Optical Illusion?

Chuckbuster

Chuckbuster

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I was at the range with a friend and his son the other day and managed to get some neat photos. One of them is shown here. While I was aware of frame flex in polymer pistols, the image of the slide surprised me. Anyway, at first I thought "Cool. The slide and frame flex during firing." But then I thought it must be an optical illusion as the slide is obviously steel.

 
looks to me like the shutter may have been open for too long which caught to movement of the gun which caused blur and distortion
 
You are right and wrong about the shutter:
there is no such thing as shutter rolling phenomenon, it is a technique and it is not a phenomenon as it can be done and duplicated almost 100% every time. The term is shutter drag and not shutter roll.
I have been a photographer for over 10 years and this is simply how the movement was captured with that specific 'photographic par'.
The slide is moving at 2 different speeds, with the muzzle portion moving up and down faster than the rear portion of the slide, this created that effect which looks like a warp.
It is not an illusion, it is how your photographic par captured that specific motion with that specific light source (you are inside of some sort of hut so you are getting reflected light only, most likely from the snow) and that setting/photographic par. More light or a faster photographic par (a combo of faster shutter speed and opened F/stop) would have resulted on a crisp-er image, if that is what you wanted, depending on the lens used of course...Etc, etc, etc.

Cheers.
 
Avenida said:
You are right and wrong about the shutter:
there is no such thing as shutter rolling phenomenon, it is a technique and it is not a phenomenon as it can be done and duplicated almost 100% every time. The term is shutter drag and not shutter roll.
Click to expand...
Sorry but you are wrong. Shutter roll is completely different from shutter drag. As you state, shutter drag is a photographic technique involving manipulation of the exposure, but shutter roll is the description of the phenomena when a fast moving (especially rotating) object is captured by a camera using a CMOS sensor which does not capture the entire frame at once but by scanning across the sensor. The slide in Chuckbuster's photo is blurred a little from the slow shutter speed, but the curved distortion is greater than the motion blur distortion. Have a look at this picture here for a clearer example.
 
giphy.gif
 
Thanks for sharing that photo. After checking wikipedia I learned about this a little bit more as I never heard about this before...
Never happened to any of the cameras I used so I assumed this used to happen or happens in the lower end CMOS/CCD sensors, it could also be older technology or maybe consumer cameras/pocket.

Not every CMOS/CCD scan the frame. At least, in the type of cameras I use, the photogram is instantaneous and what you see is a shutter drag (term that came from film photography and not digital).

CCD and CMOS sensor have been evolved non-stop for the last 8 years for professional cameras and an aberration like this would be unacceptable in a prosumer or professional camera these days. On the other hand, I can see this happening to pocket cameras still ...

anyway, very interesting!










Master-G said:
Sorry but you are wrong. Shutter roll is completely different from shutter drag. As you state, shutter drag is a photographic technique involving manipulation of the exposure, but shutter roll is the description of the phenomena when a fast moving (especially rotating) object is captured by a camera using a CMOS sensor which does not capture the entire frame at once but by scanning across the sensor. The slide in Chuckbuster's photo is blurred a little from the slow shutter speed, but the curved distortion is greater than the motion blur distortion. Have a look at this picture here for a clearer example.
Click to expand...
 
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shutter drag is usually referred to when you are using a flash and a longer exposure to get more ambient light which isnt why this happens. this picture happens because of the way an image is captured where the shutter rolls across the image and captures different parts at different points in time. It really only shows up with fast moving objects but it is correctly called a rolling shutter. You see it less in higher end cameras simply because you can tune your shutter speed better and avoid it, not because the image is taken instantaneously.
 
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