I've tested this lens alongside all the Canon 75-300 and 100-300 zooms, as
well as the EF300/2.8L, and it's clear that it is a very good lens indeed. It is
significantly sharper than the zooms (including the 100-300/5.6L) and holds its
own against it's "big brother" the 300/2.8. It's sharp wide open and even sharper
when stopped down to f5.6. I have no hesitation at all using this lens wide
Image quality is very close to that of the 300/2.8L. I'd say that the 300/4 at
f4 and the 300/2.8 at f2.8 are about equal, but at any given aperture the 300/2.8
has a slight edge. This is based on looking at images of resolution test targets.
For real world images, it's pretty hard to tell which lens shot what.
The 300/4L works very well with the Canon 1.4x TC. Again I have no hesitation
about shooting wide open (420mm f5.6) with this combinations and I'm very happy
with the results. Autofocus is still fast and accurate. In a side by side test of
the 300/4L + 1.4x TC and a Sigma 400/5.6 APO (not the new Macro APO),
the Canon lens combination was clearly better (shrper, higher contrast, more
With the Canon 2x TC you lose autofocus and some image quality. It's a usable
600/8, but I don't think this is a combination you would want to depend on if you
were trying to make a living at photography and needed a 600mm lens to do it.
I have also tried the Tamron 1.4x TC with this lens. Results were pretty good,
but not as good as with the Canon TC. Autofocus was less reliable, image quality
was lower at the edges of the frame and there was slight vignetting wide
The lens has a removable tripod collar, a built in sliding lens hood and a USM
focus motor with full time manual overide. The front element (77mm filters) does
not rotate during focusing. It's well balanced and solidly built (no
Is it better than the Canon EF400/5.6L?
A lot of people ask this, and my answer is that I don't know, since I've never
actually used an EF400/5.6L! I can say though that, in principle, I like the
300/4 + TC combination better than the 400/5.6 + TC combination. With the 300/4
you get excellent 300/4 and 420/5.6 AF lenses. plus a usable manual focus 600/8.
With a 400/5.6 you get an excellent 400/5.6 AF lens, a good, but manual focus,
560/8 and a very slow 800/11, which in my opinion isn't a very usable lens.
The EF 300/4L is a killer lens, espcially when combined with the Canon 1.4x
TC. It's much better than any zoom I've ever tested at 300mm, and it's 1/2 the
weight and 1/4 the price of the EF300/2.8L. It's the lens I take when I'm hiking
around in areas where I expect to see wildlife but I don't want to carry too much
weight. Not only is the lens pretty light (3lbs), but you don't need a monster
tripod to support it either. I've had good results using it on a Bogen 3001 (3.5
lbs) with a medium Bogen ball head. You can't do that with the bigger telephotos.
The 300/4 is an ideal compromise of size, weight, focal length, speed and
Street price for the EF300/4L is close to $1100 (1/97). A fair price for a
used lens in good condition is around $800, but I can't see any reason for anyone
ever to sell one. I'm certainly not getting rid of mine!
1997 Update: Canon EF 300mm f/4L Image-Stabilized (IS)
In early 1997, Canon introduced an IS (image-stabilized) version of
the 300/4L. The IS lens also has a shorter minimum focus distance.
Old questions about the usefulness of IS are raised again by this
lens. For example in a May 1997 Outdoor Photographer it was
stated that "for many photographers the 300/4L IS lens will replace
the need for the f2.8 lens altogether". I'm not so sure.
Just think why photographers use the faster f2.8 lens:
Faster shutter speeds to freeze action. IS doesn't help.
To blur backgrounds. IS doesn't help.
Higher quality optics. IS doesn't help.
Due to the above, better performance with TCs. IS doesn't help.
AF with a 2x TC. IS doesn't help.
And, of course, once you have the lens on a tripod, IS doesn't help.
IS does help when hand holding the lens, but that's not why most
photographers buy a 300/2.8. They aren't going to be hand holding it much. I
think few photographers will use a 300mm lens hand held very often. Think about
it. Are you really going to take a 300mm lens out in the field and leave your
I think the IS lens is a great idea, however don't get sucked in by the hype
you may see in the magazines. Given an unlimited budget, I'd get one tomorrow. I
might only use the IS function a fraction of the time, but it's nice to have when
you need it. Just think about the claims before you rush out and buy one. I own
the 75-300 IS lens so I don't have an "anti-IS" bias!. I still much prefer to use
it on a tripod when ever I can.
Note that the IS lens has 15 elements in 11 groups, while the original 300/4L
has 8 elements in 7 groups. Adding elements can result in greater susceptibility
to flare and loss of sharpness. Reports are that the 300/4L USM IS is a sharp
lens. However the Popular Photography test (July 1997) seemed to show it was very
similar in sharpness to the Sigma 300/4 APO Macro, while George Lepp's test of
the original 300/4L showed it significantly sharper than the Sigma 300/$ APO
Macro. There really isn't enough critical test data available right now (05/97)
to say for sure whether the extra elements in the IS lens cause a slight optical
degradation. If the IS function is important to you, that's probably a secondary
issue anyway. The IS lens would clearly outperform the original lens in any
circumstances in which the IS function was needed (hand holding at less than
1/350). For those using the lens on a tripod all or most of the time, optical
performance may be a concern, but we will need to wait for further testing to see
if there is a significant difference between the two lenses.
[Editor's Note: Canon settled the question that Bob raised by discontinuing the non-IS version of this lens.]
Canon EF 300/4L USM Technical Data
8 elements/7 groups [15/11 for IS]
Angle of view:
8 degrees, 15 minutes
2.5 m (8.2 ft) [1.5m for IS]
Length and diameter:
214.5 x 90 mm (8-3/8 x 3-9/16 in)
1.3 kg (2.9 lb) [1.2kg for IS]
Example Images with 1.4X Teleconverter
Red-billed Hornbill. It is tough to fill a significant portion of the
frame with a bird with any lens shorter than 800mm.
Example Images with 2X Teleconverter
Springbok captured with 300/4 lens and 2X teleconverter. Note the
lack of contrast and punch in the image. It is rarely possible to get
a satisfying image with a 2X teleconverter. You are probably better
off using a 1.4X teleconverter and cropping.
Where to Buy
The easiest way to buy this lens is from