Z6 Focus Shift Step Width Testing

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Being Locked In and with seemingly little better to do I have carried out a little Step Width Test for a Z6 and 105mm f2.8G VR lens and some coins.

The Test consisted of keeping everything common to all shots/stacks except for the Step Width. The aperture was f5.6; front element to subject distance was around 15cm/6inches. Magnification is was around 1.25. Focus Point is the serrated front edge of the Coin. Each Stack consisted of just 10 Images.

Helicon; Method B used throughout.

This is the full frame result at Step Width 1:

SW1-FF.jpg
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The following are actual pixels crops of the various Step Width results.

Step Width 1:

SW1.jpg
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Step Width 2:

SW2.jpg
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Step Width 3:

SW3.jpg
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Step With 4:

SW4.jpg
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Step Width 5:

SW5.jpg
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Step Width 6:

SW6.jpg
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Here is a comparison of Step Width 6 and Step Width 1 side by side (Step Width 1 is flipped):

SW1-6.jpg
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As expected, the differences between each step are less dramatic at the smaller step widths and more dramatic at the higher step widths.

Thanks for looking,

DG
 
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I was thinking that someone might ask for SW 7-10. 😬

Based on what i see here, getting all coins in focus at SW 1-4 at this magnification would take hundreds of images. It also occurred to me that you should be able to do three bottles on their sides at SW 6 with no problem at all?

DG

P.S. It just occurred to me that I neglected to say that each Stack consisted of just 10 Images. I have corrected that omission.
 
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It just occurred to me that I neglected to say that each Stack consisted of just 10 Images. I have corrected that omission.
For the record, when I made my previous request, I had no idea that each of those images you presented are already stacks of 10 images.

It also occurred to me that you should be able to do three bottles on their sides at SW 6 with no problem at all?
I'm also wondering about that and will have to try it at least just as an experiment. So far, I've used only step sizes 1 and 2 when using the macro lens based on Nikon's recommendation to use step size 5 for landscapes and step size 1 for macro shots. Nikon also recommends using step sizes 6 and above rarely for fear of some parts of the scene not being photographed in focus.
 

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When attempting a single macro shot, I always used an f stop of f11, f16 or such depending on the len's sharpest setting. When stacking images, why would one use a more wide open f stop? It seems with a more open f stop you would have a lot more images with only a small area being in focus........
 
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When attempting a single macro shot, I always used an f stop of f11, f16 or such depending on the len's sharpest setting. When stacking images, why would one use a more wide open f stop? It seems with a more open f stop you would have a lot more images with only a small area being in focus........
The reason to use a larger aperture is because the aperture settings you're used to using generally don't render the sharpest possible images. I use f/8 for stacked images even though some tests indicate that it's likely that my macro lens is sharpest at f/5.6. None of these details matter in my mind for small images displayed on the Internet; they come into play only when making large prints or doing pixel peeping. When making just one capture, I've often used the smallest aperture on my macro lens to get the largest depth of field and nobody has ever complained about the sharpness when viewing the image displayed here and on other forums.
 

Butlerkid

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The reason to use a larger aperture is because the aperture settings you're used to using generally don't render the sharpest possible images. I use f/8 even though some tests indicate that it's likely that my macro lens is sharpest at f/5.6. None of these details matter in my mind for small images displayed on the Internet; they come into play only when making large prints or doing pixel peeping. When making just one capture, I've often used the smallest aperture on my macro lens to get the largest depth of field and nobody has ever complained about the sharpness when viewing the image displayed here and on other forums.
I said that I use the f stop that is the sharpest for the lens, in my case f8. My question is why would I choose a more open f stop when stacking?
 
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It seems with a more open f stop you would have a lot more images with only a small area being in focus........
Maybe I've misunderstood your comment, but the point of stacking is to combine just the sharply focused dozens or more shots into 1 stacked composite image. The smaller the focus area the more images you will need to stack (step width and f/ interact too).
 

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You've now confirmed that, indeed, you misunderstood her. :ROFLMAO:
Actually, Nick is agreeing with me... LOL! Shooting wide open (i.e. an a stop of 5.6 versus f8) will result in more images to stack. Stopping down (i.e. using f8 or f11) will result in fewer images to stack.
 
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I now see what the question was!
Ideally, and as Mike notes, also for large prints, shooting at the sweet spot of the lens makes sense.
But the few landscapes I've shot were done at f/8, 11 or 16 so as to limit the number of shoots needed (allowed a larger step width) so all the shots could be taken as fast as possible to reduce the effects of anything moving. I don't shoot macro, but have done a few with extension rings.
 
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Wikipaedia has an article which covers all bases pretty well.

I agree with the f8 theory and most of what has been said.

Consider also, that you might want the Object you are imaging sharp but want the background as smooth as possible. If the object is well enough isolated in terms of extraneous detail then a really smooth bg can be obtained with f5.6 as opposed to f16-22.

Fewer images to stack is not the objective. Helicon (and Photoshop) will handle hundreds of images in a stack. My Objective is to eliminate any oof areas (in the main object) while still using the lens at its optimum aperture. The width of the (automatic) Step Width of the Z6 varies with the aperture so combining all of the variables is an interesting problem.

DG
 
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I hadn't thought about that!
As for numbers, I'm running an old and slow MacBook. . . 🐢🐢🐢
That is another variable, as is the three different "Methods" available in Helicon. I have found on at least two occasions that Method C worked better than either method A or B. Each Method has variables which can be used to get an optimum result AFTER deciding how many images, what f stop etc
 
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The width of the (automatic) Step Width of the Z6 varies with the aperture so combining all of the variables is an interesting problem.
I believe that's true regardless of the device being used, whether it's the controls built into a camera or controls built into an external device, to control the step size and the number of focus-bracketed images being captured.
 
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I believe that's true regardless of the device being used, whether it's the controls built into a camera or controls built into an external device, to control the step size and the number of focus-bracketed images being captured.
Cannot argue with that because I have only ever used the Z6 for this application. It was part of my argument for buying the D****D thing in the first place. ;)
 

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