Interview in On Landscape (Part I)

This is the first part of an interview that first appeared in On Landscape, the online magazine for landscape photographers, No. 212. The questions were asked by Tim Parkin.

Q: Can you tell me a little about your education, childhood passions, early exposure to photography etc.?

A: As a kid I always loved to spend as much time as possible outdoors, and landscape photography is a fantastic excuse for continuing that. My interest in photography though was sparked by a cousin who had pioneered a new approach to simulating architecture photographs. He used modified endoscopes which had originally been designed for medical purposes for photographing architectural models, simulating the pedestrian´s view of buildings not existing yet. This all was done long before computer simulations came up, and back then revolutionized urban development because for the first time it was possible to view planned buildings in form of models not just from a bird´s eye view, but from street level. But in the end it was a book from the Time Life series on photography in my father´s library which became life-changing for me. In that book there were two Eliot Porter images taken down in Glen Canyon before its tragic flooding which just struck me like lightning. Never had I seen before such a beauty in a photograph, and I immediately knew that I just had to visit that land of the canyons myself – and bring a camera. From there it still took me many years until my first expedition to the Desert Southwest, and even longer until I started to fancy large format photography. In the meantime I studied natural sciences, and at a glance one might think that a scientific perspective distracts from an artistic point of view. To my own surprise I realized that the contrary is the case: with a background in life sciences you inevitably have a different view on the natural world surrounding us, and this opens one´s eyes for structures and phenomena which one otherwise might have overlooked. Actually it turned out that this perspective is a steady source of inspiration, and it´s a perfect complement to a perspective primarily driven by aesthetics.

Q: Is that the “Approach of the Painter and the Scientist” you´re alluding to in your Artist´s Statement? Could you explain this approach in a little more detail?

A: Exactly, that´s how I called this confluence of scientific and artistic perception. The starting point here is the existence of two very different and ostensibly incompatible ways to perceive nature, represented by the perspectives of the painter and the scientist, and which in Robert Pirsig´s words one could call the “romantic” versus the “classic” perspective. The landscape painter is interested in a scenery as a whole, while the scientist will rather have a close look at the details, in order to understand what´s going on under the surface. For example, when seeing a dune, the painter will perceive its harmoniously curved, female forms and the play of light and shadow when the sun is low on the horizon. Were someone to hand him a camera, he would shoot images that capture the beauty, power or evanescence of what is seen. In contrast, the scientist’s interest is focused much more upon detail. He is preoccupied with causality, determinism, and natural forces and their interaction with one another. In seeking to explain why things are the way they are, he strives to trace natural phenomena back to the laws governing them. When investigating the same dune, he would examine a single grain of sand and would attribute the dune’s form, the angle of its slope, and the continual changes in shape caused by the wind to the physical properties of the grain. Through a camera lens he would concentrate on structures, patterns, and surface qualities by taking close-up shots, which would then in turn bear witness to the play of natural forces and their formative effect on animate and inanimate nature. By doing this, the researcher would render the reasons for the surface texture of the natural world visible. What fascinates me is the possibility to combine both perspectives in a single image, and to create photographs that evince two very distinct, and yet inseparably interwoven, levels: an aesthetic level (the effect of nature on the viewer) and a purely analytic level (the effect of formative forces on nature). As these levels are often located on very different scales of magnitude, an extremely high optical resolution is required for the fusion of both in one picture, and that´s where large format photography comes into play: the unequaled resolution of large format film allows to simultaneously record an almost infinite number of tiny details within a scenery, while still grasping the whole picture. Thus, a sufficiently large print – I prefer a final enlargement format of 70 x 100 cm / 30 x 40˝ at the least – allows the viewer to zoom in and out again and to switch between beholding the entire composition and viewing some of its countless details. This way, probably in most cases without realizing it, viewers switch back and forth between the perspective of the painter and the perspective of the scientist. I´m observing this frequently on the occasion of my exhibitions, and it´s interesting to see that people who hadn´t been in touch with the concept behind my images nevertheless follow exactly the path I had taken before upon creating the photographs.

Q: In most photographers´ lives there are ‘epiphanic’ moments where things become clear, or new directions are formed. What were your two main moments and how did they change your photography?

