Skswany Loc: St. Paul, MN

I took this photo of Notre Dame Cathedral a week ago when in Paris and was fairly close to the building. I shoot a Canon T3i with a Tamron 18-270 lens. The lens was set at 18mm, f/9, ISO100. The architecture is noticeably curved up on the left - which is not reality of course. When I stepped further away, the shot straightened out - well sort of (see shot #2). Just wondering what caused this. Is it a limitation with the lens at this short of a focal length? Advice and feedback appreciated!

PrairieSeasons Loc: Red River of the North

If you had made those shots with the camera parallel to the ground, you would not have the vertical lines converging. (That probably isn't the perspective you want, but it is a fact). You are shorter than the building and are shooting up which will give that effect.

If you hold a straight edge up to your monitor or print, you will see that there is a lot less curve than you imagine. The curve you see is an illusion created by the architecture itself with the facade of the building made up of receding columns.

You didn't ask how to eliminate the effect, but one possibility is to use a tilt-shift lens and another is to use the lens correction filter in PhotoShop.

ianhargraves1066 Loc: NEW SMYRNA BEACH, Florida

Having always been involved in photographing buildings of all shapes and sizes over the years it has always been a source of irritation that most every photograph I have seen of tourist attractions of such buildings as the Notre Dame Cathedral most often look like the builder did not possess a level and a plumb line.
Professional Architectural photographers would use a view camera with movements to correct the distortion with a control called a rising front . If you are undertaking a lot of photographs of buildings you can help overcome the problem by moving further away from the subject so that the camera can remain in a horizontal position. If you are well healed you can invest in a special wide angle "Tilt / shift " lens that allows you to move the lens upwards in relation to the film plane.
You can achieve a similar effect in the computer (I can only vouch for this correction in Corel Paint Shop Pro, since it is the only program I own, Its called, would you believe "Perspective" control. And takes maybe 20 seconds to achieve.

The correction however somewhat distorts the image a little in other ways and chops a small amount off the edges of the photograph.

I took the liberty of correcting both images and you can see the images that resulted. Its a kind of result of compromise which distortion do you prefer! Bottom line, put up with the distortion, stand further away so you avoid tilting the camera, buy an ultra wide angle lens and crop out the subject from the center of the photograph, buy my Sinar (best route) or a wide angle lens with tilt/ shift facility!

You "pays yer money and makes your choice!

Ian

Skswany Loc: St. Paul, MN

Thanks so much for the feedback and correcting the photo! I think I should invest in a good wide angle lens and investigate the capabilities of Photo Elements 10. It may have a similar feature as Corel. I did try to step back with this shot, but lost the full view of the church when I did so...:(

Thanks much!!

Skswany Loc: St. Paul, MN

Thanks for the advice. I will pay more attention to the level of the camera when I shoot buildings. I was not using a tripod (vacation shot and all..) AND will check out the option to correct in my Photo Elements. Thinking a new wide angle lens may also be a good addition to my gear!

PrairieSeasons Loc: Red River of the North

I wasn't necessarily saying you had to have the lens parallel to the ground. Sometimes you need the vertical angle to get the shot you want. I was just saying that the converging vertical lines is a result of that vertical angle.

Skswany Loc: St. Paul, MN

You mean the vertical lines in the building itself. Right?

PrairieSeasons Loc: Red River of the North

Yes

lightchime Loc: Somewhere Over The Rainbow

Even when holding the camera parallel to the ground you will get convergence. The best example may be the cliche of parallel railroad tracks running into the distance. They always appear to converge.



The top of he building is further away than the bottom and this "keystoning " results. There is another way to correct it in photoshop. Check help for convergence correction or look up "keystoning". It can be corrected by choosing the right options in cropping.

Skswany Loc: St. Paul, MN

Ok. I will pay attention to the lines of the building in the composition. I hope to photograph a swing bridge from the 1900's this fall. This will be most helpful.

Skswany Loc: St. Paul, MN

Will do. Thanks for the pointer on Photo Elements. There is a keystone correction in the full edit program.

ianhargraves1066 Loc: NEW SMYRNA BEACH, Florida

Incidently I used to go to school during the summer at the Lycee St. Louis which is situated on the road in front of the cathedral and I never saw any pic where the walls were not Keystoned.

Ian

ianhargraves1066 Loc: NEW SMYRNA BEACH, Florida

I would be kinda neat to play with The Leaning Tower of Pisa.

Bekkie Loc: Ohio, USA

Great information and LOL @ playing with the Leaning Tower of Pisa!

nikon_jon Loc: Northeast Arkansas

The effect you got is called 'keystoning'. From the keystone at the top of an arch only turned upside down. It is a matter of perspective. Anything you view that is farther away from you appears smaller. It happens when YOU look up at something tall, but your brain says, "This isn't quite right" and it compensates to some degree.

The camera has no brain, so it can't do that. The effect is much more exaggerated with wide angle lenses. As others here have said, you can get a lens that will correct that. Call PC lenses, for 'perspective control', but good ones are very expensive. And even with a PC lens, you have to have the camera absolutely level. Some who do this kind of work frequently, get a little bubble level that fits on the flash hot shoe. As you might guess, this kind of work is best done on a tripod.

The software solution works fine for me, but you have to allow a little more space when you shoot the pic because when the software makes the correction, it has to enlarge the pic somewhat. Paint Shop Pro software has a good distortion correction feature.