If you require the highest resolution versions (eg for reproduction in print), please contact us directly and let us know the precise intended purpose - eg which publication the image will be printed in, and when.
Please note that it is not possible to email these highest resolution images to accounts on certain mail providers (eg HotMail) due to restrictions placed by them on the size of incoming attachments.
For reference, these are the two highest resolution files available:
1) Grayscale, 3858 x 3972 pixels @ 288 ppi (8.5MB jpg, 14MB uncompressed)
2) RGB Color, 1963 x 1969 pixels @ 288 ppi (4.5MB jpg, 11MB uncompressed)