Focus stacking (or hyperfocus) (called also z-stacking, focal plane merging...) is a digital image processing technique which combines multiple images taken at different focus distances to give a resulting image with a greater depth of field than any of the individual source images. Focus stacking can be used in any situation where individual images have a very shallow depth of field; macro photography and optical microscopy are two typical examples.
In the embed at top, the left image is focused on the front of the fly, the middle image focuses on the back, and the combined image at right shows the entire insect in focus. I don't have the software or skills to do this, and my subjects rarely hold still, which is why my butterfly photos lack sharpness throughout the depth of field.
I was thinking about this process the other day while brainstorming a photo idea.
ReplyDeleteHere's a tutorial how to achieve it in Photoshop and an application of Focus Stacking in Photography from local Chicago group Phlearn (Photoshop Learn): http://vimeo.com/46841511
There's a Photoshop took called "Auto Blend Layers" that helps the process along.
If you don't like clicking links, they take a toy unicorn, shoot it with focus stacking and make a quick scene mixing a miniature toy with regular-sized people.
That's a good video. Thank you, Jeremy.
DeletePhotoshop Auto Blend Layers is great when it works, but has no user-controllable settings and often messes up with stacks of more than 3 images.
ReplyDeleteCombinezm is a free program that is not very user friendly and crashes often, but it's actually quite good when it works.
That being said, you're right...not many butterflies stay still long enough to make it work.
The closer you get, the more necessary it becomes. I often stack a dozen or so frames just to get relatively narrow depths of field like these
butterfly
skipper
evening primrose moth
For me the biggest issue is time - time to learn, and time to employ. You put a lot of work into well-composed photos, while I'm more of a "documentary" take15photosthrow14away-type of photographer.
DeleteTx, steve.
I highly recommend zerene stacker for stacking images - http://zerenesystems.com/ as it works really well, and has a faster workflow than the photoshop stacker. e.g. http://www.youtube.com/watch?v=1CwiEmTi-ew
ReplyDeleteI haven't had a chance to use it yet but the Magic lantern (http://magiclantern.wikia.com/wiki/Magic_Lantern_Firmware_Wiki) has a focus stepper script for automatically taking shots at different focal lengths. Video example at http://vimeo.com/5879032#
As an old-school (ie. pre-digital) photographer, I must admit to a wry chuckle while reading this. This kind of "hyper"-focus has been possible for decades using a large-format view camera like a 4x5 or 8x10.
ReplyDeleteThese cameras were essentially two flat boards, one of which held the lens; the other was a frosted glass plate to preview your image before committing it to film, and a bracket to hold the carrier for sheets of film. These boards were connected by a light-tight bellows and were mounted on multi-directional swivels and geared tracks that let you raise and lower them. The technique is called Tilt/Shift, and it enables you to position the opposing boards so as to ensure the entire image is in crisp focus.
The currently-available software which replicates this technique merges multiple shots into one using numerical value interpolation. The old-timers did it in one shot using their eye and brain.
I chuckle because, once again, we've had to re-invent a wheel that's already been around for decades, just to "catch up with technology". Talk about an endless cycle!