Even if you use a bubble level, some landscapes come out apparently leaning a little one way or the other. Is it an illusion, or is the bubble just not that precise? If you don't have a perfectly level horizon or some other known horizontal or vertical object, it's often hard to tell. Of course, if you are not to anal, you can always just turn it until it "looks" level, or does it? I believe I have found the solution for one kind of landscape -- the reflected image. Using the cropping tool that can be tilted, just turn the vertical edge of the crop to line up the upper image with its reflection in a still body of water. Pick only points, not lines -- tree trunks, for instance are seldom perfectly vertical. For instance, you can use the edge of the Sun or Moon, or even a particular leaf or peak. Now what do you do if you lined up a reflection and now it "looks" tilted? That's up to you, I guess -- just be prepared for people to tell you it needs straightening.
Does anyone have any other techniques for tweaking the tilt of an image - especially when you don't have still water? Waterfalls can be particularly frustrating because falling water usually moves horizontally as well as vertically, so it has a trajectory.
it's probably barrel distortion. I wondered the same thing too especially on ocean horizons until I realized that I could use a plug-in filter to corrrect the distortion.
Good Point, Richard. Exaggeration of perspective as well as barrel distortion complicates the issue. You would not think we would be so fussy about how level an image is when there is visible wide-angle distortion, but some people seem to be much more sensitive to the scene being tipped than to the fact that trees are radiating out in opposite directions. I guess if you wanted to be very precise, you would have to hang a plumb line in the exact center of the scene. Fortunately, for many images, level is not a critical factor. I think people tend to notice the scene leaning if there is water in it -- a lake, stream or waterfall. Maybe the best advice if there is no reflection for a guide is "if it looks good, it is good."
Hi,
I am a huge believer in believing the bubble level...but my level is on the hotshoe of my camera so I only have to level the camera...I've never quite understood why there would be a level built into a tripod when most of the time a nature photographer is not on level ground...so I guess it depends on where your level is situated. Maybe you already know about them, but HAMA makes a vertical and horizontal level that goes in the hotshoe...one of the best investments ever...I even use it when there isn't a horizon...and it often seems to improve the composition angle of a photo. I have had crooked horizons and have tilted it in a matte to make it look "right". But I haven't had this problem since I got a bubble level. This may be off subject from what you asked...but I love my bubble level...solves many composition problems quickly.
We appear to be talking about two different things, here: curvature and clockwise or counterclockwise tilt of a horizontal line. Curvature is caused by the lens and may or may not be correctable with software. (side note: I've seen curvature in photos made from film where the film was not perfectly flat.)
Tilted lines occur when the sensor/film plane is not level. Convergiing vertical lines occur when the sensor/film plane is not parallel to subject plane. (I am not talking about the curvilinear distortion due to lens construction).
A bi-axial bubble level similar to the one Cynthia uses will be very helpful to set the camera 'level and plumb'. I have found that if I take an extra second to carefully 'center' the bubble, I get better results; especially with 4x5.
Sometimes, even though my camera is level and plumb, a horizontal line will appear to be tilted. This usually occurs when I am shooting a shoreline that includes near and far perspective and the line 'curves' toward the center of the frame. The level says, 'level' and my eye says, tilt!'. Using movements of the view camera back, I can easily correct this optical illusion. I can also easily correct for converging vertial lines using the camera back. The only option for an SLR (without a Tilt-Shift lens) is to use software to rotate the image slightly to correct for the apparent horizontal tilt. Convergence can also be corrected with software, as long as it is not severe.
Discussion
4 repliesDoes anyone have any other techniques for tweaking the tilt of an image - especially when you don't have still water? Waterfalls can be particularly frustrating because falling water usually moves horizontally as well as vertically, so it has a trajectory.
I am a huge believer in believing the bubble level...but my level is on the hotshoe of my camera so I only have to level the camera...I've never quite understood why there would be a level built into a tripod when most of the time a nature photographer is not on level ground...so I guess it depends on where your level is situated. Maybe you already know about them, but HAMA makes a vertical and horizontal level that goes in the hotshoe...one of the best investments ever...I even use it when there isn't a horizon...and it often seems to improve the composition angle of a photo. I have had crooked horizons and have tilted it in a matte to make it look "right". But I haven't had this problem since I got a bubble level. This may be off subject from what you asked...but I love my bubble level...solves many composition problems quickly.
Cynthia Spence
www.geolightphoto.com
Tilted lines occur when the sensor/film plane is not level. Convergiing vertical lines occur when the sensor/film plane is not parallel to subject plane. (I am not talking about the curvilinear distortion due to lens construction).
A bi-axial bubble level similar to the one Cynthia uses will be very helpful to set the camera 'level and plumb'. I have found that if I take an extra second to carefully 'center' the bubble, I get better results; especially with 4x5.
Sometimes, even though my camera is level and plumb, a horizontal line will appear to be tilted. This usually occurs when I am shooting a shoreline that includes near and far perspective and the line 'curves' toward the center of the frame. The level says, 'level' and my eye says, tilt!'. Using movements of the view camera back, I can easily correct this optical illusion. I can also easily correct for converging vertial lines using the camera back. The only option for an SLR (without a Tilt-Shift lens) is to use software to rotate the image slightly to correct for the apparent horizontal tilt. Convergence can also be corrected with software, as long as it is not severe.
-PB