I am not particularly interested in doing tests on the equipment unless they do show real differences on the filed and allow the photographer to better work in real photographic situations . Almost always, the laboratory tests dwell in particular on the sharpness of a lens , tested under conditions that never happen in reality. If a lens loses sharpness at the edges, in most real situations it is completely irrelevant , while greater accuracy and focus speed could make the difference between a photo to keep and one to trash.
About 1 year ago I decided to replace my razor-sharp Canon ef 70-200 f4 (non- IS) with the EF 70-300 IS f4/5.6 that, on final balance, was more useful to use in the field compared to the previous , simply because in 95 % of cases I'm using it without a tripod and stabilizer is essential to avoid having to raise the ISO (as long as the subject is fairly static) and still essential in all situations of low light even at high ISO. Obviously the aperture at its minimum is losing 2/3 stop of light compared to the 70-200 L and nearly two over the 2.8 version of the 70-200 .
Many Canon users face a similar dilemma whether to take a lens, the ef 70-200 f4 L (without IS) or the little brother EF 70-300 f4/5.6 70-300 IS, which cost more or less the same. Pros and cons are easy to enumerate: the first has a stop more light and constant aperture over the entire focal length, a professional construction (for example, it does not extend when changing focal length ), greater durability, and above all, a much faster autofocus. I find both to be accurate on focusing. The 70-300 on the other hand offers a +100 mm focal length and the stabilizer.
If you try the 70-300 @ 200mm @ 300mm and you realize immediately that the difference is really small, especially now that digital sensors with high pixel density allow us to crop without any considerable loss of detail. Obviously the 70-200 can always be fitted with an extender (x1.4) to get the same focal length (not so the 70-300, unless you use third parts gears such as tamron), but losing 1 stop of light that, what on balance makes it identical to the other, from f4 to f5 .6 and 120-360
The Eos 1ds mark2 that I commonly use, for these tests too, has an excellent autofocus in a sense that it manages to optimize even the slower lenses, such as as the 70-300. On cameras having a simpler autofocus, like an Eos 50d or even more on a 500/600d , the focus speed of this lens may drop in very low light conditions .
In any case in today's test , which takes into consideration the stabilized version ef 70-200 f4 IS and the 70-300 f4/5.6 IS, speed difference between the two objectives of autofocus is definitely perceptible . Obviously the 70-200 non-stabilized and the stabilized one mount the same autofocus motor.
Both lenses are able to focus very precisely (no problems of front / back focus found in each case), but the 70-300 is noticeably slower and may have difficulties to lock to the subject sometimes (in low light situations and with little contrast) .
I used the 70-300 for a year and I'm very satisfied, I do not often photograph sports or animals but when it happened I must say that I was not disappointed, of course the situation requires some skill because sometimes the autofocus has some difficulty indeed. It is not possible to assist the autofocus manually, as with prime USM lenses and the 70-200 (which in general does not need it), in order to help directing the AF in the classic situations where the AF runs back and forth without properly locking on the subject that interests us.
I think that for the most demanding photographer even only this aspect is not a small difference, and note that we have not talked about image quality yet . On the field, a more solid construction of the lens is not something secondary. The fact that the lens extends when zooming out, we are talking about the 70-300, has always given me some concern , a small bump may in fact damage the lens (always attach the lens hood on these lenses , not only for light but also for protection) .
And if considered at its maximum extension, the 70-300 also becomes longer and more cumbersome of 70-200, while weight of both is very similar, the 70-200 weighs maybe a 200 grams more but nothing that makes real differences on field.
I find the 70-200 f4 IS an excellent lens not only for the quality but for the handling too, by only sacrificing one stop of light compared to the 2.8 version (which still costs twice !), we have the same image quality but weight and size are significantly reduced, which means that in the end it will always be with us when the " beast " (the 2.8) often remain at home. I made a similar choice , preferring the EF 85 1.8 USM version to the huge 1.4 , which costs 3 times as much and does not offer significant advantages (well, creamy bokeh apart), but it weighs a lot more.
Let’s go backto the test of today, a very simple and remember NOT scientific one, but precise enough to highlight differences that are really noticeable on the filed between the two.
As mentioned the autofocus of both lens is just as valid about accuracy, but speed of 70-200, probably due to 1 stop more light but also to the more professional AF motor, is much better .
Here are two crop at 100% from shots taken always at maximum aperture and @200mm focal length. We compare for now the 70-200 @ F4 and the 70-300 @ f5 . @ 200mm the latter has a maximum aperture of f5, at 300mm instead aperture is 5.6. In reality, then, in the excursion 70-200 , there is not a noticeable difference between the two lenses, which @ 70mm have both an aperture of F4, while there is a difference of 2 /3 stop @ 200mm ( f4 vs f5 ).
The 70-300’s AF is accurate (not just from this photo, it is evident from many different shots I made this year), obviously the focal plane is on the bolt , the aperture of f5 gives some more clarity to the back elements as the iron bar , the bolt is very sharp and contrasty.
This is instead of the 100% crop from the photo taken with the EF 70-200 f4 @ :
Obviously, the 2/3 more light produces a brighter image. Note that at f4 you have more blurred back elements already on the wall that is only 2 cm behind the bolt, but the bolt itself appears more contrasted than in the other pictures, but finally they appear very similar. The wall my be not perfectly parallel to the focal plane, hence a greater blurry on the left side of the image.
