Archive | July 2013

Rock&Roll, the Samyang 14mm and the hyperfocal distance

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Here’s a shot of the band Left or Right playing at Chick’s Hotel in Port Chalmers, Dunedin. To get the shot I used a 14mm Samyang lens. I was really close to the band – I managed to get myself a good spot just near the foldback speakers where I could get a good  view of the band. Since the lighting was constantly changing and I was often shooting blind – holding the camera above my head – it was almost impossible to focus accurately. I needed to use and old technique – the hyperfocal distance combined with white gaffer tape. White gaffer tape??? read on…

It’s sad that most modern lenses don’t have “depth of field scale” markings any more. If you look at older lenses most of them have a series of cryptic markings that show the hyperfocal distance.

It works like this. Let’s say you are shooting at f/16. You set the infinity symbol so that it is set to the little mark for f/16 – as in the example below, which is an old Tamron 28mm…

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The focus here is set to 1.5 metres – but that’s no longer important. It’s the little numbers on either side of the focus mark that count. They show how much will be in focus at any give aperture. So setting the infinity mark to f/16 means that I’ll have everything from infinity to just over 0.7 metres in focus. In other words, if I use this setting – the hyperfocal distance, I don’t need to worry about focus unless something is very close. So long as everything is more than, a little under a metre away, I know the focus is good.

Here’s the same indication on a more modern lens – a Canon 20mm

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The markings are still there, but they are quite small.

The hyperfocal distance is mainly useful with wide-angle lenses – it’s often too narrow to be of use with telephoto lenses.

Now, lets move on to the Samyang 14mm f/2.8.

This is a great offering from the Korean manufacturer who brought us a great 85mm and the best ever APS-C fisheye. Samyang’s philosophy is to make lenses that have fantastic optics and a solid build quality at a low price. To get the price down, something has to go – and that’s autofocus. All the Samyang lenses are manual focus only – they are back to basics lenses. They are not for everyone, but if you can focus manually, they represent a great bargain.

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There is a drawback with the ultra-wide lenses such as the 14mm and 8mm fisheye though. It’s very easy to get the focus a bit wrong. It looks OK in the viewfinder (as you would expect with these lenses almost everything is in focus all the time) but sometimes you’ll get home and notice that all your shots are just slightly soft – the focus was set to a really close distance, and you just didn’t see the very slight softness in the viewfinder. I’ve learned to focus these lenses using the focus scale on the lens rather than the viewfinder – the focus doesn’t need to be precise due to the massive depth of field, but it does need to be not horribly wrong.

And that’s where the gaffer tape comes in.

The 14mm does not have a depth of field scale, and it’s a lens where it would be really, really useful. I think I know why it doesn’t have one – the positions for the scale would  run right around the lens since the depth of field is so great at narrow apertures on this lens, that the scale might have been a bit confusing. So I visited http://www.dofmaster.com/dofjs.html, and looked up the relevant distances for a 14mm lens on a full frame camera…

At f/4 you put the focus point to 1.65 metres, and you will have everywhere from 0.8 meters to infinity in focus.

At f/8 you put the focus point to 0.8 metres, and you will have everywhere from 0.4 meters to infinity in focus.

At f/16 you put the focus point to 0.4 metres, and you will have everywhere from 0.2 meters to infinity in focus.

Since this was an experiment,  I didn’t want to do anything irreversible to the lens, so I stuck the band of white gaffer tape that you can see in the photo above, and the indications for the different apertures on that.

Then when working taking the photos of Left or Right I could quickly set the aperture  – thankfully this lens has a very wide maximum aperture – and then set the focus ring to the matching point on my gaffer tape depth of field scale. In an environment like that – changing light, moving people, focus is difficult, and it would be easy to make a horrible error. With this simple system I was able to shoot without looking through the viewfinder and to get the camera into some unusual places – holding it out, low to the ground, or up above my head. Since the 14mm takes in so much it’s easy to estimate whats going to be in shot without looking in the viewfinder.

Below are two more shots taken at the same gig – now remember this was a live gig with the punters dancing right up next to the stage – there was no way I could get these shots without getting in between the audience and the band, or lying on the floor under Callum Hampton’s feet.

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