topic Re: The Best Lenses for Minimal Depth of Field in EF & RF Lenses

The Best Lenses for Minimal Depth of Field

rs-eos — Thu, 15 Feb 2024 19:43:18 GMT

When wanting to achieve the narrowest possible depth of field, there are several factors. Three of which are focal length, aperture, and minimum focusing distance.

What follows is a current listing of mostly RF L-series lenses (with two EF L-series lenses sprinkled in which I own):

Key: MFD (Minimum Focus Distance), DOF (Depth of Field).

RF 70-200mm f/4 L @ 200mm, 60 cm MFD, 0.14 cm DOF
RF 100-500mm f/4.5-7.1 L @ 500mm, 120 cm MFD, 0.14 cm DOF
RF 70-200 f/2.8 L @ 200mm, 70 cm MFD, 0.15 cm DOF
RF 135mm f/1.8 L, 70 cm MFD, 0.23 cm DOF
RF 24-105mm f/2.8 L @ 105 mm, 45 MFD, 0.24 cm DOF
RF 800mm f/5.6 L, 260 cm MFD, 0.25 cm DOF
RF 28-70mm f/2L @ 70mm, 39 cm MFD, 0.31 cm DOF
RF 24-105mm f/4 L @ 105 mm, 45 cm MFD, 0.34 cm DOF
RF 50mm f/1.2 L, 40 cm MFD, 0.4 cm DOF
RF 24-70mm f/2.8 L @ 70mm, 38 cm MFD, 0.41 cm DOF
RF 1200mm f/8 L, 430 cm MFD, 0.44 cm DOF
EF 135mm f/2 L, 90 cm MFD, 0.45 cm DOF
EF 50mm f/1.2 L, 45 cm MFD, 0.51 cm DOF
RF 100-300mm f/2.8 L, 180 cm MFD, 0.51 cm DOF
RF 400mm f/2.8 L, 250 cm MFD, 0.56 cm DOF
RF 85mm f/1.2 L (both DS and non-DS), 20 cm MFD, 0.64 cm DOF
RF 14-35mm f/4 L @ 35mm, 20 cm MFD, 0.65 cm DOF
RF 200-800 f/6.3-9 @ 800mm, 330 cm MFD, 0.69 cm DOF
RF 15-35mm f/2.8 L @ 35mm, 28 cm MFD, 0.95 cm DOF
RF 600mm f/4 L, 420 cm MFD, 1.01 cm DOF
RF 10-20mm f/4 L, 25 cm MFD, 3.47 cm DOF

Takeaways:

Sometimes, it's not lenses with the widest apertures that will produce the narrowest results.
The top prime (hurray!) is the RF 135mm f/1.8 L
The top zoom is a tie between the RF 70-200 mm f/4 L and RF 100-500mm f/4-7.1 L. Though the 70-200 f/2.8 version is just 1/10 of a millimeter behind them, so practically a three-way tie.

Re: The Best Lenses for Minimal Depth of Field

Tronhard — Thu, 15 Feb 2024 19:53:59 GMT

Ricky, this is a very comprehensive list!
Just one point ... for me the actual DoF depends on:

Focal length - the longer the shallower the DoF
Aperture - the smaller the f/stop the shallower the DoF
Distance to subject: (as opposed to minimum focusing distance) the closer the subject the shallower the DoF. I totally get your point that the closer one can focus, the less DoF one can get and I think that is more the theme of your post.
On a more general basis. To me that is a function of the distal relationship with the subject, rather than the potential minimum distance, so the variation in DoF relative to subject distance extends out past that, as per this:

What do you think?

Re: The Best Lenses for Minimal Depth of Field

rs-eos — Thu, 15 Feb 2024 19:55:13 GMT

Wouldn't minimum focusing distance be equal to distance to subject?

Re: The Best Lenses for Minimal Depth of Field

Tronhard — Thu, 15 Feb 2024 20:06:13 GMT

Not really. Minimum focus distance indicates the closest potential distance that a lens can find focus on a subject. As I understand it, subject distance is a variable from that (minimum focus distance), out to infinity. So, distance to subject could be 1m, 10m, 100m or a km and as that value increases, so does the DoF.

