So I have heard things called tilt shift lenses which makes the buildings appear fully flat.
I also heard its mission critical for anyone that wants to take architecture photographs.
Why spend a grand on a lens that only makes buildings appear flat without distortion? Why dont we simply use photoshop?
See wikipedia.
The "shift" part makes verticals stay parallel (in the canonical architecture photo). Of course you can fix the perspective in Photoshop, but this loses either pixels or definition. If your building is half as narrow at the top, when you fix the perspective either you shrink the bottom (losing pixels) or widen the top (but being scaled up 2x it won't look as sharp).
The "tilt" lets you have a plane of focus that is not parallel to the sensor plane. I don't think that Photoshop has magic function to make really sharp something that is out of focus in the initial photo.
