FAQ

If you would like to rate other users’ pictures or upload your own pictures, you have to register.
Each user must pick a username, an email address and a password. Optionally, a display name, a location and a time zone may be chosen.
By default, the user name is listed as author of an image in the tabular view and in the single view. If the user has provided an optional display name, it will be used instead of the user name in the single view.
Image galleries of local museums and media databases of newspapers often carry historical pictures. Freely available pictures are offered by https://www.flickr.com/creativecommons/
Take a printout of the before-photo with you and try to find the original spot by comparing the printout with the live camera view.
In general: portrait mode is less suitable, since during presentation it generates black stripes left and right of the photo. Pictures in landscape modes fit best on a typical 16:9 display, if they respect the same ratio. Therefore we have optimized the single view display for the presentation of a 16:9 photo next to the Google map. Other ratios like 4:3 are also possible, however they waste a little more space.
Both the before- and the after-photo are uploaded and may/must be supplemented with a category (buildings, interior, nature, people), a title, a description, a location and the two recording dates. Important: the user must have the authorization to publish both pictures.
At least a specific year has to be provided. If the year is not known, it has to be estimated. Data for month, day, minute and second may be set to "unknown". If provided, information for location and time may be extracted from the digital image EXIF data.
If the user has recorded the picture himself, he can choose the type of license. The most restrictive would be "All rights reserved", which means, the photo may be inspected, but not distributed without explicit approval of the author. A more liberal approach would be "CC BY-ND". This Creative Commons license allows the distribution of the photo, in a commercial and non commercial setting, as long as the author is clearly stated and no modifications are made.
If you use a picture provided by an archive, which comes already with a copyright license, it is your duty to keep that license attached to the image and propagate it further.
Our image transformation makes sure, that both photos fit together pixel by pixel. For this reason, please place with the mouse up to 4 colored markers on the before-photo and the after-photo at distinctive spots, that represent the same location in the scene, e.g. the corner of a building or the top of a tower. After aligning the two pictures with our software, you may decide whether you are happy with the result or whether you would like to start all over again with a new set of markers. Be sure, to place markers both in the foreground and in the background.
All image pairs can be filtered by the categories, by the time interval boundaries and by the time interval duration. Terms within title and description can be searched as well as for user names. The resulting hits will be displayed in tabular form and will be georeferenced on a Google map. The table can be sorted column by column. You may zoom in and out of the map.
By clicking on the head of a table column all entries are sorted with regard to that attribute.
You may move a slider with the mouse. You may rate the image with up to 5 stars. You may comment on the image by typing a few sentences in a text field below the last comment.
Each user may award up to 5 stars to each image pair, that is not authored by himself. The average of all the stars given to an image results in the average rating, provided, there are enough ratings.
The forum is a place for photographers to talk about their experiences and ideas in the context of before-after-photos: Where do I get historical pictures ? What is important during the shooting of a picture ? Which cameras are suitable ? What are fancy motives ?