I recently read an article on the Steve Huff Photo blog titled Quick Comparison: Fuji X-E2, Sony A7 and Olympus E-M1. He ran a comparison between a 4/3 camera (the Olympus), an APSC sensor camera (the X-E2) and a full frame camera (the Sony A7). I found the article very informative and his examples very useful. However I did have some problem with the impression his article’s conclusion leaves. “Any of these would be superb for almost anyone wanting high quality photos. For me it would come down to usability, speed, build, etc.” Although I do agree with him that usability, speed and build does have an impact on what you shoot and the quality of the images, given that these things vary for each camera. I think implying these cameras are the same is not the best message to send people.
Every Cameras is Different
When you look at the whole package the sensor, the processor, the algorithms, the lenses, the ease of use, the ergonomics and the organization of the settings, each camera is not only capable of producing a different quality of image, it is likely to also lead you in different directions as you shoot. It reminds me of a scene in the Neil Young movie “Heart of Gold.” Neil was talking about a guitar once owned by Hank Williams. He sat down and played around with the guitar for a while. He then looked up and said “yep I think this guitar has at least a couple of songs in it,” or something to that end. In other-words any instrument whether it be a guitar or a camera, when you are using it, can influence not only what you create but the quality of your art.
I have been shooting a new series with a new Sigma 20mm 1.8 lens on a D800e and I am really liking the results, which are surprising me. The images have a different look and feel to say nothing of the distortion of the lens and intimacy with the subject matter it creates. It brings out something in me that my 24-70 just could not do, including a difference in the colours in the RAW files. I noticed a similar thing when I rented the Nikon 105mm Macro, it had a very different quality to the image and of course caused me to shoot in a very different manner. This difference does not just exist when I change lenses. When I pick up my Fujifilm X-E1, with its electronic view finder (EVF) and the range finder form factor, I tend to frame and shoot differently from the Nikon, and the colours and dynamic range of the images have a different quality from the Nikon.
So my personal experience with different cameras and lenses reminds me of what happens when I shift brushes while I am in the process of creating a watercolour, or choosing a different etching instrument when creating a plate. The different brush or etching instrument makes different marks and in working iwth the difference your artwork shifts and evolves. So with different cameras or lenses an artist can find themselves in new territory and open up new possibilities for exploration. An experience photographer will choose a different camera and lens depending on what it is they want to capture. So in someways choosing a camera and a lens, to return to the music metaphor, is choosing a certain guitar and amplification systems in order to get a certain sound.
The Gestalt of the camera is what is most important, the whole is other than the sum of the parts. How the whole package works together in your hand while in the field is key. Does it stay in your bag because it is to hard or to big to retrieve quickly. Is the size inappropriate or appropriate for the environment you are in. Are you shooting film or digital images. Do the settings allow you to rapidly adjust to changing light situations. Is the focusing accurate and easily adapted to different situations. Can you operate the basic settings quickly without having to stop your flow and descend into the settings menu, (like watercolour brushes if you have to stop and recharge your brush in the middle of loading the paper with a pigment, it can derail what you are doing). Does your knowledge what RAW images will be produced influence your approach. So all these factors influence how you shoot with your camera and therefore the quality of your images in the end.
The other half of the discussion of why all cameras and lens combinations are different lies in technical details, so if this is not your cup of tea you need read no further.
Technical Differences that Effect Quality
There are a lot of technical differences that make cameras very different from each other and therefore have an impact on the resulting images. Is the camera an APSC, full frame, medium format or large format. Is it a DSLR, rangefinder or mirrorless camera. Is the sensor in the camera a CCD or CMOS. How old is the sensor (technologically) and how does it work with the processor in the camera. Let us look at some basic issues resolution (sharpness of the image), file size, low pass filters, how big you print, and picture quality.
Lets take a look at resolution. We all know megapixels does necessarily mean good resolution, it is really the combination between sensor size and megapixels that gives you good resolution. This relationship is measure in pixel pitch (µm). To put it simply each sensor has tiny microscopic buckets covering its surface. Each bucket collects a number of light rays, then uses the collected light rays to interpret what it saw, and produces an image from this interpretation. The more light rays a bucket can collect the more accurate the interpretation. So usually the larger the sensor the larger the buckets and therefore the more accurate the interpretation and the more accurate the resolution. So as the sensor gets larger the pixel pitch increases, and by looking up the pixel pitch of a camera you can tell the quality of the resolution.
