Posts in Category: Lens Review

Phase One XT IQ4 Test Review

01 Cover Image

In September 2019, Phase One has released a new camera system, the XT medium format system. It is a mirrorless and therefore smaller camera system than the Phase One XF, and offers so many useful features. A year earlier, the IQ4 series of digital backs has been introduced, including the IQ4 150MP (151 megapixels), the IQ4 150MP Achromatic (151 megapixels), and the IQ4 100MP Trichromatic (101 megapixels). Phase One was so kind and let me test their new XT system with the IQ4 150MP digital back and the XT HR 32mm Rodenstock wide angle lens. The tables below show the basic technical specifications of the Phase One XT camera system, the IQ4 150MP digital back, and the Rodenstock lens family.


First Impressions

After spending an entire week testing the XT camera system and trying it in various different situations, I had so many impressions and experiences while working with the system. The feeling that I remember best is the one I had when first holding the entire system in my hands: When taking the XT system out of the case, my fingers enclosed the grip of a heavy piece of precision engineered metal equipment. For me personally, doing a lot of photography on a tripod, the weight was indeed a positive surprise, because on closer inspection it became immediately clear that this weight is a result from an extremely high build quality. There is pure metal everywhere, most of it on the XT body, but also on the IQ4 digital back, and the Rodenstock lens. The weight of the entire system actually indicates that it uses a greater material thickness than typical cameras, making the Phase One XT an extremely robust camera system. The overall appearance is pretty different from other cameras: The camera body has a large circular guiding rail integrated to allow for a 90-degree rotation between landscape orientation and portrait orientation without removing the camera from the tripod. This adds to the very technical look of the system. The lens also has a rather special shape that is different from most lenses that I have seen before. The XF lenses have a leaf shutter built into a small mechanical case that is integrated into the lens and that protrudes from the lens case. In addition, for a wide-angle lens like the Rodenstock 32mm, the lens barrel is longer than it would be on a single lens reflex camera. The reason for that will be explained later. The IQ4 digital back looks very similar to its predecessor, but a label on the side proudly indicates that it is the 150MP-version that offers an image resolution of 151 megapixels. The gallery below shows some details of the camera system when I first took it out of the box.

Overall Concept

The Phase One XT medium format camera system is completely modular from lenses to the digital backs. In the past with analog medium format photography, it was pretty common to have replaceable camera backs where the photographic film was loaded, but for digital camera systems, having a replaceable sensor back is pretty unique. This high degree of modularity makes the entire system a lot more interesting as a long-term investment as it can be upgraded with future generations of digital backs without having to invest in a new camera body. The XT system can also integrate with lenses from other manufacturers, like Schneider Kreuznach Lenses, Mamiya Lenses, Hasselblad V Lenses, or Pentacon Lenses via an adaptor.

It is a mirrorless camera, and therefore smaller than the XF system that I have reviewed in 2016. Admittedly, even with no mirror built into the XT body, the system is still not particularly compact. This is due to the fact that a camera lens cannot sit directly in front of a camera sensor on order to produce an image. There must be a minimum distance (called flange distance) between the rear glass element of a lens, and the sensor. With the mirror removed, there is plenty of space that appars to be useless, but it is required for proper image formation. Now that the XT camera body is totally flat, the lenses themselves have to accomodate that flange distance, explaining their additional size.

There is a quick rotation function integrated into the camera body that rotates the XF system exactly around the optical axis. This really is a great feature for all types of photography where the position of the subject should remain exactly the same in relation to the lens when the image orientation is changed. For instance, if the XF system is used for product photography, and the camera lens is perfectly pointed towards a subject that has been carefully placed in the perfect angle towards the camera lens, rotating the XF system around the optical axis will keep the perspective towards the subject intact. All the tripod mounts that I have used before actually tilt the entire camera around a pivot that is anchored somewhere at the tripod head, rotating the camera but also displacing the optical axis. This seems like a very small effect, but product photographers are going to love this solution.

An even more interesting and useful feature of the XT system is that the body has a shift function integrated both horizontally and vertically. While most other camera systems require specialized tilt-shift lenses to achieve this effect, the Phase One XT system allows shifting of the image circle for any optical system that is attached even if the lens doesn’t have a tilt-shift function itself. Shifting is extremely useful to maintain straight lines for architecture and interior photography but also when stitching two photos for panorama photography. This feature is enabled by moving the back plate where the digital sensor back is attached horizontally and vertically. Therefore, the back plate with the sensor can be moved horizontally and vertically from the optical axis. Since the back can also be shifted horizontally and vertically at the same time, the sensor can also be moved diagonally from the optical axis. To shift the camera sensor unit in either direction there are two shift dials, one on the top of the XT body, and one on the side. The horizontal dial (the one on the top) allows to shift the camera sensor 12mm to the left and 12mm to the right from the optical axis. The vertical dial (the one on the side) allows to shift the camera sensor 12mm up and 12mm down from the optical axis. There are also two mechanical displays indicating the current position of the camera back in relation to the central position.