A: Yes, there are such moments, and in my case there actually were three which really changed a lot for me. I mentioned one already – my first encounter with Eliot Porter´s photographs of Glen Canyon. The other two relate more to technical qualities, one of them being the moment when I saw the first print made from a large format photograph. This happened to be a landscape photo, printed to Cibachrome material and hanging perfectly lit in a gallery. Before that I had seen countless large format photos printed in magazines already, and they always had some sort of difficult-to-describe appeal photos made with small cameras were lacking, but that print was just amazing. Having had fancied large format photography for quite a while, this was the moment when I decided to go for it and give it a try. The other moment was when I saw my first Diasec print on an art fair – must have been the Art Cologne I think. The brilliance and perfection of that print was so far beyond anything I had seen before that I simply couldn´t believe it. Back then I had been looking for a while for a way to present my images such that they would provide an immersive experience to the beholder, and I immediately realized that facemounting would be it.

Q: What are you most proud of in photography?

A: This question fits well to what you asked before, since the achievement I´m probably most proud of is my contribution to the development of the “UltraSec M” technology, or the face mounting of prints to anti-reflective glass. I mentioned my spontaneous fascination with Diasec, and for a while I couldn´t imagine anything of higher quality than prints face mounted to acrylic. However, I realized soon that the Diasec technology has two limitations: first, acrylic is extremely sensitive to scratches. Just wipe some dust off (which Diasec prints happily attract due to acrylic´s electrostatic properties), and you already introduced a host of micro scratches you´ll never get rid of again. Second, the reflections on acrylic are highly distracting, which is almost always a nuisance except under perfect lighting conditions. You may have such conditions in a gallery or a well-made exhibition, but almost nowhere else. Hang a Diasec print opposite to a window, and you´ll have difficulties to see anything but just a bright reflecting square on the wall. Using frosted acrylic was no alternative though, since the frosting takes away from a face mounted print all the brilliance which makes Diasec so special. I then realized that the ideal material for face mounting would be anti-reflective mineral glass used for architectural purposes (the very thin anti-reflective glass used for premium-quality framing would be too thin for providing the sense of depth face mounting is aiming at). The only problem was that apparently this wasn´t offered by any lab worldwide. So I decided to push the lab which I was working with to give it a try. They were not convinced, and in the end it took me two years of regularly following up on this until they realized that their only chance to re-gain their peace would be to just follow my request. And then the – for them – unexpected happened: the result of their first experiments blew our mind – no-one of us had ever seen such a brilliance, depth, three-dimensionality and vibrancy in a print like there right in front of us. All skepticism was blown away, and they instantaneously started a project to develop a routine manufacturing process of what became known later as “UltraSec M” prints. This was an extremely exciting time – I remember countless discussions of all the technical hurdles which needed to be overcome, but we all were absolutely confident that in the end this project would become a success. It took about two more years to optimize all those tiny little steps and tricks needed to manufacture immaculate prints at an acceptably low scrap rate, but I believe that what was achieved by the lab´s staff during this time was nothing short of the creation of a new gold standard for print quality. Since then I never looked back, and all of my exhibition prints and most prints sold to my customers are made using this technology. It´s also great to see that well-known artists such as Michael Wesely, Tom Fecht or Bernhard Edmaier quickly adopted this technology for presenting their awesome work.

Q: Talking about exhibitions – you´ve been quite active exhibiting your work, and had exhibitions among others on Photokina, in a museum, and on numerous festivals. Tell me about the experience of publicly displaying your work.

A: A well-made exhibition is just a wonderful way of getting in touch with people who are interested in your work, and at the same time it allows to create an immersive experience to visitors which can´t be created by any other setup – not by a box of prints, not by a book, not by a website and certainly not by an appearance on social media. I had countless wonderful conversations with people whom I otherwise would never have met, and it´s very gratifying to experience how one´s own work seems to speak to others, reaching them in a way words couldn´t. Sometimes I observe some sort of silent dialogue going on between a visitor and a photograph. When I approach these people and ask them what they like about a particular image, most aren´t able to explain their experience. They just feel attracted in a way which escapes verbalization – quite fascinating! It must be said though that, in order to create an atmosphere in which this sort of magic can happen, some efforts are needed. Prints must be of the best possible quality, they must be large enough (my exhibition prints are between 85 x 120 cm / 34 x 48´´ and 100 x 280 cm / 40 x 110´´), they need to be well lit, and everything must be arranged such that the visitors really focus their attention on the prints and forget the environment. I believe that, for creating a really good exhibition, there is no way around shooting large format and printing big. I have seen countless exhibitions of excellent work as such, but made with small cameras, and most of the time I was disappointed. Either prints are no bigger than the size permitted by the red face test when printing 35 mm negatives or DSLR files (somewhere around 30 x 40 cm, maybe slightly larger when printing a 36+ megapixel file), and they just get lost in a somewhat larger room. Or they are at a size beyond the technical limits of the original (sometimes shamelessly far beyond that limits) – then they may look good from a distance, but become a disappointment when getting closer, leaving a sense of dishonesty to the viewer: I cannot help to feel betrayed when inspecting a print at close range, and all I then see is coloured squares instead of details. That aside – for setting up an exhibition in a room which is not equipped with gallery rails or the like I´m using a set of metal racks equipped with halogen spots, so I´m independent of any available infrastructure except a few plug sockets. This can look quite good, and has the additional advantage to allow for arranging the photographs in groups, away from the walls and responding to the show room´s particularities. But by far the most enjoyable exhibition I had so far was the one in the museum, where the curator took a full week to arrange the photographs and to fine-tune the illumination, turning the exhibition space into a room just filled with light and colors – a perfect dream!

