I've been playing around with some focus stacking. Tried a few tools, mostly produced poor results or needed heavy adjustment after. Then I tried focus-stack. First time through with no fiddling it produced this:
This was 38 frames at f/16, 1/25s, ISO 500 on a Nikon Z6, with a Nikkor 50/1.4G on an FTZ with a 12mm extension tube.
I was impressed, it's a command-line tool, but since it actually does the job, in the end a load simpler than quite a few of the GUI tools I tried.
did a great job. side note you have a couple of hot pixels.
Agreed with the first comment. I think the strategic dust and scratches camouflage any hot pixels!
David
Thanks Don, got them spotted, will map them out.
That the catch with this close-up stuff. I went over it with an IPA wipe before taking the photo.
no they are a pain shooting stacks and so is dust. i dont know why they move in a line 🤨
I also played around with focus stacking a bit. A lot of the 'guides' don't really talk about how much cleanup work there is in a good stack.
When I have time (if/when I retire?😟) I may give this one a go.
Geometry correction for focus stacking - same place in the original shots, get moved as the shots are corrected for stacking.
Which was why I was surprised that this one produced a result like this straight off.
thanks. never knew what caused there inconsistancy throughout the image. had to clean my a74 sensor today it was so dirty ,cleaned it twice.
did get a few good shots. took all day ,and then let the little spider free at the end of the session. bit out of practice and waiting for my new 10x to arrive.
Thanks for the link to focus-stack , I have used a number of focus stacking options with various degrees of success or failure 😀 I will give this a try it looks promising. Would you not have got even better results using a more optimal aperture
Try focus-stack. I've only done one image with it - but nothing else I tried got it close to acceptable.
Interesting. Possibly I could have gone lower. Bare DOF wasn't a lot even at f/16, and I didn't know when I shot it exactly how much the Z6 would step each photo. Here's one member of the stack:
I haven't personally tried any focus stacking, but my guess is that ultimate sharpness must also be accompanied by very fine steps in focus distance, otherwise you can wind up with visible periodic functions of sharpness vs distance. Shallow DOF also makes a more abrupt beginning and end of focus, depth-wise. That may be desirable in some cases, but not in others. One could conceivably use a mix; fine steps with very shallow DOF over the middle range, with tapered f-numbers at the end of the range, like so:
f/32
f/16
f/8
f/4
f/4
...
f/4
f/4
f/8
f/16
f/32
The higher f-numbers at the ends shouldn't soften any depths except their own, because the focus stacking software chooses the sharpest frame for any point on the subject.
That might give a more natural look, when the range of focus does not cover a subject completely. Some of the examples I've seen of focus stacking show the focus starting or ending abruptly on a subject. Of course, if the range of focus completely engulfs the subject against a distant background, then there is no point in tapering the ends of the range.
You're right, John, of course ideally the f-number doesn't want to be the same for each shot. However, it would be a real pain adjusting it for each one. My Z6 has a stacking function which takes a burst racking focus as it goes. It doesn't allow to rack the aperture as well. Of course, if you were building a custom macro camera as @JimKasson is, then you could organise that.
Maybe, but tricky. The lenses I'm using for macro mostly don't have electronically controlled diaphragms. At high magnification, you don't want to touch the camera or lens -- or even breathe hard if you're nearby -- during the exposure sequence.
Take a few sequences, setting different apertures for each one?
You can put a stepper motor drive on the diaphragm ring 😉
Moving during the sequence might not be such an issue, since the frames need to be aligned and transformed to correct magnification differences as you focus anyway.
