Wide angle lens distortion

[Paul_Yeo]

I would like to ask when is it most likely to have lens distortion for wide angle lens?

Is it this 2 situationz?

1) when focal length is at 17mm to 20mm?
2) when subject is near to edge of the frame?

If I zoom to 28mm with subject at the edge of the frame, will the subject be distorted?

Thanks!

 

[Paul_Yeo]

Also, if subjects are in the centre frame and focal lenght at 18mm, it will not be distorted right? :embrass:

 

[ExplorerZ]

depending on if you are close to the subject or not... even at 24mm distortion can be easily seen if subject is too close.

 

[+evenstar]

i think it's only obvious at the sides, especially corners...dead centre is not affected

 

[Snoweagle]

28mm on 35mm equivalent already have distortion.

 

[Belle&Sebastain]

35mm and 50mm respectively also have distortion

 

[Splutter]

All lenses have distortion, just that its more visibe on WA lenses, especially nearer to the edges. This can actually be minimized by having the subject more squared to your lens, meaning that if you shoot top down, have the subject "lean" backwards instead.

 

[VR Man]

Perspective distortion ?
or
optical distortion i.e. barrel distortion ?

 

[Paul_Yeo]

I understand that all lens more or less have some distortion and WA more visible.

what actually I wanted to find out is:

if I use 17-55 but zoom in on say 50mm and subject at edge, will the distortion be visible?

the distortion is bcos of the WA lens or it is more the focal length issue?

If it is the WA lens issue, then even if I shoot at 55mm, the distortion will be very obvious...

If it is a focal lenght issue, then I can try to minimise the obvious by not using maybe less than 40mm focal lenght?

 

[Paul_Yeo]

Perspective distortion ?
or
optical distortion i.e. barrel distortion ?

I am not sure about the technical terms. the subject seem to be slanted or stretched towards the edge

 

[Scaglietti]

Lens distortion is due to lens design. Lines that supposed to be straight looks bent. E.g. fisheye lens will always cause lines to be bent (except lines running right through the centre).

Perspective distortion is due to the focal length lens and the distance from subject and perspective of the lens. E.g. if you shoot close up of a human face with a wide angle lens, the nose will appear larger than the rest of the face.

 

[Paul_Yeo]

Lens distortion is due to lens design. Lines that supposed to be straight looks bent. E.g. fisheye lens will always cause lines to be bent (except lines running right through the centre).

Perspective distortion is due to the focal length lens and the distance from subject and perspective of the lens. E.g. if you shoot close up of a human face with a wide angle lens, the nose will appear larger than the rest of the face.

seems like mine is perspective distortion. so I will use 28mm & above and dead centre to have less visible distortion?

 

[ExplorerZ]

seems like mine is perspective distortion. so I will use 28mm & above and dead centre to have less visible distortion?

don have to be 28mm... even at 17mm there will be none or not much distortion if the subject is a distance away from your lens.

 

[Snoweagle]

Perspective distortion ?
or
optical distortion i.e. barrel distortion ?

What abt Pincushion?

 

[ExplorerZ]

What abt Pincushion?

pincushion is under optical distortion...

 

[Paul_Yeo]

don have to be 28mm... even at 17mm there will be none or not much distortion if the subject is a distance away from your lens.

If it is at 28mm, if at the edge of the frame, will there be visible distortion?

 

[ExplorerZ]

If it is at 28mm, if at the edge of the frame, will there be visible distortion?

eh like i say, it depends on how far your subject is from you...

 

[Snoweagle]

pincushion is under optical distortion...

That explains the distortion.

 

[Scaglietti]

Let me explain the 2 types of distortion before more confusion sets in.

Optical or lens distortion or geometric distortion (or just distortion) happens when striaght lines looks distorted due to the lens. Generally, the distortion can be classified and barrel or pincushion distortion. Some modern zoom lenses have more complex distortion that looks wavy like a bow. The distortion happens or is more pronounced nearer the edge of the photo. This distortion has nothing to do with the subject distance nor focal length and is purely due to the lens design, although cheaper wide angle lenses tends to give more barrel and cheaper telephoto lens tends to give more pincushion distortion. Compare Nikkor 16mm fisheye and 14mm rectilinear lens, the fisheye lens is design to have loads of barrel distortion while the 14mm lens is design to have minimal distortion.

The perspective distortion is due to the fact that objects nearer the lens looks larger than objects more distant. This distortion is more pronounced on a wide angle than a telephoto lens. This effect is also exagerated when nearer object is very close to the lens. This does not matter whether it is near the centre or the edge of the picture.

Therefore, care has to be taken with wide angle lens when perspective distortion can destroy the compostion, e.g. portraiture. Taking protraiture for example, although creativity may cause you to do otherwise, you generally want to keep the proportion of the human body. If you use a wide angle lens and put the head nearer to the lens than the rest of the body, the head is going to look out-of-proportionally larger than the body. Generally, telephoto lens will cause less of this problem. Many so-call portraiture lenses are medium telephoto lenses, 85mm, 105mm, 135mm, etc.