In the morning heat, I am walking towards the car; the tiny lizards scuttle out of my way. Overhead a heron is returning from its morning breakfast, and I am heading for Swan Lake. I think I can experiment a little with an APSC camera with a 35mm equivalent lens on an APSC sensor with a resolution of 24mp and a 50mm equivalent lens on a medium format camera with a resolution of 50mp. A very uneven comparison, but I am interested to see from the same spot what might come from both cameras, both with different fields of view and a different resolution. As I begin my walk, I set both cameras just above their base ISOs, and the shutter speeds were slightly different, but I leave my aperture to float. I attempt to set the focus point on the same element in the frame as best I can. When rendering the RAW images, I process one of the images and then copy these settings to the other. I know one camera has a Bayer filter and the other an X-Tran filter, so trying to equalize the process may be uneven as well.
A few minutes in, I came across this scene and made my first photograph.
The closeup below demonstrates the difference in resolution; on the left, I set the image to 100% in Lightroom and to match the two images, I set the right-hand image to 190%. Right away, I notice two things the colour from the Bayer filter appears thinner and less intense, but this could they need slightly different processing. The second more obvious difference is the APSC image at this magnification is already showing artifacts, unlike the Medium Format Image.
Rounding the East side of the lake path emerges from under the canopy, and I see an opportunity for a photograph in a much higher dynamic range. The image below is the unprocessed RAW images. The exposure is quite a bit different because of the field of view.
Here are the two images again after they have been processed. I am noticing a difference in the exposure between the two images in this high dynamic range image. The APSC camera has completely lost the blues in the sky; however, the Medium Format Camera has retained most of the sky. There also appears to be a better range of shadows in the Medium Format image.
Here are the two images again at 100 percent comparing the highlights to the shadows. Neither camera is doing a great job of the sky, but both seem much better with the shadows. This, of course, is expected as no attempt was made here to protect the highlights in either image.
The next image is at 200%; here, I can clearly see the difference in how the two cameras have recorded the shadows. The APSC camera has lost the richness in the shadows, and the artifacts are also visible.
Although many more images were taken, the image below is a spring I came across near the end of my walk; two kilometres walk around Swan Lake. Here the light is more balanced so that both cameras will produce better image quality. In the two images below, I started by processing the APSC file first and then applying the same processing to the medium format image. In this light, the performance of both cameras is very similar in terms of the highlights and shadows.
The following are the two images at 300%; here, you can see both images are struggling with resolution.
The same comparisons with the APSC image enlarged to 570%, so the grass is the same size, gives a much better example of the difference between the two images. You can see the APSC image is struggling with the fine detail to a greater degree.
Keeping in mind this is a very loose comparison between the two cameras; clearly, the resolution is different, which would impact how large you might want to print and image. The other difference is the performance of the two cameras in a high dynamic range situation; here, there is a distinct advantage to the medium format camera. However, if the APSC camera was to increase its pixel depth by combining three exposers (one-stop under, one stopover and one with the correct exposure), this should handle the dynamic range in the same manner as the medium format camera.
Another factor that gives the medium format camera a better advantage is its pixel pitch compared to the APSC camera. The APSC camera’s pixel pitch is 3.93 microns, whereas the medium format camera’s pixel pitch is 5.31 microns. This means the pixels that measure the light are larger, and therefore the measurement should be more accurate.
Regarding 35mm versus 50mm, the walk had some areas with very confined areas and expansive others, so it was a good test of what lens I might personally prefer if restricted to one lens. The following are all the pairs of photographs.
Conclusions
Keeping in minded the comparison is very uneven and therefore not very specific, I can draw a few conclusions from the walk around the lake. I think I can come to some conclusions around lenses, resolution, dynamic range and ergonomics.
Lenses
Comparing lenses on cameras with different sensors is not the best way to compare the field of view even though the field of view is constant. Light gathering capacity is different, as is the resolution, so these are very distracting variables. The other problem is the difference in compression and distortion. For example, the medium format lens on the camera was a 63mm lens. This means it has the compression of a 63 mm lens, even though the field of view is equivalent to a 50mm lens. Furthermore, the APSC camera had a 23mm lens on it that is equivalent to a 35mm field of view, but it will have an 18mm lens distortion. All this makes it very difficult to concentrate on the field of view differences. So my conclusion here is more about my experience with comparing lenses on cameras with the same size sensors than this comparison.
Having said all that, it felt like the 35mm was more useful than the 50mm in getting a framing I liked. Looking at the images after they have been processed, I think this still holds. If I had to carry only one lens or consider a fixed lens camera, I think a 35mm lens would be the easiest to live with, which explains why most fixed lens cameras are either 35mm or 28mm. It has always been a versatile field of view to work with, especially in cramped spaces and on the street. I have also found it the best lens for doing large panoramas with a wide field of view.
I think the 50mm lens does provide a different look, and one could use a panoramic technique to overcome situations where the lens is not wide enough. Three or four handheld vertical photographs with a one-third overlap can be easily merged to create a 35mm field of view, provided there is not much movement in the image. I have found trying to recreate a 24mm field of view with this lens is far more complicated than using the 35mm lens, but it too can be done, but it is more complicated than merging three images.
Resolution
When I look at how quickly the resolution breaks down in the images that come from the APSC, a difference to be expected, but I am surprised at the degree of difference. Although this difference would only be an issue if you are printing large, by that, I mean larger than 11″ by 17,” but even then, you might not be able to see a difference. If the camera is only used for internet purposes or 8 by 10 prints, even an iPhone photograph will look great. After all, it is really a 1080p world we are in with our electronic devices, from phones to TV.
Dynamic Range
This is perhaps one of the key differences between the two cameras the ability to recover detail when there is a high dynamic range within the photograph you are framing. The medium format camera I would suggest can recover well over one stop of underexposure without degrading image quality. In contrast, the APSC camera struggles before you get to a one-stop difference. To deal with a high dynamic range situation on the APSC camera, you would quickly have to resort to exposure bracketing to get the same dynamic range as the medium format camera. Of course, this difference is extremely obvious as the light gathering capacity of a medium format camera is significantly greater.
Erogonomics
Here the advantage obviously goes to the APSC camera. It’s a small compact body compared to the medium format, so it is much easier to get out of the bag and much lighter. Lenses are much smaller as well, which adds to making them easier to field. The medium format camera is larger and often difficult to get out of the bag but should you want greater depth of field. You will wind up having to use a tripod when there is less light. Although this is an obvious point, this issue is often not considered when looking at what camera to buy. If you find the camera difficult to field, it will impact your photographic practice.
Depth of Field
These images may not be large enough to illustrate this difference. Again this difference is obvious to most photographers, and if it is not, it will become quickly apparent—the larger the sensor, the shallower the depth of field. So the upside of the medium format camera is the ability to highlight a subject by using a shallow depth of field. The downside is if you want everything in focus, you will need to get out your tripod more frequently.