Introduction to Aerial Photography

Here at MAGIC we have a collection of aerial photographs from various years and at various scales for the State of Connecticut. Some years offer more complete coverage than others and some scales give better resolution than others. Currently, all photographs are black & white.  

There are several ways to make copies of aerial photographs at the map library.  

1. You can take the photo down to the copiers on the 3rd floor (this is not advised as the copiers are optimized for text).  
2. You can scan a photograph and print it out at a cost of $1 per copy.  
3. You can scan a photograph and save it electronically. 

The benefits of the paper formats are that they do not need a computer to be utilized and they are easily transported.  

The drawbacks to this format are that the resolution of the copies is not going to be as good as the original photograph and there is limited processing you can do with the image.  

The benefit of the electronic format is that it can be used in various software packages and is highly portable. The drawback is that the size of the file is large, the resolution is not as good as the original, and a computer is needed to view the files. There is a distinct trade-off between resolution and file size.  

MAGIC currently has only black and white photographs. Therefore all of the scanning should be done in black and white. The current level of information stored in a black and white scan is 256 shades of grey, or 8-bits. If your work requires greater shading then you should scan the photograph as a 16 or 32 bit color photograph. Increases in levels of shading also cause increases in the resulting file size. Most GIS and image processing package only use 256 levels of shading. We have collected information on image formats and software. 

Your next step is scanning the aerial photograph.