Comparing the image quality of Pentax 67 medium format film camera and Canon 5D digital SLR
I wanted to see how these cameras compared so I set up a test with the following parameters:
Both cameras were on a sturdy tripod, and the images were shot using a cable release and mirror lock-up. The photo was taken from indoors looking out an open window, so wind was not an issue. Both images were shot with fixed focal length normal lenses set at f/8.
The Pentax 67 image was shot with Fuji Reala 100 negative film using a 105mm f/2.4 lens set at f/8. It was scanned on a Nikon 9000 film scanner using a glass holder. (I find no image quality degradation using the glass holder, and get better focusing from edge-to-edge.) The scanning resolution was 4000 dpi. I used Nikonscan scanning software, and had Digital GEM set to 3. Digital GEM reduces film grain, and I find that this setting has little noticeable effect on image sharpness. Digital ICE was turned on, which is an infrared dust detector, and works by essentially cloning out dust spots. I don't find that this affects image quality in any noticeable way.
The Canon 5D image was shot with a Canon 50mm f/1.8 II lens at f/8, and went through Camera Raw, with no sharpening or noise reduction.
In order to compare the same cropped section of each image, and have the size be equivalent when viewing at 100% on my monitor, I had to upsample the 5D image to match that of the Pentax. I used Photoshop's bicubic smoother. (I also tried bicubic and found no noticeable difference.) The resulting images are shown below. The first image shows an overall view, with a box showing the approximate crop that is shown in the next 2 images. Clearly the Pentax is the winner.
ADDENDUM: I have added a sharpened version of each image. The 5D image was first processed with DXO Optics Pro, and then sharpening was applied in Photoshop with Photokit Sharpener—creative sharpener—high pass 2. The Pentax image was also sharpened with Photokit using the same settings.
For those who would like to process the raw Canon 5D file themselves, feel free to email me and I'll send you the raw file. I may post the results.
ADDENDUM 2: I have added at the bottom a scan of the Pentax image using no Digital GEM in Nikonscan. It is also not sharpened. When compared to the third image below (Pentax 67), you can see that Digital GEM doesn't produce significant softening. (You will have to download them to see them next to each other)
ADDENDUM 3: Please note that no output sharpening has been done on any of the images below. By output sharpening, I mean sharpening for a particular use, like print or web (as in this case). For those images where sharpening is mentioned, it is a general sharpening, using Photokit Sharpener.
