how is this image captured?

[darich]

The ambient light from the traffic light showed up at whatever shutter speed therefore if it was moving away but staying in the same place you would see extra density in the middle because that ambient light would be constant where as the outside would not because of the traffic light housing. Post production.

I understood exactly what you meant first time around....but i still disagree!!
:mrgreen:

 

[TBaraki]

the wheel is moving a lot fast then the bridge for sure no matter how you take the shot....simple physics

You sure about that? One would think the wheel would be moving the exact same speed as the bridge.

 

[(Ghastly) Krueger]

I agree with the crow saying it was taken from another vehicle going at the same speed. the trafic light is not so blurred because of the perspective and relative movement. The rail to the right of the car is not completely blurred, indicating a relatively high shutter speed.

Another argument are the reflections on the car. On the left side of the car, near the doorhandle we can see part of the bridge. If that's photoshopped it's an amazing work!

 

[shingfan]

You sure about that? One would think the wheel would be moving the exact same speed as the bridge.

in order for the car to move...there must be friction between the tire and the bridge surface....why does the tire wear out over time on the road... it is because of this friction.....and since there is friction and wearing off....so the tangential speed of the wheel would be a little faster than the bridge itself.....and even if the tangential speed of the wheel is the same as the bridge......it will be blur similar to the brige....because the wheel is not moving at the same speed as the other car where the picture is taken from....as you said yourself....."one would think the wheel would be moving the exact same speed as the bridge".....the only thing that is in still motion relative to the other car would be the red nissan and the centre of the car wheels....not the arm of the rim because it is moving at a different speed......different enough so that it should have the smae blurr effect of the side of teh bridge....not in sharp focus

tangential speed is equal to the the speed of the car + rotation speed * radius from teh centre....for sure faster than the car itself.....and faster than the side of the bridge in reality taken into account of tire wearing (there is no such thing as 100% traction)

so in order to freeze the rim arm motion...the bridge would logically be frozen as well dont you think?

 

[TBaraki]

in order for the car to move...there must be friction between the tire and the bridge surface....why does the tire wear out over time on the road... it is because of this friction.....and since there is friction and wearing off....so the tangential speed of the wheel would be a little faster than the bridge itself.....and even if the tangential speed of the wheel is the same as the bridge......it will be blur similar to the brige....because the wheel is not moving at the same speed as the other car where the picture is taken from....as you said yourself....."one would think the wheel would be moving the exact same speed as the bridge".....the only thing that is in still motion relative to the other car would be the red nissan and the centre of the car wheels....not the arm of the rim because it is moving at a different speed......different enough so that it should have the smae blurr effect of the side of teh bridge....not in sharp focus

tangential speed is equal to the the speed of the car + rotation speed * radius from teh centre....for sure faster than the car itself.....and faster than the side of the bridge in reality taken into account of tire wearing (there is no such thing as 100% traction)

so in order to freeze the rim arm motion...the bridge would logically be frozen as well dont you think?

Assuming the arm is frozen you may have a point. How can you tell the arm is frozen? Is there a hi-Res file around somewhere? I think that lighter line through the wheel is just the artifact of spokes in motion, the wagon-wheel effect, NOT a frozen spoke. I can't pick out a spoke to even make a judgment on.

Thank you for the interesting math, though. I learned something new about the physics of rolling diameter.

Regardless, I think the most convincing part of this photo is the red crane on the left side of the frame. It's further away from the focal plane of the camera so in the time of an exposure it will "appear" to have moved a shorter distance. Photoshop doesn't account for distance when applying motion blur, and I sure don't think I would be capable of selecting those bridge elements out manually.

 

[shingfan]

haha.....this is getting a little bit off the topic and getting everyone to learn so much new stuff....very interesting......

well....one other weird part is the transition of the side of the bridge....the very top edge of the fence.....the transition is a bit different before and after the roof of the car.....they dont form a linear line.....it seems like the fence change angle dramatically right at the point behind the nissan.....maybe it is coincidence.....but it is kinda weird for a bridge....transition should be continous....a sudden steeper change in angle on a bridge would be dangerous for driving as cars will be "off" the road when passing that weird transition........anyways....just thoughts.....we might be all wrong...but it sure is an interesting topic to debate on...haha

 

[darich]

in order for the car to move...there must be friction between the tire and the bridge surface....why does the tire wear out over time on the road... it is because of this friction.....and since there is friction and wearing off....so the tangential speed of the wheel would be a little faster than the bridge itself.....and even if the tangential speed of the wheel is the same as the bridge......it will be blur similar to the brige....because the wheel is not moving at the same speed as the other car where the picture is taken from....as you said yourself....."one would think the wheel would be moving the exact same speed as the bridge".....the only thing that is in still motion relative to the other car would be the red nissan and the centre of the car wheels....not the arm of the rim because it is moving at a different speed......different enough so that it should have the smae blurr effect of the side of teh bridge....not in sharp focus

tangential speed is equal to the the speed of the car + rotation speed * radius from teh centre....for sure faster than the car itself.....and faster than the side of the bridge in reality taken into account of tire wearing (there is no such thing as 100% traction)

so in order to freeze the rim arm motion...the bridge would logically be frozen as well dont you think?

