I wanted to take a photo of my brother with traffic trails behind him. Now even when I was using a tripod, and A/F was correct, I still couldn't get the subject to be sharp, despite using a self timer of 5 seconds (didn't have a shutter release).

Why is the picture blurry? What can I do to capture the effect of a clear subject with no motion blur, with a motion-blurred background?

I am using a Nikon D3300, at 3 sec exposure, f/4.5, ISO 100.

  • 2
    \$\begingroup\$ 3 seconds exposure time for non stationary objects like people won't work well. You should have used a flash or used a much higher ISO (larger than 3000, a tenth of a second exposure time would probably be fast enough if the subject does his best to stand still). \$\endgroup\$ Apr 19, 2016 at 19:15
  • 14
    \$\begingroup\$ Use another tripod... for your brother. \$\endgroup\$
    – Rafael
    Apr 19, 2016 at 19:44
  • \$\begingroup\$ @CountIblis 1/10 second is only going to give traffic trails for aeroplanes and race cars though. Best to get a proper long exposure for the trails and separately light the portrait element to take that into short exposure territory. \$\endgroup\$
    – eftpotrm
    Apr 20, 2016 at 16:19
  • \$\begingroup\$ See also: DPS's slow sync article. \$\endgroup\$
    – inkista
    Apr 20, 2016 at 16:52

5 Answers 5


If the camera is on a tripod, and we assume little or no camera movement, then there are two possibilities.

Most likely, at 3", your brother is not going to stay perfectly still and there will be some subject movement. You could fix that in part by using flash during the exposure to freeze the foreground subject.

And also, it's presumably fairly dark, so you may have trouble focusing. And at f/4.5 you will have a hard time getting both your brother, near the camera, and the traffic in the distance, both in focus. You could try moving your brother a bit further away, or use a higher aperture, f/8 or f/11 say and bump up ISO to 800 or 1600 to compensate

  • \$\begingroup\$ Okay I'm reading this everywhere - use flash? You could fix that in part by using flash during the exposure to freeze the foreground subject What exactly do you mean by this? I'd love to try this again tomorrow, provided I understand what you mean. Hope you can help :) \$\endgroup\$ Apr 19, 2016 at 19:54
  • 2
    \$\begingroup\$ Well basically you set the exposure (3 seconds) to expose the lights of the cars, with the background and your brother still fairly dark. He can move a bit, but he would be just a dark blur. Then when you add flash, it illuminates him in a very short duration, so he will not be moving during the flash and there will not be subject movement. \$\endgroup\$
    – MikeW
    Apr 19, 2016 at 19:55
  • 3
    \$\begingroup\$ See this and other questions about "rear curtain" flash. There is a good example in one of the answers, which shows some blurred subject but also a bright sharp exposure of the same subject. photo.stackexchange.com/questions/60956/… \$\endgroup\$
    – MikeW
    Apr 19, 2016 at 19:57

The issue that you are having is that your brother may appear to be still for the 3 seconds of your shutter speed but even breathing can impact the photo from being sharp. He is still moving even though it doesn't look like it.

A solution I found with doing a photo like this is to have a flash set to second curtain and hit him with the flash; it should put him into the frame as closer to sharp while the details behind can be blurred out.

A flash set to "Second Curtain" will cause the flash to go off when the shutter is about to close. There is 2 curtains in front of the sensor of the camera and when you press the shutter open, curtain 1 opens and when its time for the current to close, the second curtain will cover the sensor and allow for reset before taking the next photo. On long exposures, the external flash will go off right just enough time before the 2nd curtain closes. a link for a more detailed explanation is below.

Second Curtain - Flash

  • \$\begingroup\$ Flash set to second curtain? Sorry, I don't understand. \$\endgroup\$ Apr 19, 2016 at 19:56
  • \$\begingroup\$ I have updated my answer for a more detailed explanation of Second Curtain \$\endgroup\$
    – thebtm
    Apr 19, 2016 at 21:32
  • 1
    \$\begingroup\$ @IshanMahendru You may want to read about flash sync speed and how camera shutters work. \$\endgroup\$
    – user
    Apr 19, 2016 at 21:56

Your premise is wrong, because actually both your subjects are blurry: the cars and your brother. The difference is for which it is desireable.

To make only your brother in the foreground appear sharp, use a flash. Use second curtain sync to override the blurry long exposure of your brother with the light of the flash at the end of the exposure.

To limit the effect mostly to your brother, get him close to the flash and the car trails further away.

  1. Your brother will be moving during the exposure no matter how hard he tries not to. You need to use flash to illuminate him separately - doesn't have to be rear curtain sync, front will work just as well, just not an automatic exposure that'll force it to 1/60s. That will create two exposures in the same frame - flash power, aperture and ISO for your brother, shutter speed, aperture and ISO for the rest of the scene. I'm assuming there's nothing especially close to your brother in frame, or the flash will catch that too and light it up.
  2. f/4.5 is I'm guessing wide open for a kit lens, which won't give optimal optical performance and is unlikely to give sufficient depth of field for what you're visualising. If you stop down to f/11 you'll get about a 20 second exposure; brother in scene at the start and lit by the flash, then move him pretty much anywhere that isn't him standing still in frame (or he'll register again). That'll give you a sharper image with more depth of field, and also more time for interesting traffic trails to develop. Hopefully you're using an external flash - set the camera to manual exposure and the flash too, setting its power using the flash's distance scales to match the distance to your brother. If it doesn't expose correctly, tweak the flash power and move him slightly back and forwards.
  3. If you don't have an available flash and can't use the onboard for any reason (lens hoods for example), you can get an OK result using torches or LED lights - I've used them for light painting portraits before and the results aren't as sharp as if they're flashed but they're a whole lot better than just leaving it to ambient. The torch on your phone is better than nothing for this... Move it around during the exposure to avoid hotspots, test options, and hopefully you'll be able to get an acceptable amount of light in 2-3 seconds at which point you can mask the torch with your hand and move your brother out of frame. Underexpose him this way though and, rather than appearing too dark, he'll appear slightly transparent...!
  4. I often find traffic trails don't do enough interesting stuff in a single exposure so end up taking several and combining them for the final image. https://www.flickr.com/photos/gpwebb/12151694115/in/album-72157607097465907/ and https://www.flickr.com/photos/gpwebb/15659767304/in/album-72157607097465907/ are both composites - the single images were nice, but the composites finished them off.

Good luck! Sounds a fun project.


If, by chance, you want this to be done during the day, the trick is to find the appropriate shutter speed for the situation.
One that will allow the subjects to blur but remain visible while he is as sharp as needed. I've done this a good number of times at bicycle races. This was shot at 1/80th f 11 is0 200 focal length 32 mm on FF Nikon D700 24-70



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