Stitching with the Cambo Wide WRC-400
Smith Rock in Redmond, Oregon - Stitching with the Cambo WRC-400, Schneider-Kreuznach 43 XL T/S, and PhaseOne IQ180
For my most recent trip to Bend, Oregon, Digital Transitions was nice enough to lend me a Cambo WRC-400 technical camera along with Schneider-Kreuznach 43 XL lens mounted in Cambo’s proprietary tilt-shift mount. When I was in The Netherlands this winter, I had the chance to visit Cambo’s factory. I was very excited for this since I’ve never had any extended shooting time with a technical camera to speak of and this was a great opportunity to learn more about these cameras, and understand their strengths and weaknesses. My normal shooting, does not generally involve still-lifes or landscapes so I’ve never had any reason to purchase or further look into a technical camera. One of the two things that everyone knows about technical cameras, is that they are highly-customizable. The other, is of course that they offer superior image quality, originally harnessing large format lenses with huge image circles allowing for the smaller digital sensors to utilize the center of the image which is of course, where a lens is sharpest. Since this trip was the first time that I traveled with a technical camera, I will treat this review as initial impressions, thoughts, and comparisons.
The day before my trip to Bend, Oregon was a very eventful day for my PhaseOne IQ180, it was the first time, since my purchase of the camera (immediately after its launch) that it had been removed from my 645DF and placed on another camera. Mounting the camera is very easy, once you have the proper adapter plate for the rear of the camera, you simply place the back on the camera like you would on an MF SLR. Initially on the trip, I was planning on shooting a bunch of landscapes and so on, which would be the easiest way to shoot this camera. Landscape shooters love technical cameras because, they offer superior image quality (partly because of the quality of the lenses, and partly because the quality of the digital back), also because they don’t have a mirror, they offer very little vibrations (frankly non-existant) when firing the shutter of the camera to make an exposure. Focusing is done using the lenses helical mount, the lenses are mounted by Cambo into their proprietary mount and calibrated for use with their bodies and digital backs (as you can see here). However, generally speaking focusing isn’t really an issue (though we will address this again later) since with landscape photography more often then not things are set to infinity and shot at small apertures (for maximum sharpness).
Screenshot from CaptureOne
As you can see from this focus mask applied to the IIQ files in CaptureOne, at f/11 and focused at infinity, pretty much everything is in focus. That makes this camera particularly suited to this application. And, like everyone knows technical cameras on the whole acquit themselves of this task with particular acuity. However this is not what wound up happening. I wound up decided to relax I wound up shooting photographs around my friends house where I was staying. Now you might say, well technical cameras are also used for architectural photography, and you would be correct. However, as it turns out I wound up being very aggressive with my compositions and wound up even taking the same images at different focusing distances and compositing them later using Photoshop’s auto-align and focusing stack functions. But for now, we will take a look at the Cambo WRC-400 as a camera and then discuss my main application for this camera on my trip.
Cambo WRC-400 at Smith Rock – Redmond / Bend, Oregon
For its diminutive size and weight (120mm x 145mm and 500 grams) this camera offers a class-leading 20mm of Fall (or Shift depending on the back orientation). Arca-Swiss’s comparable offering, the Factum though weighing and being negligibly larger (137mm x 150mm and 640 grams) the Arca-Swiss factum only provides 15mm of Fall or Shift, five less then the Cambo WRC-400. Alpa’s smallest model the Alpa TC (Travel Compact) offers no tilt or shift and is 109mm x 109mm though their next model up, the Alpa STC (Shift Travel Compact) offers 18mm of Fall or Shift and is again larger, though negligibly (146mm x 140mm and 580 grams). Bythe numbers, the Cambo WRC-400 slightly edges out the competition in dimensions and weight, it does offer a larger possible stitch then the competition. All of this information, as well as a wealth of other information can now be found on Digital Transitions ‘Technical Camera Overview” and their DT Visualizer Tools are also extremely helpful allowing you to see the amount of shift possible with various lenses image circles and various sensor sizes.
However, this is not necessarily a product that you buy in and of itself. You buy this camera, because you are thinking about investing in a tech cam system, or you already have a tech cam system and you want a smaller model for hiking around or testing things out before pulling out the big guns if you need them. Of course, the only differences between different models will be their rise, fall, tilt and shift capabilities they offer since they are simply plates which act as a conduit between lens and sensor. The Cambo (like all technical cameras) offers a high degree of customizability, though it is not overwhelmingly so and focused on functionality rather then supreme customizability like some other systems. All four edges of the camera offer the same mount which means that grips, tripod mounts, and viewfinders can be mounted on any of the four sides, they simply screw in and out very easily, though securely. While I was traveling one of the mount screws on the iPhone viewfinder adapter
came loose and it was a bitch to put back in because of the positioning of the rest of the mount. However, the image to the left displays a small issue which can be encountered during field use. If you decide to change the orientation of the camera, and consequently accessory positions of the camera. If you were to do this properly you would need a table to remove, place, and then re-apply the accessories on to do it in the safest way, however this isn’t a luxury afforded to us when shooting in the field and consequently it can lead to some awkward situations like the one in the picture. The screw in for the shutter release on the Schneider-Kreuznach 43mm XL is no placed so that it is twisting the release cable around. To correct this situation, you would have to remove the grip, unscrew the cable release, remove the cable release from the grip, and then place it correctly in the grip and the finally re-apply the grip, however this is a long process for field shooting and would certainly be a pain, and then thus leaves you in an awkward place. Other then these small details, the system works very well and is secure and allows for the camera to be used in lots of different ways, especially when you combine the body with the tilt-shift lens mounts that Cambo offers.