Shooting with the Phase One XT IQ4 is a special experience! First of all, the camera is surprisingly easy to control. After starting the IQ4 which takes rd. 20 seconds, the touch display on the IQ4 offers an intuitive menu that can either be controlled via the screen or four buttons next to the display. The only electronic button on the XT body is the two-step shutter release that lets the user customize the half-press sensitivity. However, even more useful is the shutter release button on the touchscreen of the IQ4, especially when the camera is in a position where the top of the XT body is hard to reach. I started to use the on-screen shutter release button a lot. For a mirrorless camera system, the screen is also the main viewfinder where the image is checked for composition, exposure and correct focus. One thing that is extremely useful is the visual feedback of the IQ4 screen on the in-focus areas of the image. Therefore, the IQ4 marks areas that are precisely in focus with a customizable color so that the user gets an instant confirmation whether he placed the focus correctly. To check even more on the focus, the IQ4 can zoom into the image (up to 300%) during live view so that focus changes can be tracked directly on the screen, allowing to adjust the focus just down to the pixel level. The live view mode of the IQ4 also allows for an overlay with histograms and clipping warning.

The IQ4 digital back doesn’t come with any automatic or semi-automatic functions like landscape mode, or others. It requires fully manual adjustments of ISO, shutter speed, and aperture. This is certainly due to the fact that the target group of this type of camera system is professionals and not users looking for a snapshot camera. However, due to the live view mode that simulates the exposure of the final image, it is still easy to use for people who aren’t familiar with manual-only cameras. The IQ4 also brings some very nice features: Dual Exposure is a built-in high dynamic range mode composed out of two images that are taken from the same subject and combined to one shot. Another very special feature is Automated Frame Averaging where the user can select a rather fast shutter speed for the exposure brightness, but several minutes for the total time the camera records the scene. This results in a blurry look of any moving subject like a flowing river or a waterfall.

Although the Phase One XT is designed as a field camera and can be used for freehand shooting, I have decided to use a tripod as often as possible. The camera itself mounts to a tripod via an integrated Arca-Swiss-type rail that tightens itself onto the tripod mount by a finger screw. When switching the camera from landscape to portrait orientation, there is a quick release clamp at the lower side of the XT body. Once that is open, the entire camera system including the lens, the body with its handle, and the digital back rotate around the optical axis counterclockwise for up to 90 degree. This is particularly nice when rotating the camera during live view as this shows how precisely the rotation keeps the subject in place.

Using the shift dials for vertical or horizontal shifting of the sensor unit is surprisingly smooth. Both dials feature detents every 5 millimeters that give the user some tactile feedback when operated.
Shifting the camera back down (which shifts the image up) is extremely smooth because gravity helps, while shifting the camera back upwards is a little bit harder but still manageable with one finger. Shifting the camera back either to the left or to the right is equally smooth. When changing the composition during shooting, I found that it was sometimes hard to remember whether I have shifted the back on the previous shots. Therefore, the mechanical shift scales came in very handy, but also the IQ4 indicates how far the camera has been shifted into the X and Y directions.

Changing the lenses is really easy. The XT lenses are hooked in from below, and secured from the top by two locking systems. One of these locking systems consists of just a security snap lock that prevents the lens from falling out. The other locking system consists of two metal levers that apply pressure to the lens so that it sits tightly on the XT body. This not only ensures that the connection is light-proof but also that the distance from the rear glass element of the lens is absolutely precisely in the right position relative to the image sensor. When I worked with the XT system, I found that this secondary locking system was sometimes loosening itself, probably due to vibration. Luckily this didn’t result in the lens falling out, but the resulting images weren’t as sharp as before. Quickly tightening the two levers again by hand fixed that issue.

Regardless of any functions of the XT camera system, one effect has shown relatively soon: Shooting medium format is a pretty different type of photography. After less than 10 photos I realized that the manual-only settings and the large size of the image files (rd. 120 MB per image) slowed down my speed of shooting. Medium format photography is really something different than shooting with a smaller frame DSLR where it is rather normal to shoot 10 to 20 images per minute and to select the best shot afterwards. The Phase One IQ4 requires more thought about the image composition and challenges the user to get the most out of every single shot. It may seem like a very subtle factor, but this became very noticeable to me and the slower process was something I enjoyed very much.

Image Quality

Looking at the final results on the computer screen, the quality of the images the Phase One IQ4 produces was far beond expectation. There is sharpness in every part of the image, even in the corners there is almost no sign of chromatic aberration or decreased clarity. Also, there wasn’t a sign of any noticeable distortion that often occurs on wide angle lenses. It is also worth mentioning that the sensor’s color reproduction is very accurate and natural. What I found particularly impressing was the bit depth that the IQ4 offered. This became clear when I increased the brightness of dark areas in Phase One’s post-production software Capture One. Inceasing the brightness of extremely dark areas was able to bring up so much detail without visibly introducing noise, and made it look like there was no shadow at all. Below are some sample images that were shot with the Phase One XT IQ4 camera system. The images below  have not been post-processed (except for resizing them for the website) and show some of the impressive abilities of the IQ4.

To demonstrate the image sharpness, here are two larger illustrations: Demo 1 and Demo 2. Right-click on each demo and select ‘open in new tab’ to open them in full size. Then zoom into the image to view all details.


