D30 + 550EX + Flash Extender = Strange blurring of photo

[gil_batzri]

<P>I recently got a flash extender to shoot HS Football at night.

I am using a Canon D30 with one of two lenses a 100-300 5.6L

(primary) and a 70-200 2.8L (rental) I am shooting from 20+ feet

away generally. A lot of the pictures have a strange haze on the

edge of the subject (like a double image of sorts)</P>

 

<P>I am using the "sports" auto setting on the camera, with a 550EX

Speedlight and the beamer. With the f2.8 lens the shots are @f4 1/60

sec exposure time. With the f5.6 Lens shots are at f5.6 1/60 sec

exposure. The problem seems worse at the longest focal length (this

is not 100% verified) and is less apparent at the middle zoom (150mm

for the 5.6 etc)</P>

 

<P>The Flash extender is a "better beamer" from here: <a

href="http://birdsasart.com/accs.html#BEAMER">http://birdsasart.com/a

ccs.html#BEAMER</A> it is basically a bracket with a Fresnel lens

that projects the flash, it gives me 30-100 ft more reach at night

and freezes the action fairly well...</P>

 

<P>The other issue I am running into (minor) is I can not set the

flash to a manual zoom focal length. The Beamer folks recommend a

setting of 50mm for the flash, when I set the flash to Manual, 50mm

and depress the shutter button on the camera (D30) the flash sets

itself to whatever it thinks is proper (full auto mode again). </p>

 

<P>Have a look at the image, and let me know if you have any

thoughts on either of my issues. Thanks in advance for any help

offered.</P>

 

<img src="http://home.pacbell.net/thegrinc/blur.jpg">

[richard harris]

It looks to me as if there is some ambient exposure creeping in alongside the flash exposure, which is what's giving you that double exposure effect. In your situation you probably want flash exposure only, in which case you need to up your shutter speed (or close down your aperture) in order to cut down the ambient exposure. Using a faster shutter speed will not affect the flash exposure at all, it will just let in less ambient light. Using a smaller aperture will reduce the range of your flash so you probably don't want that.

 

You best be is to take control yourself, don't use the "sport" mode, use manual. In manual mode set your fastest aperture (2.8 or 5.6) and set the shutter speed to Flash sync (either 125 or 200 on the D30 I can't remember which), the flash will do the rest. You can check that the ambient exposure won't interfere by looking at the scale in the viewfinder, make sure that it is underexposing by 2 stops or more(remember that ambient and flash exposures are independent), if not you will have to stop down until it does.

[eric_onore]

At the shutter speed you are using, there is sufficient ambient light to record an image on the film. The double image is first the image frozen by the flash, and secondly the subject movement recorded by the ambiant light. This effect would certainly by more pronounced at longer focal lengths due to the greater magnification. In addition, if you are not using a tripod, you are probably experiencing a lack of sharpness due to camera shake at the shutter speed you are using..

[art_haykin]

Two things: 1) Note that only with "white" areas reveal much blur, and the above is correct. The ambient (or existing) light is doing its thing on the lighter areas, while the darker areas don't show much blur. 2) Kinda looks nice, and suggests motion.