
|
Mentor Moments
by
Scott Ferris |
BLINKIES??
July 10, 2016
Do you use 'blinkies' on your camera for review purposes, if
not, why not?
Blinkies, or highlight warnings, are an excellent tool
to use to review your exposures out in the field. One of
the truly liberating aspects of digital photography is the
ability to see what we took instantly. The trouble is
variations in screen brightness and ambient light range
don't help us accurately judge our exposures. Luckily
there are two very useful in camera tools to help, the
histogram and blinkies. The more powerful histogram takes a
greater understanding of what it represents to use 'on the
fly', but the blinkies just flash where pixels are
overexposed to give us an instant check for lost detail.
Remember, there is nothing inherently 'bad' about
overexposed pixels, if that is what you want. Just remember
when you get overexposed pixels, especially in a block,
there is no detail in that block and post processing
generally can't 'fix' it.
So how do we see these blinkies? On a Canon go into
the 'Menu-Playback (the blue options) and look for the
'highlight alert' option then just select 'enable'. On
a Nikon look under the ' enu-Playback Menu-Playback Display
Options-Highlights' and tick the box. Nikon users can often
select on or off during playback by going left or right on
the rear controller too. For other types of cameras consult
your manual or do a quick Google search with your make,
model and the word "blinkies".
Now take a picture with some overexposed highlights and look
at the review. You might initially find that distracting,
but run with it for a week or two and you should find it
helps a lot with your exposure. Remember, you will get
much better image quality if you slightly overexpose in
camera and then lower the exposure in post rather than the
other way around, understanding this and using blinkies can
really help your pictures.
MODES! THE FIRST IN A SERIES OF
POSTS ABOUT MODES
July 24, 2016
Aperture Priority, Shutter Speed Priority, Program
and even the dreaded and much argued about Manual
Modes seem to cause much confusion and anxiety when
they all do essentially the same thing! So let go
of the peer or self imposed pressure to use a mode
recommended by this pro or that blogger.
There is no right or wrong 'Mode' to use. All the
modes are making choices and trade-offs between ISO,
aperture and shutter speed. You will soon realize
you can use any mode in any situation to get the
result you want so just use the one that makes the
most sense to you.
An exposure is made up of three factors: shutter
speed, aperture and ISO. Think of an exposure as
drawing a bath, or running a bath in English.
Shutter speed is equivalent to how long you leave
the faucet open; the longer it's open the more water
in the bath. Aperture equates to how far you open
the faucet, and the wider it's open the more water
you get. ISO may seem more esoteric, but
effectively it is how big your bathtub is. A low
ISO is a big tub needing a lot of water, and a
higher ISO a smaller tub taking less water. As a
result, a bigger tub is going to result in a higher
quality bath than a smaller one!
The meter, which helps choose the aspects of the
exposure we didn't set, is going to try and fill
'the tub' just under halfway every single exposure
irrespective of what is in the scene. It doesn't
know how deep we actually want the bath (how light
or dark we want our picture). It is programmed to
adjust our three variables so the right sized tub is
just under half full.
All a mode allows us to do is tell the camera which
option we want to set. How big the tub is (ISO),
iso; how long to open the faucet (shutter speed) and
how wide to open the faucet (aperture). If we use a
mode to prioritize one or more of these criteria the
camera will then assign the other values.
My next post will go a little deeper on modes and
when one might make more sense than another. Later
I'll introduce the concept of Exposure Compensation,
EC, in our tub analogy that would be how deep or
shallow we want our bath :-)
MODES PART 2 -
THE POORLY UNDERSTOOD 'P' MODE
August 7, 2016
The poorly understood and unjustifiably maligned 'P' Mode.
Now we will begin looking at each Mode and when one might be more appropriate than another starting with 'P' or Program mode. 'P' mode gives you more control over your exposure than 'Auto' mode. (The green square on a Canon designates Auto mode.)