When handling the Phase One XT camera system, it became clear that the camera is a highly specialized piece of photographic equipment. Almost every part is made from metal, very precisely machined, creating an extremely sturdy product. It is an incredibly powerful camera for certain types of photography including interior, fashion, products, reproduction, architecture, landscape, and others. Although it is designed as a field camera (as opposed to the XF system that was designed as a studio camera), I would recommend to use it with a tripod. If combined with a tripod, the entire system weighs around 4 kilograms. It is clearly not a travel camera, and also no action or sports camera.

Phase One is always the camera of choice when extreme resolutions are required. The IQ4 digital back produces images with 151 megapixels, super smooth tonality, natural color reproduction and very high dynamic range. It offers a very easy to use interface, perfectly reliable touchscreen, live-view with focus indication and histogram overlay, and additional creative features like dual exposure and automated frame averaging.

Unfortunately, what must also be factored into these pro arguments is the little design flaw with the lens mount, as well as the price of rd. USD 60.000 for the Phase One XT with IQ4 150MP digital back and Rodenstock lens.

At the end of my camera demo week, I had to return the XT camera system to Phase One. Thank you very much for allowing me to review the XT IQ4 150MP, an impressive piece of technology.

 About the Price

For those who are asking whether a price of roughly 60.000 EUR for a digital camera system can be justified, there is no easy answer. I have collected a number of facts and considerations that try to explain the price from various perspectives:

  • Highly specialized to the most demanding purposes
    One aspect is that Phase One has a very specialized market. Their cameras cannot be compared with standard cameras because they aren’t designed for the broad market. Due to their weight and size, Phase One cameras are clearly no travel cameras. Also, their cameras are not designed for very fast applications, which makes them rather not suitable for sports, action, street, reportage or event photography, and similar disciplines. The large size of the images also make it almost impossible to use for time lapse projects.
    Their high degree of specialization make Phase One cameras more interesting for artists and photographers who need an unbeatably high image resolution because they want to produce large high-quality prints of their images. For that reason, Phase One XF and XT systems are rather popular among photographers who produce fine art, fashion, architecture, landscape, product photos, or similar forms of art for magazines or galleries. This obviously narrows down the potential target group to a limited number of specialized artists. These users, however, are often ready to invest in such a camera system because it enables them to produce phenomenal prints. If these artists then sell their fine art photographic work at prices that pay for their investment, the camera system is probably worth the price.
  • Overall concept
    Phase One cameras are known for their extremely solid and precise build quality, crafted from high-grade materials including metal on almost every part of the system. They are manufactured with high durability and long lifetime in focus. This also corresponds with the concept of modularity: One of the major features of Phase One cameras is that their digital sensor unit can be removed from the system and replaced with a different type of digital back. Looking at the newest generation of digital backs, the IQ4 line offers three different sensors (including a black-and-white-only sensor that has some incredible low light capabilities) that can be attached to a Phase One camera body. This high degree of modularity also makes the entire system more interesting as a long-term investment as it can be upgraded with future generations of digital backs without having to invest in a new camera body.
  • Equipment
    What a potential buyer of a Phase One camera can also expect is a top-level set of accessories. Phase One delivers their cameras with a pretty large set of additional equipment like a sturdy Pelican Storm Case, cover plates for the camera system and the IQ4, the battery charger and batteries, a capture one license key, a cleaning kit, an HDMI cable, an ethernet tethering cable, USB-C to USB-C cable, USB-C to USB cable, a card reader, XQD and SD cards, as well as a lens cast calibration (LCC) plate. Of course, it is not this additional equipment that justifies the hefty price tag, but it certainly underlines Phase One’s attention to detail.
  • The medium format look
    Another aspect is that medium format cameras are considered to produce images with some superior qualities.
    The primary distinction of medium format cameras is the larger size of the image sensor. This increased size of the image sensor allows for higher resolution images, and the photos often have higher color accuracy and smoother tonal gradations from light and dark areas which is more pleasing to the eye. In addition, the larger size of medium format sensors offers the photographer more control over the depth of field. For that reason, it is said that medium format cameras would offer greater creative potential. As a result of specialized medium format lenses, the images often show no or very limited image distortion. Probably as a combination of these effects, photos taken with a medium format camera have a distinct feel that is often instantly recognizable. Medium format images tend to look closer to the real scene that a viewer would see with his own eyes, creating some sort of mysterious immersion that is often described as the ‘medium format look’. This is probably the main reason why many photographers prefer to shoot with medium format systems.
  • Steeper price curve for more advanced technology
    Seeking perfection almost always goes along with exponential increases in cost. In this context, perfection doesn’t mean luxury products. It is clear that a camera that is covered in gold will come at a price of tens of thousands of EUR. But Phase One’s prices come from their technology that is so advanced that they are pushing out the boundaries of technical feasibility. This is because their cameras use so specialized optics and sensors that are very time consuming and costly in their development. And this always puts a product into the upper price category. Therefore, this argument can be a good justification for tech-geeks who want to get the satisfaction of knowing they are holding the latest state-of-the-art technology in their hands. This effect becomes also visible on many other high-tech products like audio systems, televisions, vehicles, household equipment, and others. Their price curve rises relatively slowly at the entry-levels of these products and then climbs more steeply as you enter the mid-range. Then, for products within the top 10% of quality and technical features, the price curve typically climbs very steeply, and finally for the last 1% of vastly superior products that are closest to perfection in terms of quality and technical finesse, their prices have climbed to record levels. People who want to have the largest television of their neighborhood have to pay 20 times as much compared to an average sized TV, even though the largest TV may ‘only’ be twice the size as a more affordable one. And people who want to have 151 megapixels compared to 15 megapixels of a standard DLSR, they have to pay 20 times as much. The camera’s architect, Lau Norgaard, states “If you need the highest resolution possible, this is the only one providing 151 megapixels.”
  • The Porsche effect
    The last argument to possibly justify the price of a Phase One camera system may be a bit stereotypical. As a result of a phenomenon I call the Porsche effect, some photographers might not necessarily ‘need’ such a large image resolution and modularity of the system – but they ‘want’ it. There are certainly photographers out there with some extra cash in ther account and who like to own a prestige object that they work with every day, and that clients can admire when put into action. This target group might also be affiliated with Phase One’s company history and philosophy. It is probably the same type of people who decice to buy a Porsche rather than a different brand of car, because the name represents style, high build quality and amazing performance.


