Wednesday, February 23, 2011

Image Quality Control Using Adobe Lightroom

Image Quality Control requires that each image be visually inspected for content and, well, image quality. At NYBG there are several Curatorial Assistants shooting photographs of specimens every day, producing hundreds, if not thousands, of images. As a result, I am very interested in efficiency just to keep up with production.

I am familiar with using Adobe Photoshop for image editing, but with Photoshop I am limited to working on one image at a time. When it comes to working with large numbers of files, Adobe Lightroom is a better option.

In the past few days I have QC'd thousands of photographs - this just wouldn't have been possible using Photoshop. Lightroom is still new to me, so I am learning new tricks every day. Here are the steps to image quality control that I use at the New York Botanical Garden Herbarium:

(I am also fortunate to have a dual monitor set up. This allows me to see a lot of information at a glance.)

Because of the orientation of the camera and copy table, the specimens are photographed horizontally. In the thumbnail view on the left, I can quickly rotate all of the images so that they are right side up.

Thumbnail view

The three main factors in image quality are exposure, focus, and color balance. I check these before I check content.

While it is easy to see if am image is too bright or too dark, the histogram in the upper right hand corner of the Library provides confirmation, making it easy to see if an image is properly exposed. Thanks to the overlapping color channels in the histogram, I can also easily confirm color balance.


I can get a good sense of whether or not the image is in focus using the loupe view on the right hand monitor, but to check critical focus, I zoom in to 100% magnification, or 1:1 view on the left monitor.

1:1 Magnification

Every specimen is cataloged and bar-coded before it is photographed. In order for the image to be searchable in the collection, the file name must match the bar code number. I use the Navigator window to find the bar code in the image (this also gives me a good view of focus).


I match the bar code with the file name, which I have displayed over the window. And finally, I confirm image content in the view on the right monitor. I am looking to confirm that the whole specimen is showing, that all the specimen labels are visible and legible and that the color bars and ruler are included in every shot.

Confirm content

I use the arrow keys on the keyboard to move on to the next image.

I also use Lightroom to process RAW files to Tiffs and Jpegs. There are several considerations in image processing that will be discussed at length in future posts.

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