Re: Scheimpflug in practice
Quote:
Originally Posted by
Sandokan
For rear tilt, he stated to focus on the far and tilt to the rear. Is there a reason for this?
Ye, there's a very good reason: habit.
Personally, I select the critical focus points, then shift focus back and forth between them. That tells me which way I need to swing or tilt, and roughly how much. I have a very good reason for this method too: habit.
Others will likely chime in with their ways of doing it, and all work fine and end with pretty much the same results.
That said, "Scheimpflug in practice" seldom works in the real world. There always seems to be something sticking out of the plane of focus. Scheimpflug is a great theory for understanding a bit of the physics of focus and movements, but actually trying to use it will drive you nuts. As Yogi Berra said, "In theory, practice and theory are the same thing. In practice, they're not."
Re: Scheimpflug in practice
There are many ways to skin the cat, and some ways may be more convenient than others in certain circumstances. The geometrical method I proposed was just a way to describe the process mathematically, but it doesn't by any means imply that this is the best way to do it. Fred Newman's method is excellent, and can easily be followed with any view camera without any extra tools or calculations. Whatever floats your boat, and whatever method you're comfortable with.
Re: Scheimpflug in practice
I should add that Fred Newman is using an iterative process to find the tilt and focus. Every time you tilt you also affect the focus, so you do this a few times to narrow down the best position. The number of iterations isn't magic. If you're first tilt estimate was bang on, then you may be done in one step. If you guessed your tilt wrong the first time, then the second time is just tweaking it a bit. Three iterations should almost certainly get you close enough for the girls we date, but you may need to do more on rare occasions.
Re: Scheimpflug in practice
Thanks folks. I guess you are saying that "focus on near - tilt to far", and "focus on far - tilt to rear" will both work with both lens tilt and rear standard tilt?
But will tilt be different for these?
i.e. with first one, top of lens board will tilt towards objects
but with second one, top of lens board will tilt away from objects
?
I will try this in practice just to see if simple physics is confusing me (almost 40 years since I last did lens calculations)
Re: Scheimpflug in practice
For my money the best description of how to use Scheimpflug in practice in real world situations is in Steve Simmons’ book “Using the View Camera.” Been doing it that way since the early 1990’s. It’s simple, visual, and quick. No math!
Re: Scheimpflug in practice
Let me see if I can obtain that book
Re: Scheimpflug in practice
Quote:
Originally Posted by
Sandokan
Thanks folks. I guess you are saying that "focus on near - tilt to far", and "focus on far - tilt to rear" will both work with both lens tilt and rear standard tilt?
But will tilt be different for these?
i.e. with first one, top of lens board will tilt towards objects
but with second one, top of lens board will tilt away from objects
?
I will try this in practice just to see if simple physics is confusing me (almost 40 years since I last did lens calculations)
Don't worry about the physics, it just overcomplicates things.
Think about a plane of focus. With a 35mm camera, your plane of focus will always be parallel to the film back. With a view camera, you can tilt the lens board in the direction you want to move the plane of focus. If you tilt the top of the lens board forward, then the focus plane also tilts forward. Just be aware that a small lens board tilt creates a much greater tilt in the focus plane, but it's always in the same direction.
In many landscape shots you'll have some foreground objects at ground level close to the camera, and some tall trees off in the distance. To get all of these in focus, you can envision an imaginary board that sits on top of the foreground objects, and on top of the tree. This could be your imaginary plane of focus. Now tilt the lens board in the same direction, but only a few degrees. When you focus on the near object (or the trees) they both should be in better focus than before the tilt. This will need to be tweaked if the tilt wasn't enough, or too much. The technique that Fred Newman, and others describe, is just adding a systematic methodology to achieve these tweaks. There is no magic or calculations involved. It's simply a systematic trial and error method. Once you understand which direction the lens board needs to be tilted or swung, it's only a simple procedure to refine the focus. The hard part is actually understanding which way to tilt or swing the lens board in the first place.
Re: Scheimpflug in practice
Quote:
Originally Posted by
Mark Sawyer
Ye, there's a very good reason: habit.
Personally, I select the critical focus points, then shift focus back and forth between them. That tells me which way I need to swing or tilt, and roughly how much. I have a very good reason for this method too: habit.
Others will likely chime in with their ways of doing it, and all work fine and end with pretty much the same results.
That said, "Scheimpflug in practice" seldom works in the real world. There always seems to be something sticking out of the plane of focus. Scheimpflug is a great theory for understanding a bit of the physics of focus and movements, but actually trying to use it will drive you nuts. As Yogi Berra said, "In theory, practice and theory are the same thing. In practice, they're not."
So what do you do?