When analyzing the Phase One XT IQ4 system from an engineering point of view, it becomes clear that Phase One did not just carry one feature like the sensor resolution to the extreme, but they polished and fine-tuned so many elements, and the resulting camera system is a combination of so many high quality factors that are reinforcing each other. The XT IQ4 camera system utilizes every technological way to get as close as possible to the physical limits of image formation. Here is a summary of the physical principles and key reasons that allow Phase One to deliver such a vastly superior image quality:

1] Lens Characteristics: First of all, the quality of the lenses makes a large contribution to the overall imaging performance of the system. The Phase One XT system integrates lenses that are custom-designed by Rodenstock, a lens manufacturer from Bavaria, Germany. Rodenstock has over 140 years of experience with designing all types of optical systems. For the Phase One XT system, Rodenstock created a series of lenses they call XT-HR Digaron, and they combine only the best optical characteristics: They were developed for applications with extremely high resolution sensors, and they provide incredible spatial frequency (a very technical term for sharpness) and contrast throughout all aperture settings, and they are so well adjusted to the Phase One XT IQ4 system that they even compensate for the thickness of the sensor’s protective glass.

Only Prime Lenses
For the Phase One XT system, Rodenstock designed their XT-HR Digaron series as prime lenses only. As opposed to zoom lenses that can change their focal length, prime lenses only have one focal length. This may sound like an inconvenient limitation, but there is a reason behind this concept. If an optical system had just a single lens element to perform the image formation, the resulting image would actually suffer from a number of imperfections called lens aberrations that are caused by the curvature of the lens element. Typical lens aberrations include image distortion (pincushion-type or barrel-type), chromatic aberration (lateral and longitudinal), spherical aberration, coma, astigmatism, vignetting, ghosting, and others. This causes an image to have visible defects like color fringing, or blurring. To reduce the aberrations of an entire camera lens, optical engineers place several lens elements with different physical properties into the optical system so that the lens elements cancel each others’ aberrations out. This is a highly complex design process called lens correction, and it is the reason why some camera lenses include up to 20 individual glass elements. The intensity of aberrations a lens element procudes is also depending on the path that incoming light takes through the lens. This variance makes it almost impossible to entirely correct a zoom lens, because this type of lens is designed to have different paths of light due to the different focal lenghts. For that reason, zoom lenses are some sort of trade-off between flexibility and performance. In contrast, a prime lens has a fixed focal length, and is therefore designed for only one specific path of light. Optical engineers can perfectly concentrate on the one light path that results from the fixed focal lenght, and can therefore optimize a prime lens much more than a zoom lens. This is the reason why prime lenses create sharper, clearer images with higher contrast.

Larger Image Circle
The XT camera system is designed with an integrated shift function that allows the camera back to be shifted horizontally (+12mm, 0, -12mm) or vertically (+12mm, 0, -12mm). To allow this shift function, Rodenstock’s HR Digaron lenses are designed with an image circle that is larger than in typical camera lenses so that the sensor still captures light when shifted away from the central position. It is a typical issue that the image rendering performance of an optical system is not the same across all areas of the image circle. In the center of the image circle, the imaging quality of a lens is typically the best. However, the image rendering performance including sharpness or contrast slowly decreases in the outer areas of the image circle, with areas furthest away from the center suffering the most. Even highly optimized lenses cannot completely remove this effect. However, this means that on the Phase One’s XT camera system, slight lens aberrations only start to appear on the image when the sensor is moved to the outmost shift position where it is closest to the edge of the image circle. In turn, this means if the image sensor is in the central position, it is completely covered by the inner region of the image circle where the lens has its maximum performance. This is actually a really nice side-effect of shift lenses, because they provide for ultra sharp areas even in the corners of an image (where other lenses already show signs of decreased quality). The IQ4’s image sensor measures 53.4 mm x 40 mm. The image circle of the Rodenstock XT-HR Digaron-W 32mm has a diameter of 90 mm. This shows how much space there is available for shifting, and how much edge region is ignored by the image sensor when in its central position.

