Hands On With The Phase One IQ4 150MP: Can You Shoot Long Exposures at 1/125s?

Like them or not, medium format cameras are the truth when it comes to image quality. The latest 150 megapixel juggernaut from Phase One is another example of what these systems are capable of, but there's far more to this back than just sheer resolution. Ever shot long exposures at 1/125s?

Around this time last year Phase One released the IQ4 line of digital backs. The IQ4 expanded on the IQ3 and introduced a new Infinity Platform (the UI and operating system in the backs), as well as two brand new sensors: the 151 megapixel full frame medium format IQ4 150MP and 150MP Achromatic. To date, the IQ4 150MP is the highest resolution single shot digital back available to consumers. 

Before we begin we should get a few things straight. This is a review of a medium format camera system; one that exists at the industry’s highest level. Medium format camera systems are expensive. Because of their high cost it can be easy for some to disregard their place in the photographic world, clutch their DSLRs, and exclaim with great satisfaction and righteousness that you don’t need to spend 5 figures to make great images. This assertion is undeniably correct, however, it misses a valuable point. 

Medium format camera systems do what they do better than any other tool. Like a Formula One car, medium format cameras are specially designed for a specific task: to deliver the best image quality at the highest resolutions possible. Because Formula One cars are designed to perform at the highest level, no one bats an eye if the cost of one is 10.5 million USD. The cost is justified because these cars are difficult to manufacture, are finely tuned for their intended use, and surpass all comers in turns and acceleration. The same is true for medium format. To continue the analogy, you won’t find a F1 car making stops at the grocery store, just like you probably won’t see a Phase One camera on the sidelines of a child’s soccer game. Probably.

They are professional tools purpose built to be the very best at what they do. Buying or renting medium format is a business decision that, like any option that could help improve your bottom line, shouldn't be overlooked.

(The irony of comparing F1 cars built for speed and medium format cameras that are traditionally quite slow is not lost on us). 

You’ll see me use the word “system” often in this review because that’s what Phase One cameras truly are. For starters, the business end of the camera, the digital back, can be removed from the XF body and placed on another camera body like Phase One’s new XT, with rise, fall, and shift movements as well as Rodenstock optics. Likewise, the XF body can use any IQ digital back simply by swapping them out on set. The flexibility of the ecosystem is astounding and makes it somewhat difficult to review considering the IQ4 digital back has capabilities beyond the XF body. Still, for our purposes we’re focusing on the IQ4 150MP on the XF body with current (as of writing) firmware.

Images featured in this review have been edited to taste in Capture One Pro unless otherwise specified. 

Quick Look:

• Modular Design
• 151 Megapixel Digital Back
• Unique features like Frame Averaging and Capture One Inside
• Large, heavy, and slow

• Touch screen design is effective but takes some time to move around quickly

• Wrangling 151 megapixels requires attention to detail
• Astounding image quality

• Up to 60 minute exposures

• Hardware intended to be upgraded over time and not relentlessly replaced
• Multiple connectivity options including Ethernet

• Approximately $52k for body, pack, prism, and choice of prime lens.

First Impressions

These systems are unique for several reasons, not least of which is Phase One’s commitment to expanding feature sets via firmware instead of constantly releasing new hardware. For example, Phase One recently released a firmware update for the IQ4 line that, among other things, includes two huge new features: Automated Frame Averaging and a unique ability to import a user designed Capture One Style into the IQ4 for stylistic previews while shooting.

The same is true for the XF body which has seen its own feature set expand since it was first released in 2015 with the addition of focus stacking, Profoto Air Remote functionality, seismograph, flash trim and analysis, and more via free firmware updates. Can you imagine a major DSLR manufacturer not releasing a new body for 4 years, and instead dedicating its time to just one? Because of that future minded innovation, even with the same hardware, this camera as it is reviewed today may not be the same camera a year or even 6 months from now, which is exciting in and of itself.

Phase One XF IQ4 150MP with SK 240mm LS BR mounted

I’ve worked with medium format systems my entire professional career. Either through use in the field, technical support, testing, providing demonstrations, or teaching classes, medium format has been a driving force. Because of that experience I’ve been able to see first hand how far Phase One has come in developing their camera systems. The jump from P+ to the IQ1 line of backs was enormous. P+ Backs like the P65+ and P40+ had the same sensors as the newer IQ160 and IQ140, but the interface, feature set, and subsequent usability of everything surrounding the sensor was as different as night and day. My feeling is that the jump from the IQ3 to the IQ4 line of digital backs is of a similar magnitude combined with an additional jump in image quality.

