Wednesday, 31 May 2006

Jungle Fever

Fisheye lenses in the field

We have a guy out in the jungle in Borneo at present. He's taken the Nikon 8800 + FC-E9 fisheye converter. This is the second trip to the jungle for this camera. Previously it was sent with the University's photographer. On occasion he'd get a 'System Error 2' - this seems to be a common fault with these Nikons - and was coupled with the fact that the camera was being carried by a student in between shots, and would come back with a random set of setting each time. I had figured that it might have been an isolated incident. But our man in Borneo has just reported having the same error. Its a shame as he was producing nice shots, and we'd sent him out with a 4GB CF Card - enough to get a day's timelapse.

Primary rainforest must be one of the toughest environments to take a camera, I suspect that moisture and humidity are to blame. I suspect that when the camera comes back it will work fine - as soon as it dries out. I does mean that we need to consider a new camera. This was on the cards anyway, as the quality of the FC-E9 circular fisheye's aren't great:


Even with this amount of compression, there is clear chromatic aberration, and a strong blue bloom around the edge. These are artefacts common to many fisheye lenses, but are particularly pronounced on this lens. My partner also has this camera and lens, and is displays the same behaviour - as do the many KAP photographs taken with this combination.


Finding a circular fisheye for a digital SLR isn't easy. Fisheyes are rare/specialist lenses anyway, the 'crop' factor of most current digital SLRs renders most 7-8mm lenses useless. Since the CCD in these cameras is smaller than traditional film, only part of the circle is captured. There is in fact only one lens which can be used by 1.6x or 1.3x digital SLRs, this includes all of the current Nikons and Canons except a few models I'll mention in a minute. This lens is made by Coastal Optics in the US. According to the fisheye bible, this is the same lens as marketed by iPix.

Canon make two cameras that have full-sized CCDs (actually CMOS) - the EOS 5D and EOS 1Ds MkII. These are 12.8 and 16.7 MP (Mega Pixels) respectively. The list of fisheyes available for these is slightly larger:

Sigma - We bought one of these in Nikon fit by mistake. Don't let and of the "For Digital", "DG" or "EX" confuse you. It is only a circular fisheye on a 36mm x 24mm image plane.

Peleng - This is a Russian built lens. It seems to be hit and miss in terms of quality. Hertblei, a Czech firm who rebuild Russian and Ukrainian cameras and lenses are said to produce a multi-coated version, but it doesn't appear on their list.

Old Nikons - These come up from time to time and can be adapted for Canon EOS mount. Ironically, early FD mount lenses for pre-EOS Canons, don't do so well.

Coastal Optics - As well as the lens mentioned above, they also produce one designed for 35mm film cameras - Coastal Optics confirm that this would fit a 5D or 1Ds. Interesting to note is that the digital version has f-Theta distortion < 6% whereas the 35mm version is < 2%. This lens is also double the price of the digital version.

Given the above list. The Sigma and the Peleng are the cheap options - both are available for less than £500. The Nikons are available occasionally for 1000s and the Coastal Optics is $7500. The next step was to evaluate the Sigma vs the Peleng.

There are some technical papers available on the Coastal Optics site. This chap has a good overview of the Peleng. This site has some tests for the Sigma. The real evaluation needed lots of images from each lens, below are the best from those I found on the internet:




38718695.D74S8398_s is an amazing resource for finding images like the above. They're searchable by camera, lens or keywords. The above are a mixture of Canon 5D and 1Ds MKII.

There doesn't seem to be that much between the lenses. They still show the blue ring of the Nikon FC-E9 - this is quite soft and wide with the Peleng, thinner and more pronounced with the Sigma - the Sigma would be easier to remove in post-production. They both also display signs of chromatic aberration. The Peleng is only slightly better than the Nikon FC-E9 - the Sigma is much better here. The final judgement is subjective, an authoritative assessment of sharpness cannot be made given various processing and compression these images have undergone. The Sigma though does seem to be sharper and more 'contrasty'


There is a lot of discussion on photography mailing lists about weatherproofing. Some have the opinion that cameras are usually more weatherproof than their owners - others (including the Manufacturers) who go to great lengths and costs to make their kit weatherproof.

The EOS 1 range, is Canon's premier professional range - and as such has features designed for expedition use. All sockets, buttons etc are weatherproof. Used with Canon 'L' series lenses - it is said to be tropical proof. The 5D is part of Canon's 'pro-sumer' range, and as such they make no claims about durability under harsh conditions.

There is a huge difference in price - you can almost buy three 5D bodies for the price of one 1D. It has a higher resolution sensor, and many features to ease the life of a pro-photographer. Most of these would be wasted on us. The only thing that helps me with this decision is thinking that a 5D which has been flown around the world, and ends up failing in the forest, is not cheap at all...