Larger Lenses are more forgiving
When light travels through an optical system, it is refracted at each lens element until it finally reaches the sensor. In a camera lens that is designed for a smaller photographic system, the lens elements also have a smaller glass surface. Smaller lens surfaces in turn make smaller lenses more vulnerable for production variations or little imperfections. This is primarily due to the fact that small lenses have less surface area to compensate for imperfect areas or defects in the glass. On the other hand, lenses that are designed for large camera systems such as medium format cameras typically have large glass elements with larger lens surfaces. These larger lenses are more forgiving and more tolerant towards small spots with production variations or little defects in the glass, because the relation between a defective area and the entire lens surface is smaller when the lens is bigger. Simply put, in larger lenses small lens defects will not show in the final image, because there is so much more surface area in the lenses to compensate these imperfect spots.

2] Sensor Characteristics: Secondly, the IQ4 digital back with its image sensor and the processing electronics is a unique piece of photographic equipment, and it is another reason for the superior overall imaging quality of Phase One’s camera systems.

Sensor Resolution
The IQ4 150MP digital back uses a backside-illuminated complementary metal oxide (BSI CMOS) sensor that offers an incredibly high resolution of 151 megapixels which captures the extreme sharpness produced by the lens. The active light-receiving area of the sensor consists of 14.204 vertical lines and 10.652 horizontal lines of pixels. This high resolution is stunning: It is more than 10 times the resolution current DSLRs from other manufacturers offer. If a photographer wants to print such an image with a dot density of 300 DPI (dots per inch) and without resizing the original, the print will have a dimension of 120.26 cm x 90.19 cm. However, there is a lot more about the sensor than its resolution.

Sensor Size
The size of the IQ4’s image sensor is more than twice the size of those found in high-end DSLRs. Each pixel consists of an optoelectronic receptor, called photodiode or photosite, that captures light and converts it into an electric charge. Once the photo has been shot, this charge is translated into a number representing the brightness. Having a larger image sensor also allows to use larger sized photosites. And this in turn has some substantial advantages over smaller photosites: Small photosites tend to saturate (overfill) faster and when their storage capacity is reached, they simply ignore whether the scene is actually brighter. When shooting a subject with bright areas, small photosites will sooner produce a signal that represents full white (a phenomenon called clipping) even though the real scene wasn’t completely white. Due to their smaller storage capacity, the range between absolute black and full white is rather limited, which results in a lower dynamic range. Larger photosites, on the other hand, have a lot more storage capacity for incoming light, and have therefore a higher dynamic range. This means that they aren’t very vulnerable to clipping, and they can make more accurate representations of scenes with difficult light situations. Another beneficial effect of a larger pixel size is that they reach a better signal-to-noise-ratio which results in the final images having less image noise. Also, larger image sensors offer better low-light characteristics.

16-bit Analog-Digital-Converter
The signal that each photosite on the image sensor collects is an electric charge. Each particle of light (photon) that hits a photosite creates an electron in the photodiode’s semiconductor material. If the pixel doesn’t receive any light, the storage remains empty, and no charge is generated. If bright light hits the pixel, it generates countless electrons, and therefore a higher charge. In order to process the image, the charge of each photosite needs to be interpreted, and translated into a number. This is what an analog-to-digital (AD) converter does each time when the camera reads out the sensor and stores the image on the memory card. The bit depth is a number that represents how many different brightness values the AD converter can detect in a single photosite, provided that the photosite has enough dynamic range. Conventional DSLR cameras typically have 12-bit AD converters which can differentiate 2^12 = 4.096 different brightness levels between absolute darkness and full white. They store 12-bit image files where each pixel can have one of 4.096 different brightness levels, at least when the camera stores the RAW files. JPG images are limited to a bit depth of 8 which means that pixels in JPG files can only have one of 256 different brightness levels. While 12-bit is pretty respectable, the IQ4 has a 16-bit AD converter built in, and stores 16-bit images with a 15-bit dynamic range. Again, this applies only when RAW files are selected. This means that each pixel can have one of 2^15 = 32.768 different brightness levels between absolute darkness and full white. This incredibly large bit depth is what produces super-smooth tonal gradations in the final images which are extremely pleasing to the eye, and finer color details.


Tilt Shift

Yes – I finally got one! It is the Canon TS-E 17mm f/4 L ultra wide angle lens. Here are some technical specifications and unboxing photos:

  • Focal Length: 17mm
  • Diagonal Angle of View: 104º
  • Lenses / Groups: 18/12
  • Shift Range: ±12mm
  • Tilt Range: ±6,5°
  • Aperture Range: f/4.0-22
  • Rounded Aperture
  • Manual Focus Only
  • Internal Focusing

After evaluating the pros and cons of investing in such a specialized piece of equipment, I decided to take the step and see how it can improve my architectural and urban photography. What kept me from acquiring the Canon TS-E 17mm for a long time was obviously the price – Amazon currently sells this lens for USD 2.100. However, a tilt shift lens offers some really unique features that I would like to mention:

