shallow DOF vs. macro

[stevet1]

I was reading about a shallow depth of field challenge.
In your opinion, is there a difference between taking pictures with a shallow depth of field and macro photography?
What would be the technical differences?
Are there any?

Steve Thomas

 

[Derrel]

macro has to do with reproduction ratio, and at typical macro ranges there is very very little depth of field. Shallow depth of field and macro have absolutely nothing to do with one another, except for the fact that in macro ranges there is scant depth of field and many people today are using a new technique called focus stacking, where multiple frames or computer generated into one final photo with adequate depth of field.

 

[Designer]

I was reading about a shallow depth of field challenge.

What's the challenge?

 

[stevet1]

I was reading about a shallow depth of field challenge.

What's the challenge?

Designer,

It was in the same FotoForum in the Photo Assignments and Technical Challenges sub-forum.
The thread title was "Assign# 3 Shallow Depth of Field"
Assign #3: Shallow Depth of Field
Many of the links are broken, but in looking at some of the pictures that survived, I got to wondering what the difference is between those, and macro photography.
Why would you call it one and not the other?

Steve Thomas

 

[Designer]

Many of the links are broken, but in looking at some of the pictures that survived, I got to wondering what the difference is between those, and macro photography.
Why would you call it one and not the other?

I see, thank you.

The challenge was to produce a photo with a shallow DOF, but it was not specified how to get that shallow DOF.

Given that macro photography naturally has a very shallow DOF, some photographers chose to make a macro shot, which gave them the desired shallow DOF. Just a simple choice of technique.

When you look at a DOF calculator (many free ones online) you see that there are a few variables that affect the DOF, and by maximizing one or more of those variables, you get that shallow DOF.

For your convenience, I will list them here;

focal length of lens
aperture
sensor size
distance from lens to subject

That last one (distance to subject) is what makes macro have such a shallow DOF.

 

[petrochemist]

If the image size on the sensor is less than half life size it's NOT macro
While macro shots usually have fairly shallow DOF they do not have to - if focus stacking is used (or they are taken with a technique like an electron microscope that gives vastly improved DOF)
If a macro subject is planar DOF becomes fairly irrelevant.

Many threads/competitions etc. asking for shallow DOF will specifically ask to exclude macro. A lifesize shot at f/22 will have fairly narrow DOF but it will be deep DOF for this magnification. Very few decent shots are taken at lifesize & f2.8...

A portrait shot is most unlikely to be macro, but will often have shallow DOF. This will be achieved by using a relatively long focal length, a wide aperture & having the background well separated from the subject. Again combining shots from multiple exposures can be used to overcome the limits of lens design. - A panorama stitched from multiple shots of a fast telephoto, can end up with the DOF of the telephoto yet still have the field of view of a wide angle lens.

 

[stevet1]

Okay. I think I understand the nomenclature better.

Thanks everyone.

Steve Thomas

 

[clarc]

yes but you are better off with a dedicated macro lens for better DOF and there are several in the less expensive price range. I have a 100mm Promaster macro lens that I purchased 10 years ago that was reasonably priced and tack sharp to this day
DSC_3458.JPG

 

[480sparky]

A 'dedicated macro' lens won't give you any more DOF. It's all physics. A 50mm 'standard' lens with an extension ring will, all else being equal, produce the same DOF as a 'dedicated' 50mm macro lens.

 

[wfooshee]

This is shallow depth of field, but it's not macro. 85mm f:1.8.

 

[480sparky]

Given there's no official definition of macro, you could call a ham sandwich a macro photo. It's generally accepted that macro starts at a 1:1 reproduction ratio.

 

[Derrel]

Shallow depth of field, but clearly not macro 200 millimeter lens around F 2.5

 

[waday]

Macro and shallow DOF


Spacewalk by Wade, on Flickr

 

[johngpt]

I was reading about a shallow depth of field challenge.
In your opinion, is there a difference between taking pictures with a shallow depth of field and macro photography?
What would be the technical differences?
Are there any?

Steve Thomas

Steve, now that you're getting an idea of the differences between macro and shallow depth of field, wait 'til you open the can of worms regarding bokeh...

 

[Derrel]

Selective focus vs bokeh