Handling

The XF IQ4 150MP is big and it is heavy. There’s no getting around it. The body and lenses are made from metal that feels good to the touch and communicates quality, though the metal housing would likely provide little protection in the case of a drop. Even though it consists of four distinct pieces, (lens, body, back, prism) the camera feels solid and balanced. The grip on the XF body is deep and fitted with a faux leather which makes it quite comfortable. Thanks to its deep grip I was able to let the camera dangle from my fingers at my side, even with a 240mmLS lens attached, the longest currently made for the Phase One system by Schneider Kreuznach. Regardless of the attached lens, the camera can be easily brought up to the eye when hand holding, though extended time with a large lens will lead to fatigue.

In all, the kit feels good when in hand and when on a tripod. Though heavy, it can easily be placed into a backpack and hiked with if you’re out on location or shooting landscapes in the wilderness. I know from personal experience that a well made backpack can make a huge difference here due to the weight of the body and lenses. Additionally, I’ve never had a fumble in all my time handling the XF camera system myself or when handing off to another person. 

Though hand holding is certainly doable, and many of the images in this review were shot handheld, a tripod will likely be where the XF IQ4 150MP lives most of the time. The weight of the system is such that navigating the menu on the rear retina style screen while hand holding is a bit awkward. I found myself pressing the camera flat against my chest with my left hand and using my right hand to navigate the rear menu fairly often. It looks a bit funny but it’s effective. On a tripod that issue disappears.

The XF body's button configuration displays no naming or iconography since everything is customizable. The body has three scroll wheels compared to a typical DSLR's two. The third wheel lives on the rear of the camera body closer to the prism. It is, at least by default, dedicated to ISO. I appreciate this third wheel since it makes changing ISO while the camera is raised to the eye quite simple. 

Usability

While achieving the system’s absolute best image quality and using some of the more advanced features unique to the XF IQ4 150MP system may have a slight learning curve, anyone remotely familiar with a DSLR can pick the camera up and start shooting immediately.

Speed

Once the camera is powered up it’s responsive, but it takes a little bit of time to get there. My copy took roughly 17.5 seconds from power up to being capture ready. While in the field I noticed that I would power the camera on just as I was getting it out of my bag so that it would (hopefully) be ready to go once I had mounted it to the tripod. Make no mistake, this camera is not meant to be frequently turned off or on, nor is it meant for speed. The absolute best you would be able to expect is roughly 1.4fps on the lower resolution 14bit file option. Autofocus is also somewhat sluggish, and navigating the touch screen menu system on the digital back can take some time to get used to.

IQ4 150MP, Schneider Kreuznach LS 240mm, ƒ11, ISO50

The habit of medium format systems slowing photographers down and forcing them to be more conscious of their compositions is well known. Certainly for me that deliberate approach to making images tends to result in more keepers and fewer throwaways. This was reaffirmed during my time with the XF IQ4 150MP. Then again, if you’re used to shooting quickly the system could be quite frustrating.

Hand Holding Vs. Tripod

As mentioned above, the XF IQ4 150MP is indeed able to be shot handheld with relative ease for most users. However, due to its extraordinary resolution the shutter speeds with which hand holding is practical when shooting in natural/available light and without strobe are limited. As mentioned in my article on high resolution systems, any defect visible will be compounded when viewed at 100% when you’re dealing with such high resolution, so this point is critical.

During my two weeks with the system just about any image shot handheld with a shutter speed less than 4x the focal length would result in motion blur when pixel peeping at 100%. This forced me to use higher ISO speeds with a wider aperture than I would have preferred when hand holding. Fortunately the ISO performance on the IQ4 150MP is quite good, but more on this later. Naturally if you’re shooting with strobe at any sort of reasonable flash duration this is a non issue.

Live View

Using the camera in the field was nothing short of a pleasure, particularly thanks to the improved live view on the IQ4. Though almost useless handheld, the live view on the digital back while mounted to a tripod does wonders for composition and critical focusing. I also appreciated the ability to pinch to zoom as well as double tapping to move in and out of 100% view; an improvement over the IQ3 line’s double tap and scroll option. Another addition to the IQ4 line, swiping from the right while in Live View brings out real time focus peaking as well as a RAW clipping graph, telling you what channels are being clipped in the RAW data.

