Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

Focal length, proximity to subject and amount of tilt determine how much keystoning you will get. If you are wider/closer/really tilted a lot you will have more keystoning.

The only way to minimize this and still have enough pixels left for good resolution is a shift lens. A lens will tilt will only affect the depth of field. Shifting reduces or eliminates the need for tilting the camera (and sensor) up, which is how keystoning is controlled. Once you've used one you'll never go back to trying to resolve the matter in software, but if you do plan on just a software solution, DXO Viewpoint is the very best.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

I Absolutely agree. Addressing perspective issues in the camera is the best approach. I have found that post processing remedies are only effective in very minor ketstoning issues and many PP actions bring on other distortions or quality losses. If you do a good volume of architectural work, theses lenses are well worth the investment.
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imagemeister Loc: mid east Florida

This IS the correct approach LEE ......as I have mentioned also ...the poor man's shift lens is an Irix 15mm f2.4 in Pentax mount on a shift adapter to Sony A6000 series. Use with a leveling head on tripod - I would use a 3-way head.

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jdubu Loc: San Jose, CA

Thanks to Ed and Gene for the concise info. Sometimes it is great to hear other voices reinforce what I do and what I need to learn to do. I am very judicious in where I use what lens and spend more time looking for the point of view or views that work for my client than I do actually setting up the shot. Visualizing the view works well, but sometimes I just need to go through the lenses on camera to see how it actually translates into 2D. (which is a perfect use for the back up bodies I bring)

Almost all my architectural shooting is sans people, so my base ISO is usually 160 or 320. So with a good tripod, the TSe lenses are very much worth having. Although, with full frame cameras, I never would have bought the 17mm because it is not a main focal length I would use. Luckily, I needed it for a job which more than paid for the lens.

If Canon Lee stays with aps c cameras, Ed is right about the 17mm, think twice if you are looking to go FF in the future. Do all you can on site when shooting, you will find PP is minimal after that.

Jesu S

I had the same issues when I did RE. I quit using a 17-55 or a fisheye, and switched to shooting several frames on a tripod and stitching them together in PP. If the MRIS will not accept panos, you can always crop to a "normal" aspect ratio. Don't do RE any more because the realtors think iPhone photos are sufficient.