Thursday, November 5, 2015

Natural light

For a change, I did a session on natural light. This one at 85mm wide open at f/1.4.

Saturday, September 19, 2015

Floating OCF-VAL

We had a difficult task framing and keeping the flash in place for this moving target.

Luckily, the sailors were handy enough to return ashore with everything dry, and nothing else to recall than a decently lit picture.

Sunday, August 30, 2015

Corollary: how much flash power do you need?

These settings allow me to equal or overpower the sun,

f/1.4 + ND6 = f/11 for the flash
f/2.8 + ND3 = f/8 for the flash
f/4 + ND3 = f/11 for the flash
f/5.6 + Polarizer = f/9 for the flash

f/11 is not so much flash power in principle, it all comes down to the modifiers and distance that you want to use.

Wednesday, July 8, 2015

Nailing the Off-Camera Flash exposure

When lighting with flash, you can independently control the main subject and the ambient exposure. The first is achieved by adjusting the camera diaphragm, and the second with the exposure time. Fine.

The camera sync speed sets the limit where you can get the most power out of your flash, 1/250 in my case. You can resort to use a ND filter to keep your shutter below this level. You can also use a ND filter to keep a wide aperture even in very bright conditions.

With my ISO at 100, I knew a few configurations that work well, but now my base ISO is 64, and not always I’m in a safe light zone, so I’ve put together a simple spreadsheet to calculate this things for me, both camera and flash in manual mode.
First, we need to enter two basic parameters, your camera ISO and sync speed. Mine are 64 and 1/250.
Now, you may be in a Sunny 16 situation, or even f/22 at the beach. You can perfect the math if you make a reading with the light meter of the required aperture, setting the time equal to your ISO. Say we’re at Sunny 16.
Choose your aperture. I want to shoot at  f/1.4. You want to maintain the camera shutter speed below the sync speed, so a ND filter is required. I will use a ND6, and with this combination, my shutter speed comes down to 1/128. 
With these settings, I could be shooting without flash, and the camera exposure is compensating for the ND. 
Now we want to add some flash. Since the flash is only affected by the aperture, and I'm shooting below the sync speed, all I need is to throw flash light as to read f/1.4 plus 6 stops of the ND filter, i.e., f/11.
I also want to underexpose the ambient light by one full stop, but I want the flash to nail the exposure for the main subject. Then I only need to modify the shutter speed, if I'm within the comfort zone of the sync speed.
The spreadsheet also includes a table that is updated when you modify your settings.  It will indicate for the ambient light level what shutter speed do you need for a few ND combinations. In green, those safe values below the sync speed, and the yellow entries are those combinations that give your calculated shutter speed.

For my ISO 64, there are a few useful results and easy to remember combinations:
  • To shoot at f/1.4, I need the ND 6, like it or not,
  • f/4 goes well with a ND 3,
  • f/5.6 is a good companion for a CP filter.
If you feel like trying this, the table is available as follows:

Happy OCF summer! 

Saturday, June 13, 2015

Portrait with horse.

PLM at camera right, and some patience to get the horse ears in good mood. Easy when the animal is used to being flashed.

Wednesday, May 27, 2015

Flying high

Happy to help progressing the big plane industry, this paper monster did very well. A ND filter helps to slow the shutter to show movement on the plane.

Tuesday, May 12, 2015

Fish and cats

I've had this blog a little dormant lately, as D. Manuel has noted. My apologies, I'll try to keep some constant flow again.

Some recent travel pictures. A 35mm lens keeps being my favorite for traveling, but I've replaced the usual Voigtlander Nokton Aspherical 35mm f/1.2 II for the much smaller Leica 35mm f/2.0 Summicron, only for the form factor. Now the Sony A7r fits in my jacket pocket easily, and smaller is better. Missing the f/1.2 aperture, though.