Do you always use widest aperture for outdoor portraits?

[rpcrowe]

Many of us enjoy shooting at our widest aperture for outdoor portraits in order to achieve the most narrow DOF which separates your subject from the background. Like this portrait done with an 85mm lens wide open at f/1.8 which totally obscures the background and produces nice bokeh...



However, there are times in which the most narrow DOF is not all that desirable and that could be in fashion shots in which the garment rather than the model is the main subject of the shot. Then, shooting at a smaller aperture of say, f/2.8 or f/4 (or even f/5.6) may be desirable. This also opens the door to photographers who don't have a wide aperture lens, such as folks who shoot with kit lenses.

I enjoy Andrew of Beyond Photography Channel on YouTube. He is a very witty Singapore based photographer who sometimes comes up with good tips and ideas...
https://www.youtube.com/watch?v=Ha1u5iMOMhw&t=541s

I like his idea in this video of using a small shoot-through umbrella and a hotshoe flash as a hair light in outdoor shoots. The small lightweight unit would be easy to transport and probably would not be impacted by wind quite as much as a bigger modifier. I will probably bring along a unit like this for my next outdoor model shoot...

[DanK]

In a case like this, the question in my mind is: do you want the ears out of focus? And the side of the head in front of the left (camera right) ear? If not, one needs a smaller aperture.

[Manfred M]

At one time (certainly when I first went to a full frame camera and fast lenses), that was certainly my preferred way of shooting outdoor, natural light portraits.

Over time, my shooting decisions have become far more nuanced and I pay a lot more attention to setting up my subject in a way that the background is part of the image, rather than something to be avoided. That is not to say that I don't continue to shoot with a shallow DoF, but more that I tend to think about it. Sometimes I go for an image that is sharp throughout and at other times I look for a background that is less sharp.

As a general rule, I tend to only carry a single light for location shoots but will supplement with a reflector. Depending on the situation I will often shoot so that the subject is well lit and the background is 2 or 3 stops underexposed for effect. I will sometimes enhance this in post. I have never used a hair light or rim light during a location shoot (yet).


Examples - All single light shots (large soft box):

1. Location shoot where I shot wide open to blur the background and the "hair light" is back lighting by the sun.





2. Location shoot where the background is in focus as well at the subject. Both are "properly exposed". Shot at f/6.3





3. Location shoot where the subject is properly exposed but the background is underexposed and shot at a small aperture (f/8).

[

[xpatUSA]

In a case like this, the question in my mind is: do you want the ears out of focus? And the side of the head in front of the left (camera right) ear? If not, one needs a smaller aperture.

In this particular case, those riveting eyes appear to be the main subject, unless that was accidental - or the inevitable result of shooting at max aperture by rote. In other words, the observed OOF of other features on the head could be quite acceptable.

However, generally speaking, the type of background ought to influence the choice of aperture, I would have thought. Like the entire Bay Bridge should be OOF but recognizable, so that the viewer is informed of the Californy location ... look Mom, here I am in San Francisco!

On the other hand, the background in the OP looks well worth blurring out.

[DanK]

My comment was a lot less sophisticated. I do a large number of candids of kids. (I never post them publicly, which is why none have ever appeared here.) In that kind of work, the backgrounds are often awful, so blurrier is better, but having part of the head out of focus is often not what I want. So, it becomes a balancing act. With a FF camera, I usually end up compromising at f/4.0 or so.

[Shadowman]

Rarely, whenever I hear of someone shooting wide aperture its always this or that reason and often I'm not that interested in achieving the same look or don't have a distracting background which might warrant doing so.

[William W]

Though OoF Background - and - extremely shallow DoF employing the use of large Apertures are related, the former is not solely depended on the latter: the element of Subject to Background Distance(*1) is a consideration and whilst not always possible to control for Candid Portraiture, it's good to remember that if you can get the Subject(s) far enough away from the background you can use a relatively small aperture and still have an OoF background.


"Italian Passion"
(EOS5D Series Camera; 24 to 105/4, at about 95mm, F/5.6 or F/6.3)

WW

Footnote (*1) to be technically correct, it is the ratio of the distances -
Camera to Subject :: Subject to Background

[xpatUSA]

Though OoF Background - and - extremely shallow DoF employing the use of large Apertures are related, the former is not solely depended on the latter: the element of Subject to Background Distance(*1) is a consideration and whilst not always possible to control for Candid Portraiture, it's good to remember that if you can get the Subject(s) far enough away from the background you can use a relatively small aperture and still have an OoF background.


"Italian Passion"
(EOS5D Series Camera; 24 to 105/4, at about 95mm, F/5.6 or F/6.3)

WW

Footnote (*1) to be technically correct, it is the ratio of the distances -
Camera to Subject :: Subject to Background

Bill, is there a technical reference for that?

I'm wondering if that ratio might be more properly Camera to Subject :: Camera to Background?

I'm prompted by Merklinger's treatise on focusing and DOF; see illustration Fig. 11 on document page 28.

http://www.trenholm.org/hmmerk/TIAOOFe.pdf

I do realize that the said illustration is about DOF but still relevant, I reckon ...

[William W]

Hi Ted.

No technical data at hand. I learned it long ago, at Technical College - it's etched now, as I wrote it, perhaps not a mathematically correct etching.

I am familiar (too familiar for my liking) with Merklinger. That was in our final examination papers.

Now that I pause to think, I understand what you're saying. "I'm wondering if that ratio might be more properly Camera to Subject :: Camera to Background?" You're probably correct. But thinking mathematics is hurting me at the moment, so I don't want to mount an argument either way.

***

Over the years I've adapted lots of the theory that I have learned to useful practice/technique, probably at the loss of mathematical precision in some situations: even though I retain a love of mathematics.

