Is This Lens Effect ?

ccsnet

ccsnet

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Name
Terran
Edit My Images
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Guys.... I have linked to linked to two photos but I've had this many a time and think its the affect of the lens... could you tell me if thats the case and if there is any way to fix it as its driving me barmy....

http://www.letscommunicate.co.uk/photo/gallery/index.php/Morecambe_and_Area/P1020357

Here you can see the tower is straight.... I know that as I had serveral guide lines on the job.... but if you look at the horizon ( which I know is not straight but it cant be that bad ) it leaning down.... :cuckoo:

The second is this

http://www.letscommunicate.co.uk/photo/gallery/index.php/Morecambe_and_Area/P1020358

  • Sun roof ( the green thing ) straight
  • Lines mid way straight
  • Tips of the towers at the top no where near each other

I thought I was an angle at first ( see the road ) but after having guide lines on the job and levelling the towers etc I'm as confused as ever. :bang:

Your comments are most appreciated...

Terran
 
Your second example is the most obvious, and displays the converging verticals that are the bane of the under-equipped photographer of architecture.

You can solve or ameliorate the problem with position, software, specialist lens or specialist camera.

Position: If you can get far enough back and/or up, centre the image on something at camera height and use portrait orientation, if necessary, to encompass the building. At ground level, this will mean the bottom half of the image is filled with foreground, which you'll most likely want to crop.

Software: Can smear pixels for you. Leave plenty of breathing space around the building.

Specialist lens: A wide angle with shift is usually used. You'll find examples on TP of their use. Current lenses from Canon and Nikon for digital and 35mm SLRS also have the ability to tilt. Older lenses and cheaper ones have shift only.

Specialist camera: A camera with "movements". If you look at almost any 100 year old photos of buildings and street scenes the verticals are usually fine, due to the use of such a camera.
 
I can see what you mean and the second example is the most obvious. I doubt if it was caused by the lens, but can't be sure. It can obviously be corrected by software as I've done here.




I have also corrected the perspective so you can see the effect it has.

 
Corel Paint Shop Pro X has a perspective correction tool in it. It is very easy to do.
 
The problem is converging verticals, and is caused by tilting the camera upwards at the subject. If you want to keep the building straight then you need to keep the camera level. A tilt/shift lens will let you do that, without losing the top of the building, or you could use a wider angle lens and simply crop off the unwanted excess foreground. An alternative would be to move further away and use a longer lens. That would reduce the severity of the angles involved and thus reduce the degree of convergence experienced. I suppose a really big step ladder would also work - you just need to get level with the centre of the building.

If you want to see the effect easily, just fit a wide angle lens and look at the room you are standing in indoors. You can choose a doorframe or the corners of the room. If you pan the camera up and down, even just very slightly, you will see that the vertical parts of the room are only parallel to each other (vertical) at one particular angle. As soon as you tilt the camera up the tops of the "verticals" start to lean in. Tilt the camera down and they lean out. Once you know the cause of the phenomenon you can choose to avoid it in the first place.

Of course, Photoshop or similar is another solution, but not one which I personally choose to use. I'd rather shoot straight in the first place, unless wanting to purposely create a strong "perspective" look. That's why tripods are good for architecture - they give you the time and control to line things up properly.
 
Strangways said:
Having looked at it again, the original problem of the tower heights being different was obviously caused by the converging horizontals. So the camera must have been at a slight angle to the building.
Click to expand...
MMMmm I thought I was direct..... that been said it was a double yellow line stop for photo jobby so may be.....

Just had a quick play.... seems to fix the problem.... least I know what it is next time.

Once again thanks

Terran
 
ccsnet said:
Guys.... I have linked to linked to two photos but I've had this many a time and think its the affect of the lens... could you tell me if thats the case and if there is any way to fix it as its driving me barmy....

http://www.letscommunicate.co.uk/photo/gallery/index.php/Morecambe_and_Area/P1020357

Here you can see the tower is straight.... I know that as I had serveral guide lines on the job.... but if you look at the horizon ( which I know is not straight but it cant be that bad ) it leaning down.... :cuckoo:

always take the horizon..if its the full one as naturally level...man made structures can lean

The second is this

http://www.letscommunicate.co.uk/photo/gallery/index.php/Morecambe_and_Area/P1020358

  • Sun roof ( the green thing ) straight
  • Lines mid way straight
  • Tips of the towers at the top no where near each other

I thought I was an angle at first ( see the road ) but after having guide lines on the job and levelling the towers etc I'm as confused as ever. :bang:

your lens is tilted up...to get perpendiculars correct you need to set the camera level

Your comments are most appreciated...

Terran
Click to expand...
 
Thanks Mrcrow.... thats really helpfull.... horizon handy although some times it never looked right and I'm pretty sure I know why.

Yep your right I was looking up... again as a noob you tend to think the camera will take a 'flat' image.... I think I've learnt today thats far from the case.

Terran
 
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