Today, Sigma forces us to ask the question if bigger is better
when it comes to their new 40mm Art Lens
for the Sony E-mount... because this thing is a monster.
Let's get Undone.
[offbeat music]
♪ Gerald Undone ♪
♪ He's crazy ♪
What's happening, everybody? I'm Gerald Undone,
and I'm not wearing pants.
So the 40mm Art is a lens that I was really excited about.
As many of you know, I love the 35mm from Sigma,
but it does have a couple flaws, and so I was hopeful that this
40mm would address those flaws
and be the perfect lens in that focal range.
So to tackle that question, we're definitely gonna be adding
in a bit of a comparison to the 35mm,
and to keep it nerdy, I'm also
gonna be giving you a bit of an explanation on
MTF charts, which are crazy impressive on the 40mm lens.
But before we jump into that, I just want to take a quick
second to thank Camera Canada for supplying
me with this lens so I could make this review.
Camera Canada has a complete lineup of
Sigma glass, so if you're looking to get this lens
or any other lens in the near future,
make sure you check out Camera Canada.
Their links will be in the description down below.
So, let's start with the nerdy stuff.
MTF charts are graft measurements
of the modulation transfer function of a lens.
They help to demonstrate the optical
performance of a lens by testing how
well that lens handles different spatial frequencies.
Commonly, a series of lines very close
together are used to test that lens’ ability to have
a sharp separation and contrast between the lines.
So let's pull up the 35mm MTF chart and evaluate it.
So along this axis, you have a score from zero to one.
One is 100%, or perfect, and it works its way down to zero.
Now, the score will always be lower than 100%,
because that's just the way lenses work,
but something in the high 90s is considered ideal.
And then across this axis is the distance from
the centre of the sensor out to the corner.
A full-frame sensor has a diagonal measurement of
about 43mm, so half that-- or from
the centre to the corner-- is about 21.5mm.
And this chart shows how well the lens
maintains its performance out to that corner.
Now, there's two types of lines here: there's dotted ones
and solid ones, and the dotted lines represent
meridional lines, or ones that run perpendicular
to the direction of the test is running.
And then the other lines, the solid line,
is for the sagittal lines, or the ones that run
parallel to the direction of the test.
And there's also two groups of lines separated by colour.
Now, the red lines at the top, they have better performance
because they measure fewer lines per millimetre.
This is used for measuring contrast performance and is
usually set at around ten line pairs per millimetre.
Then this lower-performing group uses a more challenging
higher density of line pairs, and this can vary from
manufacturer, but it's usually around
30 to 50, with the Sigma chart using
30 line pairs per millimetre.
And this test is used to measure the lens’ sharpness.
So now if we look at these results, we can see
that the 35mm does quite well to maintain
its performance across the majority of the frame,
but there is a dip of about 25% as we approach the corner.
The sharpness falls off a little harder, though, near the edge,
but it still maintains about 40% at the absolute corner.
So this is a great-performing lens
and is definitely worthy of the Art Lens designation.
For comparison, here's an example of
a cheaper “nifty fifty” lens.
You can see that the sharpness falls off from 80 down to 20,
with irregular performance in between.
Now, an ideal lens would be pretty much a straight line
that starts in the high 90s and finishes
there in the corner, but the closest you're gonna get
to that with a standard lens would probably
be the ZEISS Otus 55mm f/1.4, which I have the chart for here.
And as you can see, it stays well above 60,
even in the corner, and is mostly straight across.
But that lens is $4000 US.
Now, the Sigma 40mm did go up in price when compared
to the previous Art lenses by about 50%.
Most of the previous Art lenses were about $800-$900,
but the new 40mm is $1400.
So what kind of MTF chart do you get from Sigma for $1400?
This one. Now, this is absurd.
This is Otus-level and beyond in some places.
The contrast line is getting close to the theoretical
“perfect” lens, and the sharpness stays
above 90% for almost three-quarters of the frame.
There's also less distortion and significantly
less vignetting from the previous models.
Now that's seriously impressive, but it is just on paper.
So enough with the chart talk,
because I'm happy to report
that this also translates into
noticeable sharpness gains
in the real world as well.
And I've got a couple test shots here
that I think demonstrate this well.
All right, so let's start off with these
two images here for comparison.
The 40mm is on the left, and the 35mm is on the right.
And you can clearly see that the 40mm
has significant sharpness increases over the 35mm.
And for those of you that care, if we take a look at
the bokeh as well, we can see that it's much
smoother and nicer on the 40mm over the 35.
And I tried to position this in a few
different places, you know, centre of the frame
and the corners and that kind of stuff, and regardless
of what I did, the 40mm still came out on top.
So, again, let's take a look here, and we can see, again,
the 40mm is sharper than the 35, even in the bottom.
And it also has some nicer,
you know, quality and character to it.
If we look up in this extreme corner here,
we can see that the sharpness carries all the way
up into the corner, and if we look at just the way
that the light kind of, like, glows out here,
I find that the 40mm is smoother.
I don't know if this is translating well to YouTube,
but it just kind of has, like, a more polished look.
And they're also-- I should make a notice that there is a depth
of field difference, because the 40mm is a longer lens.
It's definitely shallower.
We can see here with the paper lantern
that it goes out of focus sooner.
You're gonna get a shallower depth of field with 40mm
more than you would with 35.
Now, I also shot a mat here so that we could look
at some numbers and lines.
And, again, we can clearly see that the 40mm
is sharper than the 35mm, and this carries out all the way
across the frame, where the 40mm has impressive
sharpness over on the edge, where the 35mm does--
as we saw on the MTF chart, it does start to drop
a little bit more rapidly.