All the images that I present here were taken in RAW and opened in Photoshop using the basic values of ACR then I added a small amount of sharpness, the same for both lenses. I did not correct any distortion and vignetting (but you do it easily with any RAW developing software) . Finally, photos were only balanced with levels, by raising and lowering the point of blacks and whites up to the limits of the histogram to bring back all the contrast that images my really express. Their overall brightness remains unchanged, only the contrast was recovered.
I tested the two lenses at maximum aperture. As a rule, you should try identical aperture , but in practice the photographer is interested whether a fixed aperture lens like the 70-200 can be always used at maximum aperture, and the answer is definitely YES. Only at 200mm you notice any significant decrease ... but let’s proceed with order. We present the two shots at 70 mm that allow us to highlight a few things.
F4/5.6 EF 70 -300mm IS @ 70mm and F4 ( the red areas are those used for the 100% crop that we present later) :
EF 70 -200mm f4 L IS @ 70mm and F4 ( the red areas are those used for the 100% crop that we present later) :
You will immediately notice that both zooms at 70mm produce a noticeable distortion, but the 70-200 much less. Distortion is easily corrected in Camera RAW or Canon DPP (Digital Photo Professional )
These are the two crop for the EF 70-300 @ f4, central and lateral (upper / left):
I believe that this lens behaves very well, obviously at the edges you notice a loss of sharpness and light, remember that we are at maximum aperture. Both zooms earn significantly sharpness and luminosity by closing aperture at least 5.6 @ 70mm, but f4 but it is certainly an usable aperture.
These are the two 100% crops for the EF 70-200 @ f4, central and lateral (upper / left) :
The 70-200 produces images with higher contrast and certainly more quality at the edges, as it should be expected, but the difference is not so obvious . I do not present the extreme margins of the images that I find useless in situations of real photography.
These are the two shots at 200 mm, before the 70-300 and after the 70-200, both at maximum aperture (f4 on the 70-300 and f5 on the 70-200):
We note again some distortion, and especially evident in the 70-300, and some vignetting (loss of light at the edges ) which is quite remarkable in the 70-300 but also evident in the 70-200. Stopped down it disappears . Both can be easily corrected in Adobe Camera RAW or DPP .
These are the crops for the EF 70-300 @ 200mm F5 and first the center and then the side / top:
These the crops from the EF 70-200 @ 200mm and F4 , first the center and then the side / top:
One difference you will immediately notice is that the two lenses produce different magnifications, on an equal focal length, let’s consider the 200mm: the 70-300 zooms in a little more shooting occurred at the same distance) . But the loss of light at the edges is more significant in the 70-300. The sharpness of both lenses to my eyes is the same, with a greater contrast by the 70-200 which also benefits of more brightness.
Note. It 's very difficult to have a perfectly flat wall and perpendicular to the axis of the lens, at f4 one millimeter difference can give the impression of less sharpness, so the comparison at the edges can be unreliable, however we have seen in many shots taken that the 70-200 makes it a little better at the edges.
At the same aperture ( i.e. f5 ) the 70-200 produces sharper images, as is to be expected, and by the way it seems to capture more light than the 70-300 even if the aperture is the same. It's clear that f4 against f5 receives more light, but even with the same aperture the 70-200 is a bit darker.
Conclusions:
In conclusion the two lenses behave very similar with regard to the image quality, with a more consistent quality of the 70-200 especially at the borders, which can be seen particularly at shorter focal lengths (70 , 100 and 135 mm ) of which we presented only 70mm. At 200mm both seem almost identical except for the loss of light, more in the EF 70-300, and the fact that you have 2/3 more stop with the 70-200 (which produces sharper images f5 anyway ).
The real difference between the two zooms in my opinion is not so much in the field of optical quality as in the usability on the field. The AF of the 70-200 is outstanding, fast and accurate, the construction of the lens too. We have not examined other aspects , such as the use with low light, that could make a difference .
In favour of the EF 70-300 f4/5.6 what is there? Well, needless to say, the lowest price! about 450-500 euro against 1,000 Euros for the 70-200 f4 IS L. Of course there is always the option of taking at the same price the non-stabilized version of the 70-200, which is optically excellent and shares construction and autofocus. However, the stabilizer is a very useful tool when it comes to long lenses, but the autofocus of the 70-200 is certainly superior in speed compared to 70-300 , so should be also the non stabilizer version of the 70-200 compared to the 70-300 IS.
On balance I consider the 70-300 a lens of high quality/price, at affordable price, that can be successfully used in many real-world situations due to its versatility. Obviously, it is not suitable for indoor sports or similar situations , where nevertheless even the 70-200 f4 is suffering and you are better off with prime optics or very luminous zooms such as the heavier and more expensive 70-200 2.8 IS L II .
For those who can afford it, the Canon EF 70-200 f4 L IS delivers superior performance , but not that much, as mentioned, in the optical department but on other aspects such as reliability, speed, and versatility. For a less intensive and unprofessional use I think the EF 70-300 is a more intelligent purchase , it costs half as much, but is certainly worth a lot more than half.
©2012 Marco palladino – All rights reserved
