The DSLR Field Camera
|Landscape photography is a medium that benefits from fine detail rendition.|
The large format field camera has traditionally been the instrument of choice for dedicated landscape photographers. Drawing inspiration from past masters such as Ansel Adams and Edward Weston, modern day artists like Joe Cornish and Jack Dykinga, to name but a few, have been drawn to the cumbersome field camera for one main reason: image quality. The 4x5 (and larger) field cameras provide a big film (or sensor) area and tilt/shift movements that, combined with high quality prime lenses, produce images with a three-dimensional feel that resolve even the finest details in the landscape.
Many photographers, however, myself included, have a wide range of photographic interests that include wildlife, documentary, sports and street photography. Using a field camera in most of these situations would be impractical, to say the least. And carrying completely separate camera outfits for different subjects has obvious downfalls. Even if you're willing to pack a DSLR and field camera kit for a trip, with all that equipment there's always the risk that the gear you need at any given moment will be packed in your bag instead of mounted on your tripod.
Fortunately, the high resolution of today's DSLRs (20-24MP is now the norm) means that if you stitch together multiple full resolution exposures created with tilt/shift lenses, you can get results that are impressively close to single shot field camera output.
For the past few years my own landscape outfit has consisted of a 22MP DSLR with 24mm, 45mm and 90mm tilt/shift lenses. The tilt function of these lenses allows front to back depth of field (DOF) while using the lens’s 'sweet spot' (usually around F/8) with the shift function allowing me to shoot 3 exposures that can be stitched together to create a single high resolution image. Depending on the orientation of the camera (vertical or horizontal) and direction of shift (up/down, left/right) the result is either a panoramic image (like the one you see below) or an image that more closely resembles the classic 4x5 format.
|This panorama was created using a 90mm tilt/shift lens with three separate exposures stitched together.|
It goes without saying that capturing three separate exposures for each scene you want to shoot requires a slower, more methodical approach; somewhat similar to using a field camera. In addition to your DLSR you'll need a sturdy tripod of course, with a pan/tilt head, cable release and spirit level. I typically shoot in aperture priority at f8, enabling Raw mode for the highest quality and mirror lock up to minimize camera shake.
Let's take a look at the basic process of capturing the files to be used in a multi-exposure composite image.
|Mounting the camera in a vertical orientation allows you to capture higher resolution images...||...while maintaining a classic 3x2 or 4x5 aspect ratio with relatively minimal cropping.|
With your camera in position on the tripod, compose your images by shifting the lens from left to right between each exposure (or right to left depending on where the more important image elements lie). Because the three single exposures you will be making have to be stitched together later you should allow some overlap around the edges for cropping. Find some visual markers in the scene you can use to make sure that you have at least 1/4 of the previous scene overlapping the current one. It takes a bit of imagination and practice to compose in this way but it becomes second nature after only a little while.
|The Canon 45mm TS-E shifted to the left...||...in its neutral (metering) position...|
|...and shifted to its right.|
|A tilt/shift lens allows you to manipulate the plane of depth of field so that both near and far objects appear in crisp focus.|
While the shift perspective of the lens is what allows you to pan across the scene, it is the tilt functionality that lets you achieve front to back focus without having to stop the lens all the way down to its smallest aperture.
I set my camera to live view mode and zoom in to around 50% and then perform the following steps:
- Set focus manually on the area closest to the camera that I want to be in sharp focus.
- Tilt the lens until the background comes into focus.
- Check to see if both foreground and background areas are in equal focus.
- Repeat steps 1-3 until both foreground and background are in focus.
If you've never used a tilt/shift lens before, it may take some practice before you get the hang of it. And you'll probably need a couple of iterations before you have everything you want in focus. As a general guideline I've found that a tilt of just 1 or 2 degrees is enough for most scenarios.