Q: Where/how do you get your pictures printed?

A: I have a wonderful long standing collaboration with a small company which does all the lab work for me, including developing, printing and face mounting. They own a LightJet XL which allows printing up to a size of about 180 x 300 cm (72 x 120´´), in excellent quality. When they print a new image for the first time for me, I´ll be on-site and discuss the test prints with the owner, who has an admirable understanding of colours. I learned quite a lot from these discussions, including the fact that objective colour perception appears to be different from person to person. What I mean by this is that to a certain extent colour perception is not a matter of taste, but as I suspect rather has to do with individual differences in colour receptor density and/or receptor sensitivity in our eyes, resulting in something you could call an individual white balance – an important fact to keep in mind when making or having made prints not just for oneself, but for others.

Q: Could you tell us a little about the cameras and lenses you typically take on a trip and how they affect your photography.

A: My main camera is a Sinar monorail camera, which most of the time I´m using with a 5×7´´back, in particular when air travel is involved and the 8×10´´back is too bulky. This Sinar has been modified such that I can also take panoramic shots in the format 5×13´´, which allows the production of murals in ultrahigh-resolution, several meters wide. I´m using lenses with a focal length of between 90 mm and 720 mm (35 mm / full-frame equivalent 20 mm to 170 mm), but more than two-thirds of my photographs are taken with my beloved 150 mm Schneider Super-Symmar HM, followed by a Fujinon-C 300 mm lens (corresponding to 35 mm and 70 mm full-frame lenses, respectively). I guess what I particularly like about these two lenses is that they allow such unexited perspectives – they don´t add any artificial drama to a scene and thus provide images with a very relaxed and natural look. As regards large format as such, specific equipment aside, this certainly tremendously affects a photographer´s style. The bulk, weight and slow speed of a large format camera, together with the costs (clicking the shutter once costs me around £10 / $12 for film and development), make you think more than twice on where, when and whether to go, how to compose your image, which light you are hoping for, and so forth. All the limitations I´ve mentioned render photography a much more conscious process, and that of course has an impact on the results you´ll bring home. Instead of taking two dozens of variations of a subject with your digital camera (and possibly missing the best one since you´re so busy with filling your memory card with all the variations you can think of), with a LF camera you´ll probably take just one photo, but this one has good chances to be your definite interpretation of that subject. Another but related aspect is how you are composing a photo when shooting large format, which is quite different from using smaller cameras. You see a two-dimensional image projected to the groundglass, similar to the finished print, without the illusion of three-dimensionality optical finders of small cameras are providing. This clearly facilitates that reduction from three to two dimensions which photography is all about. Then that image on the groundglass is turned upside down, which makes it easier to see an abstraction of one´s subject to shapes and colours. Finally, under the dark cloth you´re isolated from the outside world (except sometimes from biting insects, I have to admit), so you can fully focus on what you see on the groundglass. Taking this all together one has to say that all these factors which at a glance appear to be disadvantages of LF photography in practice turn to a strength, and simply lead to better results whenever speed is not a limiting factor.

