Tag Archives: crop

Mini Medium Format… or Not?

A photographer and friend asked me for my thoughts on mini medium format, or “miniMF,” camera systems. I told her the answer was complex and that I’d write it up at the blog. Here it is!

I have attempted to include several things in the article: a bit of background regarding formats, some objective facts (“the numbers”) about them and their relationships, pluses and minuses of various options, my own current subjective thoughts on what this means to me, and a few alternative perspectives.


The evolution of digital medium format cameras has been among the most interesting photographic developments over the past few years. High MP backs from companies like Phase One and Leaf became the high-end standard for digital image making, and other companies have recently entered the market. The larger sensors may provide improved image quality in several ways: greater system resolution, greater pixel resolution, improved dynamic range, less noise, and more.

It wasn’t that long ago that digital formats larger than full frame were out of reach for nearly all photographers, with costs that were frequently many tens of thousands of dollars, often for only the digital back, which had to be attached to a medium format body.

However, in the last few years several manufacturers have driven down the cost of camera systems using larger-than-full-frame sensors, and now digital “medium format” (more on that term in a moment) bodies are available for less than $7000. A range of manufacturers are now in this market, including Fujifilm, Pentax, and Hasselblad.

When the costs of larger sensor bodies were in the mid-$20k and up (sometimes very up) range, few photographers using full frame DSLR or mirrorless cameras could realistically consider them as options. But the current $6500-$9000 price isn’t that much higher than the most expensive full frame bodies. At these prices the potential improvements in image quality are enough to make folks take a closer look, especially if they are photographers who produce large and high quality prints on a regular basis.

I began to pay attention when the miniMF Pentax 645d came out some years ago (though I was a bit disappointed to find out that the sensor wasn’t really “645” size), and my interest only increased as Pentax updated to the 645z and then as Fujifilm and Hasselblad brought out competing products. I thought a lot about the possible value of such systems for my photography, and I considered getting one. I haven’t done ao — though I won’t rule it out in the future — but I would like to share some of my musings about the choices. Continue reading Mini Medium Format… or Not?

Flooded Field, Winter

Flooded Field, Winter
Flooded Field, Winter

Flooded Field, Winter. San Joaquin Valley, California. January 1, 2014. © Copyright 2014 G Dan Mitchell – all rights reserved.

The stubble of last year’s crop in a flooded San Joaquin Valley winter field

This photograph comes from a season that seems quite remote today, during the warm late-summer days of mid-August. I made the photograph back on New Year’s Day 2014, when a group of us met in the San Joaquin Valley to welcome the dawn (literally — we arrived before sunrise) of the new year by spending a day photographic migratory birds and the flat and moody Central Valley landscape. Looking at photographs like this one now always reminds me of how quick and how regular the annual cycle is, since we are now considerably closer to New Year’s Day 2015 than the first day of 2014.

This photograph could also be a reminder to the stresses to wildlife from a third drought year and the conversion of the overwhelming majority of the important Central Valley wetlands to farm land. On the positive side, this location is an example of how agriculture and wildlife protection can coexist, since it is farmed in the dry season and then flooded for the birds in the winter. And does it ever attract birds! Here the patterns left by farm machinery are visible in the waters of the shallow ponds where birds were floating on this day.

G Dan Mitchell is a California photographer and visual opportunist whose subjects include the Pacific coast, redwood forests, central California oak/grasslands, the Sierra Nevada, California deserts, urban landscapes, night photography, and more.
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Text, photographs, and other media are © Copyright G Dan Mitchell (or others when indicated) and are not in the public domain and may not be used on websites, blogs, or in other media without advance permission from G Dan Mitchell.

An Example of Corner Performance on the Canon EF 24-105mm f/4 L IS

Sample24105f16Corner.jpg
I’m taking the opportunity to use the photograph I posted earlier today to illustrate a couple of technical points about equipment and technique. Here is a 100% magnification 400 x 400 pixel crop from the far upper corner of the photograph.

Not much to look at, but that isn’t the point. At this resolution, you are looking at what would be a small section from a print that is four or five feet wide. Before I explain why I think this is important, some technical information about the image: Canon 5D, Canon EF 24-105mm f/4 L IS, 2.5 second exposure, f/16, focus point was on the foreground tree seen in the full image (e.g. – perhaps 50 feet closer than the subject of this test image), IS disabled, tripod, mirror lockup, remote release.

Some doubt the ability of this particular lens to produce sharp images. This sample challenges lens performance in a number of ways: it is a very low contrast image, the crop is from the far corner of the frame, the crop is not in the focus plane of the photograph, at f/16 the effects of diffraction blur should be just visible at this magnification.

With all of that context in mind, this cropped sample represents quite good performance. This section of the image would be very sharp, indeed, in a print at 16″ x 24″.

This photograph is not in the public domain. It may not be used on websites, blogs, or in any other media without explicit advance permission from G Dan Mitchell.

Canon 50D Announced: Competition is a Good Thing

News of Canon’s announcement of the new EOS 5D cropped sensor mid-range DSLR is all over the web today – well, at least all over the photographic portion of the web. The new body updates the X0D line from the recent 40D, primarily by updating the 1.6x cropped sensor to 15 megapixels. According to Canon this was done while increasing the performance at high ISOs, keeping the burst rate almost the same as that of the 40D, and maintaining image quality by the use of “gapless microlenses” that can capture more light than would have been the case with older designs. There are other feature updates as well, and it looks like the price will be roughly but not precisely in the same ballpark as that of the 50D… at least once the prices drop a few months after the introduction of the new camera.

What does this mean for the DSLR buyer? The answer is, “It depends.” Continue reading Canon 50D Announced: Competition is a Good Thing