la idea, grosso modo, es hacer varias fotos con diferentes enfoque y fundirlas, quedándonos con lo enfocado de cada una de ellas, con la siguiente serie creo que se ve claramente el efecto:
A series of images demonstrating a focus bracket. The image on the left shows a single shot taken at f/11 with the features of the spider closest to the camera. The center image shows the features farthest from the camera. The image on the right shows focus stacking: a sequence of 8 incrementally focused images of the spider assembled to make a composite image in Photoshop.
de la wiki http://en.wikipedia.org/wiki/Bracketing ... bracketingFocus bracketing is useful in situations with limited depth of field, such as macro photography, where one may want to make a series of exposures with different positions of the focal plane and then choose the one in which the largest portion of the subject is in focus, or combine the in-focus portions of multiple exposures digitally (focus stacking). Focus stacking is challenging, in that the subject (as in all brackets) must stay still and that as the focal point changes, the magnification (and position) of the images change. This must then be corrected in a suitable application by transforming the image.
hay un programa específico para ello, el Helicon Focus
en su web hay un cerro de enlaces con ejemplos y tutoriales:
http://www.heliconsoft.com/focus_articles.html
por ejemplo:
http://www.photographers-resource.co.uk ... licing.htm
http://www.photographers-resource.co.uk ... _magic.htm
http://ed.rosack.com/wordpress/2010/01/ ... xperiment/
aquí tenéis fotos con enfoque "horquillado" para hacer pruebas....
http://billstormont.zenfolio.com/p122994707
porque como no nos queremos gastar ni un pavo querremos hacerlo gratis...
pues nuestra opción se llama "fusión" en PS
http://www.foroderelojes.es/showthread.php?t=24048
otro tuto: (se puede descargar un programa que se llama CombineZM, gratuito, que apaña la cosa)
http://www.dzoom.org.es/noticia-5393.html