Frank Sirona

Name: Frank Sirona

Location: Germany

Description: I´ve been interested in landscape photography since I saw for the first time a number of dye transfer prints made by the pioneer of color landscape photography, Eliot Porter. After my Nikon years I had a brief affair with a Mamiya 7, until in 2004 I finally upgraded to large format. Since then I´m shooting film using my swiss made 4×5, 5×7 and 8×10 Sinar cameras. Of these, the 5×7 has by far become my favorite, since weight and bulk of a 5×7 are still somehow manageable when air travelling (flying with a 8×10 monorail is a pain, believe me!), while the big groundglass is just a joy and makes composing easier than with a 4×5 camera. Also I personally do like the 5:7 side ratio much more than the 4:5 ratio of the other two standard large formats. The majority of my work has been done in the Desert Southwest, and I continue returning there whenever I can.

Website: https://www.franksirona.com

Instagram: @franksirona

Using calculators in large format photography

Part II: Exposure compensation

Part 1 can be viewed here: Using calculators in large format photography

One of the many aspects which set large format photography apart from photography with modern digital cameras is that there is no CPU to which you can delegate such key tasks as focusing, exposure control, and others. Everything is fully manual here, which on one hand positively contributes to the experience of LF photography, but which nevertheless renders things a bit tricky. This is where little helpers in the form of calculators are coming in, and the one I´d like to present in this blog post is just amazingly simple and effective.

Figure 1: QuickDisc and the measuring strip. Figure courtesy Philipp Salzgeber.

Strictly speaking, handheld lightmeters provide the correct exposure data only for a camera focussed to infinity. As soon as the extension (i.e., the distance between lens and film plane) is increased in order to move the focus plane towards the camera and to increase the scale of reproduction, the fraction of the bundle of light falling through the lens which hits the film decreases – in other words: it gets darker at the film plane. This effect is negligible in the range from infinity to a scale of reproduction of maybe 1:10 or so, but after that – and certainly, in the range of what one usually would call closeup photography – it will cause underexposed slides or negatives if not being compensated for. If a small subject is photographed at half its size, about one full stop of correction is needed, while for a photograph at original size (i.e., at 1:1 scale) a correction of even two stops will be required. This is something users of small cameras with a built-in light meter don´t need to bother about, since modern cameras typically have TTL (through-the-lens) light meters which measure the incoming light at the focal plane, thereby automatically compensating for extension changes. However, whenever taking a close-up photograph with a large format camera is the plan, either the extension or, much easier, the scale of reproduction must be determined in order to determine the required exposure compensation.

Figure 2: Placing the QuickDisc within the subject. Figure courtesy Philipp Salzgeber.

 

It sounds difficult, but actually this goal couldn´t be any easier to achieve than by the use of a brilliant little tool called QuickDisc which was developed by astrophotographer Philipp Salzgeber from Austria (www.salzgeber.at). The large-format community owes Philipp a big thank you for not only creating this wonderful tool but also for generously making it available to anyone for free!

Figure 3: Reading the QuickDisc with the measuring strip on the ground glass. Here, the applied scale of reproduction requires the exposure time to be extended about 2.3-fold, or the aperture opened by about 1.2 stops. Figure courtesy Philipp Salzgeber.

The QuickDisc system consists of two parts: the disc proper and the measuring strip (Fig. 1). Here is how it works: The disc is placed next to the subject to be photographed so that it is located in, or very close to, the plane of focus (Fig. 2). Thereby an image of the disc is being projected to the ground glass, the size of which depends on the extension and, thus, on the scale of reproduction. The latter can now very easily be read with the help of the measuring strip directly on the ground glass, which then immediately provides the corresponding exposure correction (Fig. 3). For example, let´s assume that focussing the camera results in a scale of reproduction of 1:2. The disc´s image on the ground glass then will be 50% of the disc´s original size. Using the strip for measuring the size of the disc image will indicate that either the exposure time would need to be multiplied by a factor of 2.3, or the aperture is opened by 1.2 stops, in order to compensate for the extension. Voilá!

Figure 4: Crossing the Lines. Sandstone wall detail, AZ; exposure correction determined with the QuickDisc.

What looks a bit like magic at first actually is the result of a thoughtful translation of the laws of geometry into a real-world object. One of the elegant aspects of the QuickDisc is that absolutely no care needs to be invested into the disc´s orientation – actually it literally can be just thrown onto the subject and still provides perfect results, as long as it´s not too far away from the focal plane. In most cases, the disc won´t be perfectly parallel to the film plane so that its image won´t be a circle but an ellipse. No problem at all – simply measure the ellipse´s length, and you´re all set. Another nice aspect of all this magic is the independence of the camera´s format. Since this is all about relative and not absolute sizes (of the disc, the disc´s image on the ground glass, and the measuring strip in relation to each other), it works exactly the same way, without any further adaptations or corrections, regardless of whether you´re using the QuickDisc with a 6×9 camera, a 4×5, an 8×10, or whichever format you choose. For the same reason it also doesn´t matter whether the Disc is being printed at exactly 100% size, or smaller or bigger than that, as long as the QuickDisc and the measuring strip are printed on the same scale.

