While the weather has been a bit grim I have been playing with my ' toys ' - lathe and mill to repair some of my aging kit.
Some members ( Harry - Wolfie uses it ) may be familiar with Combined ZM. Its a freebee program that can be used to stack a series of images taken at different points of focus to increase depth of field.
Link to CZM here
http://www.hadleyweb.pwp.blueyonder....inezm_help.htm
Thinking about this I have a Manfrotto adjustable Micro plate, ( Dave posted some pics of it in post 95 here
http://www.worldphotographyforum.com...ead.php?t=1618
So I decided to do a little mod. and make a micro adjuster to replace the standard screw. This has engravings to allow precise movement of the camera platform in increments of 0.1mm. A bit fine you may think but then I am targeting this at Bugs possibly using a reversed 28mm lens. The idea being to focus on the subject leading edge and then drive the platform forward by an increment suitable for the subject to change the in focus point. This can of course also be done by refocussing the lens after each exposure but that is not as precise as I was looking for.
Test day today and I gave it a workout, and CombinedZM a bit of a hard task. I took a series of 15 images moving the plate forward in 5mm increments. Aperture was f8 throughout ( exif is in image 1 of the stack ) chosen to give a shallow depth of field. The stack was made from a series of jpegs as 15 x 70mb tiffs would probably have made my pc fall over. CombineZM did its work in about 10 minutes but I did have to crop a bit of spurious stuff it generated from the left and top sides. Motto seems to be do not quite fill the frame, but allow for a bit of edge cropping. Well pleased with the result, as magnification does alter as the image focus point changes. No doubt it is that that created the spurious information at the left and top side of the image. As an aside Combine ZM does not retain exif information.
Don
PS : As Foxy has reminded me Combine ZM is NOT available for Macs.