Some focus stacking examples

[pdk42]

All with the EM5.3 and all bar one stacked in camera. The Rhododendron is stacked from Raw using Photoshop.


Drumstick Primula by Paul Kaye, on Flickr


Silene by Paul Kaye, on Flickr


Rhodedendron by Paul Kaye, on Flickr


Tree Peony Flower by Paul Kaye, on Flickr



Octopus-style Fern by Paul Kaye, on Flickr

[sapper]

Good examples Paul.

[MikeOxon]

I agree that stacking is great for flower images. You have not mentioned the lens(es) you used. For myself, I think stacking is what really makes the 60mm macro an extremely useful lens.

[pdk42]

These are all with the 12-40. Shot at f2.8 to get the background blurred as much as possible.

[wanderer]

I use focus stacking quite a lot, particularly with flowers and fungi. I agree its great with the 60mm macro although I can sometimes see a 'halo' round the subject if you are really close. Presumably the shifting focus does this.
I also use it with my 12-100mm and occasionally with tbe 7-14mm. Its very good for placing something in the foreground in the context of its place. I use it as C1 on the top dial, 10shot, F8, single spot focus. The hand held version on the OM-1 is remarkably good.Q
I think what might be worthwhile showing are stacked and non-stacked images as a comparison.
The algorithm must be quite interesting to expose correctly for 10 or more images and produce a nicely exposed image at the end of it. I wonder if it is a variation on the composite algorithm.

[pdk42]

The halo effect is, I think, caused by variations in magnification as the focus moves (focus breathing). The algorithms deal with it to some degree, but it’s not perfect.

[pdk42]

For info, here is a quick comparison of some focus stacking PP tools. They are useful when the in-camera stacking fails. In this example, I took a shot of the 12mm f2 lens from close in using the 60mm macro. I needed to take 19 shots with a focus step of 10 to get the entire depth of focus needed. The in-camera stacking only goes to 9 shots, so could not do the range needed for this.

Here is a preview of the first few shots in the stack to give you an idea of the sequence:



Now here are the stacked results from all 19 images:

1) Photoshop

Not a great result - terrible artifacts on the front of the lens hood! On easier stacks it works fine though and it will handle ORFs directly. But it's quite slow to do the stacking.




2) Zerene

Much better result. It's also quite fast - but it needs TIFF or JPG files. No support for ORF. It's also $189 for a one-time licence of the "pro" version, so not exactly cheap.



3) Helicon

Not so good either. Lots of halo effect. Doesn't work with ORFs either. A bit cheaper than Zerene at £29/year or £111 one-off.



4) Hugin

Although Hugin is best known as a stitching tool, it will do focus stacking too - but you have to use command-line tools.

The result isn't too good though. It's free, but on this evidence it's not worth it!!



So, surprise, the most expensive is the best!! http://www.zerenesystems.com/cms/stacker

[sapper]

I got the 60mm macro at the Photography show, but here is a focus stack with the 12-100mm 10 stacked at f8 as per Wanderer. The 60mm Macro

[sapper]

I think so, I will try it again with the 12-100, which I prefer for this size objects.

[pdk42]

I think focus stacking is useful in two cases:

- To extend the DOF to be bigger than can be achieved even at a very small aperture (e.g. f16)
- To isolate a subject from its background by using a wide aperture yet stacking to get it all in focus without reducing background blur

The former is of most use for small subjects close up, esp if the background is plain. The latter is useful for larger subjects with a messy background. For medium-sized subjects on a plain background, then I don't think it's necessary since an aperture of (say) f8 or f11 will probably get it all in focus on one shot. I think this is true for your leaves and conker shot.

My original photos here all fall into the second category and I shot them wide open with the 12-40.

[sapper]

F8 does not cover the distance from front to back on this shot. I will post it here.

[pdk42]

Here's another test - this time with something that will stack in-camera. All at full size (after a bit of cropping).

Summary - all are OK, except for Hugin, which is a mess.


1) In camera




2) Photoshop



3) Zerene



4) Helicon



5) Hugin

[sapper]

Here is one at f4 with the 120-100mm which I prefer for this distance.

[sapper]

Taken at f8 in. response to Paul.

[pdk42]

Yeah - you're right (why should I ever have doubted it!!). I thought at first glance that it was photographed from above onto a flat surface - but I can see now that it isn't!

[BDennis]

Love the flower shots, these are great.

I’ve come to like the in camera stacking - one of my favourite features. I often find the high quality stacked JPEG is fine with a quick edit. I have sometimes stacked the RAWs in OM Workspace as you can cut out the really OOF ones. It is tiresome slow to use though! Wondering how much better WS will be on a M1 or M2 Mac when I can upgrade.

Thanks for the inspiration!
Bill

[pdk42]

I agree that the SOOC stacks are pretty good. I often find it hard to beat them using Photoshop. As to Oly WS on M1 Mac - it's still as slow as molasses!

[BDennis]

Oh bad news on WS then, even on an M1 Max Mac? How do they write code that runs so slow these days, it must take some doing!

[MikeOxon]

Here's another test - this time with something that will stack in-camera. All at full size (after a bit of cropping).
Summary - all are OK, except for Hugin, which is a mess

An interesting comparison. I use 'CombineZP' which used to be available for free but Alan Hadley's website seems to have disappeared. I'd be interested to see how it compares, if you happen to have a copy.
A major advantage of stacking is that while it increases the effective zone of focus when using a wide aperture, the sharpness still falls off rapidly outside the zone. Optimising the number of steps and aperture is a tricky game, if you want optimum results. I tend to use an iterative approach, viewing my earlier takes on the computer and then altering the settings accordingly. This is fine if you are working with a captive flower indoors but not so easy 'in the field'!

[pdk42]

There are various download sites that still have CombineZP available, but I no longer run a Windows PC so I can't really test it properly. I say "properly" since I do have a VM running Windows, but since the Mac M1 is an ARM CPU, the copy of Windows is for ARM64. To run a Windows Intel EXE, Windows uses an Intel to ARM machine-code interpreter. This results in pretty poor performance, esp when Windows itself is in a VM.