Since the introduction of the Canon D30, the first affordable DSLR, in 2000, digital imaging has grown dramatically.  It’s been nothing less than a revolution in still photography.  Now, in early 2007, small and medium format film photography is in decline, supplanted by the DSLR and medium format digital backs.  Large format film photography remains alive and well — a viable alternative to the pervasive digital sensor.  However, many LF photographers appreciate, and perhaps even need, to incorporate digital capture in their work without giving up the image quality and perspective controls afforded by the view camera.

There are three common ways that view cameras can be repurposed for digital imaging.  One modification is to attach a DSLR to the rear standard or rear frame of the view camera.  Of course, the largest chip on a DSLR is 24x36mm, so the applications of such a modification are fairly restrictive.  Nonetheless, such a setup can be valuable for close-ups and for distant landscapes or architectural views where lens movement is desirable.  Even some still life work can be executed with a DSLR view camera.

A second digital adaptation requires no modification at all.  A scanning back, such as those manufactured by Better Light, can be used with a 4×5 view camera straight out of the box.  A Better Light back features a capture area that’s 72mm x 96mm, large enough to work effectively with most 4×5 view camera lenses originally designed for film photography.  Simply slide the back into the focusing frame just as you would a film holder, tether the scan back to a portable hard drive, which is in turn tethered to a laptop computer, and your 4×5 view camera is now a scanning camera.  For studio work or even interiors photography this is a viable setup.  Location work outdoors is another matter.  Though its doable, it requires lugging more gear around, the setup times are longer, and you’re dependent on an assemblage of batteries (laptop, scan back, and dedicated hard drive all run on battery power) that also provides exposure times that are effectively measured in minutes rather than fractions of a second.  Nonetheless, scanning backs hold a very important place in LF digital imaging.  They have become the primary means for digital conversion of all flat art too large to be scanned conventionally.  Scanning backs are also widely used for digital still life images and for architectural interiors photography.  One of the most compelling uses of the scanning back is the capability for seamless digital panoramic images up to 360 degrees.  It requires some additional hardware that enables the view camera to rotate and capture an image in the same fashion as a rotating Circuit camera.

Phase One Flexadapter with a P20 digital back on an Ebony 45SU

The third adaptation is the one this essay is devoted to primarily and its something of a hybridization of the first two I’ve detailed above.  For my purposes, it’s the most practical and pragmatic way to facilitate digital capture with a view camera.  This modification provides for the use of a medium format digital back, in this case a Phase One P20, on a 4×5 view camera through the use of a sliding adapter that permits a quick transfer between a dedicated focusing screen and the digital back.  A P20 has a sensor that’s almost 50% larger than a full frame DSLR sensor.  It’s 37mm square with a .78 multiplication factor over a full frame DSLR.  It can be used for single captures or multiple captures can be stitched together.  A P25 or P45 sensor is 36mm x 48mm, just slightly smaller than 645 film format and can be used on a view camera in the same way as the P20.

Following is an overview of the modifications necessary for digital capture and some samples of the photography that can be achieved with this setup.  The first task at hand is to modify a sliding adapter for use on an Ebony camera.  In my case, I began with a 45SU, the view camera I’ve used for film photography for several years.  Sliding adapters are made by virtually all the manufacturers of MF digital backs, as well as by some view camera manufacturers.  Though Ebony doesn’t currently manufacture a sliding adapter, they can modify virtually any of the current offerings to fit on any Ebony 4×5 camera model.  After a great deal of research both on my end and by Hiromi Sakanashi, the founder of Ebony, we mutually concluded that the best sliding adapter for the P20 was the one made by Phase One — the Flexadapter.  So, I purchased a used Flexadapter with a mounting frame for a Sinar camera and an insert for a Mamiya 645 back.  (This is the type of P20 back I use and it can be interchanged between the Flexadapter and a Mamiya 645AFD camera body.)  The Flexadapter modification is pretty simple.  The existing frame, which is attached to the slider mechanism by 4 screws, was removed and then a frame for the 45SU was machined from anodized aluminum by the Ebony workshop in Tokyo and attached in place of the original frame.  This allows the Flexadapter to fit on an Ebony in the same way it does on any of the view cameras currently supported by Phase One.