IQ4 150MP, SK 240mm LS BR, ƒ11, ISO400, 1/1250s

Focusing

Autofocus was surprisingly accurate given its single center point. The XF tended to hunt a bit when presented with a very low contrast scene, but usually focused right where I wanted it to which is critical for such a high resolution file. Spot focusing is certainly the preferred method for best accuracy. The XF’s Honeybee Autofocus System is yet another feature which can (and has) been improved by firmware.

Though I didn’t use it in my testing, there is an Autofocus Recompose option (AFr) on the XF which will detect movements made by the user after autofocusing and employ the autofocus motor to readjust the plane of focus accordingly. While shooting landscapes I vastly preferred setting the camera on a tripod and manually focusing using the system's excellent live view and focus peaking at 100%, but used autofocus occasionally when handheld and particularly when photographing wildlife. I have to underscore the benefit of the focus peaking tool in live view which made a significant difference in locating the plane of focus, and could even be used to help guesstimate the approximate location of the hyperfocal distance.

Storage and Connectivity

Studio photographers that tether regularly: rejoice, for the IQ4 line of digital backs finally offers the long requested ability to save images to both a card and to a hard drive simultaneously while tethered to Capture One Pro. Storage options for the IQ4 line include XQD and SD cards, while connectivity options include USB-C, Ethernet (PoE), and WiFi. While tethered to Capture One it is possible to control nearly every facet of the camera from the computer, as well as charge both of its batteries (one in the XF body, and the other in the digital back).

Touch Screen

The XF body’s top touch screen is easy to use, efficient, customizable, can quickly be navigated through, and resulted in very few if any errant touches. The IQ4’s touch screen on the other hand does have room for improvement. While certainly not difficult to use, there is a bit of a learning curve, and while navigating through the deeper menus on the IQ4 I found myself accidentally hitting the home button several times and having to re-enter the menu. Though I did learn to mitigate this by a large margin, it was annoying at times. The errant touches on the IQ4’s beautiful retina style screen could admittedly be caused by habits unique to myself, like tending to scroll near the top of the screen instead of the middle.

Battery Life

Two batteries are required for this camera system: one in the digital back and one in the XF body. Fortunately the batteries are interchangeable and can use the same charger. They are also hot-swappable considering the XF and IQ4 will share power between the digital back and body, though both batteries are required for operation. 

The XF's battery will almost always last the longest since there's less going on in the body itself. The battery life of the digital back will vary dramatically depending on use. If you're frequently using live view along with the Electronic Shutter, wireless connectivity, and actively shooting for extended periods you can expect the digital back to deplete its charge in a couple hours. On the other hand, I've gone almost all day on one battery in the IQ4 shooting intermittently and using live view only when and for as long as necessary. Regardless of your shooting style, you should definitely pack extra batteries. 

Features

As you might expect, the XF IQ4 150MP is packed with unique features. This is again a testament to Phase One’s habit of releasing highly capable hardware, and developing unique tools over time that take advantage of that hardware. These new updates often result in entirely new tools that sometimes have huge implications, like the new Automated Frame Averaging tool. I will list some of the more important tools below, but will spend a bit more time on the tools I found the most useful during my time with the system.

Automated Frame Averaging

I was fortunate to receive my review copy of the XF IQ4 150MP system just after the Automated Frame Averaging function was delivered via firmware update. I’m extremely optimistic about the implications this tool could have for natural and available light photographers.

The idea here is to set a normal exposure for your scene, access the Automated Frame Averaging tool, and then tell the tool how long you would like to “expose” for. Based on the amount of time you set (from just seconds up to 30 minutes), and the length of your selected shutter speed, the IQ4 will employ its built in electronic shutter (ES) to capture tens, hundreds, or many thousands of images over that time. These images are then averaged together in camera, resulting in a normal RAW file able to be imported into Capture One just like every other image. No additional work necessary. The only difference, aside from visuals, is a mention in the metadata that a file has been frame averaged.

XF IQ4 150MP, SK 240mm LS BR, 1/25s, ƒ/11, ISO 50. Frame Averaged 30s

This averaging has the effect of mimicking long exposures while protecting highlights since the averaging effect is not additive, essentially allowing you to leave your ND filters at home while shooting “long exposures” at 1/125s. The averaging also has the effect of potentially creating an image with basically zero noise and boosting image quality even further. Noise is random, so by averaging the noise from hundreds of images of the same scene, the Automated Frame Averaging tool boosts signal and reduces noise, much like astrophotography software. Thus, you could theoretically shoot a scene at ISO6400 that is completely noise free. Not bad.

