Introduction: Scanning with a Medium Format Camera

Scanning film with medium format digital cameras, such as the Fujifilm GFX system, or Hasselblad X or H systems is becoming more common as the systems are becoming both more powerful, user friendly and affordable. However, scanning with these larger-than-normal sensors is not as straight forward as other systems, and can be very expensive if done in the most obvious way. This series of articles will focus on the decisions you need to make when scanning with a digital medium format camera.

In this specific article, we will focus on why you would want to use a medium format in the first place.

© William Sheepskin All photos were taken using a Mamiya RB67 and a 90mm f/3.8 lens on Portra 400 film. They were digitised with the VALOI Professional Scanning Kit, coupled with the FUJI GFX 100S and FUJIFILM GF 120mm f/4 Macro R LM OIS WR Lens. Negative conversions were manually performed in Photoshop.

Why medium format

If you are reading this, you are either curious or already convinced that medium format has an advantage for scanning film. While the advantages are incremental and the benefits are hard to see for most casual users, there are good reasons to use medium format.

While medium format is often criticised for being slow, both in terms of frames per second and for auto focus, when compared to high-end full-frame cameras. That disadvantage is being washed out slowly, with cameras like the Fujifilm GFX 100 II or the Hasselblad X2D. However, these disadvantages are essentially not noticed at all in a film scanning process, so older generation cameras with great sensors can be used.

Instead, film scanning allows you to use these cameras to their full potential, at low ISOs, no concern with viewfinder blackout, few pictures per minute, no need for (fast) auto focus but with the goal of perfect reproduction.

Medium format has three main advantages in terms of image quality.

Resolution

Firstly, they are higher resolution than all other format cameras. They tend to be at least 50MP, and 100MP is becoming more common. As of July 2024, Phase One even has a 150MP medium format back, the IQ4 - and the highest resolving, commercially available, sensor on the market currently, the Monochrome version of the IQ4 150MP Achromatic. There are also rumours of higher resolution sensors, into the 200MP-range. The highest resolution full-frame camera at the time of writing (May 2024) is currently the Sony A7R V at 61MP. This extra resolution compared to a full-frame sensor allows you to resolve larger pieces of film at their maximum resolution, without adding time, complexity and room for error with stitching images together or using multi-shot digital processing. While the extra resolution is not that useful for 35mm, a fine-grained medium format film can definitely display the difference, if nothing else to display the grain in more detail and improve the sharpening ability of the file without making the grain overly obvious.

Sensor size and area

Okay, you say, but I have 100MP on my phone so that’s not impressive. While a phone might have a very high-resolution sensor, the size of each individual pixel is tiny, and this brings us to the next point: The pixel size, or photo site size, is larger for the same resolution on medium format cameras. If you take a 50MP medium format and full-frame sensor, the space that each individual pixel covers is larger on the medium format sensor. This has two main advantages: Optical resolution and noise performance.

Noise is relatively simple: Due to the larger sizes of each photo sensitive pixel, the pixel can capture more light. Think of it like a funnel - the larger the funnel opening, the more rain it will catch. This increased light sensitivity helps drown out the noise that is naturally occurring in the circuit. We say that it improves the signal-to-noise ratio, essentially leading to better ability to capture shadow details. This in turn means exposure latitude is improved, since the noise does not drown out that faint information found in the shadows quite as easily. Other factors play into this as manufacturers have found new ways of improving the dynamic range of the sensor, but as a rule of thumb, larger pixels means better exposure latitude.

Optical resolution is a challenge for high-end scanning, and for all digital photography at this point. Back in the film days, if you wanted more resolution you would use a larger piece of film and a larger lens that covered that format. These days, making larger sensors is extremely challenging, partly due to manufacturing defects causing higher failure rates with larger sensors, and therefore expensive. The largest sensors commercially available are about as big as 6x4.5 film, considered a relatively small format in the film world, but huge an extremely expensive on digital cameras. The super-resolving relatively small sensors we have today are pushing beyond what we can resolve with optics being produced - we say the system has optically limited resolution instead of digitally limited resolution.

Put simply, high resolution, smaller sensors are pushing the optical resolving power, therefore increasing the size of the sensor while increasing the resolution can help resolve some of those optical constraints resulting in overall higher system resolution than on a 50MP medium format sensor than on a 50MP full-frame sensor. For example, the 100MP Fujifilm GFX 100S has a pixel size of 3.76 micrometers, only slightly smaller than the 47.3PMP Panasonic S1R (full-frame) with a pixel size of 4.27 micrometers. As you can see, the number of pixels are double while the pixel size is almost the same, at about 88% of the size. This can help the overall resolution of the system, if the lens is right - we will discuss that in the part of this article series on lenses.

Hopefully you have an understanding of why we might want to use a medium format camera for scanning film. Always keep in mind that this article series is geared at those pushing the limits of scanning, and are not a requirement for good scanning. Most of our other content focuses on affordable scanning, and you can find that on our website.

In the next section we will focus on how to choose a medium format, give an overview of the systems and look at our top recommendation for scanning right now.