Focus Stacking: Focus Never Changes

Question: ‘I tried focus stacking, but the focus does not change.  It’s all the same focus.  How do I fix this?’.

Answer: This is due to an incorrect focus mode on the body.Set it to the mode where focus is not attempted or required to capture an image in live view.

Sounds simple, doesn’t it?  First, let’s review some stacking basics:

The focus stacking feature commands the focus motor in the body or lens to change for every Slice(image) that is captured for the stack.  The amount the focus changes per slice is controlled by the Step value.  The amount of the focus change is the Step. 

The total amount of focus change is Slice x Step.

You can simulate stacking by clicking on the ‘<<‘ and ‘>>’ buttons in the Stacking tab.  Clicking those buttons should move the focus.

When focus stacking, the program clicks that ‘>>’ button, then clicks on the ‘Shoot’ button (the one with the icon of the human body at the top of the screen) for you.  It does this once per slice.

When the eprogram commands the body to Shoot, it requires that the body will not try to focus before the capture, since we are move the focus ourselves for each slice.  Camera bodies have all sorts of focus modes: focus modes for live view, and other focus modes for while it is not in live view.  Focus modes that focus on a single area of the image, focus modes for the nearest human face or moving object. Lot’s of modes.

For focus stacking, we need to set the body so that the body does not attempt to focus, or require focus while capturing an image in live view. 
This is usually called ‘Release Priority’ on most bodies, but it varies.  The actual focus mode (af-s, af-c, af-a, af-?) is also different, depending on the body, so you will need to get your body manual out and prepare to dig throught the body LCD menu.  We gave up documenting the settings required to do this a long time ago, since it varies per body and can even vary per firmware version.

The Test

How will you know that you have the correct mode?  It’s simple.

1. Disconnect the USB cable from your camera.
2. Power-on your camera, and go into live view.
3. Put the lens cover on the lens.
4. Listen closely to the lens/body.  Put your ear right up next to it.
5. Press the shutter release on the body.  You should hear an immediate click without hearing the focus motor activate first.
6. If it doesn’t click (release the shutter), then it is requiring focus before release, and that is not what we want.  It can’t focus because the lens cap is on and it is completely dark.  We need to tell the body to forget about needing focus.  We need it to just shoot anything, focus not required.

So if your body can’t do this, you need to open the manual and find the mode required to do this.  If googling for an answer, usually ‘D800 release priority’ or similar query will find others with similar questions and maybe some answers.

Some tips for trying to find the correct setting:

Do this while untethered.

1. Most bodies have separate focus mode settings for live view, and a different set of settings for non-live view.  You need the live view focus mode settings.
2. For most bodies, you need to be in live view before changing the setting.
3. Some lens motors are very quiet and you need to listen very closely to hear if it is trying to change focus.  If you still can’t hear it, take the lens cap off and focus on something across the room.  Then put the lens cap back on and try again to hear it.  Since we changed the focus position, you should be able to hear it moving to another position.
4. This works on all Nikon bodies, except some early D5000/D90’s.  It isn’t possible to get the correct mode on those bodies at all.
5. The body usually has a focus lever switch or mode that is AF or M.  Make sure you set it to AF.  Even though we aren’t auto-focusing while stacking, the AF mode allows us to still control the focus motor.  M (manual focus) mode won’t work at all.
6. On the lens, set the switch it to M/A or equivalent.  Even though we aren’t auto-focusing while stacking, this mode allows us to still control the focus motor.  M (manual focus) mode won’t work at all.

That’s it.  Easy!