light trails & missing truck

A question please? I have found quite a bit of info on light trail and long exposure photography. Samples and how to do it but can't find any note on where the vehicles disappear to. Posted an image with it's crop to show the end of the trails where the truck should be, but we see the power pole on the opposite side of where the vehicle is. Just want to know why the camera sensor detects the light this way? Light reflected off the truck body should be recorded and yet seemingly not...

The truck is moving for the whole of the exposure time so it is never in any place long enough for the sensor to record it. The power pole on the other hand does not move at all.

you can try a little experiment yourself...set up your camera on a tripod with long exposure...take one shot running around, and another just standing...you may see some ghosting of you running around, but the truck is going a lot faster, so it doesn't show up at all

sidknee wrote in post #18432573
The truck is moving for the whole of the exposure time so it is never in any place long enough for the sensor to record it. The power pole on the other hand does not move at all.

In that last instant when the shutter closes, the light of, or blur of, the truck reflects back and is the last thing recorded yet the pole is still evident. the light travels faster than the truck and in my small mind it should be seen.

DreDaze wrote in post #18432574
you can try a little experiment yourself...set up your camera on a tripod with long exposure...take one shot running around, and another just standing...you may see some ghosting of you running around, but the truck is going a lot faster, so it doesn't show up at all

Yes I've played with this in a graveyard. Ghostly effects...

Flywing wrote in post #18432618
In that last instant when the shutter closes, the light of, or blur of, the truck reflects back and is the last thing recorded yet the pole is still evident. the light travels faster than the truck and in my small mind it should be seen.

If the truck is reflecting enough light to be recorded in the last instant of the exposure it will be reflecting enough to be seen in the whole exposure. It isn't so it doesn't.

Flywing wrote in post #18432618
In that last instant when the shutter closes, the light of, or blur of, the truck reflects back and is the last thing recorded yet the pole is still evident. the light travels faster than the truck and in my small mind it should be seen.

If you want the truck, put someone with a flash down at the end. Have them fire it when the truck gets there.

sidknee wrote in post #18432630
If the truck is reflecting enough light to be recorded in the last instant of the exposure it will be reflecting enough to be seen in the whole exposure. It isn't so it doesn't.

It should at least block the light reflected from the pole????

Flywing wrote in post #18432633
It should at least block the light reflected from the pole????

Obviously it doesn't, unless it's parked in front of it for the whole exposure.

Flywing wrote in post #18432633
It should at least block the light reflected from the pole????

the last pole is the same as the other poles...they are exposed for a majority of the time of the shutter being open...they probably are darker than what they would've been without the truck driving in front of them...but of the 4sec exposure, they were probably exposed for 3.75(random number) seconds...so the truck driving by doesn't matter

PhotosGuy wrote in post #18432631
If you want the truck, put someone with a flash down at the end. Have them fire it when the truck gets there.

Or perhaps a very large torch so that I can coordinate with the shutter release. Thanks for that idea.

Flywing wrote in post #18432640
Or perhaps a very large torch so that I can coordinate with the shutter release. Thanks for that idea.

Maybe I'll forego the flash. Drivers could get miffed with some dolt bliding them...

Only for that instant that it was in front of it, which was too short of a time to effect the long exposure in the way that you are expecting it to.

Since you have correctly exposed fro the bright lights of the truck, your same exposure is far to short to gather the very minimal amount of light that the truck was reflecting.

Exif shows a 4 second exposure. You would need more like 1 minute (guestimating) to see the truck. At which point, the lights would be pure white blown out,.. you can;t ever do an exposure that will show both.

DreDaze wrote in post #18432639
the last pole is the same as the other poles...they are exposed for a majority of the time of the shutter being open...they probably are darker than what they would've been without the truck driving in front of them...but of the 4sec exposure, they were probably exposed for 3.75(random number) seconds...so the truck driving by doesn't matter

a one frame video. I'm still seeing the truck and the light is brightly reflecting through the whole exposure. you're right.

Thanks eh, semi clear here now.