Do we now have sufficient pixels? Phase One has launched its XF 100MP camera system and while you can purchase components individually (digital back, XF camera, lenses, finders), it really is a system that makes the 100-megapixels work. And the results are in a word, unparalleled.
I was entrusted with a pre-production IQ3 100MP digital back on my recent voyage to Antarctica, along with some tricked-up Capture One software and the requisite 100-megapixel sensor profiles. Externally, the back looks much like all the other IQ3s, except for the discrete '100MP' displayed in shiny letters, but the other passengers on the Polar Pioneer didn't give it a second look. As far as they were concerned, if at all, it was just 'another 80-megapixel camera'.
When you enlarge the image, you start to get a feeling for what a 100-megapixel file is all about.
However, unlike the CCD-sensor IQ180 which is my current medium format workhorse, the IQ3 100MP is a CMOS sensor. And unlike my IQ180, the IQ3 has many features and refinements that allow it to work more efficiently with the XF camera. That's why Phase One is calling their new toy the XF 100MP Camera System.
The following notes discuss my experiences with the XF 100MP in the field and assume that the reader is already familiar with the hallmark features of the Phase One medium format system: extensive dynamic range, 16-bit capture, no anti-aliasing filter over the sensor and shallower depth-of-field due to the physically larger image format. I also reviewed the XF camera in the issue before last (BP#81).
We've known Phase One had a 100+ megapixel camera in the works since it launched '100-megapixel ready' lenses in June 2015. And I think we also expected it to use a CMOS chip like the existing 50-megapixel back, rather than the older 60- and 80-megapixel CCD backs. There's a difference between CCD and CMOS capture. CCD seems to be that much sharper and clearer with less noise, providing more contrast and acutance in the image file. This is a rather unscientific description, but I felt I could discern this difference when using the IQ250 CMOS and the CCD IQ180 (apart from their differences in resolution). To be fair, both backs produce such remarkable quality, it was never a big issue. And hardly any cameras are made with CCDs anymore. The world has moved to CMOS.
However, when I opened my first 100-megapixel files on board the Polar Pioneer, it was hard to restrain an appreciative gasp. Whether a 100-megapixel CCD sensor would produce superior image quality seems to be a moot point, the CMOS sensor is so good.
I can probably confess at this stage that I had also played with an earlier pre-production back that had been gaffer-taped to an XF body. Drew Altdoerffer from Phase One in Copenhagen joined Christian Fletcher, Tony Hewitt, Antony Spencer and I on a photography workshop in Iceland. Courtesy of Drew, Christian and I were the first photographers outside Phase One to play with the 100MP sensor, but as with every new sensor release, there was an element of trial and error to get the most out of it. Some of the images I took were unbelievably good, others seemed to miss the mark in terms of absolute sharpness.
Looking back on my photos in Iceland, I now realise the importance of the Focus Trim adjustment on the Phase One XF body. Only very minor adjustments can produce incredibly significant differences in image quality. And at 100-megapixels, if you get your focus right, this new camera is the most potent image recording device commercially available for professional photographers.
A few weeks before my voyage, I received my XF body and promptly checked the focus for my four Schneider Kreuznach lenses with the IQ180 back. Two of the lenses were spot on, two required minor Focus Trim adjustments. However, I didn't have the time to test the lenses with the 100MP back as it arrived the day before I left. Would it make a difference?
On a relatively mild morning on Salisbury Plain, South Georgia, I put the XF 100MP to its first test with around 250,000 King Penguins. I wanted to photograph a three-quarter or full length penguin portrait with the penguin's eye tack sharp. Penguins have really interesting eye structures, so being able to zoom into the iris of the eye and see all that detail should make an interesting demonstration for what a 100-megapixel file can achieve.
Although penguins aren't the fastest birds on the planet, they have rapid head movements which can make critically focusing on their eyes challenging, so I spent some time courting a few promising subjects. The new autofocus system on the Phase One XF body really is quite remarkable, which is a strange thing to say, because surely all autofocus systems have a pretty straightforward role to play?
