In Praise of a Hundred

is digital killing the 100mm lens or will it return?

Image – Jerry Ghionis
85mm ≈ 127mm
One of Jerry's iconic images shot at medium telephoto length

The main fear of an article like this is that we slip into the amateur photography press style, you know the sort of thing – 'how to shoot with a 100mm lens', 'how to become a wedding photographer'. It is worthwhile taking the risk occasionally to ponder why you have a particular favourite lens (if you have a favourite fixed lens, you might be one of these zoom types!). Other photographers sometimes find that they give a tiring style a bit of a fillip by deliberately seeking opportunities to use a specific focal length, perhaps to even put the zoom down and use the feet more!

The 100mm lens has always been a fixed point in the lens population. Sitting between 85 and 135mm there are very few lenses outside either 105 or 100mm in between these two points (eg ever heard of a 115mm lens, a 125mm lens?). Not too long ago a serious enthusiast’s kit would include a 50mm, 28mm and 135mm lens – no more, no less. The arrival of the 70–210mm zoom and the ever-improving quality of that lens, (utilising rare earth elements to make more bendy glass, better computer optimisation and aspheric elements) has pushed the 135mm lens off its perch. The 70-210 lens is popular (why did they stop at 210, why not 200mm, did they really need to brag about a 3x zoom range?) because it catches the 85, 100 and 135mm options on the way to the truly telephoto 210mm.

Why should 100mm represent such a mark in the sand? Well it has twice the magnification of the 50mm lens which means it halves the natural field of view of the eye. It is thus a quarter of the area covered by the standard lens and is the point at which the telephoto effects start to become apparent – compression of perspective, low depth of field and increased recession in the background. It doubles your distance from your subject, which can make them feel less intimidated by the scary person with the camera.

For all these reasons the 100mm lens is regarded by many as their ‘favourite’, the one they would take to the desert island if Kirsty Young would only let them take one! However, digital has now arrived and, with certain exceptions, messed up the carpet by reducing the size of the chip, so that a 100mmm lens is now more like a 150mm, beyond even the 135mm! This is a problem. A focal length of 90mm to 105mm has long been considered ideal to improve the perspective of portraits and, unlike the 135mm, you do not get pushed too far back down your, possibly cramped, studio. This is the problem of using a 100mm lens on a small chip D-SLR, you are a little far away. All of this, of course, does not apply if you have a full chip D-SLR, you then have a pure 100mm back again! One interesting thought is that a 60mm lens with a 1.5x small chip magnification factor brings you back to 90mm, right where some of this all started.

Image – Mike McNamee
105mm ≈157mm
Traditionally the 100mm prime lens has been regarded as the first point where differential focus starts to show up, isolating the subject from a messy background

Development of the 100mm Lens

Nikon’s original 1948 design, acquired a legendary reputation. The basic design remained essentially unchanged throughout its life, a testament to the quality of the original design (carried out using log tables by the way!). It consisted of five elements in three groups and was used on the Nikon Rangefinder camera. It was introduced in an F-mount in 1959 and remained essentially the same unit 1971 when the five elements were rearranged into four groups. It remained in the catalogue until the demise of the manual lens.

The Nikon Rangefinder was originally issued with the following lenses: 35mm f/3.5, 50mm f/3.5, 50mm f/2.0, 85mm f/2.0 and 135mm f/4.0.

In 1993 Nikon introduced the 105mm AF-D f2.0 DC. They had noticed that the bulk of 105mm f2.5 lens users were portrait photographers and the new lens was given the ability to introduce controlled amounts of chromatic aberration to produce pleasing defocused effects. Nikon always strived to maintain a 52mm filter fitting to their lenses and only jumped to 72mm when the aperture of the 105mm lens was bumped from f2.5 to f2.0.

The Tamron 90mm Portrait Macro

Alongside the 105mm lenses almost every maker also had a 105mmm macro lens. Combining superb optical capabilities with both macro and portrait conjugates was quite a challenge and the original Nikon f2.8 MicroNikkor only accomplished this with a floating rear element to give close-range correction (CRC) and a shift from 105mm to 85mm as limiting 1:2 magnification was approached. This was followed by auto focus versions with true 1:1 capabilities from both Nikon and Canon, along with a legion of other makers around at that time.

The next move has been the introduction by Nikon of the 105mm f2.8 VR MicroNikkor, a lens that has proved so popular that it is almost certain that Canon, Sigma and others will soon follow. VR was started by Canon in 1995 and the 75-300mm f/4-5.6 IS USM followed by Nikon with the 80-400 F4.5-f5.6.

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Photo Quote: To me, photography is the simultaneous recognition, in a fraction of a second, of the significance of an event. - Henri Cartier-Bresson