I don't usually do floral photography, mostly because I suck at it (if you want to see great florals check out +Greg Mitchell's work). But I succumbed to temptation today for two reasons. First I noticed this orchid had flowered and more importantly I've been looking at close up work folks have been doing with technical cameras and wanted to give it a shot myself. There's nothing too special about doing close ups, you insert additional adaptors between the camera and the lens and in return for being able to focus even closer, you give up infinity focus. Its called an extension tube and the concept has been around for ages.
I haven't been too fond of using extension tubes with my DSLRs mostly because the lenses aren't designed for great close up performance (with the exception of dedicated macro lenses of course). I was curious to see how the Rodenstock 180mm Digiron would do with 51mm of extension. The answer is that it does exceptionally well. Aberrations are well controlled and the resolved detail is out of this world.
At these focus distances (and focal lengths), depth of field is shallow, even at nearly f/16. So I made 12 exposures started at the "rear" where the back petals of the flowers were in focus to the "front" where the tip of the lip is in focus. I first tried to use Photoshop for the stacking but the result was a mess, so I turned to Helicon which produced great results using the depth map technique (great but not perfect, there are 1 or 2 artifacts).
Using a lens with a leaf shutter for this work was beneficial. I could still trigger the strobes at the slightly higher shutter speed of 1/350s which helped to eliminate any ambient light since I made this image during the day. I used two lights for this image, one to the right in a mini softbox and another to the left with a snoot. I found my images to be a touch too cold so I ended up holding a mild warming gel in front of the shoot to warm up just one of the lights. It took a few hours to make the image since I had to work on it on and off, holding a 7 month old baby who refused to be put down. A fun project for a Sunday afternoon.