Simply speaking, autofocus systems rely on contrast to achieve focus and generally they focus on the closest object. In portraiture, we choose a single autofocus point to ensure the lens is focused on the eye and not the nose, but even this is problematic as eyebrows and eyelashes can grab the AF system's attention if the camera is inappropriately used. Focusing 'on the eye' sounds simple enough, but getting the iris and pupil razor sharp, even with the best autofocus systems, is not achieved without special effort.
This applies to DSLR and CSC cameras just as much as medium format, although at lower resolutions, you may not always perceive the differences in sharp focus. However, I was well aware of this when shooting the penguins, so I took plenty of shots with the XF 100MP as insurance. The result is that I can confirm that opening up a 100-megapixel raw file and zooming in to 100% magnification on a correctly focused image is a positively euphoric experience.
A wide-angle shot taken on Salisbury Plain with the Alpa TC, 23mm Rodenstock Digaron and the Phase One 100MP IQ3 back. A long exposure - 30 seconds from memory - and absolutely zero noise.
But was it critical focus? Or was temperature also playing a part in the process? At this stage, I hadn't adjusted the Focus Trim settings for the 100MP back, but I was about to for the 240mm Schneider lens.
I was shooting at Fortuna Bay the following morning from the deck of the ship. There was a strong wind blowing with a significant wind chill, but I could position myself out of the wind for most shots. And while the ship itself was relatively steady, it was not steady enough to use a tripod, so it was a matter of hand-holding the camera, resting it on a railing to reduce vertical camera shake.
In my experience, shooting with the 240mm hand-held was going to be a big ask, so I increased the sensor ISO to 400 and my shutter speed to around 1/2000 second. I also used the support bracket. I expected a few blurs as the ship shuddered from the wind, but I struggled to get anything that was remotely sharp. In fact, it looked like the lens wasn't correctly focusing.
Sunrise in November in South Georgia takes around two hours, so I had plenty of time to play. I opened up the XF's capture menu and adjusted the Focus Trim settings. The scale ranges from +/- 1000 and I was already at -225, so I took a series of shots at -500, -400, -300, -200 and -100. The -400 setting looked the best, so I did a second series at -450, -425, -400, -375 and -350. I settled on -375 and turned back to the amazing scene in front of me at Fortuna Bay. At 1/2000 second, the shots were razor sharp.
All the focus trimming could be done using the back's LCD screen as the differences were quite obvious, although I'm sure that tethering the back or using Capture Pilot would allow me to produce an even more precise setting.
To get the best out of a 100-megapixel sensor, you have to be able to focus your lens accurately and with the new Phase One XF camera, this is easily achievable. You have the tools at your fingertips to refine focus and after using the XF for a couple of weeks, I was constantly rewarded with super sharp results. It was almost like I had a new set of lenses the differences were so marked - which worries me a bit because it doesn't say much about my camera technique with the previous body!
Cloud formation above Drygalski Fjord, South Georgia.
So, the only thing I am wondering about is, why were the photos on the first shoot at Salisbury Plain sharp, but not the next day at Fortuna Bay? I believe it was because the temperature dropped significantly - and was colder for most of the remainder of the voyage as we travelled further south.
In speaking previously to Lau Norgaard, the technical project manager for the XF camera system, he explained that there could indeed be differences in focus positions with differences in temperature, especially with a 240mm lens which magnifies the image. And these differences would be easier to see with a 100-megapixel sensor.
While the autofocus system will work equally well at all temperatures, if you are applying an offset to the focus setting, the amount of this offset can change with temperature.
Explained Drew Altdoerffer in more detail, "Autofocus is measured at the lens's widest aperture. This is essential to exaggerate image contrast and ensure that what you’re pointed at is what the lens is focused on.
"When you trim the focus, you're telling the AF system to offset the point it thinks is correct by 'X' and, again, it does this for the widest aperture. When you apply focus trim for a specific aperture (like f11), your assessment of what is the 'correct focus point' may be swayed by the change in depth-of-field - there could be more than one point that appears to be in focus.
"With significant temperature changes, any trim is referencing a previous focus point that is potentially different.
"So, with no focus trim and shooting wide open, you would see the same results for autofocus time and time again, regardless of temperature. However, with a focus trim adjustment coupled with a temperature change, you may find the focus point needs further adjustment. As temperature decreases, the metal barrel distorts, the native focus point shifts slightly and the trim is therefore no longer valid. The autofocus is the same, but the variables the trim was based on are now different.
