Shots are up..... thanks NZ Tim!

[AXENA]

There are still others that were shot at higher than 1/125 with soft-focus issues, with the rest of the image sharp and the faces not sharp... I don't want to repost/rehash this whole issue, however, the example I posted was bad..... slow shutter speed without tripod. I do have others with much faster shutter speeds and soft-focus on faces.... I will post those to http://www.garylatimer.com/eos.htm

Sorry for the "DUH" mistake.....
Gary

[tim]

btw i'm not going to be looking at the copied and pasted exif, it's more difficult, I wanted the original files so I can look with photoshop. Will get back to you.

[AXENA]

No problem.... will FTP the files on the server.... all EXIF info will be there... same website address with links to actual files.

This is actually a better example of a soft-focus with a faster shutter speed. The AF seems to have locked on the bush behind the subject even though when taking the shot, I could have sworn that the AF locked onto the subject (yes, I know, credibility is shot after the first mistake I posted above, but I was going through 300 photos really quick). The photo is below with the EXIF (for those who don't want to download large files)...
File Name
IMG_1052.JPG
Camera Model Name
Canon EOS 20D
Shooting Date/Time
5/8/2005 2:02:37 AM
Shooting Mode
Manual
Photo Effect Mode
Off
Tv( Shutter Speed )
1/250
Av( Aperture Value )
4.5
Metering Mode
Evaluative
ISO Speed
100
Lens
18.0 - 55.0mm
Focal Length
34.0mm
Image Size
2336x3504
Image Quality
Fine
Flash
Off
White Balance
Cloudy
AF Mode
Single AF
Parameters
Tone Curve Standard
Sharpness level 0
Color tone Normal
Color Space
sRGB
Noise reduction
Off
File Size
3573KB
Custom Function
C.Fn:00-0
C.Fn:01-0
C.Fn:02-0
C.Fn:03-0
C.Fn:04-0
C.Fn:05-0
C.Fn:06-0
C.Fn:07-1
C.Fn:08-0
C.Fn:09-0
C.Fn:10-0
C.Fn:11-0
C.Fn:12-0
C.Fn:13-0
C.Fn:14-0
C.Fn:15-0
C.Fn:16-0
C.Fn:17-0
Drive Mode
Single-frame shooting

[tim]

Link to the first full sized image doesn't work, 2nd link works.

[tim]

That first picture that's underexposed was taken in full manual mode, you chose settings that are too dark. F5.6 and 1/640th at ISO 100 isn't letting much light in.

You might like to read this thread (http://photography-on-the.net/forum/showthread.php?t=56675&page=1), my post at the end of page 2 might help you out.

[AXENA]

Ah.. so you have had the same issue as well. OK... thanks Tim.... will read the links later... off to my real job now, but I do appreciate it. As for the first photo link, my FTP client said that it transferred the photo to my server, but it isn't showing up..... I give up.... I'll try again tonight. Thanks again!
Gary