Flower pictures question
Ajay Shah
Nikon 6006 with 50mm f1.8 lens (min distance 45cm), on Benbo Trekker.
Clearly we need a small aperture to get a lot of depth of field
(like f22). I found that when I used f22 the exposure was like 4s.
This poses two problems:
a) wind. Even a light breeze can blur up the picture at 4s.
What does one do? Would taking 2-3 pictures give you one good
one with high probability?
b) reciprocity failure. I was using EPX, and Kodak says "we don't
recommend using it with exposures longer than 1/8th". What does
one do? 4s/f22 is the same as 0.125s/f4, which is terrible on
depth of field.
Is fill flash the only answer? I am a bit biased against (say) one
stop of fill flash as I prefer a blurred out background rather than a
dark background. Also the inbuilt flash leads to apertures like f4
rather than f22.
At such close quarters, when using fill flash, it seems that the
inverse squared falloff of light would start mattering. I.e., parts
of the flower which are a bit further from the rest (which we're
trying hard to keep in focus) would be nontrivially darker than the
front.
-ans.
--
Ajay Shah, (213)749-8133, ajay...@rcf.usc.edu
David Jacobson
>I was taking pictures in Kerala, India with the following setup:
>Nikon 6006 with 50mm f1.8 lens (min distance 45cm), on Benbo Trekker.
>
>Clearly we need a small aperture to get a lot of depth of field
>(like f22). I found that when I used f22 the exposure was like 4s.
You mention EPX, which is ISO 64. Then the light must have been about
65 foot candles. (I got that using the calculator dial on my old
Gossen LunaSix, then used a table on back that converted meter
readings to foot candles.) That's pretty dark for macro stuff. I'd
say you will have to use flash, and probably an off camera flash at
that.
[stuff deleted]
>Is fill flash the only answer? I am a bit biased against (say) one
>stop of fill flash as I prefer a blurred out background rather than a
>dark background. Also the inbuilt flash leads to apertures like f4
>rather than f22.
>
>At such close quarters, when using fill flash, it seems that the
>inverse squared falloff of light would start mattering. I.e., parts
>of the flower which are a bit further from the rest (which we're
>trying hard to keep in focus) would be nontrivially darker than the
>front.
What I would do is get some kind of flash you can use off-camera. The
SB-24/25 is fine, but you spend a LOT of money for features that don't
work on a 6006. You could also use a SunPak 433AF, which some time
ago was only about $75 mail order. (Of course, if you're taking it
all the way to India, then reliability becomes a big issue.) You also
need the SC-17 sync cord. That's around $60 (locally), almost as much
as the flash. But lets assume that you are using the SB-24, just
since its what I have. With ISO 64 and the head set to 24mm you can
have the flash up to 5 feet away and still use f/16. The TTL quenching
will make it work ok considerably closer.
However, I have found that a single flash head tends to make harsh
shadows. I like to either mount the LumiQuest BigBounce on the flash,
or use an umbrella. (I don't have a real photographer's umbrella. I
just use a white one I found at a drug store. But white hasn't been
popular as an umbrella color recently---you might have to look a lot.)
I'm not sure exactly what f-stop you can get away with, but start with
f/11, and if it quenches try 16. A big source like an umbrella vastly
reduces any inverse-square effect.
You should use the fastest shutter speed that will work with flash.
I don't know what to do about background, since you like it light.
The technique I describe will make the backgrounds come out dark,
unless they are fairly close. If you try to do something about it by
using long shutter speeds, which you can do, then you risk blurring.
-- David Jacobson
zrep...@cc.curtin.edu.au
> In article <1kebtl...@almaak.usc.edu> ajay...@almaak.usc.edu (Ajay Shah) writes:
> I don't know what to do about background, since you like it light.
> The technique I describe will make the backgrounds come out dark,
> unless they are fairly close. If you try to do something about it by
> using long shutter speeds, which you can do, then you risk blurring.
>
Well come to macro. :-) If you set the flash well BEHIND the camera, you
reduce the difference between the light on the subject and the background.
Another thing that is very usefull is a clamp type mount. You fit this to the
leg of your tripod to mount the camera, then drape the tripod legs with white or
silver material to form a light tent.
~Paul
Matthew J. Harper
> -- David Jacobson
I too have found fill flash to be too harsh at times. To help fix it I
recently picked up a couple of tiny slave flash units (By tiny I mean guide
numbers like 18). They've been quite effective for some of the macro
photography I've done at evening out the light across the subject.
Better yet, the thing was only $20!
-Matth
Note also that a well placed slave will also help add some light to the
background and avoid the 'flower in a sea of black' problems.
--
Matthew J. Harper ! Progress Software Corp. ! {disclaimer.i}
God created heaven and earth to grow barley and hops. Now he homebrews !-)
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