[adwb]

Ok what is the trick here ,or what am I doing wrong?
I have read all about dragging the shutter and understand the concept and the theory and the reasons for using this technique, .and I have used it and slow speed sync as well before now to alter ambient light input in a image .
Example is well described here http://neilvn.com/tangents/flash-photography-techniques/dragging-the-shutter/

What I cannot get right is the technique of taking a correctly exposed image of a static subject using flash and a slow shutter speed and moving the camera or zoom to blur the background as shown here .Slice of Lemon

Every time I try this the subject is also blurred , my images look more like this example but my subject is very blurred and is not a clear recognisable form as in this example, How To Capture Motion Trails While Freezing Subjects Using Shutter Drag - DIY Photography

I have the camera on manual ,the flash on manual, the iso fixed , the aperture set for the corect exposure and the shutter at anything from 1/15th to a 1/2 second and all I get is every thing blurred inc. the static subject.

Finally iin several of the examples on this blurred technique this the shutter speed is often suggested as being 1/15 but at that speed I get so little blur it's not working like the examples posted.

Apart from the fact that my ambient light might be to high I cannot see how you get a image as shown in the second or third link examples.

If some can get this right with a K5 and hot shoe manual or pttl flash will they please tell me the settings they used?

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Last edited by adwb; 03-29-2014 at 07:29 PM.

[devorama]

A sample picture might be helpful. But most likely you're not getting the clear subject you want because too much of the image is coming from the ambient lighting and too little from the flash. Try lowering your ISO or using a higher aperture value with the same shutter speed to lower the ambient. Then raise your flash power.

[BrianR]

Definitely post a sample with exif intact. From what you're describing, you have too much ambient light falling on your subject. In the first photo of the 'slicing the lemon' link, the blurry parts are mostly from light sources in the actual scene. If the photo was taken with the flash turned off the subjects would appear extremely dark, particularly the faces. Note the blue ambient light is lighting up the fellas shirt, so that smears around during the exposure.

If you can separate the bits you want sharp from the ambient light and light them entirely with a short duration flash, this effect gets much easier to do. Otherwise it's going to be a balancing act juggling how much blur is acceptable by changing the ratio of ambient to flash, exposure time, and how fast you move your camera. The example below was a 2 second exposure, without the flashes all you'd see are the coloured lights as they are not lighting up my face at all.

[adwb]

sample as requested

Attached Images

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[devorama]

The issue is not your shutter speed. The problem is that you are moving a relatively bright part of the image over the center of the frame during the ambient exposure. The exposure is cumulative of all the light that hits the sensor while the shutter is open. So if you moved a bright object over the center at any time, that will tend to obscure your subject. You probably want a composition where your subject is surrounded by a dark background.

[BrianR]

The exposure of the cat part looks reasonably sharp. During your camera movement, you want to minimize the amount of bright background stuff going over the center of the frame where the face is as this is causing the smeared look. You can arrange the background so the parts that will go over the center are darker, or you could change the movement you're doing. Zooming in during the exposure, or rotating would keep the brighter background off the cats face since in either case it's face will be blocking the background.

An example below if it helps (all 1 second exposures). In the center shot, the rotation kept his belly in pretty much the same spot, so it ends up quite sharp (the exposure from the ambient on the belly is minimal compared to the flash). There is streaking on one side of the face, if the axis of rotation had been closer to his face this would be much less noticeable (the feet would show streaking though). With the lateral movement, there's streaking all over as bright parts of the background pass through the entire frame this way.