It is usually done by using a computer program connected to a digital camera, that is programmed to take a sequence of photographs at different but equal distances from above (with the upper surface in focus) to the lowest part of the object.  The computer then superimposes the photos, taking the best image for each part and putting them together.  Such programs are available commercially, though you must have the equipment for the computer to control the changes between the photos.

Dear Claude,

Try it with the Focus Stacking using Helicon Focus Pro for making photo stacking pictures. You can try out this computer program for 30 days, by free download.

I have thus achieved very good results. See my newest contributions.

Best reards,

Guenter

Yes, the Helicon Focus Pro is regarded as the best in our University.

Clearly, Helicon Focus Pro is a far better suggestion than mine...sorry

There a nice plugging for ImageJ from the Biomedical Imaging Group called Extended Depth of Field: http://bigwww.epfl.ch/demo/edf/

I do nothave much experience with it because I usually work with fluorescence and not with BF, but it looks a free nice alternative altough the Helicon Focus it is really impresive and not too expensive.

And maybe an alternative is to reduce the aperture diaphragm. You 'll lose a bit of light and resolution but could be a solution

Use a low numerical aperture objective

I tried Helicon Focus to improve the depth of field of bright-field images. The software is doing a really nice job and is easy to use.

The Extended Depth of Field plugging for ImageJ worked well, but not as well as Helicon (at least for my images stacks).

Thanks to all of you for the useful suggestions!

Claude

Here is a montage of the 14 images in a z-stack of Ophiopluteus larvae (10x, NA = 0.3 objective, Zeiss Axio Observer Z1 microscope):

…and the resulting image with extended focus obtained with Helicon:

Congratulations Claude, a really brilliant result!!

Best,

Guenter