 

Left: Single Image, ISO 25,600, 1/4000, Luminance Noise Reduction "0" 100% crop     

  Right: Frame Averaged for 45 seconds at ISO 25,600, 1/4000, Luminance Noise Reduction "0"  100% crop

If your shutter speed is faster than the sensor’s readout, there will be gaps between images, as indicated in the tool by displaying the word “gap”. If you're shooting in gap mode and photographing continuously moving objects over a short time you'll see ghosting. If the shutter speed is longer than the sensor’s readout time there will be no gaps between images and the tool will display the word “continuous”, which is preferred for water or other fast moving objects you’d like to smooth out.

Even though it’s using frames captured at much faster shutter speeds it’s necessary to keep the camera perfectly still on a tripod. It’s also important to ensure that there isn’t any purple fringing in any hot highlights, as the purple fringing will also be averaged making it difficult or impossible to remove using traditional methods. Lastly, I noticed some banding in shadow areas when reducing Capture One’s default Luminance Noise Reduction in Frame Averaged Images shot at ISO 25,600. Admittedly, the practicality of using Automated Frame Averaging with the camera’s highest possible ISO is nearly nonexistent except for testing the system’s capability. Given the potential for this tool I consider these issues minor and am eager to employ the frame averaging technique in the future.

Capture One Inside

Capture One Inside uses the editing core of Phase One’s Capture One software to help improve image review, live view performance, RAW processing, and more. Prior to the most recent firmware update, the IQ4 had the ability to process RAW files in camera as well as a few other tricks. Indeed the live view is much improved, but it wasn’t anything groundbreaking. That’s changed with the new firmware package which includes the ability to import a user defined style made in Capture One into the IQ4 and use that style to preview images in camera. Have a style you use all the time, or maybe you’ve created a specific “look” for a shoot with an art director? Import that into the IQ4 and see what that image will look like in Capture One immediately after capture. Nothing is written over the RAW file, so once the image is imported it can still be brought back to zero.

Image with a Capture One style. The IQ4 has the ability to display this style on the digital back after capture, allowing the photographer to see a preview much closer to the final product. 

I found this function useful during my testing to preview a specific black and white conversion I created. I appreciated getting to see subtle color adjustments I had carefully crafted in Capture One right after I took an image. Instead of the flat color of the default preview I was met with a dynamic, contrasty, drastically more interesting rendition of that image that would be far closer to the finished product. I have to admit that it changed my experience of photographing in the field for the better, though I do wish it was possible to switch between previews for the same image instead of locking the preview into the image once it’s been captured. Again, it can always be brought back to defaults once imported into Capture One.

Focus Stacking

While not exactly unique to the XF camera body, focus stacking is something the XF does extremely well. Indeed, as we’ll discuss in the image quality section, with the increase in resolution to such a high degree focus stacking has become a necessity for some scenes that wouldn’t typically require it. Fortunately the XF has an easy to use automated method for creating focus stacked images, and in Capture One a streamlined method for combining them. Using the top touch screen on the XF body, you can swipe until you’ve found the focus stacking tool. You’ll engage autofocus on the lens, and then use the front and rear scroll wheels on the XF to step the autofocus motor to select and save your closest and furthest focusing distance using live view to be precise. If it’s a lens that is programed for this function like the SK120mm Macro LS BR, the XF will recommend a number of images for the stack based on the parameters you’ve chosen, including the aperture you’ve selected.

After engaging the tool, the XF will automatically capture the recommended or user defined number of images at even steps throughout the focus range you’ve chosen. So far, this is fairly typical for bodies able to focus stack images. The benefit comes with metadata. Each image in the focus stacked sequence has a metadata tag indicating to Capture One that it is part of a focus stacked sequence. Once you’ve imported the images into Capture One you’re able to select images by the image’s sequence ID. Then via a plugin, those images can be imported into Helicon Focus for a perfectly stacked image. I employed this tool several times during my two weeks with the system, sometimes as a safety net and other times as a predetermined method for composing.

Vibration Delay, Seismograph, and Vibration Analysis

It’s easy to set up most cameras to use a 3 second or so timer while on a tripod to capture an image after vibrations from handling the camera yourself have subsided. The XF goes a step further and uses built in sensors to set up a Vibration Delay option. This Vibration Delay actually detects ambient vibrations via built in sensors and will wait to cake a capture until those vibrations have adequately subsided. The benefit here is that if you’re shooting in windy or other intermittent conditions you can set the camera to automatically make an image when there’s a short break in vibration. Simply set a window of time for the tool to work and step away. You can even set the camera to wait indefinitely to make a capture until conditions allow.