Sliding adapters are critical for digital imaging for multiple reasons.  They allow for stitching.  They permit a fast transfer between viewing on the focusing screen and capturing with the digital back.  And, most importantly, the back is secure and at the ready when attached to the sliding adapter.  (The constant removal and reattachment of a digital back to the rear standard is cumbersome, time consuming, and subjects the back to risk of being dropped.)  That said, a rear frame modification that allows for the attachment of an MF back using an adapter plate would permit a digital back to be utilized without the need for a sliding adapter.  Once the back is on the view camera, digital capture isn’t fundamentally different from using sheet film except for the need for a cable that attaches to the PC nipple on the lens shutter with the other end connected to the back itself.  This cable alerts the back to archive a capture once the shutter has been fired.

Destrehan Oak backlit by the late afternoon sun.
This image was created using the 2-stitch mode, with the Phase One Flexadapter and P20 back.
The lens is a 200mm M-Nikkor.

Because view camera lenses have image circles that are considerably larger than a 37mm X 37mm, or a 36mm X 48mm, sensor, the stitching possibilities are quite extensive.  The sliding adapter incorporates this feature in its design.  The Phase One Flexadapter can be set for single capture or for a 2-stitch or 3-stitch panoramic format.  With the P20, the panoramic image, when stitched, is approx. 37mm x 67mm (close to 1:2 aspect ratio).  However, in addition to this stitching capability, the camera’s movements can be used for manually stitching either in combination with the Flexadapter’s stitching capability or completely independent of it.  For instance, one could set the Flexadapter for a panoramic stitch, then use the rise or fall of the view camera to create a slightly overlapping panorama just above or below the previous one.  These two panoramas can then be stitched together in Photoshop using the Photomerge tool.  Or, the Flexadapter can be set to single shot mode and view camera movements can be used to stitch 2 or more overlapping exposures together.  Stitching isn’t an exact science, but it’s highly reliable.  Variations in density between 2 or more captures can occur because of subtle light changes between captures or due to variations in shutter speed between 2 consecutive firings.  Most view camera photographers, myself included, are using tried and true mechanical shutters.  These devices are quite accurate but there can be slight variations in the actual shutter speed from one exposure to the next.  So, a little bit of work in Photoshop may be necessary at the stitch seams to reconcile minor differences in density and the alignment of photographed detail.  The other challenge with stitching is subject movement.  With landscapes and architectural views, the primary nemesis is wind, which causes movement in plantings, tree limbs, flags and banners, etc., which can be somewhat problematic.

Women’s Bedroom at Destrehan Manor House, Destrehan, Lousiana.
This image was created using the 2-stitch mode, with the Phase One Flexadapter and P20 back.
The lens is a 35mm Rodenstock Apo-Digitar HR.

I know that many view camera photographers are likely thinking why should one consider using a 16MP digital back on a view camera when the best DSLRs, namely the Canon 1DsII, have a comparable number of pixels and produce outstanding results?  I can address this question with some authority as I’m a 1DsII owner and have considerable experience with this camera.  Following are a few reasons why an MF back, such as those from Phase One, Imacon, Leaf, etc. when utilized with a view camera will produce technically and aesthetically superior images to those that can be attained with the formidable Canon and Nikon DSLRs.

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Higher bit-depth:

All Canon DSLRs , and many others, capture @ 12-bit in RAW format. 12-bit capture equals 4,096 mathematical possibilities at each photosite.  Because light isn’t a linear phenomenon, values aren’t distributed equally.  For instance, in 12-bit capture if pure white = 4096, then 1 stop below that has to equal 2048 (1/2 of 4096).  The halving of values continues with each 1 stop of light loss.  Once you get to the deepest shadows (near 0), the mathematical possibilities for each pixel value are quite limited.  There simply aren’t enough values in some situations to create smooth, natural shadow gradations and in other situations shadow detail drops off abruptly to black. : MF backs, most all of them anyway, claim RAW format captures @ 16-bits per photosite.  I’ve gleaned from a reliable source that Phase One backs actually have a 14-bit processor.  These RAW files can be converted to TIFF @ 16-bit, but the actual RAW format archive may be @ 14-bit.  This may not sound like a substantial improvement over 12-bit, but 14-bit capture = 16,384 potential values @ each photosite.  16-bit capture allows 65,536 values @ each photosite.  Higher bit depth solves the problem of noisy shadows with abrupt transitions of value.  So, it doesn’t matter how many photosites you have, if bit-depth is too low, detail, particularly shadow detail, is compromised.  Think of the number of photosites as the quantity of information and bit-depth as quality of information.  You need a high level of both for state of the art digital imaging.