So in this diagram, Minimum focusing distance is #3, while subject distance #9

Re: The Best Lenses for Minimal Depth of Field

rs-eos — Thu, 15 Feb 2024 20:25:14 GMT

Gotcha. I still think they are equivalent though for this exercise since the distance between the actual focal plane and the "start" and "end" of the DOF region is mere millimeters for most part.

Re: The Best Lenses for Minimal Depth of Field

Tronhard — Thu, 15 Feb 2024 20:42:13 GMT

I totally agree that for the absolutely smallest DoF, the minimal focusing distance will be applicable. I am simply making the observation that this is a relationship of subject distance that continues as the it varies from that - so more of a generalized observation that actually underpins your point - I hope!

Re: The Best Lenses for Minimal Depth of Field

kvbarkley — Thu, 15 Feb 2024 20:40:37 GMT

If you set it at the minimum focus distance, aren't you cutting the DOF in half since, by definition, nothing in front of the MFD will be in focus?

Re: The Best Lenses for Minimal Depth of Field

rs-eos — Thu, 15 Feb 2024 21:25:27 GMT

Good question!

Re: The Best Lenses for Minimal Depth of Field

p4pictures — Fri, 16 Feb 2024 10:50:28 GMT

Great set of information, I use a TS-E 90mm f/2.8 lens when I want to be exceptionally selective with depth of field, maybe not the amount but the placement of it due to tilt.

Re: The Best Lenses for Minimal Depth of Field

johnrmoyer — Fri, 16 Feb 2024 11:22:43 GMT

Good stuff from all. Thanks @RS-EOS and @Tronhard . In case some who are less knowledgeable might read this, here is more.

One more thing to consider for depth of field is circle of confusion. This will depend upon spacing of pixels on sensor, viewing surface for the photo after it has been made (print or screen), viewing distance, and eyesight ability of the person viewing the photo. This helps define what is in focus and what is out of focus.

Depth of field will be different for a photo printed and hung in a gallery with a rope to keep people at a distance compared to viewing on a screen where a person may zoom in to look at detail.

There is a simplified explanation of depth of field and circle of confusion at: https://www.cambridgeincolour.com/tutorials/depth-of-field.htm (Some who post on forums do not like the way this site simplifies things, but I find it helpful.)

Canon support has: https://support.usa.canon.com/kb/index?page=content&id=ART157204

Permissible circle of confusion

DEFINITION:

A limiting circle of confusion within which a spot image can be identified as a spot in the photo lens, etc.

DESCRIPTION:

The range of sharpness of an image (picture) is determined by taking the resolving power of the human eye into consideration. A circle of confusion within the limit where the image is actually perceived as sharp is called the permissible circle of confusion (equal to or similar to the minimum circle of confusion). In commonly used photo lenses, the basis used to calculate the depth of field, hyperfocal distance, etc. is generally 1/30mm for a 24x36mm format or 1/20mm for a 6 x 6 cm format.

There is a draft copy of the CIPA standard on image stabilization at https://www.cipa.jp/image-stabilization/documents_e/DC-X011-2014_E.pdf and PDF page 42 of 56 has a discussion of circle of confusion.

Re: The Best Lenses for Minimal Depth of Field

johnrmoyer — Fri, 16 Feb 2024 11:27:44 GMT

I expect that the minimum focus distance specification for a lens will be based upon someone's idea of a correct or standard circle of confusion. Depending upon how the photo will be viewed, one might be able to focus on an object closer than the minimum focus distance in the specification or may need to focus at a further distance than the specification.

Also, for a zoom lens, a single distance is usually given for minimum focus distance, but that will sometimes change when one zooms.

Re: The Best Lenses for Minimal Depth of Field

rs-eos — Fri, 16 Feb 2024 11:37:04 GMT

Some of Canon’s zooms do have the same MFD at all focal lengths. Others do vary. When building the list, I always took the maximum focal length and the documented MFD at that value.

One lens I didn’t mention was the RF 100mm f/2.8 Macro. I wanted to omit macro lenses as they would have a whole different level of DOF. This lens would be 0.07 cm.