Scheimpflug Principle

Ian-Barber

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Can someone who is good at explaining, give an easy to follow description on how to use the Scheimpflug principle from a practical stand point such as how to get in the ball park for front tilts when trying achieve max depth of focus front to rear.
 
You probably need diagrams to do it justice; but maximum depth of field is achieved when the plane of the film, plane of the subject, and plane of the front (lens) panel all meet in a line. If you can visualise where the required plane of focus in the subject is you can start from there. If we take the simplest case of photographing a lake (guaranteed flat) all you have to do is adjust the front and back standards so that the converging angle they make with each other meets at the water level.

For more real life situations, it isn't quite so simple to determine the angles exactly; but in most situations it isn't really quite so critical.
 
Everyone probably has their own way of setting their camera up to make use of the S. Principle. My method is as follows.

Step 1 Guess the amount of tilt needed, and apply it.

Step 2 Focus on the far side of the lake's surface (to continue with Stephens analogy) This will be near the bottom of the focussing screen.

Step 3 Check the focus at the top of the screen to see if the lake immediately in front of the camera is in focus. If it isn't, RESIST THE URGE TO RACK THE FOCUS BACK AND FOREWARD TO GET IT SHARP. You need to know if more extension is needed to get the foreground sharp, or less extension, because if MORE extension is needed, then you need to apply MORE tilt. If less extension is neeeded to get the foreground sharp, then less tilt was needed.
I always apply more extension. If the foreground then becomes sharp, I go back to step 1, apply more tilt, then repeat steps 2 and 3.
If the foreground becomes less sharp still (with more extension) you actually needed less extension. So go back to step 1, apply less tilt, then repeat steps 2 and 3.

It may take two or three runs through, but eventually you will get the near and far side of the lake in focus. The duck that you were trying to photograph may have migrated and may now be on another lake 3000 miles away, but at least all the lake will be sharp,. And you will learn to do it quicker with practice!

Alan
 
I've emailed you a pdf and an animated gif that might help explain it all Ian - Idon't know how to post them in the forum so perhaps you can do it? ;)
 
Thanks everyone, just what i was looking for, clear simple information without having to reach out for the headache tablets or calculator :)
 
Hello Ian,

As said above, I'm sure each LF photographer has their own way of using this principle in the field, but here is how I do it:

1. With both standards set as normal (vertically), compose your scene.

2. Focus on the far distance (bottom of gg).

3. Slowly begin tilting the front standard forward or the rear standard rearward while watching the far distance focus. Slowly focus, as needed, to keep the far distance in focus until the near distance is in focus, too. Wow, this is a lot harder to explain than to do! :)

4. Once you have near/far both in focus, adjust scene focus to taste.

There are a couple of caveats to the above: 1) if using back tilt, the method I described above assumes base tilts on your rear standard. If axial tilt, then simply focus sharply on the center of the gg and tilt either standard until near/far is in focus, and 2) this near/far focus assumes your subject is on a flat plane (the lake analogy above.) If you're using it to gain DoF (which you probably are!) and have vertical subject matter (like trees, for example), then where to place focus gets a bit trickier because now the area of acceptable focus is not following a standard vertical plane. It all sounds a bit complicated, but once you do it a few times you'll have it locked down.

Oh, I forgot to mention above that you'll probably have to raise/lower one of the standards (I always use the front because I don't have rear rise/fall on my camera) to re-adjust your composition.

Good luck!
 
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