Wildlife photography by John Devries, Kent UK. Inspirational images
Canon telephoto comparison
When taking pictures of wild animals or birds the photographer is
frequently limited by how close he or she can get without alerting
the subject and frightening it off. This distance is often known
as the "circle of fear". At this fixed distance the photographer
is effectively "focal length limited". Cameras with higher
pixel density are beneficial under these circumstances as they have
more pixels on target and enable greater cropping to increase image
size. Clearly longer focal length lenses will be advantageous over
shorter ones but are heavier and are usually more expensive to purchase.
Having recently acquired a 300mm f2.8 L IS lens I wanted to see
if I could use this plus teleconverters as a substitute for the
much heavier and bulkier 500mm f4 IS lens - particularly on longer
treks or when travelling by plane.
As I also own the popular 100-400 f5.6 L IS and a 400mm f5.6 prime
(non IS ) I was able to perform an interesting set of comparative
tests. To give the lenses the best chance of performing near to
their best, I stopped them all down to an aperture of f8.
Shooting details were as follows:
All images were taken at same 9 metre distance using Canon 1DmkIV
camera,Gitzo tripod/Markins M10 ballhead, cable release, mirror
lockup, all lenses and converters optimised with microadjustment
All were taken at f8 and ISO 200 Av mode +0.33 exposure compensation.
Image stabilisation turned off. Three images taken and the best
of the three used. Images were processed in Photoshop CS5 from RAW.
Images all lightly sharpened identically using USM (300%/0.3/0).
Starting uncropped image -
fixed distance 9 metres
300mm f2.8 (300mm)
300mm + 1.4IIx converter (420mm)
100-400mm at 400mm (Nearer to 380mm)
300mm + 2x converter (600mm)
300mm + 1.4II x repeat
300mm image upsampled 1.4 times
These are all high-quality Canon L lenses and all put up a good
performance considering how small the target butterfly was in
the frame, as you can see from the starting image. At the 9m distance
it comes as no surprise that the 500mm f4 produced the best image
quality. The 300mm f2.8 image appears to be of similar quality
but of course the image size is much smaller.
Next comes the 400mm f5.6 lens. Considering its budget price,
it put in a very respectable performance when compared to the
two heavyweight super-teles. It is limited by being a slow f5.6
lens and has no IS but its image quality is remarkable for the
Since carrying out lens micro-adjustments on the 100-400 f5.6
IS/1DmkIV combination I find it is performing much better than
it did in the past when used on camera bodies where this was not
possible. When stopped down to f8 it is performing well but is
definitely less sharp and contrasty than the 400mm prime.When
the lenses are used wide open at f5.6 the differences are even
more marked (from previous experience). Although both lenses are
supposedly 400mm there is an obvious size difference in their
images - the 100-400mm actually provides more like 380mm at full
There is clearly a drop off in image quality when the 1.4x converter
is used on the 300mm f2.8L. The bare 500mm f4 is in another league
and the 400mm f5.6 is at least as good from these tests. This
came as a bit of a disappointment as I hoped that the expensive
300mm+converter combination would beat the budget 400mm prime.
I had to reduce the size of the 420 mm converter image to a 400mm
equivalent to determine that at this size there is actually little
difference - otherwise the 400mm f5.6 actually won. Unfortunately
the light changed a little between the two shots below but not
sufficiently to negate the comparison.
300mm +1.4x converter (420mm) downsized
It does offer a one-stop aperture benefit and has image stabilisation
but does not focus as fast as the bare 400 prime.
I tried upsampling the bare 300mm image using Photoshop's "Bicubic
smoother" so that the width of the image was increased by
a factor of 1.4. This was inferior to using the 1.4x converter
but perhaps not to the degree that one might expect.
Finally I tried the 300mm lens with the 2x converter. This produced
a whopping focal length of 600mm. The resultant image was very
large when viewed at 100% on the computer screen and the image
quality was a little inferior to the 1.4x converter but not by
much considering he huge size.
The use of extenders with the 300mm f2.8 lens do clearly degrade
quality of this excellent lens but still produce very usable results
- even when pixel-peeping at 100% as we are in this comparison.
I would not however consider the combinations to be serious competition
to the bare 500mm f4 which (along with the 600mm f4 and 800mm
f5.6) remain the first choice for bird photography. It must be
said though that these tests were conducted using a cable release
and mirror lockup which is not practicable to use in the field
when photographing moving creatures. Under real-world conditions
the photographer's long-lens technique will become very significant
and the differences between the lenses will reduce.
There is no question that the 400mm f5.6 gives you the best bang
for your buck in this test. It is quite a bargain when used within
The bare 300mm f2.8 L IS lens remains one of Canon's very best
lenses and has not been seen at its best in these tests. If the
lens-to-subject distance had been reduced to match the size of
the 500mm f4 image the image quality differences would be very
similar and could even go the 300's way - but that is a test for
another day !
Canon 300mm f2.8 on the Gitzo tripod with 500mm
f4 on the ground. Both are sporting Lenscote
I wanted to further compare the 300mm f2.8 lens with and
without converters against my 500mm f4 reference lens. This
time instead of using a fixed distance I wanted to use identical
framing (magnification) in each case. In other words, I
had to place the tripod closer to the subject at the shorter
focal lengths and move it further back for the longer lenses
.I achieved this by framing a ruler identically in the viewfinder
in each case, this was then subsequently removed for the
I took shots at a variety of apertures but have presented
those at f8 in the comparisons below.
My subject was my usual favourite model - Chimpy. He was
sporting a feather hat which provided the focal point for
the images. (marked in red). The camera was the 1DmkIV and
I used ISO 800 as the light was poor.
Starting image framing:
500mm f4 Control:
300mm f2.8 bare
300mm + 1.4x converter
300mm + 2x converter
All lenses and combinations put in an exceptional performance.
When viewed at 100% there were no real surprises. The bare
prime lenses put in pretty much identical performances and
the 1.4x converter caused a very subtle loss of resolution
- visible on the fur above Chimpy's eyes. The 2x converter
caused a further reduction in resolution but was only visible
in these huge 100% crops. I would not hesitate to use the
300mm f2.8 L with either converter but I would still use
the 500mm f4 if I did not have to carry the lens far. When
travelling by plane or on a longer hike I will be taking
the 300mm plus extenders in future !
To finish, here is a shot of a nuthatch at 420mm - taken
with the 300mm f2.8 plus 1.4x converter:and the 1DmkIV camera.