Hi, I am Charl from Pangolin Photo Safaris....
and today I will be talking about focus bracketing. A really cool
feature, built into some camera bodies.
First, I will explain what focus bracketing is and when it might be
useful, then I will show you how to do it.
Step by step.
And finally, I will also demonstrate how I blend the images together
into one single composite.
Before we get started.
I want to mention that I'm using a Canon EOS R3 for this
focus bracketing tutorial.
Most of Canon's mirrorless bodies feature focus bracketing, and the technique
will apply to any other camera brand that has this feature built in.
it might just be called something different within the menu system, like
focus shift, shooting on Nikon bodies,
for example...
Focus bracketing is a technique that is used most often in landscape or micro
photography, where multiple images are taken within different points
of focus, to extend the depth of field.
These images are then merged together, in software, combining the focus
of each individual frame to create one final, super sharp composite
with as much detail as possible.
This technique has been around and is used for a long time.
But what is new is that modern cameras now take some of the workload off you.
Focus bracketing
was traditionally done by manually focusing the lens on
different points within the scene or subject, which can be a tedious afair.
With the focus bracketing feature built-in, and enabled, the camera will
now automatically take multiple shots.
Shifting the focus slightly within the scene without the photographer having to
move the focus ring on the lens. You do however still need the software to blend the
multiple images together on your computer.
I personally use Adobe Photoshop for this, but there is also other stacking software out there.
Now that you know the principle of focus bracketing, I want to walk you
through the actual process of doing it.
Set your camera to either full manual mode, or like I have, to manual with Auto ISO.
Just so you can be in control of both aperture and shutter speed.
In the past,
most photographers use very narrow apertures, like F/16 to F/22
to achieve a large depth of field.
The downside of using these narrow apertures is defraction
and therefore not ideal sharpness.
For those of you who don't know, the fraction is a negative effect that occurs
when light bends as it enters a narrow opening, which essentially reduces image sharpness.
With built in focus bracketing, we can now choose an aperture value that
lies within the sweet spot of the lens we use.
Meaning, where the lens performs the sharpest focus. For most lenses,
this will be around two stops up from the maximum aperture.
For example, if you have a 2.8 lens, you will use an aperture of 5.6
for the focus bracketing. Since you are photographing static subjects,
or scenes, and ideally use a tripod.
The shutter speed of your camera
doesn't have to be super fast.
However, if you shoot hand held, like I have...and out in a nature, rather than in
a controlled environment, you still want to make sure to have a shutter speed minimum
equal to the focal lens you are using.
I have double it to give me more room for error.
So 1/200 of a second shutter speed with a 100mm lens that I use.
So, basically you want to get a good balance between sufficient shutter
speed, but not too high ISO value that introduce grain in the images.
Now that we have set aperture and shutter speed, and my camera is adjusting the ISO
automatically, all that is left to do is making sure that the lens is set to auto
focus as focus bracketing does not work
if the switch is set to manual focus. Within the menu, look for focus
bracketing or focus shift shooting.
The name will depend on your camera brand. Once enabled, choose how many
shots you would like to take.
This will depend very much on what you photograph.
If you shoot wider scenes like landscape, you will need fewer images than
doing close-ups of a flower or an insect,
for example.
So basically, the shallower the depth of field, the more images you should take.
I am by no means an expert here.
And since I've tried this out handheld, I couldn't take too many shots.
As alignment of these later would be very hard.
So mostly I had set a number of shots to around 20.
Of course, if you are on a tripod and take more images, you will get sharper results.
The next setting you must decide on is the focus increments, which describes
how much the focus shift between exposure. With larger aperture values,
you can increase the focus shift. If you use a very wide aperture, which means
the depth of field is much smaller,
you will want to use smaller increments, of course.
This will be a bit of a trial and error exercise.
I've started out with the standard setting of 4 on my camera.
Exposure smoothing, which is the last option, means that if enable, the camera will
suppress changes in image brightness that might occur during focus bracketing.
