Friday, February 19, 2010
Today I happen to have handy a bunch of different flashes I always wanted to compare. Yes. Which one is more powerful, and by how much? The best way to show this is to use a light meter, put it at ten feet from the flash set at full power and measure what people call the "Guide Number". Basically the required aperture to illuminate a subject as medium gray. This is a useful number for undiffused strobes as for them it turns that:
Guide Number = aperture x distance = constant.
So if we measured f4 at 10 feet, the guide number GN is 40, which means that at 5 feet we will achieve the same exposure at f8 (closer, brighter, and so we can use a narrower aperture).
The higher the GN, the more powerful the flash. This of course at the same ISO.
So here are the numbers, I used ISO100 in all cases. Packs and flashes were all at full power.
Elinchrom Ranger S head with standard reflector + "A" Ranger RX pack. GN 250 $2100
Elinchrom Ranger Ring Flash + "A" Ranger RX GN 220 $1500+$1700
Alien Bees B800 +standard reflector GN 130 $280
Alien Bees B400 + standard reflector GN 90 $225
Canon 580ex II (zoom 80/28mm) GN 130/90 $440
QFlash+standard cone GN 110 $1080
Lumopro GN zoom 85/28mm GN 90/71 $120
Canon 580x II + Coco Ring Flash GN 35 $440+$80
Btw, I have found another test here on Flickr. Results are similar.
So what have I learned?
1) more expensive flashes have more power and the area where they are able to light uniformly is *much* larger (and rounder!) than with the cheaper speedlites (see the image). But greater power comes with a price (and greater responsibilities, but that is another story).
2) The Canon 580x II is good! More powerful than the LumoPro and the QFlash, but *only* if you use the zoom feature. Read the manual..or pay $300 extra bucks compared to the LumoPro, which is a lot easier to use (see and extended review)...mmm.
3) The Canon+ the Coco Ring flash performs well, but the output is not that great, unless you are in studio. The zoom factor makes no difference with the Coco attached.
4) The QFlash is weak sauce for the price $1080 (head+pack)
4) The Speedlites are a tad cooler than the Elinchroms.
5) The Ranger pack has two outputs: A and B. A is 1+2/3 stops brighter.
6) the ABees Long throw reflector increases output by 1 stop! (from the Flickr Strobist group test)
Monday, February 8, 2010
Judson and I were asked to give a quick demonstration of the Softliter II (the one Annie Leibovitz uses) for portraits. This set up used a Softliter sl-5000 (the mid sized one) and a profoto head for the top portraits (Hey Paige!) , and a Canon 580x II for the bottom one (Mister Plax Photo trying to get the perfect Rembrandt...). Strobe was high on camera left and bounced on a white board to camera right. We used a 5D Mark II with 24-70 f2.8 USM Canon lens. You can see the Softliter reflected on the window...
Tuesday, February 2, 2010
I needed a second image of the patent black boots I photographed some weeks ago, so I went for a different, more metallic style. This time I shoot from above (camera was rigged on a boom). Lights: Diffused top flood, two strip lights very (very) low on the table to give edge to the shoes. And a small softbox from below. The difference? I used a metallic, sheer textile over a plexiglass as the surface on which the shoes lay down. The image on the left uses a similar set up, but adds a blue/yellow color palette and the top light is harder.
Small trick: I used a few small plexiglass cubes to angle the shoes the way I wanted. I used photoshop layers to increase the contrast on the background and usual details clean up.
Shot at ISO 100, f11, 1/125th. 35mm, with a Canon 7D.