ijing 2008 
1043 
trol System 
i (LPIS) in 
v Spaceturk 
MEDIUM FORMAT DIGITAL CAMERAS - A EUROSDR PROJECT 
G. J. Grenzdôrffer a 
a Rostock University, Chair of Geodesy and Geoinformatics, J.-v.-Liebig Weg 6, 18059 Rostock, 
Germany-(goerres.grenzdoerffer)@uni-rostock.de 
Commission I, ThS-2 
KEY WORDS: Digital airborne imaging systems, certification, accuracy assessment, standardisation, calibration 
ABSTRACT: More medium format airborne camera systems are in operation globally than the well recognised large format digital 
imaging systems. EuroSDR has initiated a digital medium format project to investigate the market, the geometric and radiometric 
potentials as well as current trends and future developments. After a categorisation of small and medium format systems an in depth 
comparison to large format cameras is given. Beside the apparent differences in size and system cost, the special problems such as 
differences in the interior orientation, the minimum GSD and the photogrammetric workflow are addressed. Medium format cameras 
require geometric and radiometric calibration. Medium format cameras have established their own markets and application domains, 
such as strip mapping and the joint operation with a laser scanner. A market overview compares five different camera systems. A 
description of current trends and future developments concludes the paper. 
1. INTRODUCTION 
Beside the well known large format digital photogrammetric 
cameras such as the DMC or UltraCAM-D, professional digital 
medium format cameras are widely used to acquire digital 
airborne images. Medium format digital systems are used for a 
wide range of applications. Some of the applications are unique 
to medium format and in other applications medium format 
cameras compete against large format cameras. For instance, 
medium format camera systems have developed special markets 
for joint applications with laser scanners and corridor mapping, 
and they are very competitive for small-area large-scale 
mapping projects, rapid response applications for disaster 
monitoring, and for image acquisition for 3D-city models. The 
market for medium format cameras is rapidly increasing; 
however available medium format systems differ greatly in 
terms of performance, reliability, accuracy and price. In order 
to get a status report on the current situation and an insight into 
the geometric and radiometric properties, EuroSDR 1 has 
initiated a project on medium format digital cameras. 
1.1 Objectives of this paper 
The main objective of this paper is to inform about the first 
phase of the 2-year project, which was completed in April 2008. 
Thereby an extensive report describing the currently used 
professional medium format systems has been prepared. 
Furthermore, the paper will cover the following points: 
• Categorisation of digital medium format camera systems 
• Medium format cameras versus large format cameras 
• Geometric properties and calibration 
• Radiometric properties and radiometric workflow 
• Application analysis 
• Documentation medium format cameras / systems 
• Current trends and future developments 
Last but not least, this paper will list open problems which need 
to be solved. 
1 http://www.eurosdr.net/ 
2. CATEGORISATION OF DIGITAL MEDIUM 
FORMAT CAMERA SYSTEMS 
At first a categorisation and a separation between small format, 
medium format and large format cameras has to be made. In the 
literature several surveys dedicated to medium format cameras 
can be found, e.g. Cramer, 2004, Petrie & Walter, 2007, GIM 
International, 2008. Beside the technical aspects of the digital 
medium camera itself, the focus of the EuroSDR survey will be 
on professional medium camera systems. 
Figure 1 gives a categorisation of small and medium format 
camera systems that not only takes the camera itself into 
account but also other important issues for airborne camera 
systems. 
Components 
Small format 
Low-cost Amateur 
Medium format 
Semi-Pro Pro 
Digital Video- / Consumer camera 
< 12 MP 
High end digital SLR Camera, (12 bit, 
16 MP) or better 
Industrial digital camera, (12 - 16 bit, 
(22) - 39 MP 
X X 
X 
X 
x X 
GPS / L1 DGPS 
RTK - GPS 
X X 
X X 
Simple GPS- flight management system 
Professional flight management system 
X X 
X 
X X 
Stabilized platform 
GPS - INS (x,y,z < 0.1 m co,<p,K < 0.01°) 
X 
X 
System Price [€] 
<5.000 <25.000 
<50.000 >250.000 
Figure 1: Comparison of small and medium format camera systems 
The different components of the airborne imaging systems 
strongly influence the quality of the images, the efficiency of 
the airborne and photogrammetric workflow and the reliability 
of the system. With respect to the EuroSDR project the 
characteristics of state-of-the-art professional medium format 
digital cameras for airborne applications are: 
• Single lens - single focal frame - single shutter