A big issue when doing extreme closeup photography is limited depth of field. In some cases this is a nice effect (many great photos emphasize some central item of interest by throwing everything else out of focus). A solution for times where extensive depth of field is desired is to stack a sequence of digital images taken with various focus settings. This requires computer software to do the work, and there are a number of choices.
When taking a series of images for image stacking, note that you do not want to refocus the lens between shots, but instead change the camera to subject distance using a focusing rail or some equivalent scheme. Refocusing the lens will change perspective as well as focus, which is not what you want. You want to move the focus plane through the subject and change nothing else.
Here is what I am told you need to do:
My buddy John says that he tried it and thought it did a terrible job. He now uses Zerene Stacker.
The little birdies have told me that the GIMP can do focus stacking via: Filters->Combine->Depth Merge
I no information about how good the results are.
Next (from 2006 to 2008) came CombineZM.
CombineZP is the current work by the author (Alan Hadley),
and it boldly is open source (under the GPL)!
The source can be downloaded from Alan Hadleys site as combine.zip. I also stashed my own copies of his source (as of 8-26-2011) here:
CombineZ runs only on windows, so a Mac (or Linux user like me) is out in the cold.
People have set up CombineZM to run under Wine in linux. See this thread that describes how a fellow did it. There were some unexpected issues, such as using winetricks to install Microsoft Visual C++ 2003 libraries:
mkdir ~/.wine/drive_c/Program Files/CombineZM. Download CombineZ-m.exe and fftw3.dll from CombineZM’s websit and put them in the folder. wget http://www.kegel.com/wine/winetricks chmod +x winetricks sudo mv winetricks /usr/local/bin winetricks vcrun2003 wine ~/.wine/drive_c/Program\ Files/CombineZM/CombineZ-m.exe
Combine Z was written in C++ (for the windows platform -- visual studio C++). I briefly contemplated the idea of porting CombineZ to linux, but this would be no small task. The visual studio CPP environment almost seems to be engineered to make porting difficult. For details, click this Windows Software Porting link.
My friend Joe has used this with satisfaction for some time, but is now thinking of switching to Zerene Pro because he is purchasing the Stackshot rail system.
Check the Zerene systems website. The "Personal Edition" costs $89 USD and runs on Windows, OsX, and Linux, which ain't bad. The "Professional Edition" costs $289, and is really the same thing, but with fewer restrictions with what you do with the output.
There seems to be one exception to all this, and that is support within Zerene for the stackshot rail, you have to buy the professional edition to get the rail support. The stackshot is a product from Cognisys Inc and as of September, 2011 was selling for about $600 (this is the rail, motor, and controller). So, by the time you buy the rail and the pro edition of Zerene, you have spent nearly $1000. Note that the stackshot mounts the camera using an Arca clamp (or can), which is nice.
Zerene is written by Rik Littlefield (editor/administrator of Photomacrography.net)
What I like is that they support linux users like myself, but it is not clear if that support will continue to include the StackShot.
Here are some packages that I have taken a look at:
There is also EnBlend-EnFuse, which does both HDR, panorama stitching, and focus stacking (sounds great!).
Tom's Mineralogy Info / email@example.com