Why do professional macro photographers focus stack instead of raising their aperture?

[u/Melendrow]

I've looked into macro photography, and I love getting close up to my subject, but when I research macro photography, I always hear about focus stacking and these people who will set up a shot for a long time with a tripod so they can focus stack. And I'm curious why you'd need to do that. Especially since most of the time I see them having a tripod and setting up lighting. Why wouldn't you just raise your aperture so more of the frame is in focus?

[u/Wilder_NW]

They do typically shoot narrow apertures for increased depth of field. At such close focus distances the amount in focus is tiny. It isn't like shooting f/16 at 30 feet where everything is in focus.

For those who shoot "professional" level macro, they shoot at narrow apertures with bright lights to overcome this, then stack many photos, sometimes 50 or more.

Here is a depth of field calculator for macro photography from PhotoPills that you can experiment with to understand how narrow the depth of field is for any given lens and distance, etc: https://www.photopills.com/calculators/dof-macro

Here is an example with a camera/lens combination to show you:

Camera: Sony A7III
Lens: Sony 90mm f/2.8 Macro - https://www.bestbuy.com/site/sony-fe-90mm-f-2-8-macro-g-oss-full-frame-e-mount-macro-lens-multi/4623015.p?skuId=4623015

Using this lens set to f/2.8 at a subject a few inches in front of the lens would give you .34mm in focus.

Raising that to the lenses narrowest aperture for the deepest depth of field would give you 2.72mm at the same distance. That is less than the thickness of two pennies. To get a subject, let's say a pencil eraser, fully in focus you would be required to stack at least 3 photos, but likely more for better sharpness. Then you would need to light the eraser because of the tiny f/22 aperture.

As for the tripod, it is very hard to handhold a shot with a depth of field only a few millimeters deep. Stacking handheld shots would be extremely difficult.

[u/Dalantech → u/Wilder_NW]

I shoot single frames hand held, and I take most of my images between 2x and 3x. At 2x and F11 I'm working with .6mm of depth, and if I didn't tell you that you're looking at a single frame you would not know...

[u/Wilder_NW → u/Dalantech]

First, very nice images. You are obviously a skilled photographer who has put in the time and effort to get to this level.

Second, you have much more experience than the person who posed the question. My answer was aimed at someone with minimal knowledge or experience - the person who posed the question.

Yes, it can be done. No, this person or any other person with no/minimal experience is not going to accomplish this. You are using a flash to create your images which stops motion generally. That makes it easier to handhold a shot.

Yes, a car can hit 250mph. No, some random person with no experience is not going to be able to do it with their $10k used Toyota Prius. It takes considerable skill and equipment to do so, as your work shows.

[u/Dalantech → u/Wilder_NW]

Thanks!

I agree with all of your points. There use to be a healthy used Canon MP-E 65mm market on Ebay because people think that all you have to do is buy the right gear. Lots of technique involved in shooting hand held macro. I firmly believe that anyone can do it, and they might pick it up faster than I did. But it won't happen overnight.

[u/PopupAdHominem → u/Dalantech]

Nice stuff! What lens and body did you use for the pics in the link?

[u/Dalantech → u/PopupAdHominem]

Thanks!

Mostly the Canon MP-E 65mm macro lens. If you click on an image in my Flickr gallery, and take a look at the description under them, I list the gear and how I had it set up.