22 total posts
You're not telling us enough.
Is the flash firing? How do you know?
Where is the flash head aimed?
Are the batteries fully charged?
Is the ready light on when you shoot?
Is the diffuser and/or reflection card deployed?
What aperture and shutter speed is being selected?
Are you using any flash compensation? Exposure compensation?
What mode is the flash in, and what output has been selected? (Those are controlled on the flash)
What are you focusing on?
What does the background look like?
thanks for any help
Yes the flash is firing, I can see it. The flash head is aimed at the subjects, Yes the batteries are fully charged and the ready light is on. I'm not sure what the diffuser or reflection card is. I have a catchlight panel and the wide panel. If that is what you mean, no I do not use them.I am shooting on the P so it choses a shutter speed of 60 and the aperture is 4.0 tp 5.6. I did not use the flash compensation this time. The flash mode is on ETTL Zoom 35mm and then auto zoom for image size. I am focusing on 3 to 4 people sitting at tables and then couples dancing. back ground us usually dark. Boy if you could help I would be forever grateful.
You say that there are several people in the picture. How are you focusing? Is there anything in the pictures that is exposed properly? If so, the auto exposure may be based on the wrong part of the picture. Make sure that the key part of the picture is a focus point.
An ISO of 100 - 400 will normally work fine. Use the higher ISO if you want a deeper depth of field and a lower ISO to get a shallower depth of field.
ISO does not affect depth of field. Aperture does. A higher
ISO merely 'turns up' the light amplifier. This should not be necessary with a flash in use. A higher ISO allows a faster shutter speed to be used.
However, the focal point is an interesting idea. Are the people being photographed dark skinned and/or dressed in dark clothing? It is tougher to get a good exposure on, for example, African Americans. Also, are their surroundings, background, tablecloth, etc., very light or white in tone. That could fool the camera because the surrounding reflects a lot of light.
You should definitely insure that your subjects fill the frame as much as possible so that surrounding reflectivity is not a problem.
Another thought. Shoot in raw format. Raw will not change your exposure, but, with a raw file, you can increase the exposure on the computer to bring out the darker areas.
If the shutter speed is fixed, the aperture will be smaller
I understand that the ISO will not, in itself, affect the DOF. However, if the camera is set to program (green) and the shutter sync speed is set at 60, if you increase the ISO, will the aperture be reduced (bigger number),? Thereby increasing the DOF?
Given that the shutter speed and ISO are fixed, I assume that the aperture is the variable and will therefore change. So by changing the ISO you can change the aperture. If not, how is the aperture determined in this situation? Anyway, that was my theory.
'P' is similar to auto mode. The shutter speed is not fixed.
It is selected by the camera as is the aperture. If the ISO is increased (more amplification), the camera will respond as if more light is available. It may use a faster shutter speed in response, or it may increase the f stop for the aperture. I just did a quick test on my 20D. An increase from ISO 100 to 200 went entirely to an increase in shutter speed. 100 to 400 went mostly to shutter speed but also uped the aperture 2/3 stop. I don't know what the camera's processor will choose to do under all conditions, or if the change will be beneficial. However, increasing ISO will increase the noise level in the digital image. I would not do it unless I needed more shutter speed especially when photographing people at 5-10 feet with a flash.
BTW, the 20D with the 580 flash can go as fast as 250 on the shutter speed. It is not maxed out at 60.
Thanks for the good advice
Ok so using a ISO of 200 or 400 would be better VS 800?? The People were not dark skinned but may have had darker clothing on, and yes the tableclothes were white..hummm. I usually do try to have the people fill the frame, but a good thought to remember. I had the same problem with the Bride and Groom and the cake Brides white dress and a white cake probably fooling the camera too. So maybe zoom in do the FE lock say on the faces and then zoom out recompose and shoot???? I have never shot in RAW before so I guess thats something I need to try. Thanks for taking the time to give me great pointers!
I read this second, so you probably hadn't posted it yet.