  • Probably the most interesting feature is that a Tilt Shift lens can help avoid parallel lines to converge on an image
  • The lens provides an incredibly high resolution and sharpness even in the corners due to the large image circle
  • An asperical lens reduces image distortions
  • Four ultra-low dispersion lens elements reduce chromatic aberrations in the corners
  • Sub-wavelength structure coatings minimize ghosting and flare
  • Independent Tilt and Shift Sliders
  • The entire lens can rotate ±90° to switch between landscape format and upright format
  • Locking screws prevent accidental shifts and tilts
  • L-Series – the lens is extremely well made and durable due to metal structure and weather sealing
  • Includes Canon LP1219 soft lens case

With these features, the Canon TS-E 17mm is predestined for architectural and real estate photography. When holding the lens in my hands for the first time, I wasn’t expecting so much weight – but this is totally fine as it will be set up on a tripod 90% of the time. Due to the L-qualification, the build quality is top of the line. I am fascinated by the precision how every moving part slides when moving the tilt or shift units. There is even a protective rubber-like surface between the tilt and shift parts that prevents dust or spray water from entering the gaps – although I am not planning to use it in the rain. The focus ring has a convenient size and rotates very smoothly. Manual Focus is certainly something to get used to, but it still works pretty good when keeping the shutter button on the camera half-pressed while focusing and waiting for the camera to indicate an in-focus situation with a short beeping sound. Altogether, I am looking forward to taking it on my next journey!!

The Ultimate Camera System – The New PHASE ONE XF 100MP Camera

XF-IQ3-100MPFor those who like what they see but don’t know what they are looking at, the image above shows the new Phase One XF 100 medium format digital camera system.

Medium format cameras are especially appreciated by professionals for a couple of reasons. These types of camera systems offer a high flexibility that allows a photographer to configure the camera to the requirements of the job. They consist of a camera body that accomodates the reflex mirror, the phase detection sensor, a ground glass, and a focal plane shutter. However, differently than other digital single lens reflex cameras, medium format digital cameras typically have large openings on the top of the body and on the back side. The upper opening allows the connection of different viewfinder options such as eye-level viewfinders or waist-level viewfinders. With a waist level viewfinder, a photographer can hold the camera in front of his waist or leave it standing on a table and look down on the viewfinder like on a final print. Although technically being a relict from the old days of photography, some photographers claim that waist-level viewfinders can be favourable during portrait photography as the subject might feel less targeted because the photographer is not directly looking at them. It also changes the perspective at which the subject is shot which makes photo models appear taller.

The opening on the back side is designed to connect exchangeable digital backs. These are independent modules that contain the image sensor on the connecting side, an LCD display on the rear side, and plenty of powerful image processing electronics inside. The ability to change the image sensor is certainly a unique feature of medium format camera systems. Medium format digital backs offer a variety of sensor types and formats, from square to rectangular shaped sensors. The dimensions of medium format image sensors vary from 54mm x 40mm to 67mm x 56mm – this is an active sensor area over four times larger than the area of a 24mm x 36mm full frame sensor. These huge image sensors offer some rather substantial advantages. They typically consist of larger pixels that offer an outstanding dynamic range. Still, even with the increased pixel size, medium format sensors also provide
resolutions higher than those of regular DSLR cameras. The majority of medium format cameras provide resolutions of 40 – 60 megapixels. These high resolutions are especially important for the production of large, detailed prints like posters or advertising spaces.

Medium format digital cameras are designed to conform the most demanding requirements of professional photographers, and they come with a price tag far greater than many can afford. Therefore, these systems are typically used for highly specialized purposes such as aerial photography, night sky and astro photography, photo archiving, scientific documentations (insects, other), but also product and fashion photography. Professionals worldwide swear by the realiability and high quality delivered by these powerful systems.

The Phase One XF 100MP Camera System

In January 2016, Phase One released their new XF 100MP which was the first camera release of the year. Their new camera system uses a Sony CMOS sensor that creates images with a resolution of 100 megapixels and the sensitivity (ISO) can be chosen between 50 and 12.800. The sensor records images with 16 bit color depth, and the dynamic range of the system covers a total of 15 stops! With a sensor unit of that quality, the lenses must be able to keep up with the resolution. Therefore, Phase One equips their system with ultra sharp prime lenses of Schneider Kreuznach with leaf shutters and fast autofocus.

Technical Specifications

Image Sensor

Resolution101 Megapixel
Long Exposure Up to 60 minutes
A/D Conversion16 bit Opticolor
Dynamic Range 15 stops
Sensitivity (ISO)50 - 12800
Crop Factor1.0
Sensor SypeCMOS
Sensor Size (mm)53.7 x 40.4
Active Pixels11608 x 8708
Pixel Size (micron)4.6 x 4.6

Focus & Autofocus (Honeybee Autofocus Platform / HAP)

Autofocus SensorHAP-1 1MP CMOS Sensor
Autofocus ProcessorHAP-1 Processor with Floating Point Architecture
Autofocus Assist lightHAP-1 Precision White light
Hyperfocal Point Focusingyes
Upgradeable Autofocus configurations & Patternsyes
Autofocus ModesSpot, Average, Hyperfocal
Interchangeable Focusing ScreensMatte (default), Split, Center Prism

Capture and Light Metering

Capture Drive Modes Single / Contiunous / Low vibration / Exposure bracketing 2-7 frames
Toggle Mirror-Upyes
Capture from Liveviewyes
TTL Light MeteringAverage, Spot and Auto
HAP-1 Light Meteringused with waist level finder (Spot)
Focus Confirmation90° Prism: yes / Waist level Finder: on top screen
Viewfinder black-out time150ms (FPS), 400ms (LS)
AE Lockyes
Exposure compensation+/- 5 EV

For more information on technical specifications, check out the Visual Guide of the XF 100MP on the Phase One official website.