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Greater dynamic range: 

All MF backs use CCD sensors.  These sensors require more power, produce more heat, and require more circuitry for image processing than CMOS sensors.  However, they have potentially greater dynamic range than CMOS.  A CCD sensor with a 14 or 16-bit analog to digital processor is capable of producing more dynamic range than a CMOS sensor with a 12-bit or 8-bit processor.  Anyone who’s compared the tonal scale of 35mm film to 4×5 film can fully appreciate what additional dynamic range can achieve in critical situations.  To try and quantify exactly how much additional dynamic range is achievable is a good way to start an argument.  Phase One claims that their backs are capable of a maximum of 12 f-stops of dynamic range.  I lack the technical skill or testing equipment to either validate or refute that claim.  I can only state from practical experience that the P20 seems to have about 2 stops more usable dynamic range than the 1DsII.

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Better lenses: 

View cameras allow for inherently more flexible lens designs, particularly for the most challenging optical design — wide angle lenses.  All DSLRs have a mirror between the lens and the sensor.  The rear lens element has to be forward of the mirror, so true wide-angle lens designs aren’t possible.  Lens designers spent decades overcoming the challenge of producing quality wide-angle optics that didn’t interfere with the mirror function of SLRs.  The solution became extreme retro-telephoto lens designs that placed the vertex behind the rear element.  The first retro telephotos were truly lousy — soft corners, barreling, chromatic aberration, and internal flare were common complaints.  But, SLR lens designers relentlessly improved these lenses.  Most of the current flaws in the best retro-telephoto wide-angles can be readily fixed in Photoshop post-production.  In the end, some outstanding wide-angle photography can be achieved with these lenses.  That said, none of these lenses compare to the best digital view camera lenses currently available from Rodenstock and Schneider.  I haven’t personally tested any of the Schneider digital lenses, but the feedback I’ve heard about them has been good.

I have had personal experience with Rodenstock’s 35mm Apo-Sironar Digitar HR and I would describe it thusly: tack sharp edge-to-edge, perfect rectilinearity, outstanding contrast and color balance, minimal chromatic aberration and that only occurs with extreme movement.  If Canon has a wide-angle as good as this one in a comparable focal length, I haven’t found it yet.

French Quarter street view taken with 35mm Rodenstock.
Note that this lens is extremely sharp, perfectly rectilinear, and no chromatic aberration is visible.
Vignetting is minimal.  This is superb performance for any wide-angle lens, film or digital.

My lens experiments are currently on-going, so I can’t really comment on the entire view camera lens range.  However, one discovery I’ve made is that the 200mm and 300mm M-Nikkors are absolutely superb, extraordinarily sharp, digital lenses.  Perhaps I was most surprised by the performance of the 300mm, a lens which will cover 8×10 format, and which seems to have superior sharpness and contrast to my 300 f4 L IS Canon.  I’ve also been experimenting with enlarging lenses mounted in a Copal press shutter.  I’ve achieved very good results with 2 El-Nikkor enlarging lenses: a 135mm and a 75mm.  Both lenses cover the P20 sensor and can be used for panoramic stitching.  The 135mm is designed to cover 4×5 film with no movement and the 75mm is designed to cover 6x6cm film with no movement.  The 135mm provides ample movement with a P20 sensor in stitching mode, whereas the 75mm is marginal.  This lens is best utilized in single shot mode and has acceptable movement in this capacity.  The quality performance of these lenses with digital capture is possibly due to their design as process lenses.  I mention the viability of enlarging lenses for digital capture because of their low cost relative to digital lenses of comparable focal length and coverage.  A final point about digital view camera lens designs is that virtually all of them are apochromatic designs, which means that the optics are designed to precisely align red, green, and blue wavelengths of light to the same plane.  Chromatic aberration is a constant problem with digital imaging, particularly with wide angles.  Apochromatic lenses are inherently better at correcting this problem than non-apochromatic designs.

In the final analysis, a Canon 1DsII remains an important digital camera for me.  My Ebony 4×5 is the only camera I still use as a film camera.  I long since abandoned film in 35mm and 120 formats.  4×5 film, however, is a different matter.  As good as high-end DSLRs are, in numerous situations an MF back on a view camera yields markedly superior results, even in single shot mode.  In stitch mode, there’s really no comparison.  Multiple P20 captures stitched together are clearly superior to a DSLR.  In fairness, DSLRs can be used for stitching by panning the camera or by using PC and tilt/shift lenses.  The advantage of a view camera as a stitching camera is that the focusing screen is capable of showing the photographer the framing for the stitched image.  So, the panoramic composition can be seen just as with a film camera.  Also, lens movements produce much more reliable stitching results than with panning.  Panned frames stitched together have to be interpolated to a new perspective because each capture is taken from a slightly different angle.  It works fairly reliably, but occasionally the results can be very poor.

