Can a pan squeeze a moving subject?

[rpcrowe]

I don't know if this P-51 Mustang aircraft is squeezed and shortened due to panning or if it is just an optical illusion...



It sure looks squeezed in comparison to this image of another P-51...



Please see my Planes of Fame collection at https://rpcrowe.smugmug.com/Planes-of-Fame/i-CxLTNvC

or my post at Planes of Fame Series

[pnodrog]

Most shutters travel vertically so unlikely to cause any distortion, especially as at 1/100 sec it will be wide open for most of the duration of the exposure. As you have panned well/fast enough to keep the plane sharp I think it is probably correctly proportioned.

Nice shots, pity about the power lines but I suppose pilots hate them even more than photographers.

[DickyOZ]

The P51 changed shape a fair bit over its lifetime as new marks came out. So since your photos are of different planes I would say panning is not to blame for any perceived or actual squeezing.

Nice shots all the same. There is a P51 flying from Caboolture airfield a few klm from us but I have yet to get a decent shot of it in the air, I bever seem to have the camera handy when it is overhead.

[Manfred M]

Paul I think you are referring to the effect one gets with focal plane shutters and in that case you do get distortion. If you were photographing a moving rectangle, it would end up looking like a trapezoid. I'm not sure if the effect has a name, but I know in video work it is referred to as "rolling shutter".

http://maisonbisson.com/post/10531/f...er-distortion/

Richard - I wonder if what we are seeing is the flattening effect of a long focal lens on a subject that is not completely perpendicular to the focal plane and that would lead the the plane looking distorted. If you look at the landing gear, it is offset, so I suspect this is what is happening in these shots

[NorthernFocus]

Since the lettering on tail and fuselage don't look out of proportion I'd say the plane has been modified. P-51s are used a lot for racing etc. so I suspect it has been tweaked for performance reasons.

Couple of nice shots. I really like the second one.

[Shadowman]

Nice captures.

[pnodrog]

Paul I think you are referring to the effect one gets with focal plane shutters and in that case you do get distortion. If you were photographing a moving rectangle, it would end up looking like a trapezoid. I'm not sure if the effect has a name, but I know in video work it is referred to as "rolling shutter".

http://maisonbisson.com/post/10531/f...er-distortion/

Richard - I wonder if what we are seeing is the flattening effect of a long focal lens on a subject that is not completely perpendicular to the focal plane and that would lead the the plane looking distorted. If you look at the landing gear, it is offset, so I suspect this is what is happening in these shots

I am aware of the distortion effect to which you refer. However it can only be apparent (if at all) at shutter speeds higher than the normal X sync when the image is effectively exposed sequentially. As the shot was taken at 1/100th of a sec with a horizontal pan that distortion effect is not a factor.

[Manfred M]

I am aware of the distortion effect to which you refer. However it can only be apparent (if at all) at shutter speeds higher than the normal X sync when the image is effectively exposed sequentially. As the shot was taken at 1/100th of a sec with a horizontal pan that distortion effect is not a factor.

You are right - the effect requires the moving slit mode of a focal plane shutter above synch speed and I really need to read more carefully when responding to posts at 3:00AM

[Saorsa]

It's not squeezed. Every extant P-51 in the world is pretty well documented on the internet. Look for the name on the aircraft and search for P51 and the name.

The two images here are Diamondback and Spamcan. It does appear that Diamondback does have a modified empennage and other modifications for racing.


Here are the images for Diamondback





Here are the images I find for Spamcan

[rpcrowe]

Thanks Brian...

I had not thought of using Google to find information on a specific airplane. I did use it to identify as a P-51 with an Allison engine, this aircraft, Mrs. Virginia, which I thought was an A-36 Apache (Mustang with Allison engine converted for ground attack)...

[Ken MT]

What is the U in the background?

[Saorsa]

What is the U in the background?

Something somebody carved into the earth.

There are plenty of odd things around.

Some of the old airways beacons were indicated by large concrete arrows that could be seen from the ground and pointed to the next beacon.

[rpcrowe]

We have a community college here named Palomar Community College. There is a very large "P" on the side of a hill near that school. Perhaps the U is for a school or for a town nearby...

[Dave Humphries]

What is the U in the background?

My atlas shows "UNITED STATES OF AMERICA", I assumed it was that