Phase One was so incredibly generous to lend me their new XF 100MP system over the weekend (16./17.04.2016) allowing me to create test photos and to share my impressions with you. The gallery below shows the camera system, the lenses included and further components.

First Impressions

Phase One delivered the camera along with three lenses and additional equipment in a heavy black suitcase. The first impression was really stunning. After opening the suitcase I was surprised by the rock-solid build quality (all black aluminum), and the weight of the camera. (As per the specifications, the camera body with the 90° prism viewfinder and the IQ3 100 digital back as well as two batteries weights around 2,1kg. The Schneider Kreuznach 80mm LS f/2.8 lens adds roughly 500g to the system.)

On closer inspection, almost every camera part is made of aircraft grade aluminum and feels virtually indestructable. Even smaller elements like the four control buttons of the digital back and the flash card compartment lid are made of aluminum. All surfaces are completely black, and only some buttons are kept in their original metal-appearance. Surprisingly, the black aluminum is not very susceptible to fingerprints – they simply disappear after a few seconds. The Phase One XF has a very puristic design and extremely clean appearance. The connection systems that keep lenses, viewfinders and digital backs attached to the body feel very safe and are totally easy to use. All Schneider Kreuznach lenses are made of solid metal, too. Their focus rings have a toothed surface and provide very good grip. The price for the new Phase One XF 100MP system with a lens is around USD 49.000,00. The image below illustrates the entire scope of delivery.


The camera itself consists of two main units. The camera body has its own power supply and a touch screen controlled XF menu. The digital back also has an individual power supply and an IQ menu, controlled by four customizable buttons and touch screen. I suspect the XF menu to be the quick menu only, although it offers a wide range of shooting modes, including high dynamic range, time lapse, and other useful features like a seismograph and a level. Conversely, the IQ menu is actually the main control option because of its large LCD screen, the photo review function with histogram options and tons of fine tuning settings. Of course, both menus are permanently synchronized so when an option is selected on the IQ menu, it instantly adjusts the same setting in the XF menu, and vice versa. Although it sounds complicated to use, I found both menus so intuitive that I didn’t even have to open the user guide a single time. The following galleries clarify the purpose of each individual menu.

The XF Menu

The IQ Menu


Finally I took the camera to a couple of locations in Munich where I tried to find out about its capabilities, and probably about its limits. I attached the Schneider Kreuznach 35mm LS f3.5 wide angle lens to the camera and went to BMW World and the Pinakothek of Modern Art. I have particularly tried to capture scenes with difficult light situations such as dim interiors with bright spotlights and windows. A few other shots include a snake that I captured with the 80mm lens and the 120mm macro lens. Please note that the gallery contains JPG files that do not include the full dynamic range. Unfortunately, the lossless TIFF files could not be loaded into the gallery.

One aspect is interesting to mention. The Phase One XF relies on one single autofocus point in the center of the screen. This might sound like a disadvantage compared to other DSLR cameras that often have more than 60 AF points. With only one AF point, one might miss the flexibility to focus on a subject off-center to achieve a more interesting photo composition. However, with a resolution of 100 megapixels, there is virtually no need to focus on different positions as the final image can be cropped until the desired composition is achieved. Therefore, a photographer can really concentrate on shooting and must not think about composition.

While I thought it would be easy to focus on the center, with the aperture wide open I sometimes found it challenging to direct the focus point exactly on the spot I wanted. The autofocus system is so precise that the autofocus point needs to be perfectly in the right spot. With the autofocus point just slightly shifting from the eye to the eyelash, it will be the eyelashes that stand out and the eye softly blurred. When I shot the snake, it took practice until I got the eyes in focus. If there is something in focus, however, there is no discussion that sharpness and clarity is beyond comparison.

On another note, I would like to mention the speed at which the Schneider Kreuznach 80mm LS f/2.8 lens focused. This lens is so reactive and fast that for small focus movements, I couldn’t even see the focus ring move but simply “jump” from one focus distance to another. When keeping the shutter button half-pressed, the lens starts to hunt the subject with incredible speed and accuracy. I am used to fast focusing by my Canon EOS 7D, but I was deeply impressed by the Phase One / Schneider Kreuznach focusing speed.

Finally, the power sharing was a feature I really loved. As described above, both camera units have their own power supply, but in fact they are sharing power if one unit runs out of battery. This can happen if the IQ menu is heavily used for picture reviewing and adjusting settings more on the IQ digital back. As soon as the battery inside the digital back is discharged, the XF unit provides power to itself and the digital back. Of course, this also happens vice versa.