35mm Rodenstock Apo-Sironar Digitar HR with a 45SU.
The lens can be focused at infinity mounted on a recessed board on the 45SU, but virtually no movement is possible.
Note how the front standard is nested inside the rear frame.

So, in the final analysis MF digital backs do produce results superior to the best DSLRs in the vast majority of situations.  Putting together a view camera system for digital imaging with an MF back requires a good deal more homework than a DSLR system, however.  One of the first, and most significant, decisions relates to the type or model of view camera to be adapted to digital imaging.

Ebony makes a wide range of view cameras in 4×5 format, as well as 6x9cm format.  In my view, those models that work most effectively as hybrid film/digital cameras are the 4×5 non-folding models.  This may seem counterintuitive.  If an MF sensor is no larger than the smallest 120 film format, why wouldn’t a 6x9cm Ebony model be the best choice for digital shooting?  The answer is that it’s not the back, but the sliding adapter that is best suited to 4×5 format.  Firstly, most sliding adapters are designed to fit 4×5 cameras.  They can be easily modified to fit on a 6×9 view camera by changing the mounting plate.  However, a sliding adapter is heavy — heavier than the view camera it’s attached to, in some cases.  It’s an awkward fit, akin to putting oversized off-road SUV tires on a sports car — not only is it ugly to look at, but performance is poor to boot.  So, 4×5 cameras have the best scale to spread the load of a sliding adapter and when married to it, the overall package possesses acceptable balance and rigidity.  Ebony’s 4×5 non-folders work better than the folders because of their superior capabilities at minimal extension.  An MF sensor is much smaller than 4×5 film and the lenses that will commonly be used with it have much shorter focal lengths.

Schneider and Rodenstock are now making digital view camera lenses in 35, 28, and in the case of Schneider, 24mm focal lengths.  These focal lengths are as short as the wide-angles in 35mm photography.  Most view camera designs never anticipated the need for lenses of this focal length.  When I began the process of adapting a 45SU to work with a P20 digital back, it seemed to be a very successful conversion.  However, I had no wide-angle capability.  My widest film lens was a 75mm Nikkor-SW.  As soon as I fitted the camera with a 35mm Rodenstock, I ran into limitations.  I could focus the camera at infinity with the 35mm, but I had no movement.  The bellows were fully compressed.  Any attempt at rise, fall, or shift and the lens standard collided with the rear frame.  The 45SU works well with digital lenses down to 47mm, but not with lenses of shorter focal length than that.

¾ view of an Ebony SW45 with Flexadapter mounted.
The 35mm Rodenstock Apo-Sironar Digitar HR is focused @ infinity.
Note that the lens standard is forward of the rear standard so that full movements can be utilized without any restrictions.

After a bit of research, I determined that the Ebony SW45 would be an excellent camera for film/digital hybridization.  The SW45 is specifically designed as a wide angle view camera.  It has a minimum extension of 46mm—11mm less than a 45SU.  With an extension back in conjunction with 35mm extension tubes, a 300mm lens can be used and this setup is quite sturdy.  Movement is ample and the design is quite simple and straightforward.  Of course, the decision about the viability of any given Ebony model for conversion to digital imaging will be based on the type of photography you’ll be doing.  If you don’t need wide-angle capability, then almost any Ebony 4×5 model will convert well to digital.  Just bear in mind that a normal focal length lens for MF digital will be in the 50 to 65mm range.  Preserving the option for movement in this focal length range will challenge a traditional 4×5 field camera design.  Another consideration is that although Schneider makes a 24mm lens that can be fitted on a view camera, the ability to view its image with a conventional focusing screen and to accurately focus a lens of such a short focal length is yet another challenge.  I haven’t had hands-on experience with a 24mm lens with any Ebony view camera.  However, I’ve done enough research to conclude that an SW45 has sufficient minimal extension to focus the lens at infinity.  The Schneider 24 has a flange focal distance of 40mm and on a recessed board, it should work on an SW45.  That said, this will be a tedious lens to work with on any view camera—the image will be exceedingly difficult to view on the ground glass and focusing accuracy will be suspect.  I personally can’t recommend a lens shorter than 35mm for use on a view camera.  With a P20 sensor this focal length gives a comparable field of view of a 28mm lens on a 35mm camera.  With a P25/45 sensor, the field of view is comparable to that of a 24mm.  By comparison, a 24mm lens would be comparable to a 17mm lens on a 35mm camera or the 58XL Super-Angulon on 4×5 film.