"Of course, none of this would ever be seen with 24MP sensor, but with 100MP, well, it’s impossible to ignore!"
So, two take-aways from this experience. First, if you need to adjust the Focus Trim on the XF camera, it's easy to do on location. Second, precise focusing with a 100-megapixel sensor is incredibly important, but when you get it right, the results are simply sensational.
So, what camera are you using? Elephant Seals on Livingston Island.
One of the biggest challenges with medium format CCD sensors is the ISO rating. To get the best out of my IQ180, I am on ISO 35. I might be able to push it to ISO 100, but much past that and noise becomes visible.
With a CMOS sensor, the test camera had a native ISO rating of 100, so I already had an extra stop and a bit. Since then, Phase One has announced the base ISO will be 50, but shooting from a moving ship and wanting to use the lens's optimum aperture (around f11), I found I needed ISO 200 and 400 from time to time.
And I wasn't disappointed. My first impressions are that there is little to no difference between ISO 100 and 400, but this does depend on there being sufficient light. As expected, if there isn't much light around (or you underexpose your shots), noise is more easily seen, no matter what your ISO setting.
From ISO 800 and up, noise is really well controlled although I think this is at the expense of image sharpness. The default settings in Capture One 9 with the pre-production profiles did seem to soften the image a little. Image sharpness and detail could be recovered in the software, but at the expense of more visible noise - but I'm simply stating the obvious as this is how noise reduction works.
Noise suppression will no doubt be refined by the software engineers, but you also have to be careful about what the noise on a 100-megapixel sensor really means. Will it be visible in the final reproduction? My experience is that when you're making a print, a lot of the noise you see at 100 percent magnification on the computer screen simply isn't noticeable in the final reproduction, especially if you're not making exhibition size prints.
During development, Phase One was very aware of how well the Nikon D800 worked in terms of noise and, given Sony makes the sensor chips for both companies, it feels the noise performance of the XF 100MP matches the D800, but is perhaps a whisker behind the newer D810. This is a difficult thing to compare, but if you were to re-size your 100-megapixel file down to 33-megapixels (similar in size to the 36-megapixle Nikon), then based on the files I have taken to date, I think the claim is very reasonable, even at ISO 3200!
Long exposures were easy! And if there is any noise at ISO 100, then I can't see it. The images are flawless all the way out to two minutes and I am sure you will be able to shoot longer than that.
Of course, long exposures have other challenges, especially with a 100-megapixel camera. Your camera body only has to move, sway or vibrate a fraction of a pixel width and you'll blur the image, so a steady tripod, well grounded, is essential.
I guess using the XF 100MP is all about quality control. The more you put into the control over your camera technique, the better your results will be. If you're unhappy with your results, downsize the file to 50- or 25-megapixels (view it at 50% or 25% on screen) and you'll probably find all your problems disappear!
On this trip, I rarely had the camera on solid ground, so keeping the camera perfectly still, having lots of light to work with and ideal shooting conditions were never going to happen. Yet despite the difficulties of the location, the Phase One XF 100MP produced image quality that I am very pleased with. Very, very pleased. I also used the IQ3 100MP back on my Alpa TC with a 23mm Rodenstock Digaron lens and again, very, very pleased.
In some ways, the XF 100MP is just an incremental improvement on an 80-megapixel back, but it's also a full 20-megapixels extra resolution and that increase is more than many professional cameras have in total.
For fine art photographers printing at 180 ppi, the 11,606 x 8,708 pixel image means you can produce a 65-inch wide print without up-sampling.
The CMOS back also makes Live View a dream to use (important for the Alpa and Phase One's A-series cameras) and the new system features mean the camera works just as well tethered in the studio as it does in the wilds of Antarctica. The XF 100MP was put through some very trying conditions (as some of the photos will show), but it didn’t falter (except for cold batteries).
So, in summary, professional photography has taken yet another step forward. The Phase One XF 100MP is the new standard by which all imaging will be compared. No, medium format is not for everyone, or for every job, but if you want the ultimate in image quality, this is the system you need.
You can check out more on the Phase One website - click here.