R5 focus stacking - focus increment?

[Bazsl]

Is there a definitive explanation of the Focus Increment setting in the R5's focus stacking feature? For example, if I set the focus increment to 10 does that mean that the R5 will shift focus by more than the depth of field? If not, why not shoot with a focus increment of 10 all the time? After reading everything I can find I don't understand why the focus increment setting exists. Why do I need it? Thanks for any information you can point me to.

[Ray-uk]

It depends on the lens in use, as each lens responds differently according to its focusing mechanism. You probably need to carry out some trials to evaluate the focus shift for the lens you are using.

As a guide a 100mm lens at f11 focused at 1:1 has about 1.3mm DOF so the focus increment would need to be about 1.0mm but what this relates to in the R5 numbers would have to be determined by the user.

[Bazsl]

You are able to calculate the DOF for a 100mm lens at 12 inches at f11 so why can't the camera? I appreciate your answer but your answer is a guess and I am looking for something definitive from Canon if it exists. Thanks.

[kvbarkley]

This was the key part of Ray-UK's answer which you glossed over:

"It depends on the lens in use, as each lens responds differently according to its focusing mechanism. You probably need to carry out some trials to evaluate the focus shift for the lens you are using."

The lens control loop thinks in terms of units which are dependent on the lens - not in terms of actual distance units. It would make no sense for a telephoto with a minimun focus distance measured in feet to focus in terms of mm.

[Waddizzle]

---

@Bazsl wrote:

You are able to calculate the DOF for a 100mm lens at 12 inches at f11 so why can't the camera? I appreciate your answer but your answer is a guess and I am looking for something definitive from Canon if it exists. Thanks.

---

The camera will only focus where you tell it to look using an AF point.  It has no idea what it is looking at, either.  You have to define the entire image gathering process.  

It is not all that different from setting up an intervalometer for a theme lapse exposure.  Both tasks require some thought, planning, and setup on the part of the photographer.

[DougFraser]

I am wondering how people illuminate close up subjects when focus stacking? I normally use a ring flash for my macro work but now that I am getting an R5 I am looking forward to focus stacking by the camera but I don't think this allows you to syn with the flash so just wondering if others have this issue and how they are addressing it?

[jrhoffman75]

This is extracted from an article on The-Digital-Picture.com

""... Canon engineers have revealed nothing about the calculation process involved in the Focus Bracketing feature. We can infer that the system is factoring-in the lens (and focal length) in use; the actual lens aperture in effect; and the initial sharp focus distance applied by the photographer. In other words, it’s probably safe to assume that the amount of focus deviation at Level 3, from shot-to-shot with a 100mm macro lens, initially focused at its nearest focus distance and with an aperture of f/4, is different than it would be at level 3 with the 16-40mm lens at f/11, pre-focused at 4 or 5 feet away for the first in a series of landscape shots.""

Quotes on the website (which this is) are attributed to Rudy Winston of Canon.

[Bazsl]

Thanks John. I feel much better knowing that Rudy Winston is as much in the dark as I am. 🙂 It would be very nice if Canon engineering would give us a clue as to the meaning of that one mysterious setting and how to use it.

[Waddizzle]

---

@Bazsl wrote:

Thanks John. I feel much better knowing that Rudy Winston is as much in the dark as I am. 🙂 It would be very nice if Canon engineering would give us a clue as to the meaning of that one mysterious setting and how to use it.

---

This is from the R5 User Guide.  It requires some trial and error to get it "right".

[FloridaDrafter]

---

@Bazsl wrote:

Is there a definitive explanation of the Focus Increment setting in the R5's focus stacking feature? For example, if I set the focus increment to 10 does that mean that the R5 will shift focus by more than the depth of field? If not, why not shoot with a focus increment of 10 all the time? After reading everything I can find I don't understand why the focus increment setting exists. Why do I need it? Thanks for any information you can point me to.

---

Hello Bazsl,

I don't own a camera with built in focus stacking, so I use dedicated software to do it. I am curious to know if when you do it with the R5, does the camera give you an option to select "nearest" and "farthest" focus points when you start your stack? I've searched a bit to get the procedure, but haven't found any in depth info on it.

FD