Couple pictures taken with flashes...they seem a bit dark

[FlipsidE]

Hey all,

Well, I'm now on my 6th Digital Rebel from Best Buy and I think I finally might have gotten a good one. I went to a different Best Buy, and this group of employees was A LOT more helpful. I'm FINALLY back home with a camera that finally seems to be clean (no dead LCD pixels, no dust or dead/hot pixels on the sensor, and no physical blemishes on the body). If I decide to use Best Buy for high dollar items from now on out, I will probably just choose to go to that store (about 25 miles away) first. I could have saved A LOT of time and stress had I done that.

So, I'm snappin away pictures and going over them with a FINE toothed comb. But, when I look at them, it seems that some of the pictures taken with a flash are a bit dark. Now, I'll say that this is the first time I've taken pictures with my new 420EX when it's light outside. I noticed it was dark, so I took off teh 420EX and used the on-board flash and got the same results. Is this fairly typical? Is there an issue with my shutter closing too quickly? If this is normal, how do I fix it? Btw, both these pictures were taken on full auto mode on the camera. The first one is the 420, the second is the on-board.

http://www.wesculbertson.com/420EX_800.jpg

http://www.wesculbertson.com/BuiltIn_800.jpg

Thanks in advance

FlipsidE

[CyberDyneSystems]

How close are you?

The 420 may be lighting up the wall above and behind the PC like nobody's business :D

Getting the hang of using a flash takes time.. there is no reason to expect that youll get exactly what you want straight out of the box with no practice. What gets exposed well and how depends on aperture, ISO, shutter etc.. you have posted none of this info.

I would suggest you do a lot more shooting with the flash and experiment before asuming there is a problem.


And.. actually in this "case" I think it did a good job by NOT blowing out the white fsace plate.. that's what I would have expected to see.

:)

[robertwgross]

There has been some conjecture that ETTL works pretty good for normal or average tone subjects, but as you move off into the blacks or whites, then ETTL starts to struggle more. But then, that is why Exposure Compensation was invented for some cameras.

---Bob Gross---

[FlipsidE]

Thanks for the quick replies guys! I think I *might* finally have a good camera.

FlipsidE

[FlipsidE]

There has been some conjecture that ETTL works pretty good for normal or average tone subjects, but as you move off into the blacks or whites, then ETTL starts to struggle more. But then, that is why Exposure Compensation was invented for some cameras.

---Bob Gross---

Honestly, this issue really only shows up on blacks and whites so far as I can tell. Seems the other colors cause some fairly bright pictures. But, I'll keep my eyes on things over time and see how they work.

Thanks

FlipsidE

[KennyG]

The first shot is at ISO100 and the second at ISO400.

If the focus point was the lighter color CD drive then you would get under-exposure of the darker areas.

[scottbergerphoto]

Just a couple of points to add:

The flash fires at about 1/10,000 of a second and is not affected by the shutter speed unless you go over the max sync speed of the camera (~1/200) in which case only part of the frame will get the flash. To use flash at faster shutter speeds you need a flash that can be put into High Speed Sync mode.

In strong ambient light there is an automatic reduction of fill flash. The camera reduces flash output because it thinks you are using the flash just to fill in shadows. In some Canon camera models you can turn this off in Cfn.s or avoid it by putting the camera in Manual Mode.

Your pictures look pretty well exposed to me at the area in focus. The black looks black with some detail and the computer grey looks grey. In ETTL (not ETTLII), the flash output is biased to the active AF points.
Regards,
Scott

[CyberDyneSystems]

Just a couple of points to add:

The flash fires at about 1/10,000 of a second and is not affected by the shutter speed unless you go over the max sync speed of the camera (~1/200) in which case only part of the frame will get the flash.

...but the exposure can be affected non the less, fopr instance if you use a slow shutter speed to gain detail in the background relative to the focused subject...

This may not have any bearing for these images.. but it does play a part in general.

[scottbergerphoto]

Just a couple of points to add:

The flash fires at about 1/10,000 of a second and is not affected by the shutter speed unless you go over the max sync speed of the camera (~1/200) in which case only part of the frame will get the flash.

...but the exposure can be affected non the less, fopr instance if you use a slow shutter speed to gain detail in the background relative to the focused subject...

This may not have any bearing for these images.. but it does play a part in general.
The shutter speed would not account for any underexposure of the flash. That I believe was the question. :wink:
Scott

[CyberDyneSystems]

Well.. not to continue to belabor this..

...well I guess I am.. :roll: :)

the only questions asked were...

Is this fairly typical? Is there an issue with my shutter closing too quickly? If this is normal, how do I fix it?

Your reply essentially gave the impression.. at least to me... that shutter speed has no bearing on flash exposure.. period.

Perhaps I misinterprate your remark.. but that was my understanding.

In my reply to your statement I was quite clear in saying that though it did not have any relevance to the photos above (in fact I think we agreed that the photos above aren't even suffering at all)

I was merely clarifying that shutter speed most certainly can have an effect on exposure in flash photography..

...again,
This may not have any bearing for these images.. but it does play a part in general

So in these photos, again I think we are agreed.. but a fast shutter speed CAN have an effect on underexposure in flash photography in general, ei: if you want more exposure of your background,. you can do so by slowing, or "dragging" the shutter.

[scottbergerphoto]

Just for clarity, the shutter speed, as long as it is below the x-sync speed, will only affect the exposure of the ambient light and not the flash as the flash exposure is controlled by the camera to subject distance, the aperture and the duration of the flash. It's important for the original poster to understand that a flash exposure combines contributions from ambient and flash and what affects each.
(No need to yell, my hearing is fine.)
Scott