First time i've seen friction and tyre wear used as evidence of no photoshop being used!!! One of which is invisible and the other takes months or even years to happen!!

Can you actually see that in an exposure of around 1/125 sec the camera would catch that the road surface is stationary yet the tyre has rotated a bit and some worn off?
And you spotted that from that web sized image?

The outer edge of the wheel will be moving faster than the centre but only because the circumference is larger for any given point, further from the centre.
Since the wheel is one unit and rotates at a certain speed, the outer points must travel faster to cover a larger distance in the same time that a point closer to the centre will cover a shorter distance.

And THAT's why the spokes MAY be blurred - not because of tyre wear!!!!!

 

[DocFrankenstein]

The ambient light from the traffic light showed up at whatever shutter speed therefore if it was moving away but staying in the same place you would see extra density in the middle because that ambient light would be constant where as the outside would not because of the traffic light housing. Post production.

It's not going away THAT fast!

 

[ladyphotog]

It's not going away THAT fast!

For you to see blur on the road you would see the added density in the light.

 

[shingfan]

First time i've seen friction and tyre wear used as evidence of no photoshop being used!!! One of which is invisible and the other takes months or even years to happen!!

Can you actually see that in an exposure of around 1/125 sec the camera would catch that the road surface is stationary yet the tyre has rotated a bit and some worn off?
And you spotted that from that web sized image?

The outer edge of the wheel will be moving faster than the centre but only because the circumference is larger for any given point, further from the centre.
Since the wheel is one unit and rotates at a certain speed, the outer points must travel faster to cover a larger distance in the same time that a point closer to the centre will cover a shorter distance.

And THAT's why the spokes MAY be blurred - not because of tyre wear!!!!!

read my message carefully...the tire wear plus friction on the road is explanation as to why the outter radius of the wheel is moving faster than the fence.........so if the fense and road have such a significant stretch.....the outer edge of the rim would expect to be quite blur as well (which it doesnt seem that blur to me....or i feel it to be rather sharp when i open and enlarge the image in photoshop)....that's all......is just something in doubt.....i wouldnt say who is right or wrong as i'm not the photographer of this image nor am i an expert on photography

 

[DocFrankenstein]

For you to see blur on the road you would see the added density in the light.

Let me introduce the concept called perspective.

The object becomes smaller proportionally to the distance you moved away from it.

If you moved 3 times further away from it, it's 3 times smaller.

If you moved 1% futher away from it (which is the case here) the object becomes 1% smaller.

I'm sure if you could examine just the light, you'd see that the outer one hundredth of the circle is slightly less bright.

But you can't... not with this resolution.

QED ladyphotog


Haha
The "tyre" wear argument is moronic. :lmao:

 

[darich]

.....is just something in doubt.....i wouldnt say who is right or wrong as i'm not the photographer of this image nor am i an expert on photography

I still don't agree with your arguement but i do agree with no one is right or wrong and that's why we're debating.

But as you said since you weren't the photographer and the poster wasn't since he/she is asking about it, I'm surprised no moderators have removed the image and made it a link since that's what normally happens!!

 

[bisdakr]

sorry I put a quick post and forgot about the rules, I've fixed it and made it a link, this isn't my picture but was wondering at what my settings should be on a picture where i'm in a vehicle taking a picture of another car, I want to have the car focused and catch the movement of the wheels and the ground. 1/125 speed? will this catch the movement of the ground and freeze the car?

 

[ladyphotog]

Let me introduce the concept called perspective.

The object becomes smaller proportionally to the distance you moved away from it.

If you moved 3 times further away from it, it's 3 times smaller.

If you moved 1% futher away from it (which is the case here) the object becomes 1% smaller.

I'm sure if you could examine just the light, you'd see that the outer one hundredth of the circle is slightly less bright.

But you can't... not with this resolution.

QED ladyphotog


Haha
The "tyre" wear argument is moronic. :lmao:

Obviously you don't understand light and therefore you make personal attacks at people for stating their opinion. That type of thing is really not needed here. Learn how to state your opinion without attacking others, it says more about you than the person you are attacking.

 

[TBaraki]

sorry I put a quick post and forgot about the rules, I've fixed it and made it a link, this isn't my picture but was wondering at what my settings should be on a picture where i'm in a vehicle taking a picture of another car, I want to have the car focused and catch the movement of the wheels and the ground. 1/125 speed? will this catch the movement of the ground and freeze the car?

Yeah, I think 1/125 would be a good starting point.