F/1.8: Wow.

This is the photo I alluded to in yesterday’s blog -- the dome of the Medici Chapel in Florence. This is a 3-frame HDR composite with 3 f/stop increments between the images. The contrast between the bright windows (which have no detail at all) and the shadows was extreme; this is why I needed such a wide range of bracketed exposures. If I could have used a tripod (which was prohibited), then I would have shot 7 frames with one f/stop between them, but hand holding the camera (and pointing straight upward is quite awkward -- it’s tough to be perfectly still) meant I didn’t have confidence that the software could align 7 images. What you don’t see in this picture is the scaffolding from the lower right section I had to remove. That was quite challenging, but I was determined to do it. I had to copy and paste sections of the dome over the scaffolding; I used the clone tool just a little to do touch up. I photographed this dome in 1991 with medium format (6 x 7cm) transparency film, and I used to think it was a good image. Compared to this digital HDR composite, the film photo is terrible: bad color, too much contrast, and shadows with little or no detail. My settings for this were f/1.8, 1600 ISO, and I used the new Sigma 14mm ultra wide angle lens. The incredibly large lens aperture meant that the ISO could be significantly lower than had I been shooting an f/2.8 or f/4 lens.