Maximizing the depth of field for 360 degrees images by optical method.
The customer could be demanding. Recently, the jeweller from Warsaw, who was my client, has commissioned 360-degrees images that had to be extremely high quality. Requirements, which I’ve heard, can be breathily summed up:
Products on the photos should look much better than in real life
I’ve got tempted and used tilt-shift lens 24 mm that is elongated of 1.4x converter (pictures). That way, I obtained more or less a standard focal length (about 54mm) with just a small full frame of my camera.
Bulky equipment is difficult to use and, unfortunately, it has to be mounted on a trivet and not on the Composer’s rail. However, I have also behold some crucial bonuses, which turned out to be worth struggling:
The extended depth of field with a diaphragm 11 (not 22, or higher).
The reduction of diffraction- sharp, shiny stones, clear and glisten gold (link to the article about diffraction).
A very short exposure time, therefore there is lack of image noise.
The effect is parallel to that made by using focus stacking (read an artickle), although it seems to be done with far less effort and without additional digital processing. In case of 360-degrees images the digital processing would mean compositing 60-90 images for a single ring!
It seems that, in many respects, this is a perfect lens for shooting jewellery, although it requires great skills and experience from photographer. This is high cost option as well – around 2000EUR.
A little bit of physics…
Tilt & Shift is a very interesting group of lenses that allow moving or inflecting its optical path with respect to the primary axis (something along the lines of the large format camera equipped with the bellows, where this function is in the standard).
Such an operation lets us i.a. take pictures of a high building without a need to raise the camera (which allows avoiding the effect of vanishing point, so that you could have feeling that the building is leaning backward) and the ability to creatively manipulate the depth of field. Both of those features are very useful while shooting jewellery, because due to them, you can avoid geometric distortions. Additionally, the depth of field significantly increases due to changing the orientation of a plane, in which the objects are captured sharp. It (the orientation of a plane) doesn’t have to run perpendicularly relative to the optical axis of the lens, but can be set at an angle (picture of lens’ setting bellow)
Examples of the presentation made in MODE Composer, setting details: Av = 11, At = 1/30, ISO = 100.
and up side down technique for the same shots (read how to prepare an up side down presentation)
Dominika Apanasewicz www.studioavior.pl