How Too Much Tilt Can Tilt the Beginner's Brain
When starting out in LF, most start out trying to use far more camera movement than needed to accomplish our objective (no pun intended). Here's an example of how it could become confusing, which I happened to recall today from my own past experience. Perhaps it will help someone new to LF photography.
I was using a 210mm lens on a country scene. I was by a road on a low hillside. A barn with tall trees close by it stood perhaps 1,000 ft. or more away, on high ground about the height level at which I was standing. In between, the ground in front of me as I faced the barn sloped down to the level of a large pond, perhaps 20 feet below. The closest grass in my composition remained at about my level and lay perhaps 20 feet from the lens. I wanted everything in focus.
From under the dark cloth, I started by tilting the lens enough to have the center of the barn and the nearby grass simultaneously in focus. However, the pond was then way out of focus. But what astonished me, was that shifting the focus to the pond at this setting required moving the front standard backward, i.e., the pond was now the far focus and the distant barn the close focus. Huh?!
The key to the conundrum is to remember what happens as we tilt (or swing) either standard. Imagine two marks painted on the plane of focus, one at the top of your framing, the other at the bottom. For simplicity, let's assume that the lens will be tilted around its center. Starting at vertical with the camera levelled and movements zeroed, as we slowly tilt the lens forward, the plane-of-focus starts tilting (more than our lens board) from vertical increasingly toward horizontal, the imaginary top mark moving farther away from the camera and the bottom mark getting closer to the camera. "Far" focus will remain on the far side of the plane, which will be increasingly underneath the titling plane; "near" focus will remain on what was our side of the plane, and thus increasingly above the tilting plane.
The cause of the seemingly opposite focusing direction in the scene described, was the degree of tilt. By tilting so much that the grass and barn were simultaneously in focus, the plane of focus had been made nearly horizontal. Therefore, I was actually focusing on the distance from the camera to the grass in an almost vertical direction, just as if, had I used no movements, I would have had to aim the camera down toward the grass mot far from the front foot of the tripod. With the plane of focus in this orientation, therefore, in order to bring the pond into focus meant focusing farther away (thus bringing the lens closer to the film), because the pond surface surface, about 20 feet below my feet, now lay on the far side of the plane of focus, which had been place somewhere around 7 feet from the lens.
In my case, the picture I had hoped for was not really within the capabilities of the lens. The depth-of-field I wanted would have required an f/ stop of about 64, and even if I had had it marked on my lens, the diffraction would have surely taken the edge off the crisp Ansel Adams look I was imagining.
I hope this may be useful.
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Re: How Too Much Tilt Can Tilt the Beginner's Brain
Re: How Too Much Tilt Can Tilt the Beginner's Brain
Well, that was a much easier task than expecting everything from below your toes to infinity to be in focus. How much tilt is enough? - whatever it takes to get the job done. What many beginners fail to realize is that you don't necessarily have to do it all using front tilt only. If the camera is aimed downward somewhat, returning the rear vertical will not only restore the verticals in the scene, but also do much of the heavy lifting with respect to near/far plane of focus. Then just make up the difference with the front standard. That way you don't need to use near as much of the hypothetical image circle, or quite as small an f-stop.
"Crisp Ansel Adams look" - ha! Ever seen many of his images enlarged more than 2 or 3 times?
Re: How Too Much Tilt Can Tilt the Beginner's Brain
Quote:
Originally Posted by
Ulophot
The depth-of-field I wanted would have required an f/ stop of about 64, and even if I had had it marked on my lens, the diffraction would have surely taken the edge off the crisp Ansel Adams look I was imagining.
I hope this may be useful.
Over the years I have taken many images with my 210mm, 250mm, and 300mm lenses at f/64 that enlarged to excellent(and sharp) 16x20 prints. I recall reading that Ansel Adams had no qualms about closing down to and using f/64... he just didn't enlarge those negatives to 40x60" or larger.
Re: How Too Much Tilt Can Tilt the Beginner's Brain
He sure as hell did enlarge a number of those negs to 40X60's, or have them enlarged under his supervision at a more adequately equipped pro lab. F/64 was the name of the movement; and they often stopped down further than that! But until his later years, AA didn't have anywhere near the level of camera precision or lens quality we routinely expect today. "Fine-grained" films back then are what we would call buckshot today. "Fast" emulsions back then used a cable release connected to a Carbon 14 clock on the other end. So no, his big enlargements (really only 6X from 8x10 film) are really quite mushy unless one backs away quite a bit when viewing the print.
I never personally like to stop down 4X5 lenses more than f/32; with 8x10, f/64 is equivalent, though I prefer not to stop down more than f/45 if contemplating a 4X enlargement (8X10 to 30X40 inch). That's because viewers really do get nose-up to even my larger prints. If the detail is there, it pulls them in. Leave that "normal viewing distance" nonsense to outdoor advertising companies and the Marlboro Man, who looks perfectly sharp on a billboard thirty feet across from a normal viewing distance of a quarter mile.
Re: How Too Much Tilt Can Tilt the Beginner's Brain
"Crisp Ansel Adams look" - ha! Ever seen many of his images enlarged more than 2 or 3 times?
Yes, but you surely know what I'm talking about, even though you do know how to machine to within 3 quadrillionths of a millimeter. There are 8x10 contact prints, and 16x20 -- hardly a small print -- is, of course, only 2x for the big negs. And even those old, thick, slow film emulsions can have a breath-taking effect with certain images. And for someone like me, who knew little but 35mm for my first decade of photography and had seen few truly fine print originals...
Re: How Too Much Tilt Can Tilt the Beginner's Brain
Depends on the picture. If one wants to give the impression of sharpness everywhere it is often preferable to accept a small loss of definition everywhere than to use a wider aperture. Tilts and swings are not useful in anywhere near as many situations as a newcomer is led to believe. They can also be detrimental.
Quote:
Originally Posted by
Drew Wiley
He sure as hell did enlarge a number of those negs to 40X60's, or have them enlarged under his supervision at a more adequately equipped pro lab. F/64 was the name of the movement; and they often stopped down further than that! But until his later years, AA didn't have anywhere near the level of camera precision or lens quality we routinely expect today. "Fine-grained" films back then are what we would call buckshot today. "Fast" emulsions back then used a cable release connected to a Carbon 14 clock on the other end. So no, his big enlargements (really only 6X from 8x10 film) are really quite mushy unless one backs away quite a bit when viewing the print.
I never personally like to stop down 4X5 lenses more than f/32; with 8x10, f/64 is equivalent, though I prefer not to stop down more than f/45 if contemplating a 4X enlargement (8X10 to 30X40 inch). That's because viewers really do get nose-up to even my larger prints. If the detail is there, it pulls them in. Leave that "normal viewing distance" nonsense to outdoor advertising companies and the Marlboro Man, who looks perfectly sharp on a billboard thirty feet across from a normal viewing distance of a quarter mile.
Re: How Too Much Tilt Can Tilt the Beginner's Brain
Well, Michael's assessment wouldn't work in about 90% of the pictures I've taken in my life. View cameras have tilts and swings for a good reason. Otherwise, just buy a box camera for sheet film.
Re: How Too Much Tilt Can Tilt the Beginner's Brain
Uh-oh. What have I started this time?
Re: How Too Much Tilt Can Tilt the Beginner's Brain
Don’t worry - me and Drew often end up arguing about this stuff but it’s light hearted jousting, and we sometimes agree.
Quote:
Originally Posted by
Ulophot
Uh-oh. What have I started this time?