Sand Storm, Desert Ridges

Sand Storm, Desert Ridges
The dust from a nearby sand storm obscures a series of ascending ridges.

Sand Storm, Desert Ridges. © Copyright 2019 G Dan Mitchell – all rights reserved.

The dust from a nearby sand storm obscures a series of ascending ridges..

On this afternoon I made quite a few photographs, and they range from a few with striking sunset and dusk colors to others that are almost devoid of details in the blowing sand and dust. Yes, it was a sand storm day, and that is precisely what drew us to this portion of the valley. High winds from the southwest were raking the sand dunes and raising giant, fast-moving clouds of sand and dust. They raced across the valley, traveling northeast toward the Amargosa Mountain range.

I made this photograph very close to the point where we entered the cloud of dust/sand. We had come up from a part of the valley further south, and as we got closer to the dunes and the source of the haze the dust began to obscure the sky and the view. We stopped here before entering the worse of the cloud and made a few photographs looking into it, with the tall mountains to the north nearly obscured


G Dan Mitchell is a California photographer and visual opportunist. His book, “California’s Fall Color: A Photographer’s Guide to Autumn in the Sierra” is available from Heyday Books and Amazon.

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Format Size Comparison Data

The following charts summarize various data that are useful when comparing formats, either film or digital. (Not all possible comparisons are shown.) Some additional background regarding some of the traditional film formats known as “medium format” is found at the end of this post.

Basic Formats Data

Comparisons Normalized to Full Frame Format

Comparisons Normalized to miniMF 33×44 Format

Comparisons Normalized to 645 Medium Format Film

Comparisons Normalized to Full Frame at 4:3 Crop

Comparisons of Square Formats Normalized to 6×6 Medium Format Film

Comparions Normalized to 6×17 “Panoramic” Medium Format Film

Visual Comparison

The following illustration shows the relative sizes of some common digital and film formats. (Not all variations are shown.) The leftmost group includes common digital formats. The next group — indicated in yellow — includes common traditional formats collectively known as “medium format” film. At the far right is 4×5 “large format” film.

A chart showing the relative sizes of several digital and film photography formats ranging from micro-four-thirds to 4x5 film
A chart showing the relative sizes of several digital and film photography formats ranging from micro-four-thirds to 4×5 film

Notes on this illustration:

  • 645 film is shown in both the “landscape” and “portrait” orientations in order to make clear that it shares the 56mm dimension with the other types of medium format film. (The portrait version is partially hidden the landscape version.)
  • There are multiple variations on “large format film.” Shown here is the most common 4″ x 5″ size, the smallest of the large format film formats typically still in use.

About Medium Format Film

While those of us who have “done photography” for a long time are familiar with the traditional “medium formats,” those without that perspective may be less (or not at all) familiar with the meaning of the term. Medium format” traditionally (for many decades) referred to film formats using (primarily) 120/220 film with a 6cm (60mm) physical width. While details of these formats are included in the tables above, here is a brief contextual overview:

  • 645 format (1) is the smallest of the traditional common film medium formats. It is named based on “6cm x 4.5cm.” In actual use the frame size is slightly smaller than the 6cm film width at about 56mm. (This is typical of film medium formats — the “6” always refers to the physical film width, not the smaller actual image size.)
  • 6×6 format produces a square image of approximately 56mm x 56mm, and is the next larger film medium format above 645.
  • 6×7 format uses the 56mm width-determined dimension for its shorter side, and thus has a larger area than 6×6. (It approximately replicates the 5:4 aspect ratio of LF film.)
  • 6×9 format also keeps the 56mm dimension its shorter side, but expands the longer dimension to produce a 3:2 aspect ratio – like 35mm film and full frame digital.
  • 6×17 format (also known as “panoramic format”) is the largest common medium format. It also uses the 56mm dimension for its short side but greatly extends the long dimension to produce a 3:1 aspect ratio.

(1) While Pentax names its miniMF digital cameras using the “645” term, they do not use 645 format sensors. They use 33mm x 44mm sensors, just like Fujifilm, Hasselblad, and others. Additional note: On a few occasions, Fujifilm has referred to 33mm x 44mm format as “super full frame.”

(For comparison purposes, note that the dimension that is 56mm on 645 film format is 44mm on miniMF. When comparing to the other medium formats, the analogous comparison is between 56mm and 33mm.)


G Dan Mitchell is a California photographer and visual opportunist. His book, “California’s Fall Color: A Photographer’s Guide to Autumn in the Sierra” is available from Heyday Books and Amazon.

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Desert Globemallow

Desert Globemallow
Desert globemallow flower and buds, Death Valley National Park

Desert Globemallow. © Copyright 2019 G Dan Mitchell – all rights reserved.

Desert globemallow flower and buds, Death Valley National Park.

This desert globe mallow is one of my favorite desert flowers. In most cases that I’ve encountered, there may be a few scattered bushes, sometimes filled with these intensely orange flowers for a few springtime weeks, and especially abundant after wet winters.

2019 seemed like a slightly odd spring for wildflowers in Death Valley, where I made this photograph. A lack of early winter rains lead many to expect a rather poor wildflower season. However, even though it didn’t create the famous “superbloom” conditions, there were quite a few flowers in many places. They seemed to come a bit later than expected this year — perhaps a result of the drier early winter season and then very heavy rains just before the start of spring.


G Dan Mitchell is a California photographer and visual opportunist. His book, “California’s Fall Color: A Photographer’s Guide to Autumn in the Sierra” is available from Heyday Books and Amazon.

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Colorful Desert Hills, Morning

Colorful Desert Hills, Morning
Multi-colored strata in eroded desert hills

Colorful Desert Hills, Morning. © Copyright 2019 G Dan Mitchell – all rights reserved.

Multi-colored strata in eroded desert hills.

The colors of some of the strata laid bare in desert regions like this one are sometimes wild and occasionally unbelievable. The blue tones often provide some of the most striking surprises, since that may be the last color we expect to see in soil or large expanses of rock — reds, browns, yellows are far more common.

I made this photograph in a little area that is almost a lab of eroded forms and varied colors. I like to photograph here in the morning, when I often have the place to myself and when there is the possibility of soft, low-angle light. Here the strata of tan, red, and blue materials run at right angles to the lines produced by erosion.


G Dan Mitchell is a California photographer and visual opportunist. His book, “California’s Fall Color: A Photographer’s Guide to Autumn in the Sierra” is available from Heyday Books and Amazon.

Blog | About | Flickr | FacebookEmail

Links to Articles, Sales and Licensing, my Sierra Nevada Fall Color book, Contact Information.


All media © Copyright G Dan Mitchell and others as indicated. Any use requires advance permission from G Dan Mitchell.

Photographer and visual opportunist. Daily photos since 2005, plus articles, reviews, news, and ideas.