Compare aerial photographs by era: from 1928 to fiscal 2007

Published: August 11, 2026 / About 15 min read

When you try to compare old aerial photographs, the first stumbling block is "which eras of photographs can be used". Aerial photographs by era are not photographs of the whole of Japan taken uniformly in the same year. Several groups of photographs, with different purposes of photography and different photographers, are piled up in layers by era. This article looks in turn at the character of each of the nine eras, where you can see them, and how the appearance of the photographs themselves differs.

Nine eras are stacked up

The photographs you can see on this site are nine eras. Eight of them are aerial photographs by era, in order from the oldest: around 1928, around 1936-42, 1945-50, 1961-69, 1974-78, 1979-83, 1984-86, and 1987-90. The remaining era is FY2007 from the aerial photographs by fiscal year. The labels of the aerial photographs by era are said to have ranges because the photographs of one era were not finished in a single summer but were taken region by region over several years.

The eight eras up to 1990 are all aerial photographs taken from aircraft, and satellite images are not included.

The important point is that these nine are not provided equally for every piece of land. The older the era, the narrower the area photographed, and even the eras after color began lean toward urban areas. No single place has all nine, and at many locations about four to seven can be used. There are also locations limited to two or three, and locations where only one era can be used.

The "Eras of photographs for this location" section of a location page lists only the eras for which photographs are actually provided at that place. It is built so that you never choose an era and get no photograph.

The nine eras in Showa and Heisei years

Seven of the nine eras fall within the Showa era, and the ones that reach into the Heisei era are 1987-90 and FY2007.

The photograph from around 1928 covers only the area around Osaka

The oldest, from around 1928, is an era for the area around Osaka only. The coverage that the Geospatial Information Authority of Japan (GSI) publishes is the area of the City of Osaka (as of August 2026), and unlike the other eras, you cannot choose it in regional cities. Within the city, inland locations such as Morinomiya (Former Osaka Army Arsenal), Umekita (Grand Front Osaka), and Kyocera Dome Osaka (Iwasaki-cho), and waterfront locations such as Universal City (Western Konohana Waterfront), Cosmo Square (Sakishima), and Nanko Port Town, can go back to this era. The photographs also reach just outside the city boundary, and can be used at locations in Hyogo Prefecture such as Around Amagasaki Q's Mall and at inland locations in Hokusetsu such as Kento (Former Suita Rail Yard).

The image is black and white, but it does not give an impression of being coarse. If you open this era at Morinomiya (Former Osaka Army Arsenal), the rows of houses of the town appear in detail fine enough to tell the buildings apart one by one. In the middle of the frame, the moats of the castle surrounded by dense woods and a trapezoidal enclosure jutting out appear clearly, and to the east of them a bright lot with few buildings spreads. The surroundings are a mosaic in which paddies and fields divided long and narrow like strips mix with dense rows of houses. The lines of roads and railways are thin and sharp, and you can follow the framework of a town in the 1920s just as it was.

The photographs from around 1936-42 were taken by the army

The next oldest, from around 1936-42, are photographs taken by the army. The center of the coverage is the area around Tokyo's 23 wards and the City of Osaka, but that is not all. This era can also be used at locations in Kanagawa Prefecture such as Musashi-Kosugi and Ukishima / Tonomachi King Skyfront, at locations in Chiba Prefecture such as Maihama, and at locations in Kyoto Prefecture such as Otokoyama Danchi (housing complex). Conversely, many regional cities have no prewar photographs, so comparison with the prewar period works only within the range these two eras reach.

If you switch to this era at Takashimadaira Danchi, most of the frame is paddies divided by a grid of paddy ridges. A levee and the course of a river cross the upper part, and at the upper right a large white roof that looks like a factory is visible. The lower half is settlements wrapped in woods and fields cut into steps on the slopes. The whole is black and white in a soft tone, and white dots and thin scratches from the film are scattered across it. They look less like flaws of the photograph and more like a record of the time the photographs of this era have passed through.

These two prewar eras have one property that differs from the six eras of 1945-90. The two prewar eras can be zoomed in further. However, location pages show every era at the same magnification, so this difference does not appear there. It comes into effect when you zoom in further on the map that you can move freely across the country. At magnifications where those six eras become coarse, these two eras keep the rows of buildings and the outlines of woods. In exchange, you cannot choose these two eras when the map is zoomed out wide.

