Strobist Exercise 102-1-2b (Self Portrait, Modifiers)

As you know, I'm following Strobist exercises. I'm now on 102-2-1, and am trying to "guess" off-camera flash exposures, w/o using my Minolta IV-F flashmeter. If I can "guess" by chimping, that would eliminate 1 more piece of equipment. BTW, the Minolta is quite accurate, and for serious portraits/family gatherings, I would use the Minolta if I had any doubts. Maybe with practice I will reduce those doubts.

So my first picture is my first guess. D200 set at ASA=400, WB=Auto, Mode=Manual f5.6 & 1/250 (the fastest synch speed on the D200. Off-camera Nikon flash SB-800 set at 1/8 power. On camera flash of the D200 was set at 1/128 power, mainly to trigger the SB-800. The on-camera flash did not really have any effect on the image. All images pure jpeg, no post-processing.

Well, my self-portrait was too bright, but only by about 1 stop, so I set the flash to 1/16 power. Actually I did an intermediate step by taking a shot (not shown) at f8.0, and judge the exposure of my face to be fine. So then I reset the aperture to f5.6 (to maintain that depth of field), and then set the flash to 1/16 power. Just an easy way for me to do this, as the flash was on a stand, set at 5 1/2 feet. If I changed the flash, I would have to lower the stand, etc. etc
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I wanted to lower the speed, but as you can see from the background, the flash overpowered everything. I tried some images, but there was hardly a change--no surprise here. So I fashioned a plastic snoot with velcro. I took this picture w/o changing exposure, and guess what, the face came out just as theory said it would--perfectly. Of course the background was dark:


So now I could play with the speed. I put the speed down to 1/50, and the background became somewhat lighter.


For more control, I place the lightstand nearer. I guessed the effect was 1 stop, so this time I reduced the aperture to f8.0 from f5.6. Worked like a charm. Of course the background was wayyyy dark:

So I next decreased the speed to 1/50, to get the effect I wanted. Well, not exactly, but I could see the improving effect:



How accurate was my f8.0 when I moved the snoot nearer? I measured w/ the Minolta, and found I was at f8.8, or about 3/4 a stop off. But you know what? I like my "GUESS" portrait better than the measured one! Compare the measured one is below with my guess above. View only the head/shoulders portion, where the meter measures the flash. Don't judge the background.


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