Walker XL? Parallelism of front and rear standards?

[joelorbita]

Hi, I was just hoping someone could elaborate on this statement on the Walker website with regards to his XL line of cameras.


"with a fixed back which addresses the inevitable problem that afflicts all view cameras when used with extreme wide angle lenses, namely parallelism of the front and rear standards; critical depth of focus declines as focal length diminishes as does the need for swings and tilts."

Just wondering how important this is and from what focal length we are talking when this problem really occurs.

One question I have is, if you are pointing the camera up at any building, how do you correct converging lines if you are unable to move the back? I would have thought this is somewhat essential?

Look forward to someone who could explain this to me. Thanks Joel.

[Larry H-L]

Generally, one would try to NOT point the camera up.

Instead, try to keep the back parallel to the front surface of the building and use front rise.

[jeroldharter]

Generally, one would try to NOT point the camera up.

Instead, try to keep the back parallel to the front surface of the building and use front rise.

Yes, but sometimes you need indirect rise and need to tilt the camera upward and then zero out the front and rear standards with tilts if the lens has adequate coverage. I would not like having a fixed rear standard. But I can't answer the original questions.

[IanG]

Yes, but sometimes you need indirect rise and need to tilt the camera upward and then zero out the front and rear standards with tilts if the lens has adequate coverage. I would not like having a fixed rear standard. But I can't answer the original questions.

You don't need this with a camera designed specifically for wide angle work. With a 5x4 camera lenses less than 90mm need quite small angles of swing/tilt for quite large effect, likewise the amount of rise as well,

Ian