Should the effects of swing/tilt be apparent on the GG during the composition phase?
Should the effects of swing/tilt be apparent on the GG during the composition phase?
yeah. i see them.
Absolutely. What you see on the GG is what you get on film.
for subtle movements (swings and tilts can often be subtle for focusing) a loupe may be needed to see the subtle focusing changes.
Daniel Buck - 3d VFX artist
3d work: DanielBuck.net
photography: 404Photography.net - BuckshotsBlog.com
As already noted, the effects can be subtle, particularly for wide angle lenses. The region in focus is a wedge which swivels on the so-called hinge line which is in line with the lens on a line parallel to the film plane. How wide it opens depends on the aperture, but it is always much narrower closer to the lens than far from the lens. So the changes should be most evident for subject points close to the lens.
Note that the hinge line is below the lens if you tilt down, to the same side that you swing if you just swing, and somewhere intermediate if you both tilt and swing. Its distance from the lens depends on the tilt/swing angle, the larger the angle the smaller that distance. It can never be smaller than the focal length, but you would have to have an enormous tilt/swing for it to approach the focal length, which will never happen in practice. For a small tilt angle, the hinge distance is approximately 60 times the focal length divided by the tilt/swing angle. So if you used a 5 degree tilt with a 150 mm lens, the tilt distance would be approximately 60 x 150/5 = 1800 mm = 1.8 meters. This rule breaks down for large angles. The exact rule is that the hinge distance is equal to the focal length divided by the sine of the tilt/swing angle.
Not a dumb question at all. The answer is "yes," but it sort of depends on what you mean by "apparent." You'll probably have to use a magnifier on the GG, especially after stopping down
Wilhelm (Sarasota)
I usually recommend getting one of the gg brighteners to make the image easier to see. These usually brighten the image about 2 stops.
steve simmons
www.viewcamera.com
Good day Steve,
What do you mean by a "gg brightener?"
Do you mean a fresnel gg such as the ones produced by the specialty gg maker?
Tomaas
yes, Bromwell Marketing has them, Beattie, Linhof, etc. If you can find Bill Maxwell in Georgia he supposedly makes a good one as well. As far as I know, all of these will replace the stock gg on your camera.
steve simmons
You could try starting with a normal lens (150 or thereabouts on 4x5) and setting up your camera so that it is close to the ground.. if you are about a meter away from the ground you'll need between 5 and 10 degrees of tilt to get the focus 'hinging' about the ground at your feet. You should then see the ground at the far distance come in and out of focus as you move your focus backwards and forwards but the ground in the foreground should stay in focus all of the time (or if you've got the tilt wrong, it will stay out of focus most of the time)..
Working close up focus and close to the ground is a good way to learn though..
Tim
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