DSLR Photography Forum

Full Version: CombineZM Focus Stacking
You're currently viewing a stripped down version of our content. View the full version with proper formatting.
Has anyone heard of focus stacking? It's like HDR, only with depth of field as opposed to exposure, and apparently is commonly used in macro photos, where depth of field is usually lacking. By taking multiple photos, each with different focal points, you can stack / combine them into a single image that has more of the image in focus. Needless to say, you'd probably need a tripod, and make sure that the scene doesn't change significantly between shots.


Haven't tried it but, if you have, do share your experiences.
I have had this programme for a couple of years but have not yet fired it(or myself!) up and got to grips with it.
I came across it via the excellent Max Lyons site when I first got into panos and mosaics and PTGui; the heads on the forums there were really keen on its development. As usual, this collection of pioneers, who were busy cracking out gigapixel images by stitching together images that would take a day or so to blend, were busy extending the frontiers. I gather(or rather am guessing) that the nuts and bolts of it is more akin to stitching/blending than the algorithms used in either "real" or faux HDR?
I remember some rather spectacular results being posted, after these guys had spent a day or so watching the dos commands do their thang: a spider and web at "macro distance" being as razor-sharp as the horizon, for instance. I had the distinct feeling that getting on top of it all was harder and involved even more manual labour than stitching and blending from user-plotted control points(and why I became addicted to mosaics, knowing they then took so much hard work is beyond me).
I'm delighted it's still not merely going strong but out there and well exceeding the audience and expectations of the initial developers who spent long labours of love over its gestation; lovely to hear of this again after all this time, thanks for the usual vigilance Jules(you must have eyes in the back of your head, the amount of stuff you seem to be aware of!)
I use focus stacking from time to time with a program called 'PhotoAcute'. (Helicon Focus is another that I've heard good things about.) It seems to work by finding the sharpest areas in each photo and then merging them, but there's also a fair bit of distortion and perspective correction going on behind the scenes as well. There needs to be some overlap in the depth of field of each image, but other than that, there's no real maximum or minimum number of images that needs to be used for it.

This is an older photo of mine, done on a tripod with slight adjustments of the focusing distance between each shot. Twenty-five separate images went into this one photo, but I also 'over-shot' it so that Photoacute could do its best up-resolution processing on it as well:

[Image: 755398554_adD7y-M.jpg]

This is more of a macro image, and was 21 photos merged together. For this one I was using a focusing rail, which allows very slight camera movement between each photo. Since changing focus also means changing the magnification, shooting near 1:1 is much better this way:

[Image: 683574735_Pe6wu-M-1.jpg]

I'll also use it for more landcscapy things on occasion. Yesterday I photographed this installation in a suburban art gallery's sculpture garden. I wanted the rock with the inscribed name to be sharp, but enough DOF to do that would have also brought the thin screen of trees and apartment building into focus as well. This was two images, handheld, at f/2.8:

[Image: 853357322_Tpqt5-M.jpg]
@Zig - eyes in the back of my head, yes; time to try everything out, no, unfortunately. Big Grin

Matthew, thanks for the sample images - it certainly looks very interesting. The flower especially looks awesomely detailed and rich. Do you have to do anything special when stacking - e.g. dial the exposure down - or does the software automatically work it out for you?