This is obviously very helpful, and that is why I have it enabled.
Now that everything is set up, focus on the closest point of the subject
you are photographing, and press the shutter button completely down to let the
camera execute the focus bracketing.
The camera will now continuously shoot...shifting the focal position
to its infinity, and stops
after the specified number of images have been reached.
As mentioned before you ideally want to use a tripod for focus
bracketing, but I wanted to see whether it could be done hand held too.
And since I'm a wildlife photographer, I have tested this
once again, out in the field.
I am out here on The Chobe River, and right behind me is a Nile crocodile.
The crocodile is lying nice and steady...
It's not moving.
And we also, uh, the boat is banked.
So, we are also not moving.
So, what I would like to get here is a sharp image all the way from the
tip of the nose until behind the eye.
Now I have a 500mm fixed lens here, and with the distance that I am, it's almost
impossible to get a sharp image, even if I'm shooting at F/16 or even F/32.
Um, I also don't really want to use that F stop. I'd like to try and avoid
the fraction, and of course the high ISO.
So instead I'm going to use focus bracketing here.
Um, I positioned myself nice and low here in front of the crocodile.
Um, I'm going to use this little cushion here to go really nice
and low in front of the crocodile.
As for the setting, I like to shoot manual in AUTO ISO.
A shutter speed is 1/1000 sec.
Aperture is F/8.
I like to use F/8...it falls in quite a sweet spot of this
lens...it's a nice sharp aperture.
The thousand shut speed is double my focal length.
So,
...it's not too slow.
...it's not too fast.
Should have a nice sharp image with this.
I'm also underexposing with two thirds...just the way the light is falling.
So don't lose any details.
And if I look through my camera, um, I'm running at the moment...
my ISO is around 640, so I'm really happy with the settings. So, I can go
and, um, enable my focus bracketing.
A number of shots I'm using here....
I think 20 is more than enough.
So between 10 and 20, but I think 20 is enough. Focus increments....
I'm going to use the default on four.
Uh, I think with the distance I am at the moment, I think four will be enough.
And then I've also enabled exposure smoothing.
Okay, now that I have all my settings dialed in, I will go and
focus on the closest point towards me, which is the tip of the nose.
So for this, I like to make use of a single focus point
just to be more precise.
And then when I have focus, I'll press the shutter release button
and let the camera do its thing.
So the bracketing is done.
Um, just for comparison later on, I'm also gonna take one
photo at F/16 and one at F/32.
So we can just compare the three differences, um, to see
which one came up much better, of course.
Back in Lightroom, you can see the stack of the crocodile images.
I've already made some basic adjustments on the first image, which I now sync to
the rest of the stack. To bring them into Photoshop, for the actual stacking process,
I make sure all images are selected and then right click.
Edit in and open as layers in Photoshop.
This might take a while, depending on how many images you shot.
Once they are open and layered, I select all layers, and go
to edit auto align align layers.
This function is extremely helpful when shooting hand held and out in the nature.
Where there might be slight movement between each frame, due to wind.
After that, we can let Photoshop stack them by going to edit,
auto blend layers, and stack images.
I have both options underneath checked, to help correct any errors that might
occur during the stacking process.
I now like to crop the stacked composite.
And here is the final result.
Nice and sharp from the tip of the nose.
Up until behind the eyes.
As you can see, neither F/16, nor F/32, produces this depth of field.
All that these narrow aperture did, is making the background more
distinct and therefore distracting.
Whereas the focus bracketing method deliver a beautiful sharp
crocodile, and yet a pleasing bokeh.
if your camera has focused bracketing, it will be worth
checking out...an experimenting with it.
Perhaps you can make use of it photographing the small stuff...
which is the name of one of the Pangolin Photo Challenges this year.
Entries close on 31 October 2022....
And who knows?
You might just win a trip to The Chobe staying at the Pangolin Chobe Hotel.
Make sure to check the link in the description below for more info on that.
Happy photographing and good luck! Until next time.