IQ4 150MP, SK 240mm LS BR, 100% Crop

Left: Single Image, 1/10s, f/11, ISO50 with Vibration Delay, Focal Plane Shutter

Right: Frame Averaged for 30s at 1/10s with Vibration Delay, Electronic Shutter

Using those same sensors, the XF can display a seismograph showing you in real time what vibrations are acting on the system which could prevent a perfectly clean image. The system will even present a graph in the Vibration Analysis tool describing ambient vibrations just before, during, and just after capture. This could be invaluable for those in specialty situations dealing with long exposures. That way when you tell your client to stop walking like a Clydesdale on the second story wood floor, you can actually show them at what point during the exposure they caused the blurred image.

Aside from the Vibration Delay tool which is quite handy, the usefulness of the Seismograph and Vibration Analysis tools are debatable. The Seismograph is a fun party trick, and I suppose the Vibration Analysis tool could be useful in some special situations. I’m sure someone, somewhere could put them to work on a regular basis, but for most users the benefits of these two tools will be few and far between.

Time Lapse

You won’t find any video capabilities in the IQ4 150 since Phase One has dedicated it and the XF to being the best still capture devices they can be without diluting their menu and functionality with below modest video functions. I actually appreciate this choice, and would rather see Phase One continue to be pioneers in still capture rather than moving time and resources towards the video world. Fortunately the two mediums join beautifully when it comes to time lapses, something both the the XF and IQ4 line of digital backs are capable of together or separately. Imagine a 14k video file created from full frame medium format RAW files and all the flexibility those RAW files in Capture One afford...

Other notable features include:

    •    Flash Trim
    •    Flash Analysis
    •    Hyperfocal Distance Tool
    •    Built In Profoto Air Remote
    •    Removable Prism Finder (can be exchanged with waist level) 
    •    Leaf Shutter lenses capable of syncing with strobes at up to 1/1600s (think overpowering ambient daylight with flash)
    •    Electronic Shutter of the IQ4 150MP. The digital back is basically a camera all on its own, and is the best candidate for a technical camera in the history of medium format. Phase One has taken full advantage of these features by releasing the XT. 

Image Quality

Yes, I’ve saved the best for last. Image quality is where Phase One’s bread is buttered. As you would hope with such a high resolution camera, the image quality is indeed the stuff of legend. I don’t intend to be hyperbolic, but it’s difficult to express just how impressive the images that come out of this system can be. This is the point where I have to talk about judging quality because web resolution files don’t even begin to do this camera justice. 

Sure, viewing a crop at 100% online is a helpful way to judge certain aspects of the file, but the depth these images have can only be appreciated when viewed at full size or when printed large. Put simply, if you can view the entire image without turning your head or adjusting the view on your screen, you’re missing out. This is because the level of detail found in a well- captured image from this system is beyond a fitted view. In my experience with even the 100 megapixel IQ3 100MP I’ve discovered details and enjoyed subtleties in my photographs that I’ve never seen before, like a grazing elk in the far distance of a landscape. It’s even changed the way I shoot since I know that pointing this camera at a given scene will reveal features that I may not even be aware of while I’m in the field. It’s like the most satisfying, creative, and expensive game of Where’s Waldo you’ve ever played.

XF IQ4 150MP, SK 240mm LS BR, 1/1250/s, ƒ/11, ISO 400

100% crop

Sensor Specs

The 151 megapixel 53.4x40mm Back Side Illuminated CMOS sensor with a pixel pitch of 3.76μ nestled in the IQ4 150mp spits out 16bit files with 15 stops of dynamic range that weigh in around 240mb/image when shooting with the back’s highest quality file type, the IIQ 16bit Extended. All file types are compressed in a completely lossless compression except for the 14bit Smart which Phase One says is technically lossy, but features a highly efficient compression. Images are 14204px by 10652px, meaning that at 300 DPI you can expect a native print size of 47.35x35.51 inches. Huge.

