Movement to correct distorted lines?

[tony_black1]

correct the distorted lines when I am directing the camera with an angle of

30degrees or so from 45th floor looking through the buildings downwards.

 

Which movement I need to correct the distorted horizantol lines?

 

The lens is a 150mm rodenstock lens.

[michael_briggs2]

Do you mean vertical lines? Having convergence in horizontal lines is normal practice. A convention in perspective rendering is to keep vertical lines parallel. This is an artistic decision. If that's what you want to do, keep the camera back plumb, i.e., perfectly vertical and perpendicular to the horizon. The easiest way to do this is to set all camera controls to neutral and keep the camera level. Then, for your example that you want the view to be downwards, use front shift down -- move the front standard with the lens downwards until you have the view that you want.

[tony_black1]

sorry vertical lines. i am pointing out the camera from the window to downstairs to shoot the buildings etc. but there is quite a bit of distortion of vertical lines which i dont get this distortion with my mamiya rz 110mm lens.

 

i am very surprised if this kind of distortion accepted normal for 150mm rodenstock .

[leonard_evens]

As Michael pointed out, in order to keep verticals parallel, you need to keep the back vertical. He told you one way to do it. Another way to do it is to point the camera down and then tilt the rear standard back to the vertical. To keep everything in focus, you would probably also want to tilt the front standard so it is parellel to the rear standard and also vertical.

 

This all assumes you are talking about using a view camera with a 150 mm Rodenstock lens. If you just point the camera down without making any adjustments, the resulting image shouldn't look too much different from what you see with your Mamiya RZ67. The normal focal length for 6 x 7 format is about 90 mm, so 110 just a bit long. A corresponding lens for 4 x 5 would be about 180 mm. With a longer lens, you magnify the image more, so, although the convergence angle doesn't change, there might be a subjective difference. But that seems unlikely in your case because of the modest relative increase in focal length.

 

I think you should explain in greater detail what your problem is. Your camera doesn't use different laws of optics, so I think there must be some misunderstanding. If you can post an example or two, it might help.

[leonard_evens]

I just noticed that you describe distorted horizontal lines. In which way are they distorted? Are they curved? If so, something is seriously wrong with your lens. Are they straight but converge, when you want them parallel? That would be because your back is not parallel to the plane containing those lines. You can correct that by appropriate movements. As i said previously, you have to give us more details about just how the camera is pointed relative to what you are photographing.

[friedemann_pistorius]

In general, to avoid distorted lines you have to keep the camera back parallel to the lines.

<p>For vertical lines, keep the camera back absolutely vertical and use up/down shift movements on front or back, depending on your camera's capabilities.

<p>For horizontal lines (not the horizon itself, as I understand your question, but on/in buildings, for example), keep your camera back again PARALLEL TO THIS LINE. This means you'll probably have to use lateral shift movements (direct or indirect method, depending on your camera's capabilities).

<p>In architecture photography, people often combine vertical and lateral shift movements to keep vertical/horizontal lines vertical/horizontal.

 

<p>If I misunderstood something, please correct me.