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Hi,
I am looking for a diffuser filter. I am using Cokin 830
now but am not satisfied yet. I heard there are other
filters that provide a sharp image yet still soft. Please
help.
Any advice will be appreciated.
I would like to address your concerns over the subject of
soft focus. This is a topic with as many opinions as
there are photographers. In the end, however, it still
comes down to how the images look. Most photographers I
have encountered over the years who have been frustrated
with soft focus filters have generally shown that they
didn’t understand how a drop in soft focus filter
works. Understanding some of the basics may offer some
hope and eliminate the need to spend big bucks on glass
filters that almost have the words “drop me”
printed on them. Many of the drop in filters offered at
trade shows these days have a lot in common. Black stuff.
It might be black dots printed all over the glass, it
might be black netting or tulle layered with the glass or
it might be tulle all by itself hanging in a frame.
Others create variations to the surface of the filter
making it less than perfectly flat. These tiny ups and
downs catch light within the scene and spread it over the
darker areas reducing the contrast and hard edge
qualities of the image. If you look at all these
approaches, they all do pretty much the same thing to a
greater or lesser degree. They reduce contrast. I
regularly look at all the sample images done with these
filters and see very few major differences. Seems the
most expensive filters always show examples using the
most beautiful models and glamorous clothing. Must be a
coincidence. So how do they reduce contrast? By spreading
the highlights into the shadows mostly. In doing this,
the shadows are no longer as dark as they once were and
the overall look to the image is softer. Depending on the
design of the filter one can occasionally detect a
distinctive glow around lighter objects and pinpoints of
light. This romantic effect that creates a dream like
look is what many photographers are looking for. Their
problem is that while they may indeed have a quite usable
filter, they may not be doing a number of other things
correctly to optimize its effect.
Many photographers today use very large light sources such as soft
boxes (not what I prefer). These produce very soft lighting patterns
with almost no defined shadows if they are used near to the subject.
They may also use a a soft ratio with a stop or less difference between
the main and shadow sides of the subjects face. Another factor that is
often overlooked is the adjustment of your meter's ISO rating.
Black tulle costs about a third of an F stop per layer. If you use two
layers, you just underexposed your image by two thirds of a stop. With
all digital photography, maintaining proper exposure is critical. We
don't have the latitude like we did in the days of conventional film.
The exposure needs to be pretty much right on the money.
Add up all of these contrast reducing issues when
combined together and you don’t have soft focus.
What you have is mush. Just a muddy image that is not
pleasing to the eye at all.
The big secret to using soft focus filters is to create a
balance between the various elements.
The elements being:
1) Size of light source
2) Depth of ratio
3) Compensation of meter ISO for light loss
The best things to do when using soft focus filters are:
Reduce the size of the light source a bit. This will make the shadow
edge more defined so it will not be lost in the filters effect. This is
difficult to do with any fixed size light source. This is why I love
diffusion panels. I get to control the size of the light source
precisely. You can't do that with soft boxes or any other fixed size
light source.
Also, you should increase you ratio a bit thereby making the shadows a
little darker to offset the reduction in contrast from
the filter.
Adjust the ISO on your meter to compensate for the filter. For clear
filters, one ISO setting is usually just fine. If you are
using black tulle, then you should compensate one setting
for each layer. All tulle I have measured blocks about a
third of a stop per layer.
In short, to achieve beautiful soft focus you need to
balance a little harshness in with the softness. I
personally use the Cokin 830 for all of my boudoir
photography and some regular portrait work. I find its effect to be a perfect blend of
romantic glow without making the images look out of
focus. Some extreme filters can over do it the effect and
should be avoided. Consumers still want to see eyelashes
even when you are adding a soft glow to their image.
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