Scheimpflug Rule when near is higher than far
Every time I see an explination of the Scheimpflug Rule it includes an example like a rock in the foreground and then a mountain (which is much higher) as the far point. Using front tilt, tilting the standard forward allows the film plane, subject plane and lens plane to meet at a single point. I understand this much and have used it successfully in the field.
What to you do though when your foreground is higher than the background. See first picture attached - I shot this a week ago (one of the first exposures I made with my new Chamonix!). I simplly used the focus near, focus far, observe distance in between, focus at the middle point and stop down. Incidentally, the results using this method were not that succesful for this shot, as with my 135 stopped down to F32 I didn't get adequate sharpness throughout the image.
In this situation, can I use front tilt, except tilting the front standard backwards? See my little sketch -red lines represent film plance, lens plane and subject plane. To me this should work, but I've never tried it in the field. I have tilted the front standard backwards before (and the rear forwards) but only to get most of the image out of focus.
Tim
Re: Scheimpflug Rule when near is higher than far
I can't answer your question, but I had to say that I like your drawing :D
Tim
Re: Scheimpflug Rule when near is higher than far
Hi, to get the foreground in focus you will need to use forward tilt on the front, or back tilt on the rear standard. It might be easier if you think of it this way: take your diagram and rotate the whole picture until the red line is horizontal. It then becomes just like a normal landscape. It's easier to just try it out to understand, rather than theory.
Jon
Re: Scheimpflug Rule when near is higher than far
I'm just impressed anyone can spell 'Scheimpflug'.
I had to cut and paste. I second the nice drawing.
Re: Scheimpflug Rule when near is higher than far
I would think that tilting the lens back would work but I'm not a Scheimpflug expert. In a difficult tilt situation I don't really give much thought to Scheimpflug as such, I just tilt until the camera starts working the opposite of the way it should (i.e. to the point where moving the front standard forward starts to bring the far into better focus and moving it backwards starts to bring the near into focus). At that point you know you've tilted too much and you can just back off a little to get close to the optimum tilt. Scheimpflug isn't all that easy to use in the field if you use it by trying to envision the meeting point for the three planes because that point is often several feet under ground (or somewhere up in the air above the camera in your case).
Re: Scheimpflug Rule when near is higher than far
can I use front tilt, except tilting the front standard backwards?
Yes absolutely! That seems to be solultion here.
Re: Scheimpflug Rule when near is higher than far
I think Jon Shiu has it right. Don't think of each landscape element being higher than the other in terms of pure elevation... think of it being higher relative to the optical center or line of sight of the lens. Your camera is actually pointed down, since the horizon is at the top of the frame.
If the foreground was truly higher in the frame than the distant rock, you wouldn't be able to see the distant rock. I've modified your diagram to illustrate.
I think a strong front forward tilt, or a strong back rearward tilt (tilting the back towards vertical) would have worked here. Probably the back tilt, to correct perspective and to preserve coverage.
Re: Scheimpflug Rule when near is higher than far
I second Jon & Sheldon's point. It does not matter what is elevation wise higher and lower, but that the image portion on the lower portion of the image (upper on ground glass) is closer and the image elements in the higher part (lower on ground glass) are further away.
Most likely your problem was not enough forward tilt, or you may have run the lens out of coverage. As a *rough* approximation, the lens plane equally divides the angle between film plane and image plane. Let's assume you pointed your camera zero-zero at an angle of 20 degrees down. The image plane looks like at an angle of approx. 70 degrees: Difference = 50 degrees, put lens plane at 25 degrees to split the 50 deg. 25 deg front tilt is quite significant. You can get away with a bit less tilt and stopping down, so that depth of field will provide acceptable sharpness in the desired areas.
Re: Scheimpflug Rule when near is higher than far
Tilt won't rotate the plane of focus more than 90 degrees, so you'll need to point the camera down. For starters, imagine the camera axis more or less aligned with the red line in your diagram--it's then a matter of tilting the front forward (or the back backward, or combination thereof), much as you would do in a normal situation.
Re: Scheimpflug Rule when near is higher than far
Quote:
Originally Posted by
Jeff Conrad
Tilt won't rotate the plane of focus more than 90 degrees, ...
Yes it will. Try it!
This is a quite common situation for me, when I'm up on something high shooting down. I use front drop for quite a lot of my landscapes, simply because all the interesting bits are below me!
Use front foreward tilt if you want the foreground to be sharp too. Front backward tilt puts the near bit of the wedge up in the air over the camera, which may not be what you want.