The 1945-50 photographs were taken by the US military

The 1945-50 photographs, just after the end of the war, were taken by the US military and cover the areas around major cities across the country. There are locations such as Minato Mirai and Kaihimmakuhari where this era captures the sea surface before reclamation began. Even on land where hills were cut away into residential areas, the appearance before any work began remains in this era.

On land where the two prewar eras are not provided, this era is the oldest photograph. Away from the areas around Tokyo and Osaka, locations that can go back to the prewar period become far fewer, so in regional cities this era is usually the one that extends the "then" side the farthest. Conversely, on land where this era is not provided either, the starting point of comparison drops to 1961-69.

If you open Yokodai, the terrain of branching yato valleys spreads across the whole frame. Long, narrow paddies along the valley floors run as bright lines, and the slopes of the ridges are patches of fields and dense woods. There is very little that is man-made, and the settlements are only dotted here and there at the mouths of the valleys. It is black and white with strong contrast and coarse grain, but you can read the relief from the light and shade alone. When you want to check the terrain before it was leveled by grading, this is the most reliable era.

1961-69 is the baseline for comparison

1961-69, which falls in the period of the postwar economic boom, has coverage extending over wide areas of the whole country. Whether in urban areas or in suburban new towns, you can assume that a photograph of this era will almost always be found, and when you open a location page on Kakomap, this is also the era shown first at almost all locations. Because this era captures the terrain just before grading began in earnest, as at Tama New Town (Tama Center) and Senri New Town (Senri-Chuo), it is also an easy era to use as the starting point for contrasting before and after development.

The image is black and white, but quite different from the era just after the war. If you look at Kozoji New Town in this era, the tones are flat and calm. Most of the frame is woods on the hills, irrigation ponds sunk in black are dotted about, and farmland shows at the lower left. In the corner of the bottom edge a river with sandbars appears bright, and in front of it a railway crosses, with the town gathered along the line. White streaks of grading have begun to be cut into the top of the hills, and the photograph shows land at the entrance to a great change.

Color begins with 1974-78

1974-78 is the first era in color. Moreover, it covers almost all of Japan, including mountain areas, so even on land with neither prewar photographs nor photographs from the 1960s, this era can stand as the "then" side. There are also locations such as Kamaishi Station Area (Former Steelworks) where this era is the only partner for comparison.

However, color also brings more confusion. If you switch Kozoji New Town to this era, the frame looks divided into different colors in horizontal bands, even though the land is continuous. The upper band is yellowish green, the middle reddish purple, and the bottom green. The boundaries between the colors are the seams between flight courses, and are thought to be the result of joining photographs taken on different days or on different film. The land did not change, so the steps in color themselves are not used as material for reading.

As you get used to the colors and look on, things that were hard to tell apart in black and white separate. The white road network of graded residential land, the roofs of mid-rise residential buildings in rows, the bright brown of freshly cut bare ground, and the green of the mountains each appear as separate things. The small pond in the middle and the sandbars of the river at the bottom edge can also be read by the difference in color between water and soil.

The three eras from 1979 to 1990

The three eras 1979-83, 1984-86, and 1987-90 cover mainly urban areas. Because the photographs follow one another every few years, at places where reclamation or grading advanced in stages, the appearance partway through remains in separate photographs. You can sometimes pick up, in different eras, the stage where only the seawall was built, the stage where lots were cut, and the stage where buildings stood.

1979-83 is an era that tends to come out dark and heavy. If you look at Yokodai in this era, shadows and woods are crushed to black, and against the fineness of the residential areas covering the hills, the overall tone feels quite heavy. The diagonal rows of residential buildings of the danchi, the bright green of the golf course spreading at the lower right, and the bright brown of bare ground being graded serve as landmarks within that darkness.

1984-86 is characteristic in how water surfaces appear. If you open Rokko Island in this era, the sea surface is deep navy and sinks almost to black, and within it the artificial island floats in the middle of its construction. Whitish reclaimed land not yet graded, dug-up lots the color of soil, groups of warehouses with blue and red roofs already built, boxes lined up in the container yard, and straight seawalls and bridges all appear at the same time in one photograph.