From my personal view, medium format cameras are an interesting combination of scientific precision tools and photography. They represent the constant pursuit for technical perfection in optoelectronics and a philosophy of creativity. I have seen for myself that they are very specialized and certainly not suitable for every photographic application, but for countless other purposes they are unsurpassed in image quality. The Phase One XF 100MP is the best camera I have ever seen and that I have ever had in my hands. The resolution of 100 megapixels is impossible to describe, and I was even more impressed by the huge dynamic range it is capable of perceiving. Also, the high speed and precision of the Phase One Honeybee Autofocus Platform was totally new to me. Concluding I would like to thank Phase One for this great opportunity!

Testing the new Canon EF-S 10-18mm Ultra Wide Angle Lens

I found out about a new Canon ultra wide angle zoom lens at the beginning of this week. It is the Canon EF-S 10-18mm f/4.5-5.6 IS STM that immediately caught my attention.

In terms of ultra wide angle lenses, there is also the Canon EF-S 10-22mm lens that I have always loved to use and that provides a pretty good image quality in my opinion. For me, the downside of the Canon EF-S 10-22mm lens is actually the price that is still around EUR 550,00 at the moment. In addition, I also use the Canon EF-S 17-55mm which is such a great lens that I try to use it as much as I can. With a minimum focal lenght of 17mm, it eventually makes all focal lenghts larger than 16mm useless on the 10-22mm so that I do effectively use it for 10-16mm only. This is almost half of the focal range of the 10-22mm that I do not neccessarily need. For my personal setup, the Canon 10-22mm is 90% more expensive than for anyone who needs it’s full focal range.

In comparison, the Canon EF-S 10-18mm is a more economic option for me. Also, it provides some pretty nice additional features such as a stepper motor (indicated in the lens name as STM) and an Image Stabilizer unit (IS). The image stabilizer is interesting because normally wide angle images are not really vulnerable to shaking, however it can probably assist in getting images even sharper.

I have done some research on the Internet since the beginning of the week and learned that many people describe the Canon EF-S 10-18mm as a very powerful ultra wide angle lens. It has some minor disadvantages such as a variable maximum aperture over the focal range and the lens is predominantly made of plastic elements. On the other hand, the image quality (which in my opinion should always be the most striking argument) is slightly better than the quality provided by the Canon EF-S 10-22mm. Last but not least, the price is EUR 279,00 (Amazon Germany on 12.07.2014) which supported my decision.

I purchased the Canon EF-S 10-18mm on Wednesday, 9th of July 2014, and received it yesterday. Here is a short review on both general information and my personal impressions of my new lens.

General Information

The Canon EF-S 10-18mm f/4.5-5.6 IS STM is only supported by crop-sensor cameras and therefore does provide a slightly different impression of focal ranges to the viewer. Given a crop-factor of 1.6, the resulting images are equivalent to 16-29mm on a full frame camera. This lens features a stepper motor which is known for its ultra fast and silent focus performance. The diaphragm – consisting of seven blades – has a maximum aperture of f/4.5 at 10mm, immediately reduces to f/5.0 at 11mm and reduces once more to f/5.6 at 15mm. The lens consists of 11 lens groups totalling 14 lens elements. Here is the official Canon diagram showing the internal structure.

Internal Structure


The Canon EF-S 10-18mm does also feature an Image Stabilizer that can compensate the longer exposures resulting from the limited aperture. According to MTF Charts, overall lens resolution is quite impressing, see the official Canon Chart below.

MTF Chart


Here is a short description on my personal impressions related to the Canon EF-S 10-22mm lens. I took some time today and documented the unboxing process so you can participate in this ceremony =)

In terms of weight and dimensions, my expectations were met and the Canon EF-S 10-18mm is a bit smaller and lighter than the Canon EF-S 10-22mm. It has the lens cap “CAP E-67II” included which I personally like very much because it is easier to remove and re-attach to the lens than previous lens cap designs. The filter ring has a 67mm diameter and does not rotate when focusing, however the lens slightly changes length (approximately 4mm) when zooming in and out.

Having expected a plastic feel, I was a bit surprised that the overall build quality is pretty decent. The zoom ring has a rubber coating and feels solid with no gaps between the zoom ring and the lens barrel. Zooming in and out gives a constant feedback with no changes in pressure. The focusing ring is placed on the very front of the lens and it allows to do manual focusing. The focus ring is extremely easy and smooth to turn and gives a feeling of precision, although I would not want to miss the stepper motor to perform the focusing.

For an ultra wide angle lens at a very favourable price, I was sceptical about the image quality. I did some quick test shots today and I was frankly surprised that image sharpness was pretty high and constant over the entire scene. There is barely some distortion at any focal lenght and also chromatic aberration is low. I do not have a detailed comparison between the Canon EF-S 10-22mm and the new Canon EF-S 10-18mm, but my impression is that the new lens can definitely keep up with the expensive version.

One thing I have to say is that I was slightly disappointed by the lens mount which is also designed in plastic. Although plastic technology has brought up some really resilient and durable materials – as the lens barrel itself shows – plastic is still not so popular in high-quality products.

There is also a professional review of the Canon EF-S 10-18mm on the website of Ken Rockwell.