aren't boring the pants off everyone but I
may just be about to!
IRIS sometimes feels as though it's been cobbled together from a random selection of beautifully machined components which somehow still don't quite fit together. Here are a few thoughts which you have probably already had yourself but, if I'm lucky, something might help.
The first suggestion is to use the FZ18's RAW mode. I don't believe that IRIS can read and convert Panasonic's RAW files, which is a shame, but if you have, or can find, software that can convert your RAW files into 16-bit TIFF files that can be read by IRIS then that is definitely the way to go in my opinion.
Before I start IRIS I copy all the images I need to use into a temporary folder and make sure that this folder is the IRIS working path (Settings dialog from the File menu).
Open each of the TIFF files in IRIS and then save them as PIC files. For a sequence you want to stack together the last character in the name has to be numeric - I use names like "holmes_1" (IRIS will add the PIC extension).
For simple processing I also expose a single "dark frame" while still outside with the same ISO and exposure length as the proper image files. With that frame saved in PIC format I open each of the image files and then subtract the dark frame (Subtract... from the Processing menu) and save the result (e.g. "holmes_md_1").
As an aside, if you start from 16-bit TIF files it's possible that you may be seeing very little of your images in the main window. The Threshold dialog allows you to fix this but remember that until you save a file in an 8-bit format (such as JPEG) the Threshold dialog settings don't actually alter the image files - they just map the 16-bit depths into a range that your monitor can display sensibly.
Let's say I have two files, "holmes_md_1" and "holmes_md_2" which I want to stack. The first thing is to align them. I have had variable results using the IRIS Stellar Registration dialog (accessed from the Processing menu). I prefer to align manually using the QR2 command described here
. Open a command window (the icon to the left of the "camera" icon on the toolbar) and type QR2 holmes_md_1 holmes_md_2
and hit the Enter key. IRIS prompts you to select three stars and displays holmes_md_1. I like to pick a star in the top left, bottom middle and top right in that order. The star should be nice and small and preferably not too close to other stars - if the star has "trailed" then pick, for example, the top left extremity of the trail. After you have selected the third star IRIS will display "holmes_md_2" and prompt you to select the same three stars. You need to do this in the same order and IRIS helpfully displays a small circle around the original position of the first three stars to help you find the corresponding stars in the second image. With that done IRIS chunters away for a while. When it has finished remember to save the aligned image as, say, "holmes_mdal_2". If needed this process can be repeated as many times as needed (e.g. QR2 holmes_md_01 holmes_md_27
). The last step is to open "holmes_md_1" and immediately save it as "holmes_mdal_1".
Phew! Now for the fun bit. From the IRIS Processing menu select "Add a sequence...". The generic name you need is "holmes_mdal_" (number left off
). Type in the total number of images and select the method of addition to use. Because we are working with 16-bit files it is probably a good idea to select "Normalize if overflow" and I usually go with "Adaptive weighting" and 2 or 3 iterations because I don't know any better. After you hit the OK button IRIS can take quite some time to do the processing but eventually it stops and you should see an image (the Threshold dialog may be useful here). The first
thing to do next is to save the result (e.g. "holmes_st") as, almost unforgivably, IRIS doesn't have an Undo function.
After that you can spend hours (and hours and hours...) tweaking the image. With the final result saved as a PIC file you can then either export a 16-bit TIFF file for further tweaks elsewhere or set the final Thresholds and convert to JPEG.
I hope something in the above helps sort your problem. Let us know how you get on.
P.S. For those who are tempted to download IRIS it's available here