Speaking of the iPhone viewfinder adapter, it is the most utterly useless and kitschy accessory possible. It is a very nice mount, which will take the camera of the iPhone and with a wide-angle adapter allow for wide-angle use with Alpa eFinder for iOS (Now known as Viewfinder PRO). While the app and adapter both work as advertised, there is no possible reason for you to ever need this item (by my humble approximation). When using the camera it is far faster to take a test shot and then view it on your digital back to check composition, which is the only thing that that this app can do for you. Consequently it is a bit clunky and is good for nothing else other then draining your iPhone or iPod Touch’s battery, which is absolutely wonderful if you are photographing in a remote location where you might need to contact someone in an emergency, or alternatively if you need to play Words With Friends after (or during) a shoot.
Now, lets look at some of the images;
This is the image, alluded to in all of the supporting materials for this article above. It was taken at Smith Rock at the appropriately named Smith Rock National Park in Redmond Oregon, outside of Bend, OR. This was the most straight forward of all of the images I will be showing. The camera was set up on a tripod, focused to infinity, a light reading was taken, settings were adjusted and then the most complicated part simply involved taking the 5 stitched images and their LCC”s. This is not a fast process to be sure, but it ensures ultimate image quality. The general consensus seems to be that it is better to take the LCC exposures at the same time as the normal exposures. Though, I have been told that you can take the images later if you ensure even, and similar lighting / exposure time and use the same focus distance and aperture. Having tried both methods, I can say that taking them on site is certainly better, though if you make a mistake or omit something you can work with a LCC that was taken after the fact, it may just take some extra tweaking. Once you import the file and convert it to an LCC in CaptureOne (right clicking and selecting the option from the drop down menu) and apply it to the base image you have some options to tweak how strongly the LCC corrects the image and this generally seems to be an effective substitute in a pinch.
Please observe this series of images;
Image 1 is a focus stack of image 2 and image 3. Images 2 and 3 are both stitches of 5 images taken with the tripod in the same place, with every setting in camera and in CaptureOne being exactly the same except for focus. Obviously in image 2 the focus is on the panther and in image 3 the focus is on the background of the image, the fireplace and the painting. Now, the key difference between these two stitches is most notable in the lower left hand corner of the two images. As you can see, the amount of table between the lower left hand corner of the panther sculpture’s base and the bottom of the frame changes. In image two, focused on the panther there is less, and when the image is focused on the background there is more. Now, when I was making these images this was not something that I noticed, I assumed that there would be no difference in the composition of these images. The issue in this, of course lies focus stacking, focus stacking aligns the two images based on their similarities and then determines what is in focus in the two images, and then combines and blends those areas to increase the apparent DoF of the image, i.e to have more in focus. When there are areas that do not align, this creates an issue, this issue will either result in an awkwardly blended area, or it will result in an area which needs to be cropped out of the image which will then change the composition. This is a phenomenon which is called focus breathing, or breathing. What occurs, is that while you are shifting focus, the Angle of View (AoV) of the lens changes. Many DSLR lenses do this, and it is one of the things that makes them less then desirable for videography since this is not an effect that you expect and can be an issue if you attempt to rack focus. Some higher-quality DSLR lenses, as well as of course, cinema lenses correct for these issues. Focus breathing is certainly an issue for cinematic purposes, however here, with technical cameras, it is a surprising minor annoyance. Considering the high level of precision which is one of the defining characteristics of technical cameras, one would assume that this would have been something that would have been thought of and correct for when developing the lens mount. That said I certainly do not believe that this is exclusive to Cambo or a slight on their system. And frankly for most individuals this might not be a problem, but when engaging in a fairly aggressive composition AND focus stacking it is certainly something that must be considered. Now, using the PhaseOne IQ180′s live view (which we will discuss later on more) you can see the changes in the AoV and composition of your image as you shift focus from point to point and can correct for it before taking a series of exposures and investing a considerable amount of time in the capture and editing of these images.
This final image that I made from the basic idea behind the shots above corrects for focus breathing and also ads a few other images focused at different points to make the DoF even greater then it was when I was stacking two images. Also the exposure times were increased slightly from 22 seconds at ISO50 to 25 seconds at ISO 50. While this doesn’t sound like much, considering the long exposure process with the PhaseOne IQ180, it does add a significant amount of time. For one exposure to be made, there are 25 seconds of the shutter being open, and then 25 seconds for a dark frame to be made to reduce the heat noise from the sensor on the image. This means that each single exposure takes 50 seconds. 50 seconds for 5 images becomes 250 seconds. Then this number must be doubled since not only do you have to take the 5 images, you also have to take their resulting LCC’s, meaning that we are now at 500 seconds for one stitch. Then these 500 stitches must be multiplied by the 5 different planes of focus which were used to create this final image. This means for the in camera time used to create this image we are now at 2500 seconds, or around 42 minutes. Suffice it to say, a chair was involved in the making of this image. That is a lot of time, and also a lot of time for a mistake to possibly be made, and trust me mistakes were made. However eventually the 42 minute dance was complete and the image was created. The overall sharpness of the image combined with the excellent exposure which was eventually achieved make me very happy, and for me, it was worth it to spend all of the time going through various iterations and changing the composition of the image to make it.
This last image I only really include to reiterate the point that this system is extremely versatile. You can position the camera, and sensor in any position you want to allow you to make any image that you want. When you stitch 5 images for a total of 40mm (of stitch) you will yield a native image area of 53.7mm x 80.4mm (IQ180′s image sensor is 53.7mm x 40.4mm) This allows for an aspect ratio slightly shorter then that of 6×17 medium format (120mm) film format.While people laud the errors of using 6×17 or panoramic formats vertically (and I am right there with them), certainly stitching vertically like what is done in this image, can provide an interesting image making area to allow you to get everything you want into a scene.