I think you're beginning to get some clues. Yes, I would keep the ISO at 100 or 200. With a flash, high ISO is not needed.
You are now seeing/remembering large white objects in the picture. Those, obviously, reflect a lot of light which the TTL sensor in the camera sees. They could easily cause it to shut down the flash too soon. Try to reduce the size of those large, light colored areas.
I would not worry too much about locking exposure when using a flash. The camera's meter will not compensate for the flash, so locking exposure is a bit meaningless. The flash occurs VERY QUICKLY. Shutter and aperture are almost irrelevant as long as the shutter is fast enough to ignore ambient light. On the other hand, flash compensation can boost the lightness of the image. That may be your #2 tool in cases like this. #1, of course, is properly framing the image.
Thanks so much,
I think you are talking my language!! I will definately try the flash compensation and be aware of white objects that will give a false reading for the sensor. Thanks Thanks....
One way to accomplish this is to use Slow Sync.
It will not work in P mode.
Use shutter priority and set the shutter speed to about 1/15th of a second.
The shutter stays open long enough to gather enough light that the background will not be in total darkness.
Of course, you should use a tripod when using 1/15th of a second shutter speed.
You might give it a try at 1/30th of a second.
You might be able to hand hold the camera at that speed.
You can do a Google search on "slow sync" and learn more about it.
OK, I confess. I thought he/she meant the subjects were
too dark. If the flash is lighting the subjects, but not their surroundings, that makes more sense.
Clarification on that point is needed.
Yes my subjects are dark
Whoo you guys are confusing me. My subjects ARE dark and of course the background is really dark. I was shooting with a 18-55 lens gathering 3 to 4 people together and shooting across the table. So should I have my ISO on 200 or 400 then the camera would allow a longer exposure and then increase the flash compensation on the camera? Or running on the green P and having the flash on does the camera just do its own thing regardless of how I set the ISO???
I think you can forget ISO. It will not help brighten your
subjects. Since your subjects are dark, the slow sync described will not help either. It would allow the background to be lighter, but will not capture your subjects if they move at all.
The question revolves around why is the camera shutting down the flash so fast? I'm assuming it's working OK, and is seeing light from the flash reflected back to the camera. It sees enough light to cause ETTL-II to shut off the flash. It could be a tablecloth, a white dress, or something else which is confusing the camera.
The other possibility is that the subject's clothes and skin are not reflecting enough light back to the camera. In that case, the flash would completely discharge, but fail to light the subjects.
Have you tried either moving closer to the subjects, or zooming in? The goal is to fill more of the camera's view with the subjects so that other things do not confuse it. Also, moving closer will increase the amount of light hitting the subject.
It could be quite useful if you would post one of your photos online so we could look at it.
posting on line
I would like to have you take a look at a photo, however I do not have a web site, Is it possible to do it on this site?
You should be able to upload it to
I use www.photobucket.com for posting photos on this forum.
Sign up for a free account and upload your photo.
They will post the photo to your account and provide three links under the photo. Copy the topmost link and post it in your reply on this forum.
Read across some articles :
When shooting any event without using slow-sync flash speed;you only want the flash light main active light source, you must turn the light metering mode to center-weighted average metering and adjust the camera to manaul mode - readjust the aperture and shutter speed for the desire outcome. In addition to that, also turn the custom functions ( ETTL II categories ) to Average instead of evaluative before shooting. Therefore, ETTL II system will properly work using the high-sync flash. A little complicate, but worth trying. I did try it and it amazingly worked out.
If the camera is set to manual manual
If the camera is set to manual will the exposure metering still be automatic by controlling the duration and/or intensity of the flash?
Your question is ambiguous.
If you mean the meter reading which is seen in the viewfinder of the camera, it will not be affected by the presence or absence of the flash. It also does not control the flash.
If you are talking about the ETTL-II system which controls the flash, then, yes, it is still automatic. You can, of course, adjust flash intensity, duration, etc. to some extent with the flash compensation setting on the camera, and other settings on the flash unit itself.
A little more ...