Getting right to the point … the focal point
I like to do macrophotography – getting really close in on small features such as flowers and insects. But it has always had a significant limitation – depth of field. Not all of your subject is guaranteed to be in focus.
I use a 100mm macro lens on a full-frame Sony digital camera for this sort of subject and the depth of field is barely more than 2-3mm when tightly focused on. This is fine if your subject is small or lies within that focal plane but more often than not you have to choose which small part of the subject is going to be clear and sharp.
But now … technology to the rescue. My new computer has a super powerful processor that does not fall over when huge files are thrown at it and I have some new software (Affinity Photo) that enables “focus stacking” and which makes use of that powerful computer chip. Today I started experimenting. Meet my friend Ramsbottom.
Basically you focus on the front of your object and take a picture. You then focus in steps all the way through it taking a new photograph each time. until you have a stack of images from front to back. Load them into the software, press the button and sit back. It takes the in-focus parts of each image, discards the rest and combines them all to give you a single image at the end that is sharp all the way through.
First image in the stack is focussed on the nearest part of the subject
The last image in the stack is focussed on the furthest part of the subject – all the rest is fuzzy because of the limited depth of field
Combine the two images above with another four steps between them and here is Ramsbottom, revealed in all his Wooly glory. (There will be spiders in the future and very tiny flowers and mosses etc)
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