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Coordinating, Developing, and Delivering Highway Transportation Innovations

 
REPORT
This report is an archived publication and may contain dated technical, contact, and link information
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Publication Number:  FHWA-HRT-16-007    Date:  January 2016
Publication Number: FHWA-HRT-16-007
Date: January 2016

 

Long-Term Bridge Performance (LTBP) Program Protocols, Version 1

Long-Term Bridge Performance Program Logo

Photographing for Documentation Purposes
LTBP Protocol #: FLD-DC-PH-002


1.

Data Collected

 
1.1 None. This is an instructional protocol to provide specifications for photography for onsite documentation and data collection.  

2.

Onsite Equipment and Personnel Requirements

 
2.1 Equipment:  
2.1.1 PRE-PL-LO-004, Personal Health and Safety Plan.  
2.1.2 Digital camera (FLD-DC-PH-001, Photography Equipment Requirements).  
2.1.3 Tripod (optional).  
2.1.4 Markers (optional).  
2.2 Personnel: PRE-PL-LO-005, Personnel Qualifications.  

3.

Methodology

 
3.1 Plan and gather photographic documentation following these guidelines:  
3.1.1 All personnel in any photographs must be wearing proper safety equipment.  
3.1.2 Take photographs using the highest resolution possible.  
3.1.3 Document the bridge structure (elevation view and plan view, if possible).  
3.1.4 Document any defects found for each bridge element.  
3.1.5 Document the surrounding site (waterway or highway underneath the structure).  
3.1.6 Document data collection efforts.  
3.2 To maximize the value of photos for the Long-Term Bridge Performance (LTBP) Program, use a multiscale approach to photography:  
3.2.1 Large scale:  
3.2.1.1 Work from a large-to-small or a general-to-specific scale.  
3.2.1.2 Approach the bridge in an organized manner, capturing all critical subjects.  
3.2.1.3 Provide global context by capturing traffic signs, lights, lanes, pedestrian travel routes, etc.  
3.2.1.4 Take images in cardinal directions for later reference.  
3.2.1.5 Provide panoramic shots of the entire scene.  
3.2.1.6 Provide point-of-view shots of interest, including overall shots, pedestrian views, driver views, and underside shots.  
3.2.2 Midrange scale:  
3.2.2.1 The midrange scale provides relative context between specific bridge components and the structure as a whole. Components or features could be deteriorations or structural elements.  
3.2.2.2 Pay careful attention to the background of the image to avoid distracting backgrounds.  
3.2.3 Closeup scale:  
3.2.3.1 These images are used to provide intimate details of features or deteriorations.  
3.2.3.2 For closeup photos, carefully focus the image. Closeup focus requires a stable camera and adequate lighting.  
3.2.3.3 Fill the viewfinder with the subject.  
3.2.3.4 Closeup detail makes any sort of context impossible. Therefore, add external context such as scales, arrows, comments, direction of traffic, cardinal direction indicators, and numbers marking each feature.  
3.3 Creating a photo log: Create and maintain a photo log throughout the day.  
3.3.1 The log should include the following information:  
3.3.1.1 State and bridge number.  
3.3.1.2 Bridge element (FLD-OP-SC-001, Data Collection Grid and Coordinate System for Bridge Decks; FLD-OP-SC-002, Structure Segmentation and Element Identification System).  
3.3.1.3 Date.  
3.3.1.4 Image number.  
3.3.1.5 Comment or description.  
3.3.2 Include the State, bridge number, and date in the photo log file name.  
3.4 Immediately review images, if possible, to verify the quality of the image.  
3.5 Store the photo log and the raw image files according to FLD-DC-PH-003, Image Naming.  

4.

Data Collection Table

 
4.1 None.  

5.

Criteria for Data Validation

 
5.1 None.  

6.

Commentary/Background

 
6.1 Photography has an important role in documenting field data collection efforts. This protocol provides guidance on photography as part of the LTBP Program field data collection effort.  
6.2 Several photography techniques are valuable for LTBP Program documentation photography.  
6.2.1 Depth of field:  
6.2.1.1 Depth of field is the amount or area of focus of an object.  
6.2.1.2 Depth of field typically decreases with longer focal length lens, larger aperture sizes, and smaller camera-to-subject distances.  
6.2.1.3 Small depth of field can make it difficult to ensure the subject matter is entirely in focus.  
6.2.1.4 Blurring the background of an image and highlighting the subject in focus may be a beneficial technique.  
6.2.2 Exposure:  
6.2.2.1 Most modern cameras determine how much light to allow in (known as metering) based on an average of the entire scene captured in the viewfinder or image extents. This can result in overexposed or underexposed images. This requires practice and careful checking of images.  
6.2.2.2 Exposure settings can be manually configured or the camera metering can be modified based on the situation.  
6.2.3 Bracketing:  
6.2.3.1 Bracketing limits the effects of exposure issues by capturing the same image three times at different exposure levels.  
6.2.3.2 Bracketing is a feature of many modern cameras and can be used to provide backup images.  
6.2.4 Daytime flash. Using a flash during the day may seem counterintuitive to many, but it can be used to put light into shadowed areas, and to add balance to an exposure.  

7.

References

 
7.1 LTBP Protocols:  
7.1.1 PRE-PL-LO-004, Personal Health and Safety Plan.  
7.1.2 PRE-PL-LO-005, Personnel Qualifications.  
7.1.3 FLD-OP-SC-001, Data Collection Grid and Coordinate System for Bridge Decks.  
7.1.4 FLD-OP-SC-002, Structure Segmentation and Element Identification System.  
7.1.5 FLD-DC-PH-001, Photography Equipment Requirements.  
7.1.6 FLD-DC-PH-003, Image Naming.  
7.2 External: None.  

 

 

 

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