Figure 5: Shapes in Blue. Detail of a frozen lake in Yosemite NP, CA; exposure correction determined with the QuickDisc.

In order to include this excellent little helper in your kit, simply go to Philipp Salzgeber´s QuickDisc home page  www.salzgeber.at/disc/index.html, download the manual, and the Disc, print out the Disc on a piece of thin white cardboard and cut out QuickDisc and measuring strip. I have laminated my copy, which renders this little gem not only free, lightweight, and very helpful, but even waterproof. What more could one ask for?

Figure 6: Granite and Aspen Leaves. Fall scenery in the Eastern Sierra, CA; exposure correction determined with the QuickDisc.

Using calculators in large format photography

Part I: Depth of field

Correct focusing, as trivial as it may seem to users of small cameras like an SLR or even an autofocus camera, can become – and more often than not actually does become – a challenge when working with a large-format camera, in particular when the term “focusing” is meant to encompass all the correct camera adjustments needed to obtain a flawless, throughout sharp image with sufficient depth of field (DOF). Given that the superior technical quality of the final print is one of the major reasons for using a large format camera, it is clear that the LF photographer needs to understand and master proper focusing.

Figure 1: Silver and Gold. Stand of old Cottonwood trees in Colorado; Sinar 5×7´´, Apo-Ronar 9/300, RVP 100, 1 sec @ f/22 +2/3. This is an example of a shot which would seriously suffer from an insufficient depth of field – had both the branches close to the camera and those in the background not appeared tack sharp, this shot wouldn´t have made it into my portfolio. The moderately long lens required stopping down to a bit less than f/32 – needless to say that this was determined using the technique described in this blog post.

The reason for the difficulty to perfectly focus a LF camera simply is the fact that in large format everything is – well: larger. Among others this means that the focal lengths in the LF world are much longer than for small cameras – for example, the normal lens for a 4×5″ camera has a focal length of 150 mm, and the normal lens for an 8×10″ camera is 300 mm. Unfortunately, the depth of field of a lens decreases with increasing focal length, and it is exactly this theme of limited DoF which is a large format photographer´s steady companion. While in smaller format photography long lenses are often used to isolate an in-focus main subject from an out-of-focus blurry foreground and/or background, this is not often done in large format photography. Rather, here one normally tries to bring all elements of a composition into focus (or, more precisely, into the DoF zone within which everything appears if not perfectly, then at least sufficiently sharp). But how can this be accomplished with an average three-dimensional scenery when even a super wide-angle lens for an 8×10″ camera, equivalent to a 20 mm lens for 35 mm cameras, still has a focal length of 120 mm?

Stopping down is the first thing which comes to mind, and in LF photography this is absolutely essential: in practice you will never shoot wide open, both because of the minute DoF at open aperture and because traditional LF lenses, other than some modern digital lenses, are designed to be really sharp only when stopped down. Typically an LF lens´ “sweet spot” (the aperture where sharpness is at its maximum) lies somewhere between f/16 and f/22, regardless of its speed. Having a close look at how LF lenses perform, it often can be observed that a lens shows its highest performance in the center around f/16, with the corners being noticeably less (but still acceptably) sharp. Stopping down to f/22 then allows the corners to catch up, while sharpness in the center already begins to slightly degrade due to diffraction. So as a rule of thumb one may say that for many if not most LF lenses f/22 provides the best overall sharpness, with resolution in the corners being not much behind the performance in the center – of course always provided everything is in focus. While theoretically DoF can be increased by stopping down further – some LF lenses allow to stop down to f/90 or even f/128 – for formats of 8×10 and smaller stopping down a large format lens to beyond about f/32 is no good practice, because then diffraction kicks in and will start to visibly degrade image quality. It is often overlooked how dramatic this effect is: while diffraction limits the theoretical maximum resolution of a lens at f/22 to 68 lpm (= line pairs per millimeter), stopping down to f/45 cuts the achievable resolution down to only half of this value, 34 lpm. At f/64, only 24 lpm is left, and now even two thirds or more of the lenses resolving power are being wasted – that´s not why you decided to go for an LF setup.

