Sunday, 27 January 2019

Two-Dimensional


Winchester Road, Southampton

Although I don't do it very often, sometimes I like nothing better than to wander about town with a long zoom lens. The one I own is the "cheap" Fuji XC 50-230mm f/4.5-6.7 (equivalent to 70-300mm in 35mm terms), a lens at which most gear-head photographers would sneer, but its modest specifications enable it to be small(ish) and light, and optically it's absolutely fine. That is, it's good enough for me.

It seems to be a feature of human vision that the brain can isolate items of interest within the whole field captured by the eye, so that something quite tiny, in absolute terms – like, for example, the moon, occupying just half a degree of arc, which (I think) means you could fit 360 of them in the sky, edge to edge, from horizon to horizon – becomes subjectively huge. It's a very good and useful trick, a sort of neurological "digital zoom", but can only be duplicated photographically by actually narrowing the angle of view. With a long lens, you can really concentrate on the lovely, often quite graphical things that tend to happen in the distance where widely separated objects are brought into juxtaposition with each other. A slight movement of the head, or a step sideways, and a whole new combination presents itself. The combination of "foot zoom" and optical zoom is unbeatable, if you tend to like what you see out on the horizon.

Redbridge Hill flats, Southampton

I also like the sense of compression given by a long lens. I enjoy pictures that display a strong two-dimensional sense of design – it's one of the great pleasures of Japanese prints, and the western art inspired by them – and, if you can get the balance of aperture and point of focus right (which, with a long zoom, can be difficult, especially if you're a lazy person who prefers to work in auto-everything mode), the flattened perspective is very two-dimensional. I do wish the camera manufacturers would provide an automatic hyperfocal [1] setting, however, which would simplify getting this balance right. How difficult can it be? I always prefer things to be sharp from front to back: I was annoyed by the soft focus on the rearmost branches in the picture below, for example, as it restores the illusion of three-dimensionality. But then it was taken as dusk was falling at 16:30 at the widest available aperture. I suppose I was lucky to get anything useable at all; with any luck whatever that thing is will still be there the next time I pass by that tree.

The contemporary obsession with shallow depth of field and the quality of the resulting out-of-focus background (so called "bokeh", from the Japanese for "blur") as a marker of "good" photography is mystifying to me. The idea that one would spend hundreds, even thousands of pounds on a big, heavy, "fast" lens to hang on a camera (ideally, one with as big a sensor as possible), merely in order to blur out as much of the background as possible – "just like a professional" – is hilarious. Personally, I much prefer a slow lens, one which isn't pushing the optical envelope. A kit zoom  – the sort that comes bundled with a camera – has always suited me fine. Apart from the benefits in cash outlay, size, and weight, it means you're also always in with a good chance of some decent depth of field. Not least because in Auto mode you're not having to fight some software developer's urge to use, at every opportunity, the biggest, light-greedy, shallow DOF aperture available. A modest f/5.6 will do just fine, thanks.

But I think that's probably quite enough gear-talk for 2019.

Southampton Common

1. "The hyperfocal distance is the closest distance at which a lens can be focused while keeping objects at infinity acceptably sharp. When the lens is focused at this distance, all objects at distances from half of the hyperfocal distance out to infinity will be acceptably sharp."

10 comments:

Kent Wiley said...

I know it's a lost cause, but I will repeat the word anyway. When it comes to long lenses and DoF, they work remarkably well. Tripods. There, I said it.

Mike C. said...

Kent,

I take your point, but wandering around town with a tripod?? I prefer a convenient lamp post or railing...

Mike

Andrew Sharp said...

Mike

Leaving the gear stuff to one side, it's interesting how the apparent size of objects depends upon how far away we think they are.

For example, it seems that when the moon is high in the sky we judge it's size as though it were 1 or 2 miles away. When it's close to the horizon it is "obviously" much further away than that (at least 10 miles) so we see it as bigger even though the image on your retina, or photographic plate, is just the same size.

Presumably this is why photographs taken with a lens that reduces the difference in the apparent size between figures that are close and those much further away get interpreted as being of people of lilliputian dimensions (i.e little people closer together).

Or, as Father Ted patiently explained to Father Dougal, "small cow close, big cow far away"

Huw said...

Mike,

That first picture is great - I love the purple fringing on birch trees - and you're right about hyperfocal distance (didn't even need the footnote!).
Although will quibble with you about format and DoF, but perhaps another day.

Huw

Mike C. said...

Huw,

Thanks, I was pleased with that one, too (helped by "leaning on a lamp post at the corner of the street...").

I cannot understand why programmers capable of coming up with "face recognition" cannot build in the simple maths of hyperfocal distance. Setting aside "circles of confusion", AFAIK the only variables required are lens focal length and aperture. Even if the camera/lens combo can't set the focus for you (really?) you'd think at the very least a beep could go off when the correct focus distance is achieved manually!

Re. format and DOF, quibble now, or you may have to wait until my next gear post in 2020! ;)

Mike

Mike C. said...

Andy,

Surely Father Ted says, "big cow close, small cow far away"??

Mike

Huw said...

Mike,

Not sure if this link will come through: https://www.youtube.com/watch?v=MMiKyfd6hA0

And not feeling up to a quibble about DoF and format (although I have MFT / ASP-C / FF cameras, with definite pros and cons) this year. Will save for 2020.

Do feel like I should have made some amusing comment about birch trees, purple fringing and chromatic aberration, but can't quite manage it!

hUW

Mike C. said...

Huw,

Thanks for the link -- I'd forgotten about the model cows! Father Ted is possibly the funniest thing ever on TV...

Mike

Andrew Sharp said...

Mike

Ted and Dougal were in a caravan, Dougal was playing with a toy cow and getting it muddled up with the full sized, but little looking, cows outside.

It was indeed very funny, but for the life of me I can't remember the actual words.

Very comic writerly they must have been.

Mike C. said...

Andy,

Follow Huw's link -- it's all there. Still hilarious!

Mike