On 16 Feb 2006 at 9:12, Don Williams wrote: > That must take a long time. CombZ will stack > 100 pictures in five or six minutes. Helicon > Focus (less configurable) is faster, but in > the case of the blue flowers it produced > strange halos in some places -- around very > dense areas for example. Having both programs > is useful for the stuff I do. When things > move, both produce artifacts. But should I > start injecting microscopy into this group? > Perhaps it would be out of place? But maybe > not as far out as religion?
Please don't hesitate, I'd much prefer to read about microscopy. As an aside I've found that automated applications which use stacked images at different exposures to generate a single wide exposure latitude image also exhibit some very noticeable halos and colour aberrations even if there is very slight movement in in the subjects between frames. > Anyway here goes: > > http://www.kolumbus.fi/mimosa/HOLD/401-452.jpg > > this is a stack of 52 images in 2 um steps > taken at about 450X under phase contrast. The > object is the Lorica (siliceous skeleton) of > a small aquatic protist -- the name of which > escapes me for the moment but is irrelevant > anyway. This is a good example of how well > CombZ does it's job. The depth of focus > obtained is about 100 micrometres. That's a pretty amazing image, how was this type of image achieved before digital stacking was available? Also I noticed significant CA in the composite image, do you apply any CA compensation to the individual images before subjecting then to the combine process? Not often would I envisage that I'd need to stack more than 4-5 images in the case of 1:1 macro subjects, this is why it's not such a daunting task to effect it manually. Also the control afforded by being able to decide which areas you wish to extend the DOF in rather than it being a blanket treatment allows a bit more creative freedom. I expect that CombZ would be of use to me occasionally but I will need to experiment. Thanks again. Cheers, Rob Studdert HURSTVILLE AUSTRALIA Tel +61-2-9554-4110 UTC(GMT) +10 Hours [EMAIL PROTECTED] http://members.ozemail.com.au/~distudio/publications/ Pentax user since 1986, PDMLer since 1998