Traditionally in 'P' Mode you choose the ISO and the camera sets the shutter speed and aperture. Remember our bathtub analogy? You can quickly change those settings to a more appropriate one for your image and the camera will still fill our bath up to just under halfway! Lets use a few exposure examples.
As I write this with my camera in 'P' Mode I set my ISO at 100 and the camera has set my exposure at 1/250 second with an aperture of f5.6. It chose those values for a middle ground balance between shutter speed and aperture values. To get the same exposure all of the combinations below will give you the same amount of light!
For a different setting all I need to do is roll the dial next to the shutter button and the camera will scroll through all these different exposure combinations! So if I want more depth of field I turn that dial to give me a higher aperture value, but at the inevitable cost of slower shutter speeds. If I want a faster shutter speed I turn the dial the other way but there will be correspondingly less depth of field. 'P' Mode is like having the best of both aperture priority and shutter speed priority modes at the same time!
So when is 'P' mode a good choice? Anywhere you want the camera ready in an instant but where the subject matter or compositional priority between shots will vary. So field trips, vacations, street photography, and events, especially when using a zoom lens, are all times to use the 'P' mode.
Next time shutter speed priority and when to use it. Also, at the end of this series on Modes I'll mention all that technology has added to the exposure equation. Remember all the modes do is determine the optimal ISO, aperture and shutter speed faster. If they aren't doing that they are just getting in your way so practice with another method that is more intuitive to you. Just because your camera has umpteen Modes doesn't mean you need to be proficient in every one of them. Please email me any questions via the club.
MODES PART 3 - APERTURE PRIORITY
August 21, 2016
Now we will look at Aperture Priority, designated as Av for Canon, A
for Nikon, and the Mode I use most often.
In aperture priority we set the ISO (how deep we want
our bath) and the Aperture (how open our faucet) and the camera works out what
shutter speed to use (how long to leave the faucet running) to attain consistent
exposure.
As you know the Aperture setting allows us to
prioritize the depth of field, or how much of the scene is in acceptable focus.
For landscapes, we might want everything from a foreground flower to a mountain
range in focus so we would choose a ‘smaller’ aperture value, something like f16
or f22. This can result in a long shutter speed and we may need a tripod
to get sharp images. On the other hand, if we are taking a portrait and trying
to isolate the subject by blurring the background a ‘wider’ aperture like f1.4
or f2 will work better.
But we can also use Av/A Mode to get our fastest
shutter speed in changing light. For instance, while taking pictures of
birds in flight where clouds keep the light values changing if we select our
lenses widest aperture (lowest number), then the camera will select the fastest
appropriate shutter speed to get a consistent exposure. This means we can
concentrate on getting the framing and focus right and not think about the
exposure.
Now a really nice modern twist on camera control and auto exposure is Auto ISO.
This works particularly well in the above scenario. Again we want to take
pictures of birds in flight and with the fastest shutter speed to prevent motion
blur and the lowest ISO to maintain image quality. We would set our camera
to our 150-600mm lens’ widest aperture, f5.6, choose Auto ISO and the camera
will set the shutter speed over 1/500 sec because it knows the focal length
being used. Then if the light drops too much, rather than drop the shutter
speed and cause motion blur, the camera will increase the ISO to maintain the
fast shutter speed.
I’ll cover Auto
ISO in more detail later but the next installment will be shutter speed
priority, Tv for Canon users and S for Nikon users. But in the meantime have a
play with Aperture priority, it is amazingly flexible and if I could only use
one mode is probably the one I’d pick.
Don’t
forget to bring your camera to all the meetings and whenever we have time we
will cover whatever we talked about in the last newsletters. Practice makes
perfect and 10,000 hours practice make a master :-)
MODES PART 4 - SHUTTER PRIORITY
September
11, 2016
Going back to our tub analogy where how open the faucet is
corresponds to the aperture, and the depth of water we want in our tub equates
to the ISO, the simplest aspect of our exposure triangle to get our heads around
is shutter speed, or how long we leave the faucet open.