On the other hand it needs to be seen that picture elements which are clearly out of focus are even worse than an overall somewhat “soft” image suffering from diffraction. Accordingly the goal will be to make sure that all parts of a subject will be within DoF, and at the same time to achieve this without stopping down too much. Camera movements (which are not part of this blog post) are often absolutely indispensable for obtaining sufficient overall sharpness of an image, but even with perfect adjustments of the camera it often remains a challenge to find the best possible compromise between sufficient DoF and limited diffraction.

I believe it´s fair to say that in the practice of LF landscape photography you´ll almost never be in the situation where you have any DoF to waste. Rather, DoF has to be seen as an invaluable and limited resource you have to be very considerate about, and more often than not to fight for – every carelessness will almost inevitably result in a loss of sharpness somewhere (or everywhere) in your image. If you locate your focus point at the wrong distance, too close or too distant parts of your subject will appear out of focus. If you don´t close the aperture far enough, DoF won´t suffice, and both too close and too distant picture elements will look blurry. If you close the aperture too far, diffraction will degrade resolution across the entire image. This situation might remind some people of thermodynamics, where the first law says that you can´t win, while the second law then informs you that you can´t even break even, and in any case means that proper focusing requires all your attention and skill.

From this it becomes clear that for a rational approach to focussing it will be indispensable to know exactly, once the camera has been set up and all movements made, from where to where DoF needs to extend, and which focus setting and which aperture will be needed to provide exactly this DoF, not more and not less.

What comes in extremely handy here is a DoF calculator like the one Rodenstock used to make (Fig. 2). The concept behind this calculator is strikingly simple so that it´s very easy to use: you just have to determine the extension difference between the near and the far focus points on your camera, which directly translates to the aperture needed for your shot. This sets the Rodenstock calculator apart from the numerous electronic DoF calculators available today, some of which are web-based (which doesn´t help much anyway when you´re out in the middle of nowhere) while others come in the form of smartphone apps. Unfortunately most if not all of these electronic calculators, and in any case all which I have seen so far, require you to enter the near point and the far point as measured as the distance between your camera and selected elements of your subject, not as extensions of your camera. This renders them virtually useless for outdoor use unless you find a way to reliably determine these distances in the field.

Figure 2: Rodenstock´s depth of field calculator

For determination of the extension difference it´s ideal if your camera has a scale like many monorail cameras have (Fig. 3). If your camera is not equipped with a scale, you can use a millimeter scale ruler which for this purpose could be removably attached to your focussing standard, e.g. using velcro. Once the two focus points have been determined, you´re almost done: just position the focusing standard at the exact middle between the near and the far focus point and close the aperture to the value required by

Figure 3: The millimeter scale on a focussing standard. The example shown here is the front standard of a Sinar Norma camera. Sinar´s monorail cameras allow choosing from either the front or the back standard to be used for focusing, depending on the situation.

the distance between the two extreme focus points. This value can either be read from your calculator (Fig. 4; read: with an extension difference of 4.0 mm, the calculator suggests f/16) or be taken from one of the tables below. The beauty of this approach is that the effect of the focal length on DoF is already factored into the extension difference itself and does not need to be further considered or corrected for. For example, an extension difference of 4.0 mm will always require stopping down to the same aperture, regardless of whether obtained with a 47 mm superwide lens or a 300 mm long lens. Also, forget about the “one third / two thirds rule” – using the focusing method presented here, the correct focus point is at the middle between the near and the far focusing point, nowhere else.

Figure 4: Reading the Rodenstock calculator

While the Rodenstock calculator works for essentially every LF camera, its use is particularly straightforward with cameras which allow both the front and the rear standard to be used for focusing, and which have fine drives with an engraved millimeter scale. These features in this combination won´t be available for most flatbed cameras (in which case you´ll have to improvise a bit), but they are pretty common in case of monorail cameras (e.g., Sinar). For these the workflow is as follows:

  1. Coarse focusing by adjusting the distance of the standards on the rail. While doing so, make sure that the fine drives of both standards stay in the “0” position.
  2. Fine focusing using the drive of one of the standards to the far point – the drive of the other standard remains in the “0” position.
  3. Fine focusing using the drive of the other standard to the near point – don´t touch the first standard in this step anymore.
  4. Reading the additional extension (in millimeters) needed to shift the focus from the far point to the near point.
  5. Determining the appropriate aperture corresponding to the additional extension using the calculator; stop down accordingly. Don´t forget the correction for an appropriate circle of confusion, as described below.
  6. Moving the second standard back to the exact middle between the near and the far focusing adjustments (i.e., to 50% of the additional extension) – and you´re ready to shoot.