Resolution of the Three Cameras
Lets look at the three cameras from this perspective the OMD EM1 is a 16megapixel sensor with a pixel pitch of 3.7µm, the Fujifilm X-E2 is a 16 megapixel camera with a pixel pitch of 4.82µm and the Sony A7 is a 24megapixel camera with a pixel pitch of 5.9µm. So you can clearly see that as the sensor size gets larger more light rays are being measured by the pixel buckets on the sensor surface. There is a direct relationship between the increase in pixel pitch and the increase in dynamic range, accuracy of colour and accuracy of resolution. (Keep in mind as technology improves the same size sensor has been able to create more efficient pixel buckets, but this perhaps is getting too technical).
File Size and Resloution
In addition to the accuracy of the pixels there is also size of the files expressed roughly in megapixels. However to be more accurate the Olympus’ camera files are 4640 pixels by 3472, the Fujifilm camera’s files are 4896 pixels by 3264 but the Sony camera’s files are 6024 pixels by 4042. So although the megapixels in both the Olympus and Fujifilm cameras are similar their pixel pitch is considerably different, this is due to the larger APSC sensor in the Fujifilm camera, compared to the much smaller 4/3 sensor in the Olympus camera. To get an idea of the size difference look at the diagram below, the Olympus sensor is represented by the green, the Fujifilm by the blue and the Sony by the purple.
Printing and Resolution
From a printing standpoint and especially since recently printing three 50” photographs. I could definitely see at that size the difference between my old D700 full frame 12 megapixel camera and a D800e full frame 36megapixel camera. I have also printed from a Panasonic 4/3 and a Fujifilm X-E1 usually at least 13″ by 19.” Again I can see that the print quality from the Panasonic is not as good as the Fujifilm camera, and the Fujifilm not as good as the D800E. So clearly from this stand point, if you are printing large the larger sensor provides much better print quality.
How Big You Print Determines How Much Resolution you Need
In the 8.5″ by 11” world of printing, which is often what most people print, I suspect that a 4/3 camera would have enough detailed. At this size I think the author of the article is probably right anyone of the three cameras would do a good job in terms of resolution. So it seems that as sensors and processors improve in quality, and therefore resolution, dynamic range and exposure accuracy improves, one can rely on more compact mirrorless interchangeable lens cameras to create good quality small prints. When it comes to television I suspect even an iPhones might do the trick in a pinch, as the resolution of full high definition television is 1920 pixels by 1080 or 2.1 megapixels.
Low Pass Filters and Picture Quality
The article compares a 24 megapixel Sony camera with a low pass filter and a Fujifilm 16 megapixel camera without a low pass filter combined with a hybrid sensor. To my eye the resolution gain between these two cameras is not as significant as it should be. Due likely to the Sony camera using a traditional Bayer filter with a low pass filter. What does a low pass filter do? Put simply it takes the native resolution of the sensor (or sharpness of the image) and puts it slightly out of focus, in order to prevent moire. Keep in mind the Olympus OMD EM1 also has no low pass filter. It has been suggested that dropping this filter gives a camera a 10% bump in resolution, however I have never been able to confirm this figure. I now own two cameras without a low pass filter and never had a moire problem. I find it interesting that medium format cameras have never had this filter, so I am not sure that they are really necessary. So whether there is a low pass filter in the camera or not this has an impact on image quality.
Camera Colour Gamut and Quality
The Steve Huff article talks about how differently the Fujifilm X-E2 handles highlights. So clearly he sees that the Fujifilm has a different quality from the other two cameras. I know from having owned a number of different brands of digital cameras that they all handle the image exposure and processing in a different manner. The Fujifilm X-E1 I own seems to have a beautiful colour range in its RAW files quite different from the RAW files coming from my Nikon D800e. In testing the two cameras in low light I also discovered quite a difference. The Fuji camera was able to recover a better colour gamut from the shadows but the Nikon recovered a better dynamic range. So clearly the algorithms or programming that ultimately creates the images in these two cameras is not the same. If you have the opportunity to look at RAW images coming out of Leica cameras, you will see yet again a very different quality of image from that camera. This of course is likely due to the extremely high quality of the lenses but also a very different sensor and processor.