Canon EF zoom lens - 24 mm - 105 mm F/4.0

...to accompany my then new Canon EOS 5D around 18 months ago. I have to confess, I spent over two weeks prior to making my purchases deciding just which lens I should choose as my 'standard' zoom - this, or the also highly regarded Canon EF 24-70mm f/2.8 USM. In the end, I chose the 24-105 for reasons which I will divulge as we go along.

This lens is designed primarily for use on FF (Full Frame) DSLR's or 35mm film SLR cameras, the 4.4x ...
...range when used on Canon APS-C DSLR camera due of course, to the 1.6x crop factor of the smaller sensor. The range of this lens covers all the most popular focal lengths within it's range and of course, in a completely stepless and smooth transition from serious wide angle, through to what might be described as 'longer' short telephoto. Within this range are specific focal lengths which I (and many others, I would think?) might describe as 'classic' ... more

I purchased this lens brand new to accompany my then new Canon EOS 5D around 18 months ago. I have to confess, I spent over two weeks prior to making my purchases deciding just which lens I should choose as my 'standard' zoom - this, or the also highly regarded Canon EF 24-70mm f/2.8 USM. In the end, I chose the 24-105 for reasons which I will divulge as we go along.

This lens is designed primarily for use on FF (Full Frame) DSLR's or 35mm film SLR cameras, the 4.4x zoom range presenting a somewhat less attractive 39-168mm focal length range when used on Canon APS-C DSLR camera due of course, to the 1.6x crop factor of the smaller sensor. The range of this lens covers all the most popular focal lengths within it's range and of course, in a completely stepless and smooth transition from serious wide angle, through to what might be described as 'longer' short telephoto. Within this range are specific focal lengths which I (and many others, I would think?) might describe as 'classic' focal lengths.

Starting - well? From the beginning I suppose. At the wide end, 24mm can certainly be considered a 'serious' wide angle, providing excellent scope from the obvious landscape and seascape subjects, through to architecture and interior photography.

35mm can be considered the 'ideal' focal length for 'involving' and 'immediate' street photography, including street scenes, reportage and close-up and personal street portraits etc. Providing of course, you don't mind getting in pretty close to your subject matter. Highly involving people pictures are often the forte of the 35mm focal length.

Next we move on to 50mm which we might normally consider to be that of a 'standard' prime lens on 35mm and full-frame digital cameras. And, so it is! With a viewpoint similar to that of the human eye - basically, what you see is what you get! If you wish to record things strictly as they are, then this is the ideal focal length. However, the same focal length can also be employed for slightly unusual and perhaps, more 'dynamic' close-up portraits. While we tend to consider short telephoto lenses 'most' suitable for such work, the 50mm focal length provides a somewhat more dynamic and 'involving' perspective when used close in. The shorter focal length and close proximity of the camera to the subject, produces slightly exaggerated perspective which, while not always desirable, can be used effectively for more involving and creative work.

Moving now to the telephoto end of the zoom range, 75 to 80mm might be considered an ideal 'portrait' range, particularly for head to waist-length shots. Whilst this lens can achieve good results at this range, I would consider the alternative EF 24-70mm f/2.8 L USM better for this task, due entirely to it's full f/stop larger maximum aperture,, where it provides reasonably shallow DOF (depth-of-field) and more pleasing OOF (out of focus) highlights. Even when using the EF 24-105mm f/4 L IS USM lens at it's maximum zoom of 105mm and at full f/4 maximum aperture, bokeh or OOF (out of focus highlights) are still not as attractive. I tend to use the longer end of my 24-105mm lens purely for 'reach' rather than more specifically for portraits. In fact, I have just recently purchased a Canon EF 135mm f/2 L lens to serve this purpose.

For me, one of the great advantages to this lens over the 24-70mm, besides the fact that it is both lighter at 670g and more compact, is the incorporation of an excellent IS (Image Stabilisation) system. The 24-70mm lens does not have this facility and personally, I find the effective 3 f/stops IS to outweigh the 1 f/stop advantage at maximum aperture of the 24-70mm lens, permitting the use of shutter speeds up to three times slower than might otherwise have been expected to obtain still perfectly sharp results. Of course, it must be remembered that no image stabiliser can counteract subject movement, only that caused through camera shake.

This lens is designated 'L' (Luxury) grade by Canon and as such (although not 'all' are), it is sealed against moisture and dust. However, I would recommend taking it out too long in an Indian monsoon or immersing it in a bucket of water. It really isn't designed to withstand this sort of exposure to the elements! It is however, extremely well built has quite a lot of metal used in the construction along with a great deal of high quality glass - 18 elements in 13 groups no less! This includes 3 aspherical elements and 1 S-UD (Super Ultra-low dispersion) one The lens takes a common 77mm filter.

Everything operates as should be expected for an 'L' series lens - very smoothly and precisely - with no sloppiness of slackness anywhere. The lens feels very substantial indeed and whilst relatively compact, does extend considerably when zooming towards the long end of the zoom range. In it's favour, the front element doesn't revolve either when zooming or focusing, so using polariser filters in no problem. With ring type USM (ultrasonic) AF, auto focus is both extremely fast and very quiet. FTM (full time manual) focusing is available, even when used in One Shot AF mode but is rarely needed due to the accuracy of the normal AF system.

As regards to performance, it is a case of mixed blessings. Vignetting is not much of a problem on this lens. Sure, there 'is' some, at maximum aperture and 24mm setting but
it becomes negligible after stopping down the lens by just one f/stop to f/5.6.

Resolution or, 'sharpness' is generally EXCELLENT throughout, with the best performance being attained in the 24 to 70mm focal length range. Performance, while still VERY GOOD, has softened just a little at the 105mm setting at maximum aperture. The corners are where this is most noticeable but even here, it improves considerably on stopping down where, at between f/5.6 to f/8 GOOD++ is attained in my opinion. Optimum sharpness throughout is perhaps attained at f/5.6 and f/8 where it is generally EXCELLENT - at almost all focal lengths.

The problem areas of this lens are with distortions and CA's (Chromatic Aberrations). At 24mm focal length, the lens exhibits quite obvious barrel distortion. Considerably worse than the Canon EF 24-70mm f/2.8 L lens in my opinion. Midway in the zoom range, around 40 to 50mm, this changes to pincushion distortion but, nothing so noticeable as the barrel distortion at the wide end and this shouldn't be a problem under most circumstances.

To add to the slight disappointment, the lens also suffers from noticeable CA's (Chromatic Aberrations) or 'colour fringing', particularly at the 24mm end of the zoom. Whilst this is not a problem with all subjects, it can be annoying when dealing with high contrast ones or with some backlit subjects, especially trees or open building construction which might be set against a bright sky for example. Although CA's do decrease a little as you zoom in more closely, it is only beyond 50mm focal length when they become so low as to be of no concern. With the specification of this lens, I am however, a little surprised!

Having said all this, the lens is in my opinion, in many ways, superior to the 24-70mm f/2.8 L USM lens. It has longer reach, which 'is' very useful, a 3 f/stop IS (Image Stabilisation) and in most areas, resolution 'is' marginally better than the shorter lens. It is also far less bulky and somewhat lighter. It's just a shame that Canon didn't provide the 'best' of 'both' in this product.

Highly recommended. If you've a full frame Canon DSLR.

David Chamberlain 

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