In conclusion, Ebony view cameras because of their many specialized models and wide-ranging designs are quite adaptable to digital imaging with MF backs.  But, modifications and the acquisition of some specialized digital lenses will be necessary for most users.  The provision for stitching is a compelling feature of digital view camera photography.  In many ways, it can be thought of as an alternative to scanning back captures.  Four, or more, slightly overlapping frames can be captured in less time than a scan capture.  But, for field work, the time it takes to make multiple captures, is less significant than the fact it can all be done untethered with much of the same ease as shooting with a DSLR.  A digital view camera system with a sliding adapter and an MF back can be contained in a backpack or shoulder bag and is generally a slightly smaller and tidier setup than when shooting film.  Speaking of which, with minimal time and effort you can switch from digital to film on the fly.  Yes, you can do this with a DSLR by simply bringing a film body along.  But, for many purposes this is akin to relying on the little outboard on the stern of a sailboat.  It’s not a good feeling when you are well out to sea and you have to resort to the marine equivalent of a lawnmower to bring you home.  35mm film just doesn’t work for me anymore.  The quality I’ve come to rely on isn’t always there.  However, with a digital view camera system, your alternative means of creating photographs is with 4×5 film.  A medium you can rely on for the highest quality, at any distance from the shore.  For me, a camera system that allows for shooting 4×5 film images and which in a matter of a few seconds can be making digital captures with a medium format digital back is a tantalizing piece of equipment.

May 2007

by Richard Sexton

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Update:

Between the time this essay was written and its publication here, Canon announced the 1D Mark III camera, which features 14-bit processing of raw files. So, the statement that “all Canon DSLRs feature 12-bit processing” was out-dated on arrival. I personally believe that 14-bit processing is one of the most intriguing features of this new camera and I hope it’s an indication that all future 1 series Canon DSLRs will process raw files in 14-bit.

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Richard Sexton is a noted commercial and fine art photographer who also teaches photography at New Orleans Academy of Fine Arts. He is a professional consultant to Ebony Camera Co. Ltd. Additional information about his work is available on his web site:www.richardsextonstudio.com.

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Below is a list of specialty companies and fabricators
that can help facilitate the process of hybridizing a view camera for digital capture:

Ebony Co. Ltd.  www.ebony camera.com

Provide modifications of Ebony cameras and modification of accessories for use with them.

Kapture Group: www.kapturegroup.com

Manufacturer of sliding adapters, and specialized plate adapters for attaching MF backs directly to view cameras.  They also manufacture a Quad Stitch sliding adapter designed for 4-stitch captures.

SK Grimes Photo Machinist: www.skgrimes.com

A repair and fabrication shop that custom manufactures an adapter plate that allows a Canon EOS camera body to attach to any view camera with an international back, i. e. any Ebony 4×5 camera model.  They also make special adapters for fitting barrel lenses, i. e. enlarging lenses, to Copal shutters.

Phase One: www.phaseone.com

A leading manufacturer of MF backs and their sliding adapter, the Flexadapter, is of high quality construction and is smooth in operation.  They also offer what I consider to be the best raw converter currently on the market—Capture One Pro.  Phase One has also recently announced their P20+ back in a Mamiya mount for $10,990. The older P20 (non+) may still be available for $6,990US.  If you can find a dealer who still has them at this price the cost for an MF digital system is now competitive with the Canon 1Ds Mk II.

Better Light: www.betterlight.com

Better Light is the leading manufacturer of scanning backs and for some view camera photographers, a scanning back may be preferable to an MF digital back.

I’d like to thank a number of individuals for providing assistance in the form of advice and technical information that was helpful in putting the equipment together that’s profiled in this essay:  Ian Wilson, International Sales Coordinator for Ebony Camera; Jeff Taugner, Badger Graphic Sales, an Ebony reseller in the U.S.; Dave Gallagher and Tim Palmer of Capture Integration, a Phase One Dealer in the U.S.;