Summary of your problem--- Keystoning is caused by not being exactly perpendicular (both ways) to the center of the door or house, etc. Bulging in our out is due to the lens, called lens distortion, and this varies quite a bit lens to lens, and if your're using a zoom lens, it will vary one way or the other based on focal length. Every lens is different; there are no rules; the newer the lens and more professional the lens, the better you will be. Wider angle tends to make things worse, but not so bad if you have a really, really good / expensive lens! Both of these problems are easily fixed in Photoshop (Lens Correction), so I would highly suggest trying this if you are serious about photography. If you try to minimize keystoning with camera placement, you will GREATLY reduce any creative input to your photos. You will be forcing yourself to be in a special spot, and you lose most creative potential for composition (which is always 90% of any photo). I'm an architectural photographer, and I must straighten EVERY picture I take, even when using tilt/ shift lenses. If you want things to be perfect (of course you do...) then you must jump into Photoshop or equivalent. I was typical portrait photographer for 16 years, then switched (almost overnight) to FT architectural (past 13 years). Yes, it happened--- but I had what you might call lots of "providential circumstances". If you are serious about photography, have a brainstorm session about how to SELL your work and MAKE MONEY. Then you can buy all kinds of fancy new gear and lens-- and if you make a magazine cover now and then, you are in "Photographer Heaven". I can teach you if you are serious...... Cheers------- Wayne