Canon EF fisheye lens - 15 mm F/2.8

...new in preference to the Canon EF 15mm f/2.8 fisheye, primarily because I thought it might be a better lens than the now aging Canon version. The Canon lens has not been updated in many years, having been designed originally for 35mm Canon EOS cameras. The Sigma on the other hand, is a more up-to-date design, benefiting from more recent developments in both lens design and technology and 'should' therefore, I would have thought, been a superior offering. ...
...as 'good' as the old Canon lens. Very good results are in fact possible but a little work is necessary post production, through image editing software, to get the very best from it. Also, a little aforethought helps when shooting with this lens and some appreciation of both it's abilities and shortcomings are rewarded in better results.

In my experience, shooting with a Canon EOS 5D full-frame DSLR camera, I have found it essential ... more

I purchased this lens brand new in preference to the Canon EF 15mm f/2.8 fisheye, primarily because I thought it might be a better lens than the now aging Canon version. The Canon lens has not been updated in many years, having been designed originally for 35mm Canon EOS cameras. The Sigma on the other hand, is a more up-to-date design, benefiting from more recent developments in both lens design and technology and 'should' therefore, I would have thought, been a superior offering. I was wrong!

The Sigma is by no means a 'bad' lens, simply not quite as 'good' as the old Canon lens. Very good results are in fact possible but a little work is necessary post production, through image editing software, to get the very best from it. Also, a little aforethought helps when shooting with this lens and some appreciation of both it's abilities and shortcomings are rewarded in better results.

In my experience, shooting with a Canon EOS 5D full-frame DSLR camera, I have found it essential to shoot ONLY in RAW mode in order to retain the utmost quality in the original file. After initial processing in Adobe Camera Raw or Lightroom WITHOUT applying any sharpening, I then convert the RAW to a 16 bit TIF file and carryout sharpening using either USM (Unsharp Mask), Smart Sharpen or High Pass filter, depending on subject matter. Occasionally, a combination of High Pass Filter and USM may be required to attain the very best of the lens's capabilities. Since purchasing my Sigma lens, I have had the opportunity to compare the Canon 15mm f/2.8 and in my opinion, the Canon lens is marginally better.

As one of Sigma's EX (Excellence) range of lenses, it sports the familiar 'smooth' black crinkle finish which, I have so far found to be both attractive and hard wearing. Quality of construction is GOOD but perhaps not quite up to the standard of some other Sigma EX lenses in my opinion. The lens is quite small, light and compact and will fit into most photographer's kit bags quite easily although it has to be said, this is something of a specialist or 'effect' lens and consequently, probably won't travel 'everywhere' with you.

Like all Sigma lenses, it comes complete with front and rear caps - the front being an unusual 'slip-on' affair which unlike the Canon version, does at least stay in place when fitted. It also comes with a very nice soft case and a metal gelatine filter template. This being necessary to cut filters from gelatine to fit into a special slot situated at the rear of the lens due to the bulbous front lens element and built-in non removable petal-type lens hood prohibiting the fitting of normal front mounted filters. Polarisers therefore, are completely out of the question!

Although this lens doesn't feature internal focusing, it doesn't noticeably extend when focusing and of course, as a prime lens of fixed focal length, doesn't have any zoom mechanism to consider. The lens also doesn't feature the HSM (Hypersonic Motor) which 'is' incorporated into many other Sigma lenses. So rather annoyingly, the focussing ring turns when auto-focusing and is also a little noisy. Not so much perhaps in 'real' terms but in perception. Such a small lens might be expected to focus more quietly in my opinion and for these reasons, the AF seems somewhat unsophisticated and even perhaps, 'crude'.

Of course, this design does not permit FTM (Full Time Manual) focusing either, which with HSM lenses 'is' available when shooting in One Shot AF mode. Whilst this might not at first seem to be much of an inconvenience, due to the extreme DOF (depth-of-field) available, one should consider that it 'does' in fact have a maximum aperture of f/2.8 and, even with such a short focal length, it is surprising just how 'little' DOF is available at maximum aperture, particularly when utilising the lens's excellent close focussing ability (15cm).

It should be considered that this lens is designed primarily for use on FF (full-frame) digital SLRs' or 35mm SLR cameras, when the full dramatic effect of the 180° diagonal angle of view can be enjoyed. This is not the case when used on smaller APS-C sensor DSLR cameras where much of the effect is lost, due to the smaller sensor utilising only the central part of the image circle. Whilst results still might be considered 'interesting', it has to be said, much of the lens's 'impact' is lost.

If you do not have, cannot afford or simply don't 'want' a FF (full-frame) DSLR, it might be worth considering a used 35mm SLR camera body specifically for this lens. After all, they are ridiculously inexpensive now and widely available. If you have a film scanner - dedicated or flat-bed - you could have the film 'processed only' and scan the resulting slides or negatives. Well worth considering in my opinion.

Performance wise, well? With this type of extreme design, all the normal expectations are thrown out of the window so to speak. We certainly cannot discuss 'barrel distortion' because this 'is' what this lens is all about! Amazing barrel distortion and, great fun! Very effective indeed, with the right choice of subject matter.

Vignetting? Well yes, there is vignetting at full aperture but this is easily corrected in software and in any case, is quite interesting in many situations. It does diminish as you stop the lens down to smaller apertures so, if you really don't like it, you can at least avoid it.

CAs' (Chromatic Aberrations)? Well, I'm not too sure really. I can't say that I have noticed a problem with CAs. They might be present but if they are, they're so small that I haven't yet become aware of them. The thing is, most objects or at least, those in the middle to distant range, are rendered so small that it would probably be impossible to measure chromatic aberrations. Not in my experience anything to be concerned about.

Resolution or 'sharpness' is my only slight criticism of this lens, as discussed at the beginning of this review. However, good results 'are' easily achievable. In fact, with just a little work and familiarisation with the characteristics of the lens, VERY GOOD results indeed are possible.

It is not realistic to talk about central and edge resolution specifically as so much field curvature is evident (the nature of the lens). And it is therefore, quite impossible to provide worthwhile or meaningful comments. Effectively, when focusing at closer distances and in particular, when using wider apertures, it is advisable to consider quite carefully, precisely just 'what' you want to render 'biting' sharp in your photograph and focus accordingly. It will probably not be realistic to expect to have it all 'biting' sharp.

This lens is certainly great fun and capable of high quality, creative and interesting work providing, you avoid the clichés so evident when many use this sort of lens.

Recommended 'if' you've got ideas for it's use. However, if you use Canon cameras, the Canon EF 15mm f/2.8 is perhaps 'just' a little better in my opinion.

David Chamberlain 

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