I'm in the market for a perspective correcting lens (i do mostly architectural photography), but would love some info from others. Is it best to go with a 24mm, 28mm or 35mm shift lens? What should I look for? Does Nikon make the best?

-- Sherri Tracinski (srt@tracinski.com), March 13, 2001

Answers

Large format is really the way to go if you're serious about Architecture.
I use a 35mm PC Nikkor for some work, but the movement is severely limited, and the preset operation makes it slow to use. I don't know how the 28mm version compares, and Nikon don't make a PC lens in 24mm focal length.
I'm going to be a traitor to my Nikon system, and suggest that the Canon tilt-and-shift lenses might be more flexible; that's if you must use 35mm for this kind of work.

-- Pete Andrews (p.l.andrews@bham.ac.uk), March 14, 2001.

I assume you mean 35mm?

If so I believe that as far as marques are concerned only Canon and Nikon make (tilt and) shift lenses. Nikon make 28mm and 35mm shift lenses and an 85mm tilt and shift macro lens. Canon make several wide angles including a 24mm. All are manual focus (obviously).

A Ukrainian company makes both tilt, and tilt and shift, lenses with various fittings including Nikon AIS. The UK magazine Amateur Photographer examined one 28mm 'Arsat' lens and found that optically it was excellent, but that the finish was not up to Japanese/German standards. The UK price was about GB£300 (~US$450)which compares favourably with Nikon and Canon (>twice the price).

-- Leif Goodwin (leif.goodwin@mail.com), March 14, 2001.

I'm not an architectural photographer, Sherri, but I am something of a Nikon Geek. I hope that with that background -- plus a bit of marketplace knowledge and a smidgeon of high-school physics -- I can add something.

The high-school optics comes in with the three things that the PC lens designer has to handle:

• the smaller the film size, the more the neg has to be magnified, so the higher the resolution has to be
• the wider the angle of the lens, the more the retrofocus that has to be built in to allow the mirror to swing
• the more the lens can shift, the larger the image circle the lens has to project on the focal plane

The lens designer has to juggle these and it ain't easy. The simplest way out of the quandary is, as Pete says, to use large format.

This gives you more scope to compromise resolution. A 35mm neg has to be enlarged 8x to give you an 8"x10" print. A 4"x5" neg has to be enlarged only 2x for the same effect; if you can enlarge it 4x, you can make a 16"x20" print which is as large as most people ever print.

Moreover, a large format camera doesn't have a moving reflex mirror to worry about, so the lens doesn't have to be retrofocus. You can concentrate your design on providing a large image circle. Which a number of lens manufacturers, including Nikon of course, have done.

But when you say Nikon, I'm sure you mean Nikon 35mm, which is a great deal more versatile than large-format. An N80/F80 SLR can be used as a top-grade point-and-shoot at a family event one day; the next day you can put it on a tripod, put a spirit level in the hot shoe, and turn on the grid lines in the viewfinder, giving you a decent architectural camera.

Nikon was the first manufacturer to make a Perpective Control lens for a 35mm SLR with the PC 35mm f/3.5 in 1962. Ironically, that original version -- because of its historical importance to collectors -- could well be the most expensive option I mention in this post! Nikon continued to make a PC 35mm f/2.8 lens for decades, withdrawing it only about 18 months ago when the PC Micro 85mm f/2.8 came out. It is readily available secondhand, and you could probably still find a new lens if you hunted hard.

The 85mm f/2.8 lens -- which is a tilt-and-shift lens like Canon's 90mm f/2.8 TS -- is what you get if you ease up on the second requirement I mention above. At that focal length, you don't have to worry about retrofocus designs, so you can concentrate on resolution and image circle. This is super for the tabletop photographers -- using tilt and Scheimpflug's rule to get the whole of a display cabinet in focus, for example. The snag for architectural photographers is that it is often not possible to get far enough away from a building to be able to use such a long-focal-length lens.

So, who makes, or has made, wide-angle PC lenses for 35mm SLRs? As you can guess, I'm not going to choose one as the best: a 24mm lens is much more versatile than a 35mm lens, but cannot hope to compete head-to-head on resolution. All these lenses come from clever designers working hard to balance the needs in different ways:

• Zeiss makes a 35mm f/2.8 PC lens for Contax SLRs.
• Nikon and Pentax both make a 28mm f/3.5 PC lens.
• Leitz makes a 28mm f/2.8 PC lens for Leica R cameras.
• Canon and Olympus both make a 24mm f/3.5 PC lens. Canon's lens -- the 24mm f/3.5L TS -- tilts as well as shifts.

And there's always medium format, of course. The World is changing there, and it's the fault of the digital backs. The large-format lenses for monorail cameras are balanced for image circle at the expnse of resolution; but even the highest resolution CCDs are much smaller than 4"x5", so that balance has to change.

Enter the medium-format monorail. The Hasselblad ArcBody (with special Rodenstock lenses) and the Rollei X-Act (which takes ordinary MF/LF lenses from Rodenstock, Schneider and Zeiss) look to me like something from another planet, but have all the tilt and shift you could ask for. Closer to normality are the Hassleblad FlexBody and the Zeiss PC-Mutar 1.4x converter for Hasselblad; they take ordinary Zeiss lenses. I've included them for completeness, and because I don't get many chances to talk of "ordinary" Zeiss lenses. :-)

Later,

Dr Owl

-- John Owlett (owl@postmaster.co.uk), March 15, 2001.

Forgot to mention that you can also correct for perspective distortion in photoshop. The book "Silver Pixels" by Tom Ang includes an example. Just scan the image and then apply the distortion. Assuming you have a PC and scanner of course.

-- Leif Goodwin (lgoodwin@racalinst.co.uk), March 16, 2001.