I also used this as an opportunity to
go through and check the different apertures
to see if there was a sweet spot for the lens,
and I did find that it was probably around
f/5.6 where was at its sharpest,
but the improvements were marginal and the lens still
looks amazing even wide open.
And it's kind of crazy that we're seeing this much of
an improvement against the 35mm,
because keep in mind, we're not comparing this
against low-end glass.
We're comparing this against
another Art Lens. But that being said,
if you're somebody that likes to punch in on your photos quite
a bit, then you'll definitely see some serious advantages when
using the 40mm, even when compared to other Art lenses.
But to show off just how crazy sharp this lens is
and to demonstrate that cropping capability
I was just talking about, Julie and I took this lens
to the local wrecking yard to shoot some smashed up cars.
[heavy, discordant instrumental]
♪
Thanks to Julie for operating the camera,
and making me look kinda cool while I took pictures.
And I'll put links to those photos in the description
if you want to download them and play around with them yourself.
Now, to address some of the issues
that I alluded to with the 35mm,
let's talk a little bit about focus breathing and autofocus.
The 35mm breathes heavily.
Here's some footage to show just how much of
the frame gets pushed when you go from infinity to minimum.
Keep your eye on the width of the tape measure
and the edge of the table on the left side.
Now let's run it again, but with the 40mm.
So the 40 definitely still breathes noticeably,
but it seems like an improvement
of about 30-40% over the 35mm, so that's something.
Now, with autofocus, AF Single was never
an issue with the Art lenses.
They have really strong motors that are designed
to throw all that heavy glass quickly.
They do a great job and I've never had any issues.
The issues come in with the smaller, smoother movements,
which is usually most noticeable in video when doing focus pulls.
The 35mm, for instance, is a bit jerky and also a bit
sluggish when it comes to video AF.
But first, let's look at some continuous
burst-fire focusing and see if the keeper rate is higher on
the 40mm as the subject gets closer to the lens.
So to test this, I did three runs each,
starting with a 35mm, with me walking toward
the camera through mixed lighting.
I have the latest firmware on the a7 III,
so I just let it do its magic by choosing
the best AF mode between
face, eye, and subject.
And I found results that I'm pretty much used to.
It struggles with the smaller movements up close,
but overall, after three runs, I managed
to get 25 out of 30 shots to be keepers, or about 83%.
So overall I wouldn't recommend the Art lenses for sports
or action, but they're perfect for anything slower than that.
Now let's see if the 40mm is any better.
Overall I counted 33 out of 37 to be usable, or about 89%.
So there did seem to be a small but consistent
improvement at that closer focusing range.
With video, though, I had trouble deciding
if there even was an improvement.
Here's the 40mm lens with
the AF speed set to “fast.”
And you have to set the speed to “fast” on
the Sigmas or it's too sluggish.
With Sony lenses, I set the speed to “normal,”
but “fast” is required to get similar
performance on the Sigma lenses.
As you can see, it still has that weak spot up close,
but it recovers pretty quickly, and there's no issues with
locking on or holding focus when at a normal distance.
But is this an improvement over the 35mm for video?
That's hard to say. I had to slow it down to 50%
to even tell, and it seemed like the lenses
were just trading blows more than there was a clear winner.
Sometimes the 35mm was faster, sometimes the 40.
So no obvious improvement there in my opinion.
All right, now let's get to the most noticeable difference
with the new lens... it's a little bit bigger.
[crickets chirping]
OK, it's actually 50% bigger and weighs almost twice as much,
at 1.2 kilos, or about 2.6 pounds.
And this is noticeable when you're using it, obviously,
and this focal length is often used for street photography
and other environmental portraits, and one
of the things that street photographers often look for
is something a little bit more inconspicuous.
Well, that ain't gonna happen with this lens.
If there's one thing this lens is,
it's conspicuous as a motherf-- And when paired
with the Sony a7 III, it actually suffers from
that issue where the lens goes lower than the body, and this
can cause problems if you like to use longer tripod plates,
because when you put the plate on, it actually pushes back up
against the lens which can put tension on your mount.
And it doesn't feel well-balanced on most Sony
bodies, which tend to run a little bit small.
It's definitely front-heavy and quite tiring on the grip,
and if you like to use back-button focus,
it's nearly impossible to shoot one-handed with.
Also, when it comes to the focal length itself,
I was curious to try it out and see if it felt more
normal to me than the 35mm, which I tend to like.
But I don't know if it was because of the extra
distance from my eye to the front of the lens element,
but the subject definitely felt too close to me based on what
my normal field of view offers, so I actually prefer the 35mm.
But take that with a grain of salt,
it's a completely subjective opinion.
Now, in the interest of fairness, it's not
all negative points when it comes to its size.
It is Sigma's first Art lens to be completely
dust and splash-proof, and that's pretty awesome.
And its optical performance is like that of a high-end cine
lens, which are usually pretty large anyway.
And it still keeps its mechanical focusing ring,
which will allow for smooth and accurate focus pulls,
even when using a nonlinear camera.
But with all that on the table, the question becomes simple:
it's 50% bigger and 50% more money,
but, in exchange for those penalties,
you get one of the sharpest lenses available.
So, how important is sharpness to you?
Let me know your answer in the comments below.
But that's gonna be it for me. I hope you found this video
helpful, or at least entertaining.
And if you did, make sure you leave it the old thumbs-up
and consider subscribing if you haven't already.
But if you did not find this video helpful or entertaining,
feel free to hit the dislike button twice.
Alright... I'm done.
♪