How to supply images for herbaria@home

1st Draft 24/10/06

Equiptment

At Manchester we have found that fairly mainstream modern digital cameras are very capable of capturing high quality images of herbaria specimens. We are currently using an 8 Megapixel Nikon coolpix 8800, but good results were also obtained with a 6 Mpixel Canon SLR.

We use a copy stand to support the camera, but a tripod would probably also be fine. Flourescent photoflood lighting is used to illuminate sheets (we found that camera attached flash-guns tended to create too much flare).

Ideally a scale bar should be included in the image.

Image size and resolution

The project can cope with whatever size/resolution of image you choose to supply. We have found that high quality JPEG compressed images are of sufficient quality and are preferable to huge uncompressed Tiff or Raw files. To create these set your camera's image quality to it's highest setting below raw. As a guide an 8 Megapixel jpeg image of a herbarium sheet will be up to 4Mb. If for archiving purposes you still prefer to create huge uncompressed images then please supply us with high-quality JPEG compressed images for use online.

Please do not post-process images (e.g. to correct colour, rotate or crop images), if this is needed we will run a batch photoshop macro to make all the changes in one go, repeated editing of JPEG images progressively degrades quality so it's best to have only a single editing step.

Identifying images

For later identification each sheet needs to be assigned an identification number or code which is unique for each sheet. This can be in any format, depending on the conventions of an institution. This code should be marked on the sheet.

We can automatically look up Flora Europaeae and Kent numbering schemes, so if sheets are filed on that basis then it sufficient to identify taxa using just the number. Full identification details (genus, species and author) are needed otherwise.

Please send us images as sets of sequentially numbered files with a list of which number ranges match which taxa and which unique identifiers.

e.g.

img00456.jpg - img00461.jpg  kent162.3.3x4 P1236-P1241

where Pnnnn is an example unique identifier, and the taxon is Epipactis purpurata x helleborine

Please send images on CD or DVD to Leander Wolstenholme at Manchester Museum herbarium, (we will eventually arrange an way to upload images directly to the website, but this is not yet in place) Please include the specimen list and your contact details in a file on the CD.

Return of data

Once your sheets have been documented then the details will be made available for you to import back into your current database system. The precise details of this will be dependent on what database system you are using, but we aim to be be able to export data in formats that can be imported by most museum systems, and in other standard formats for herbaria data exchange.