XF IQ4 150MP, SK 240mm LS BR, 1/13s, ƒ/11, ISO 50

The files exhibit gymnast like flexibility and can be manipulated to an extremely high degree for both highlight and shadow recovery. Also on the table is a maximum 60 minute exposure time. The IQ4 150MP additionally features a throwback from Phase One’s CCD days: an IIQ 14bit Sensor + option which reduces the resolution by 75% and effectively produces a 37.7 megapixel file. Phase One says that this goes beyond traditional pixel binning and is actually handled on the sensor.

Sit back for a moment and appreciate the fact that in today’s terms a “reduced file size” is 37.7 megapixels. 

Sharpness

The Blue Ring Schneider Kreuznach lenses designed for Phase One’s XF camera system are excellent, though heavy, and handle their mammoth task quite well. I requested the SK 35mm LS BR, SK 80mm LS BR, and the SK 240mm LS BR lenses for my review and found each of them to hold up solidly to the demanding sensor. I shot mostly with the 240mm, as I’ve recently found a new appreciation for longer focal lengths, and when paired with such a high resolution sensor the combination is a recipe for revealing hidden details, though certainly difficult to hand hold due to its weight and tight focal length. The 35mm and 80mm lenses were also exceptionally sharp, but I want to mention specifically the quality of the 35mm and the sharpness it was able to retain in the corners. At 35mm, a 22mm equivalent, corner and center sharpness is exceptional at ƒ/8 and ƒ/11, with diffraction moving in at ƒ/16.

Phase One IQ4 150MP, SK 35mm LS BR, 1/6s, ƒ/11, ISO 50

 Extreme Bottom Right Corner, 100%, Default Sharpening applied in Capture One

Again, due to the back’s extremely high resolution, care must be taken when critical sharpness is of absolutely importance. You may be surprised at how little depth of field you have to work with when shooting at ƒ/11, and how little movement is needed to have an effect on the image. I found that, particularly when using the 240mm lens, employing the IQ4’s electronic shutter with a vibration delay on a tripod was the only option for utmost clarity. Becoming familiar with the XF’s Focus Stacking tool is definitely recommended considering the reduced amount of usable depth of field due to the high resolution sensor. What might have passed as in focus with a 50 megapixel capture wouldn’t come close to being considered in focus at 150 megapixels, particularly for longer lenses. 

ISO Performance

Being unable to use an image shot at ISO 200 because of excessive noise in a medium format capture seems like a tiny dot in the rear view mirror. The IQ4 150MP's base ISO is 50 with a high point of 25,600. At low ISO the IQ4 handled beautifully. It continued to do so up to ISO 800, beyond which you begin to run into increasing loss of detail due to noise suppression. I found the files easily usable at ISO1600 for my own use, though I prefer to reduce luminance noise reduction to taste so that what noise there is exhibits itself in a way that is similar to film grain and isn't mushed due to Capture One’s noise reduction.

XF IQ4 150MP, SK 80mm LS BR, 1/320, ƒ/8, ISO 800, Handheld

100% Crop, Default Noise Reduction Applied in Capture One 

Sensitivities beyond this are not outside of consideration, however their usability will have to be judged subjectively based on intended output, though 25,600 will likely be a non starter for most uses. As mentioned above, frame averaging can help reduce the noise levels of high ISO files, though you’re not likely to shoot at high ISO very often if you’re also able to keep the camera on a tripod for seconds or minutes at a time. Still, the option is there. And if you're able to output a noiseless file, why not?

Summary

What I Liked

• Image quality

• Integration with Capture One

• Unique features like Automated Frame Averaging 

• Variety of vibration reduction tools

• Raw clipping graph

• Focus peaking

• Huge potential for printing

• A slower pace 

• Third scroll wheel for ISO

• More responsive touch screen

What I Didn't Like

• Size and weight (heavy) 

• Extra care required for absolute best image quality due to its high resolution

• Slow to power up

• Battery life of digital back

• Menu system's learning curve 

• High cost

Conclusion

The XF IQ4 150MP stands alone as a leader in resolution and image quality, as a paragon of dedication to future development in the form of unique new tools like frame averaging via firmware updates, and as a system on the cutting edge of what it means to be a still camera. Even so, it is far from perfect. Measured by its ability to be a jack of all trades it falls hard and flat. Its lack of speed, heavy weight, high cost, and its need for care and attention to take full advantage of what it is able to offer make it not for the average photographer. But for those that understand its needs and are willing to take the time and thought to use it as intended, the results are in a league of their own. Now with the release of the XT, the capability of the IQ4 line of digital backs has been increased yet again. I, for one, can’t wait to see how Phase One continues to develop this system via firmware. What will this system be capable of next?