0

Recently I photographed some eyewear with my "Canon 24-70 2.8 L" at 70mm (70 mm decision is for a matter of correct ratio between filling the format with subject and it's perspective rendering the client asked for). But, even closing down to f22 the depth of field turns out to be a little too shallow for my needs. Please, do you know if using "Canon 24-70 2.8 L II" or "Canon 24-105mm f/4 L IS II" I could improve DoF? Or, any other Canon lens that could do better at 70mm? Thank you!

  • 1
    Depth of field is only controlled by magnification and aperture. Tilt/shift lenses can slightly change the area in focus, but they won’t magically increase DOF. Focus stacking is the only remedy. – Mike Sowsun Sep 21 '19 at 10:15
6

Have you considered spending less & achieving more?

I'd be heading straight for Zerene Stacker or similar & taking half a dozen shots whilst pulling the focus ring in manual.
This is known as Focus Stacking.

You then wouldn't also be fighting the diffraction limit you get at narrow apertures.

One layer…

enter image description here

11 layers, stacked

enter image description here

I've got better at it since this, but this one shows quite an extreme effect, front to back.

Time taken to shoot approx one minute; to stack, approx one minute - it really is quite a quick process once you got the hang of it.

For something as large as glasses, you could probably do it at f8 in 3 or 4 layers.

You can either pull focus, pull zoom, or get a macro rail thereby moving the entire camera back & forth. I've tried all three & I can't make up my mind which is actually best. After each pull I wait a couple of seconds to reduce any potential shake in the tripod, then have a 1s mirror up delay. I also use a wired release.

  • I think the generic term for this is "focus stacking" (en.wikipedia.org/wiki/Focus_stacking). There are other software options for this and some cameras can do it themselves. – Eric Shain Sep 21 '19 at 16:36
  • 1
    My comment was a suggestion on how to make your otherwise excellent answer better. – Eric Shain Sep 21 '19 at 18:27
  • 1
    @EricShain - Yes, sorry, I was in a rush & kind of missed the obvious intent. Detail added, thanks. – Tetsujin Sep 22 '19 at 8:02
4

Another way is to use a tilt-shift lens, and tilt the lens to have a focus plane that is not parallel to the sensor. To quote this page:

Product photography is a great use for the Canon TS-E 90mm f/2.8 Tilt-Shift Lens - Especially medium and small-sized products such as plates of food, model cars, bottles ...

2

If a 70mm focal length and the distance to object are absolutely required for correct framing, then, aside from aperture, the other variable you can change is the sensor size - smaller sensors give more depth of field with all other variables constant.

If all you really need is a specific framing of the subject, a longer lens, and an increased distance to the subject can give you the same scaling of the subject (although foreground, background, and perspective will be correspondingly different) at the plane of focus, and correspondingly larger depth of field.

  • 1
    +1 Or frame the shot wider and crop afterwards. Less resolution for the final picture, but they can use their existing camera and lens. – Lawrence Sep 20 '19 at 14:28
  • 2
    If the client wants a specific perspective, everything can change except the distance to subject. A crop-frame would require a shorter focal length, which would generate a deeper DoF, but that's an expensive call to make, only to find it's not quite enough ;) – Tetsujin Sep 20 '19 at 14:34
2

Usually, I would say:

It's not the camera, it's the lens.

However, now I say:

It's not the lens, it's the camera.

Some newer cameras have a focus bracketing feature. You take a number of shots with automatically set focus. The feature is fully automatic. Later, you can use focus stacking to combine the focus bracketed shots into one.

The reason you have the difficulty is that you are taking macro shots of a small object. At macro distances, the depth of field is very shallow even if you use a small aperture.

0

If third party lenses for the canon system are acceptable there are a couple that go to f32

For example • Sigma 24-70mm F2.8 EX DG Macro - discontinued but can be found used for £450 • Tamron Di SP AF 28-75mm F/2.8 XR - costs €270 new

That should give you a bit more depth of field, if it is enough will depend on your subject of course.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.