flash problems: can anyone tell me what i am doing wrong this pic and others seem to be coming out a bit dark, i posted earleier in the week to say i was having problems and then...

billozz Loc: Birmingham, England

can anyone tell me what i am doing wrong this pic and others seem to be coming out a bit dark, i posted earleier in the week to say i was having problems and then thought i had solved it. i dont think i have. i have a 450d and the flash is a jessops 360afdc.
not sure if exif will show but shot at 1/125th, f/3.5, iso 100
thanks in advance
Bill

Weddingguy Loc: British Columbia - Canada

billozz wrote:

can anyone tell me what i am doing wrong this pic and others seem to be coming out a bit dark, i posted earleier in the week to say i was having problems and then thought i had solved it. i dont think i have. i have a 450d and the flash is a jessops 360afdc.
not sure if exif will show but shot at 1/125th, f/3.5, iso 100
thanks in advance
Bill

Bill . . . Is the flash compatable with the 450D, in that it is using ETTL? If the flash is ETTL it means that it will automatically adjust the amount of light coming from the flash . . . if not, you would have to adjust your F/stop according to the distance from subject to flash.

When I use flash indoors I usually have my ISO set to 400. That might improve things in both ETTL and manual settings.

Another possiblity for the under exposure is the area in which you are shooting. Looks like a large tent that might not be returning as much light as the room in which you were getting better results.

A little more info on the flash compatibity and the suggested guide number of the flash would help giving suggestions for improvement.
Hope that helps.

CHG_CANON Loc: the Windy City

Bill, you'll have to store the original to provide access to the EXIF data. Is the problem there's not enough coverage for the group? Does the 450D fully control the flash or is the flash manually set separate from the camera? Looking at images for this model and the picture showing what looks like an available white ceiling, are these results from a bounce of the light? As others have comments, we'll need a few more details for better suggestions / analysis.

Bill Houghton Loc: New York area

From what I see, and I'm no expert, you might have been better off bouncing the flash off the ceiling. It appears the white in the customs fooled the flash and camera into thinking it was enough light. Only the folks in the center are lit. When I bring up the curve in PS, the two folks in the center go into whiteout and still not enough on sides or others. That's just my Two Cents. Bill

billozz Loc: Birmingham, England

Weddingguy wrote:

Bill . . . Is the flash compatable with the 450D, ... (show quote)

hi there thanks for the reply, yes the flash is controlled by the camera, it is ettl apparently at least the ettl light on the flash is on when using it, also the flash does change its coverage depending on what area of the 18-55 lens i am using. i have stored the original this time so that exif data is shown.

Weddingguy Loc: British Columbia - Canada

billozz wrote:

hi there thanks for the reply, yes the flash is controlled by the camera, it is ettl apparently at least the ettl light on the flash is on when using it, also the flash does change its coverage depending on what area of the 18-55 lens i am using. i have stored the original this time so that exif data is shown.

There are several things that could cause your under exposure using ETTL . . .

1) Not high enough ISO - suggest 400 as a "norm" indoors
2) Flash Exposure Compensation accidently set at a - (minus) setting.
3) Because your lens is a F/3.5 to F/5.6, even though you set it at F3.5 . . . if you zoom in on the subject it will reset itself to up to F/5.6, which could cause under exposure.
4) If your batteries are low on power, it is always possible that the flash has not fully re-cycled before you shoot. Always check the ready light on the back of the flash.
5) If in a very large space, with dark or very high ceilings, not much light bounces back to the subject. Without this "bounce-back", the effective distance of most flashes are greatly reduced.
6) A combination of some of the above situations could cause be the cause.

Here's a short video that might help:

http://youtu.be/wLeaX_WXUJ8

Hope that helps some.

billozz Loc: Birmingham, England

Weddingguy wrote:

There are several things that could cause your und... (show quote)

the venue was a large marquee so quite a dark room, take your point about the isoi had 100, can u explain why 400 would make a difference? if ttl is working then surely i should get the same exposure regardless of iso setting, or have i got that wrong?
fec was 0 so no probs there.
i was in a very large marquee so again maybe your point about bounce back is valid.
batteries were ok and i waited for ready light before shooting.
just to add one other thing, i have noticed that i dont always see F/stop and iso shown on the reaar of my flash its as if the camera and flash arent communicating, should that info always be there?

jdubu Loc: San Jose, CA

Theoretically, yes, the same exposure. But in practical terms, the environment you are shooting in will affect what your equipment can do easily or work really hard to accomplish.

Setting your iso to 400 will give you 2 more stops of light capture, and that gives your flash a better chance to illuminate properly in TTL. If at 100 iso, the flash is at it's power limit or not capable of illuminating properly in a dark venue, the 2 stops will save your shot.

Weddingguy Loc: British Columbia - Canada

billozz wrote:

the venue was a large marquee so quite a dark room... (show quote)

Can't say about the info showing on the back of the flash as it depends on the flash unit and I don't know that one.. Looked at the Exif info on your image and noticed another possibility for your under exposure cause . . . You have the camera set on "spot" metering mode, which may have been aimed at the center ladies white dress. That would tell your flash that it was giving out lots of light (but only for the white dress) and would result in the rest of the image being under exposed. Especially for group shots I would recommend "evaluative" metering mode, which would take into consideration the entire field.

bkyser Loc: Fly over country in Indiana

The flash is lighting up the subjects, but with a low ISO you aren't getting any ambient light. Looks like your flash wasn't quite up to the challenge of lighting anything much further than your subjects, or your Aperture was too small. (that determines how much light from the flash hits the sensor. The ceiling looks dark, so bouncing wouldn't work. Often during a wedding reception, for the first dance, I like to shoot with ISO 100, so you don't see much else going on, and people in the background, just the Bride and Groom.

billozz Loc: Birmingham, England

Weddingguy wrote:

Can't say about the info showing on the back of th... (show quote)

thats a very good point about the spot metering, i suppose if i switched to evalutive it might be better, i have a halloween party at the weekend i will give it a try. i am thinking of trying some sort of modifier but am really unsure which one to go for there are so many. really appreciate your help i'll let you know how it goes as there isnt really anyway to practice until im there

Weddingguy Loc: British Columbia - Canada

billozz wrote:

thats a very good point about the spot metering, i suppose if i switched to evalutive it might be better, i have a halloween party at the weekend i will give it a try. i am thinking of trying some sort of modifier but am really unsure which one to go for there are so many. really appreciate your help i'll let you know how it goes as there isnt really anyway to practice until im there

I've tried them all and the one that works best for me is the Lite Genius Lite-Scoop. It's available on Amazon here:
http://www.amazon.com/Lite-Genius-Lite-scoop-Reflector-diffuser/dp/B007PKCZV0/ref=sr_1_sc_1?ie=UTF8&qid=1382383601&sr=8-1-spell&keywords=litegenius