Selective Focus with a Tilt Lens
Finding a Tilt – Shift lens is easy and if you are selective about what you buy; it doesn’t need to be as expensive as you think.
Understanding the geometry involved is not so simple; especially for perspective control and the articles I have found and read since getting my lens have only gone part way to helping me understand the subject.
For that reason I am going to try and explain the somewhat trial and error methods I have applied to learn how to use the lens and hopefully make the subject simple enough to understand for your average user.
What seems to stop many people from moving to Tilt-Shift is the limited availability of lenses, price of the main ones from Nikon and Canon and the ease of “faking” an image using photoshop or all of the apps that you can get for your iPhone.
As this is an Analogue blog you would not expect me to suggest anything other than the mechanical approach and especially as using a Tilt-Shift is going to force you to understand much more about your camera than you’d ever imagine – and that can’t be a bad thing.
This is a Ukrainian Lens made for the Medium Format cameras from Kiev by Photex and identical to the Arsat 80/2.8 I have for my Kiev 60 and it is available as new with your choice of 35mm fitting (or even 4/3rds digital cameras).
For my lens, I opted for the Nikon fitting so that I could use it on my F2A (only it didn’t fit until I bought a non metering finder without the overhang at the front for the camera).
It would have been good to know about this before hand as having a flat front to your camera with these lenses is important for them to be able to move freely in all directions. What you have to take into account isn’t so much the square back plate as the two knobs used for the Tilt and the Shift of the lens as this lens also turns through 360 degrees and they need a clear path.
This lens allows 11mm of Shift, 8 degrees of Tilt and 360 degrees of rotation and so you can basically do anything with this lens that the bellows on a View Camera will let you do.
The reason for the Medium Format lens on a 35mm camera is probably quite obvious – it is to ensure the frame is always covered with the lens allowing for the large amount of tilt and shift possible.
If you don’t want to get a dedicated lens and you have a range of Medium Format lenses that you can use on your 35mm camera – you can always buy a cheaper adapter that will generally give you a limited amount of tilt and in some cases a little shift – but generally only enough for a little perspective control and no selective focus of note.
The Lens Baby will also allow good Selective Focus and Hartblei also do some great smaller lenses at 35 and 45mm.
For the first part of this article I am going to talk about Selective Focus as this is the gimmicky part of Tilt-Shift and it is where you will produce your “miniature fake” images.
Selective focus can be used to direct the viewer’s attention to a small part of the image while de-emphasizing the rest of the image.
With a lens pointing directly in front of you – the focus point is not a single point but a plane parallel to the film plane. This means that if you are using a focal length of 5 meters and your camera is on a tripod pointing directly ahead – that everything 5 meters in front of the film plane is in focus – irrespective of height.
You would image that this focal plane would be concave but compound lenses are very good at righting this effect and keeping the focal plane flat.
Using the Tilt on your lens, say full 8 degrees tilt and keeping the camera on the tripod pointing directly ahead will give you a small wedge shaped focal plane.
Combine this with the widest aperture you can for your lens and you will get a very small and angular Depth of Field (area that is in focus).
The final part of the trick to getting miniature fakes is to be above the object you want to minaturise by somewhere between 30 and 45 degrees.
I have read on a few sites that B/W Selective Focus doesn’t work – but I guess it depends what you are looking to achieve. If you want to shoot vehicles that look like toys – then bright primary colours will fit this better.
You will also note from the above shot that people do not minaturise as well as simple shapes – buildings, cars etc but again if you want to selective focus just to get an image like you have seen elsewhere – then perhaps an app is going to suit you better.
The direction of Tilt is incredibly important and it is very counterintuitive if you want to miniaturise an image.
The above image was taken with maximum Tilt of 8 Degrees, f2.8 and the focus on my wife and friends – but with the Tilt downwards. In this case you will get the selective focus but not miniaturisation.
This one was again taken with the Tilt at 8 degrees downwards but with the lens at f5.6 – broadening the area of angular focus and again with no real minaturisation apart from to the middle sides of the image.
This one is however a good example of what happens when you Tilt the lens upwards by 8 degrees and open it up fully to f2.8 and shoot at infinity and 30 degrees.
When the lens is Tilted up to maximum it also means that the area of sharp focus is just above the half way line – important to know when you are trying to get a particular image.
If you shoot too vertically you will not get a great miniaturisation either (and this is the below image – taken from the roof directly to the road underneath) and to understand this fully you need to start to understand the Scheimpflug Principle – named after Austrian army Captain Theodor Scheimpflug, who used it in devising a systematic method and apparatus for correcting perspective distortion in aerial photographs.
Great books and information on line for this subject center around the View Camera and I will hopefully attempt to simplify some of this when I talk about Tilt for Perspective Control in a later article.
As I said above – this is only a little area of what a Tilt – Shift lens can achieve and is not how most of these lenses have traditionally been used.
Following on from this article (at some point in the future) will be one covering Shift and another covering Tilt for Perspective Control and probably some other about using Selective Focus in other ways than just miniaturisation.
Addendum – 29th August 2011
Night time using Portra 400 film at f2.8 and 1/60th with tilt at +8 degrees.
I think the subject for selective focus is much more important than I had assumed as it just doesn’t seem to work too well on all subjects. Also, shooting beyond infinity on the lens seems to be critical to get the effect to work.