CKSandberg Photography fine-art photography and photo education

Further Adventures in Medium Format…

Fujifilm GFX 100S

As faithful readers of these articles know, I moved from shooting in (digital) 35mm format to (digital) medium format in 2012. I started with a 40 megapixel Pentax 645D and moved in 2015 to a 52 megapixel Pentax 645.

I enjoyed shooting with both those DSLRs and they were my go-to cameras for the last nine years. The increased quality of the images from those cameras convinced me not to ever go back to the smaller 35mm format. But, much as I appreciated their overall performance (of the 645Z in particular), I became less and less excited about taking them out into the field due to their weight and bulk.

Here’s what I mean: the 645Z by itself weighs 3.42 pounds. But you need a lens. A short telephoto lens, such as the HD Pentax-DA645 28-45mm F4.5ED AW SR, weighs in 3.24 pounds. The camera + lens package comes to 6.66, and that just seems to get heavier and heavier each mile on the trail!

So when higher-end mirrorless cameras began to emerge, I was ready for a change. Remember that the “R” in SLR/DSLR stands for “reflex”: the mirror that permits the photographer to view through the lens and see exactly what will be captured, and then flips out of the light path when the shutter is pressed so light can reach the film/image receptor and the image. A mirrorless camera, by definition, lacks that mirror and its accompanying complexity.

A quick illustration is below: the left camera body - an SLR - needs to have room for the mirror (in blue) to swing out of the way when the shutter is pressed so that

light can fall on the film or imaging sensor. The right camera body - mirrorless - can be significantly shallower because there is no swinging mirror to accommodate. There is also an overall reduction in the complex parts of a traditional SLR, which can further shrink the necessary volume of the camera. (illustration by Shigeru23, CC BY-SA 3.0 <>, via Wikimedia Commons.)