The payoff is that you can now set your lens aperture to the optimal f-stop for sharpness, usually around F/8. Without a tilt-capable lens you'd be forced to shoot stopped down to F/16 or F/22 to increase depth of field, which unfortunately, leads to lens diffraction which softens image detail.
When determining exposure it's important that the metering is done with no shift applied, as light fall-of can be an issue at extreme ends of the shift. Make sure your lens is in the neutral (middle) position. I meter with the camera in aperture priority mode and always make a test exposure to see if any compensation is necessary.
Many landscape images will need some kind of exposure balancing between a dark foreground and bright sky. This can be done the old way with ND graduated filters. Or you can opt for an HDR solution by merging 2 or more exposures. You can even combine both techniques to cover a really high contrast range. If you use an ND graduated filter, just make sure that the filter sits correctly at all 3 shift settings (left – middle – right).
|A bright sky against a relatively dark background requires you to either use an ND graduated filter, HDR multi-shot technique, or, in extreme cases a combination of both.|
Once you are happy with the exposure it is important to switch the camera to manual exposure and apply the settings you used while in aperture priority mode. Shifting the lens changes the amount of light that reaches the sensor and any exposure mode other than manual, the camera’s light meter would seek to compensate for that, resulting in over or underexposure. To be able to properly stitch the 3 images together it is vital that each exposure is made with the same exposure settings.
Now you can finally make the exposures. I highly recommend using a cable release and enabling mirror lock up on the camera. Because the lens has to be shifted manually there is always some vibration so it is also helpful to wait a few seconds before releasing the shutter. In the field the sequence goes like this: Shutter release. Lens shift. Mirror lockup. Count to three. Repeat.
This technique obviously has its limitations in certain situations. The most obvious occur whenever there are any moving subject in the frame. People and animals, as well as clouds, foliage or anything else moved by wind can cause problems. You can use a long exposure time to blur water and clouds, making it easier to stitch the image files together. Outside of that, however, you must either wait for a calm day or shoot several series and hope for the best.
|In Photoshop I used the Photomerge tool to combine these three individual HDR images.|
After importing the image files into your Raw converter, make sure that any adjustments you apply (white balance, curves, etc.) to one image are then copied over to the other two as well. Having images with different individual settings makes it very difficult to stitch the files and get a natural, realistic result.
|After a final bit of cropping and Curves adjustments, I arrive at the final composite image.|
After all this work, the obvious question is, 'How is the actual image quality?' Not surprisingly an image made with field camera can still be superior in detail and resolution. The difference lies with the lenses. When fully shifted the image quality on a DSLR-compatible tilt/shift lens deteriorates significantly. So the corners of the final image can be relatively poor. In addition to loss of sharpness and detail you're likely to see an increase in chromatic aberration (CA) in the corners as well. These flaws do vary by degree from lens to lens, however. Of the 3 lenses tilt/shift lenses I own, the Canon TS-E 24mm f/3.5L II and TS-E 90mm f/2.8 are very good performers even fully shifted (see an example of the 24mm lens below). My Canon TS-E 45mm f/2.8 unfortunately could be much better.
|A stitched image created using the Canon TS-E 24mm f/3.5L II lens on an EOS 5D Mark III.|
|Left corner 100% crop||Right corner 100% crop|
An alternative approach of course, would be to use a dedicated panoramic head instead of tilt/shift lenses to create the images to be stitched. But apart from the additional equipment to carry, I find that using panoramic heads is a much more involved process than I'd prefer, and with the performance of at least two of my tilt/shift lenses, the payoff is just not worth it. So for me, the DSLR plus tilt/shift combination works very well. I can shoot high resolution landscapes and architecture without having to carry a second camera system should I come across wildlife or documentary opportunities. remember, photography is nearly always about compromise, and this is one that I'm happy to make.
Carsten Krieger is a professional landscape and wildlife photographer based in the West of Ireland and author of several books on the Irish landscape and nature, including his most recent title, Ireland's Coast. To find out more about his work please visit his website: www.carstenkrieger.com.