1987-90 is also on the dark side, with colors leaning slightly toward green. If you look at Takashimadaira Danchi in this era, a river and the green space of its floodplain continue along the top edge, and sports grounds with rows of infield shapes can also be seen. Left of center there are long rows of mid-rise residential buildings, and at the upper right the large blue roofs of a group of factories and three white spherical tanks. Residential land packed without gaps lies below the railway and the main road running diagonally. If you compare the same place with the paddies from around 1936-42, you can see plainly what happened over half a century.

The era shown first and how to switch

When you open a location page, the comparison viewer runs with one of the eras available at that place selected. The rule for the choice is "closest to about 60 years ago", and the nearest era is chosen automatically from the eras provided for that location. As a result, many locations start from 1961-69, and Kamaishi Station Area (Former Steelworks), where that era is not provided, starts from 1974-78.

There are three places for switching eras. One is the era buttons of the comparison viewer. Only the "then" side switches, and today's photograph stays fixed as the base for comparison. Just below the viewer, the highlight of the era being shown appears in one line. When you change the era, that text changes with it.

The second is the timeline chart in "Eras of photographs for this location". If you click or tap one of the eras in the row, the viewer switches to that era. The third is the table of photograph highlights in the history section, and the era column there can be used for switching in the same way. It is built so that you can jump on the spot to an era that caught your attention while reading.

You can also choose from three ways of showing then and now: an overlay where a slider moves back and forth between then and now, a form that splits the screen into left and right to see both at once, and a form that switches automatically at a fixed interval. The way of showing is kept even when you choose a different era, so if you go down to older eras in order without breaking the same composition, it is easier to follow the order in which changes happened.

When the place you want to compare is not provided as a location page, open Explore the map. Anywhere in the country, you can move the map and overlay old and current aerial photographs. The "then" side selected first there is 1974-78, because it is the era with photographs for almost the whole country.

Points to keep in mind when comparing

When you look across eras, keeping the differences in the nature of the photographs themselves in mind keeps you from getting lost. First, the season and time of day of photography do not match. The color of paddies and fields, how thick the trees are, the direction and length of shadows, and the brightness of water surfaces change from era to era for that reason alone. When the same land looks different, it is worth stopping for a moment to think whether the land changed or the conditions of the photograph differ.

Even within the same era, things are not uniform. The photographs of one era were taken region by region over several years, so the time of photography may be several years apart at neighboring places, and the boundary between black and white and color may lie inside an era.

When you cross between black-and-white eras and color eras, the kind of clues changes. In black and white you cannot rely on color, so you tell uses apart by the shape and size of roofs, the way shadows fall, and the way buildings are lined up. In color, the bright brown of freshly cut bare ground, the green of grassland and woods, and the darkness of water surfaces each appear separately, so it becomes far easier to read how far grading had advanced. Even for the same change on the same land, the line of reasoning you can read differs by era.

It is also reassuring to know how things look when you go outside the coverage. A place without photographs becomes a pale plain fill. It is not an error but a sign that the photography of that era did not reach that far. When the map is zoomed out wide, the two prewar eras cannot be chosen, and this is the same: they become selectable as you zoom in.

Location pages also show indicators of change in urbanization that compare the old and current photographs mechanically. They are only a rough guide, so instead of judging by the figures alone, comparing the photographs themselves is the reliable way.

About the source credits

The aerial photographs by era and the latest nationwide photographs are published by GSI under its content terms of use. Under GSI's terms, they may be copied and redistributed if the source is stated, and when they are processed, a statement that they were processed is also required. The photograph tiles do not count as basic survey results, so an application for approval under the Survey Act is not required.

On Kakomap, the comparison part of each location page shows "Source: processed from GSI Tiles (aerial photographs by era / latest nationwide photographs)" (locations with an FY2007 photograph also list aerial photographs by fiscal year, and locations that show the year and month of photography also list single photographs), and links to the list page of GSI Tiles. On this list page you can check, era by era, which tiles are provided under which terms. Together with the sources of elevation and railway lines, this is also organized on the Sources and data page.