I’ve never liked converging verticals when photographing buildings, trees or anything else containing vertical structures, I’d go so far as to say I detest them. If one wants to avoid cutting off the top of such scenes when correcting and cannot afford to spend time setting up a tripod and fiddling around with keystone correction in the camera or justify the cost of a special shift/tilt lens as I can’t then the answer is deceptively simple and straightforward. Do not crop too tightly, this goes against my usual habit of cropping in camera. Here one needs to allow for what I call “wiggle room” as it’ll be needed when using perspective correction software such as DXO Viewpoint (my choice of software) or similar. So, leave some space above the building/scene and also, to a lesser extent to the sides of the frame. How much to allow is something that one gets a feel for the more one does it. Allow way too much and one ends up cropping and that’s something that I try and avoid having to do.
If one wants to roughly approximate what happens when correcting perspective using such software then take one’s hands and place them sideways on and horizontally parallel to one another and tilt them inwards towards each other at a slight angle, say 10-15 degrees so that your fingertips point inwards towards each other . Then line the tops of your fingers up with a horizontal surface say the top of one’s computer monitor. The top of the monitor then becomes the top of your image frame. Now, without changing position move your hands so that they are vertically parallel to one another. Note that the tips of your fingers now extend above the top of the monitor and thus anything in the top of the frame will now be cut off if one chooses to maintain the given aspect ratio. One can choose to make the image un-constrained which can often work in which case you’ll probably end up with a squarer image, not so good when considering framing options though. 🙂
Note the squarer image, in this shot I almost allowed enough room at the top but the very top of the cross would have been cut off if I’d chosen to maintain the 4×3 aspect ratio. Moving back a fraction or zooming out and that wouldn’t have been the case.
Plenty of room in the above shot to get everything corrected.
Same in this shot although I only just made it 🙂
Plenty of room here too, I’d have hated to have the top of the Colosseum chopped off. In this case it’s the buildings to the extreme left and right of the frame that I chose as my reference when correcting.
Finally, here’s a few more shots which worked well.
Hope this is of interest,