While this description may sound a bit lengthy and complicated, in practice it´s absolutely easy to follow, and in the time needed for reading this paragraph you could have focussed your camera according to this technique two or three times.

Unfortunately Rodenstock has not only discontinued their line of outstanding LF lenses, but they also don´t make this fantastic tool anymore, so you´ll have to look for one of the places where they still have a couple of these calculators remaining on their shelves, to spot some forgotten stock which may show up from time to time, or get a used one. As of July 2019, you can still buy the calculator from the following sources: US  B&H (USD 79.95), Badgergraphic (USD 44.99); UK  Linhofstudio (GBP 34.00); Germany  Foto Mueller (EUR 37.20), W. E. Schoen (who actually designed the Rodenstock calculator; EUR 42.00). Alternatively you can laminate either a photocopy of the calculator (or a small number of photocopies with the calculator being adjusted to different scales of reproduction and to different front tilt angles, if that is relevant for your photographic style) or simply a printout of a table with the most important numbers (see tables 1-3). For those who are frequently working at reproduction ratios in the 1:1 to 1:20 range, Linhof has published a depth-of-field chart which also works on the basis of extension differences.

Finally, there is still one more interesting variation of the theme: DoF scales on the focussing knobs of some monorails which you can find, e.g., on Sinar´s f2 and P2 cameras. For those with the necessary patience and skills, instructions of how to make such a scale for other cameras (e.g., an Arca Swiss F-line) have been published on QT Luong´s Large Format Photography page.

Table 1: f-numbers for 1:∞ scale and zero front tilt. In deviation from the Rodenstock calculator, f-numbers already have been corrected for a smaller circle of confusion (see main text) and can be directly used without further correction. The (corrected) numbers in the table are based on those indicated by the calculator and thus depend on the shooting format. As explained in more detail in the main text, I nevertheless recommend using the values determined for 4×5 also for 5×7 and 8×10. Depending on the lens you are using, working at f/32 (fields shaded in grey) typically does not provide optimal resolution due to diffraction and tends to soften what actually should be tack sharp. Yellow fields indicate the onset of clearly visible image degradation due to diffraction. I cannot recommend stopping down to f/45 or beyond regardless of the format you´re using; this is nothing but an emergency solution if nothing else helps. Orange fields mean that you should seriously consider further refining your camera movements or even to change your composition since diffraction will seriously limit image quality. An alternative, although very time-consuming at the post-processing stage, would be focus stacking of images shot at a bigger aperture (of course only feasible if you use a hybrid workflow via scanning your film). A dash indicates situations in which stopping down beyond f/64 inevitably would cause such a loss of image quality due to diffraction that using a large format camera probably is not a good choice here. Finally, those rare situations in which a very small extension difference would allow to work with an aperture larger than f/16 (which would be out of most LF lenses´ “sweet spot” of sharpness) are indicated by an “o”. Here, in practice an aperture in the classic f/16…f/22 range is recommended.

However you implement this all in practice: working with precise focus adjustments and carefully determining the optimal aperture for each of your subjects will eliminate a lot of guesswork from your LF photography, and can lead immediately and effortless to technically significantly improved images.

In practice, a number of points need to be kept in mind though.

First, a correction factor has to be considered if you either use front tilt and/or are shooting a close-up subject, with a scale of reproduction of more than 1:20 or so. A nice thing about the Rodenstock calculator is that such parameters can be factored in very easily by making appropriate adjustments to the calculator; when working with a table, a little bit of guesswork may come in again. Table 2 provides the f-numbers for a reproduction scale of 1:10, table 3 the f-numbers for a tilt angle of 30°.

Table 2: f-numbers for 1:10 scale and zero front tilt. Like in table 1, f-numbers are corrected for a smaller circle of confusion.

Second, to my experience the circle of confusion used for these DoF calculations (which corresponds to the international standard circle of confusion of 0.03 mm for the 35 mm format) is too optimistic and does not fit today´s expectations regarding the sharpness of a somewhat larger print. I experienced this already many years ago on when using the DoF scales of my manual 35 mm Nikon lenses and bumped into the very same problem again after moving to Large Format. In order to overcome this, I recommend closing the aperture by one more stop than the calculator (or the DoF scale on a 35 mm lens) suggests. In the example of Fig. 4 above, I´d use f/22 instead of f/16 as the working aperture. In my hands this correction by one-stop provides highly satisfactory results, but the necessary correction will depend on your particular requirements, first of all the size at which you intend to print and the viewing distance from which your prints are expected to look flawless.

