Another Lens

When someone mentions a “standard lens” most of us automatically think of the “nifty fifty” and indeed for 35mm that is standard. Funny really, as across all formats, it’s the most un-standard! The general rule is that whatever the diagonal of the negative/sensor, that in mm would be the “standard lens” for that format, hence 25mm on a micro 4/3rds camera, 80mm on a 6×6 medium format and so on. The one that is the farthest away from the “rule” is 35mm film being 50mm – it should be 43mm!! The reason for this is that while Oscar Barnak was popularising the use of 35mm motion picture film for use with stills, via Leitz/Leica cameras, Leitz already had a 50mm lens on the drawing board, close enough it was adopted.

Rather than pull back to something closer over time, many have gone the other way! A large number of Spotmatics were sold with 55mm lenses – so too were a lot of Zenith cameras!

When one goes to large format, like everything else – it gets a bit more complex. The “field of view” is considered more into the equation, so that if one does the maths, the long edge (horizontal) gives a different crop factor to the short edge (vertical), and vice versa. That’s why in 5×4 135mm 150mm and 180mm could, and are by many, all considered a standard lens! The 150mm, piggy in the middle, is widely regarded as THE standard.

I’ve just purchased a “standard” lens for my 5×7, that is 210mm!! I went for the Nikkor-W f5.6.

The main things to gleam from the info provided, and maybe the things to look out for when deciding on such a lens are: It’s a f5.6 lens, plenty bright enough for large format, it’s a different game! There are “brighter” lenses but they are huge, heavy and expensive – 3 reason’s I don’t want one! Also of course it’s worth pointing out that although this is the “standard” focal length – it’s still 210mm and a wider aperture will give such a shallow depth of focus I would question it’s usefulness in the real world anyway! This one closes down to f64 – more useful, but as we all know the best part of any lens for quality is about half way – that’s somewhere around f16 -f22, should give a decent depth.

Perhaps equally, maybe more important is “coverage”. One of the main attractions of large format, apart from the quality of image are movements. Shift/Tilt/Rise and so on. To use these without getting vignetting (dark corners!) the lens must produce an image circle that is large enough to cover the film – even when it’s off centre. This lens covers 243mm diagonal at f5.6 and 295mm at f22 – that allows for plenty of movement!

By happy coincidence is has a filter thread of 67mm and I happen to have a full set of black and white filters in my collection that are underused and ready to go! So… I pressed to buy button and 3 days later fitted it to my home made lens board!