So when would we prioritize shutter speed by setting a speed and
letting the camera decide the aperture? The key use is when you have a subject
in motion and either to need a set shutter speed to prevent motion blur or a
speed to allow a certain amount of subject blur.
One example would be one of our regular subjects, birds in flight.
If you know it takes 1/800 second to freeze the tips of the wings when taking
pictures of a pelican then you would set that as your shutter speed and let the
camera take care of the rest. Or if the subject is soccer players, and you know
a running person's foot has a small amount of blur at 1/300 second then go for
that speed. If you don't know what shutter speed you need to get the
freeze you want then take a few test pictures at different shutter speeds and
zoom in on the review screen on the back of your camera.
Conversely if you want subject motion, like at a fairground at
night or moving traffic for light trails, or to show flowing motion of a
wedding reception first dance then choose slower speeds. I'll use several
seconds for fairground lights to over one minute for traffic trails, to 1/4th to
1/30th second at wedding receptions.
Other scenarios where I would use shutter speed priority would be
an airshow where there are propellor driven planes to make sure I get a good
amount of blur in the propellor (the 'rule' is a full circular blur).
Another is taking images of moving cars or motorcycles where, if the shutter
speed is too high, then the background and the wheels are so sharp it looks like
the subjects are stationary.
The main point is to be deliberate, go out with the intention of
taking a specific type of image and take control of your camera to make it
deliver those images.
Don't forget to bring your camera to our regular
meetings, if we have time we can always play with these various modes and gain
the familiarity we need with our cameras to help get the results we want when we
go out taking pictures.
MODES PART 5 - THE DREADED
M MODE!
September
25, 2016
Manual or M Mode gets so
much bad press I feel sorry for it! First, it isn't a 'professional' only thing
and it isn't intimidating, it is just another camera setting that can enable us
to get an image with consistency. And consistency is the byword for choosing M
Mode. M Mode doesn't select any camera settings automatically, it ignores the
meter reading and relies on user input to select aperture, shutter speed and
ISO.
Here is a challenge, put your camera in P Mode, take
a picture, and look at the shutter speed and aperture your camera used. Turn to
M Mode, put the same settings in and take a picture. The picture will look the
same, right? See, M Mode isn't scary; it just does what it is told and
completely ignores inbuilt smart technology.
M Mode gives you complete control of your exposure
so you can prioritize depth of field or shutter speed while allowing consistent
exposures. What shooting situations would make you want that? On last week's
field trip we had a couple of perfect scenarios. Under the covered arena the
light was consistent on the dressage horse and rider but the background varied
between strong backlight and shady foliage areas. This changing background could
easily throw your meter reading off even though the light on the subject was
consistent. To avoid this take a picture, check the subject's exposure and
select the settings that give you a correct exposure for that subject. Then
using those settings your exposure will be correct for any shot of that subject
whether it is in front of the bright or dark background.
Another perfect example is event photography of
bands or other stage performances on a stage with the subject consistently
lighted but various lighting changes behind that subject. Often in these
situations forward facing lights can come into our field of view and cause a
camera in a metered Mode to under expose the subject. M Mode ignores that light
and allows you to expose your subject consistently.
M Mode is also the best mode when using studio
lights. The subject illumination will be consistent, but you control the actual
exposure. This is probably where the 'M Mode is what professionals use' idea
came from as many of them use studio lights. M Mode also can give you additional
flexibility for more exposure compensation than the +/- 2 to 3 stops your camera
allows.
M Mode has some real strengths, but, it also has
some weaknesses. If the illumination on your subject is changing then M Mode
won't help and you would have to constantly change your settings to keep up. Who
wants that? M Mode also doesn't work as a general 'walk around' setting and can
be very frustrating if you try to use it as one. Remember its strength, a
consistently illuminated subject. If you are in a situation where you have that
M Mode will shine and can make very difficult exposure situations simple.