Table 3: f-numbers for 1:∞ scale and 30° front tilt. Correction like in tables 1 and 2.

Third, the logic behind these calculators assumes different scales of reproduction for different film formats. For example, it is assumed that because an 8×10″ negative needs to be enlarged only half as much as a 4×5″ negative for obtaining a print of the same final size, the allowable circle of confusion is twice as big for an 8×10″ camera. With this concept I do not agree, because I don´t want to pay four times as much for an 8×10″ sheet of film and its development and carry three times the weight in the field, only for obtaining essentially the same image quality which I can easily get out of a 4×5″ negative. While theoretically these numbers of course are correct, they suggest using the larger formats (5×7″ and 8×10″) in a way which I deem pointless. Instead I personally think that whenever possible the values determined for 4×5″ should be used regardless of whether shooting 4×5″ or larger, even if that means that in practice an 8×10″ camera will only provide superior results in comparison to smaller cameras with subjects which have not much depth and thus allow to work at f/22…f/32. Due to the deleterious and inescapable effect of diffraction, an 8×10″ negative shot at f/45 won´t contain more detail than a 4×5″ negative of exactly the same subject shot at f/22 from the same distance with a lens having half the focal length. It thus is just more expensive, without providing any advantage in image quality (except maybe looking more impressive on the lightbox).

One last thing: I absolutely don´t advocate focus stacking in large format photography, since it can be extremely tedious and cumbersome to perfectly combine the scans of two or even more differently focussed images to one flawless image file. One reason for my reluctance to do focus stacking is that in my experience for unclear reasons the scans to be combined tend to show distortions which prevent them from fitting perfectly. This effect renders their combination an editing nightmare which can cost you many hours if not days of work until everything is perfect. And don´t even think of letting the software do this for you – dismay would be guaranteed. That being said, unfortunately there are occasions where there simply is no real alternative to focus stacking, namely when in order to obtain the required DoF for an image you´d need to stop down so seriously that diffraction would essentially eat up all the advance large format has over smaller formats. In such cases, and they come up from time to time, I definitely prefer to combine two images shot at f/32 over one single image shot at f/64 which would be guaranteed to lack overall sharpness. In such instances you need a tool to set your two (or more) focus points as precisely as you can, and for this again a DoF calculator is simply indispensable. Fig. 5 is an example of a successful focus stacking project, but this took me more than two days of not very pleasant computer work until the two 400 MB scans had been seamlessly merged into one file.

Figure 5: Carboniferous. Hoodoos and coal bed in New Mexico; Sinar 5×7´´, Nikkor T-ED 9/360 mm, RVP 100, focus stacking of two exposures taken at 1/4 sec and f/32. Due to the difficult topology of the location there was no way to switch to a different composition which could have alleviated my focussing problems. I thus decided to apply focus stacking and to “split” the shot (which otherwise would have required stopping down to f/64) into two separate exposures at f/32.

Taking all these aspects into account, DoF calculators are a reliable, inexpensive and easy-to-use means to replace all the guesswork otherwise needed by a rational approach to focussing and stopping down. In order to get the highest technical quality out of large format photography you need to work as precisely as possible, and these calculators provide you with exactly the information you need to reach that goal. I´m using mine for practically every single shot, and I know that I´d be way less satisfied with the sharpness of my images if I didn´t.

Part II – Using calculators in large format photography


Name: Frank Sirona

Location: Germany

Description: I´ve been interested in landscape photography since I saw for the first time a number of dye transfer prints made by the pioneer of color landscape photography, Eliot Porter. After my Nikon years I had a brief affair with a Mamiya 7, until in 2004 I finally upgraded to large format. Since then I´m shooting film using my swiss made 4×5, 5×7 and 8×10 Sinar cameras. Of these, the 5×7 has by far become my favorite, since weight and bulk of a 5×7 are still somehow manageable when air traveling (flying with a 8×10 monorail is a pain, believe me!), while the big groundglass is just a joy and makes composing easier than with a 4×5 camera. Also I personally do like the 5:7 side ratio much more than the 4:5 ratio of the other two standard large formats. The majority of my work has been done in the Desert Southwest, and I continue returning there whenever I can.

Website: www.franksirona.com

Instagram: @franksirona