For this situation (i.e. Portraiture at common/typical Subject Distances) - I find that using the Camera to Subject :: Subject to Background ratio - then 1:3 is 'usually OK' to get a 'reasonable BGB', but 1:5 is really much better.

In the sample image it was at least 1:5, probably more like 1:6.

Anyway, for my (aging and single malt affected mind), Camera to Subject :: Subject to Background ratio is easier to reckon in the field.

Hope that assists, I doubt I can provide much more.

Bill

[Manfred M]

Interesting discussion Biil and Ted.

Going back to my training on this subject (almost 50 years ago), I was taught very much along the lines you suggest, Bill. The commentary dealt with what was sharp in front of and behind the subject. My suspicion is that photographers just passed on what they saw in practice without going into the math. None of the commercial photographers I knew had any interest in math and physics per se.

When in comes to absolutes, I'm quite certain that Ted and Harold Merklinger are correct and the actual drivers are the distance from the camera to the specific areas in question as an absolute reference. From a practical photographic standpoint, the rules of thumb are far more useful from a practical standpoint as photographers tend to deal with the relationships relative to the subject. We generally want the subject in sharp focus; we want the areas in front of the subject to be reasonably sharp so that they do not end up as distractions and we want the area behind the subject to be soft so that they do not compete with the subject.

[xpatUSA]

Bill and Manfred,

The more I think about the ratio that I mentioned; I think it may act to normalize 'the number', i.e. the number stays the same whether talking macro, portrait or landscape. Thus "1" represents the background being at the same distance as the subject, irrespective of the subject distance from the camera. "2" represents background twice as far as the subject and, interestingly, a number less than one represents foreground! It also avoids any awkwardness due to a distance becoming zero for some reason and certainly avoids obfuscation due to DOF or hyperglycemic distances.

Of course, it's all based on angles in the end - and "most of us" would rather not think about those ...

[William W]

Aside:

. . . it's all based on angles in the end - and "most of us" would rather not think about those ...

It is NOT thinking about angles that does me in, it is the bending.

[xpatUSA]

Aside:

It is NOT thinking about angles that does me in, it is the bending.

LOL.

Some humble pie, My earlier post re normalizing contains some hog-wash ... both ratios normalize and either one obviously works well enough.

This is interesting, and almost on-topic:

https://www.diyphotography.net/defin...feet-nonsense/

The movie is cool, lots of 3D animation.

"Dolly Zoom" hmmmm ...

[Manfred M]

Of course, it's all based on angles in the end and "most of us" would rather not think about those ...

You are far more numbers driven than most photographers. I am often accused something similar by people at my photo club and I am far less numbers driven than you.

In my case, I am simply interested in the math and physics behind what my camera and lenses are doing, but am much more interested in the blend of the physics (and math that is used to explain the physics), the impact of how the human visual system processes that data (i.e. physiology) and of course the psychology (which is really a significant part of what drives our likes and dislikes in the final image).

I suspect our backgrounds make bias us in that direction.

I often dealt with engineers could be too numbers driven. I always asked them two questions when they were assigned to work on projects I was responsible for delivering:

1. Was the data we would derive from the proposed analysis going to result in meaningful information in moving the project forward?

2. Was it critical to do the analysis now or should we wait to see if doing it would be more or less meaningful down the road?

I am a firm believer that one can get into a state of "paralysis through analysis" all to easily. If the engineering work was critical to my ability to deliver the project on time and on budget, I was "all ears", but it the work would not have meaningful impact on the final product, why would I waste time and effort on it?

Numbers are important, but only to a point. If doing the work gets me information and understanding at a level that results in a stronger final image, they I am certainly interested. If not, I'm with Bill, something to consider over a nice single malt.

[mariah]

For taking portraits I normally use to blur a little less in the background. The photo looks unnatural if the background is blurred too much. I would always prefer less blur photos.

[William W]

For taking portraits I normally use to blur a little less in the background. The photo looks unnatural if the background is blurred too much. I would always prefer less blur photos.

It's difficult to quantifying "I normally use to blur a little less in the background" and "looks unnatural if the background is blurred too much" without examples; however, the commentary generally seems to imply an at odds view with the mainstream thinking.

On the point of "looks unnatural", I think that one premise for Photographers seeking to background blur is to achieve in a 2 dimensional product what the eyes and brain do in our three dimensional world: look at the person next to you and focus on their eyes - the background is OoF.



The Photographers' passion to achieve "Subject Isolation", is not limited to Photographers - Painters and Sketch Artists do similar - and Photographers don't do it only for Traditional style or Candid Portraiture: other examples where Subject Isolation via Background Blur adds emphasis to the Image; its Meaning; and Story -







WW
Images © WMW 1974~1996 / AJ Group Pty Ltd (AUS) 1997~2020

[Manfred M]

For taking portraits I normally use to blur a little less in the background. The photo looks unnatural if the background is blurred too much. I would always prefer less blur photos.

What you are saying is personal taste and nothing more. I look at it much the same way Bill does; what am I trying to do with the image?

Sometimes I want a very wide depth of field where everything is quite sharp and at other times, I want a very shallow depth of field so that the background does not compete with the subject. When shooting in a studio setting, I generally use a narrow aperture to get a large depth of field because I am total control of the background.


1. This is an outdoor natural light shot. I wanted a soft and out of focus background that does not compete with the subject.






2. This is another outdoor shot with fill flash. Here I wanted the background to be sharp to give that old time view to the whole scene.






3. This is a studio shot where I shot with a small aperture. The background is simple and complements the model

[Chataignier]

I agree with Manfred that it is a matter of taste, however, in the original question you said "....widest aperture" : lets not forget that very few lenses give their best resolution/sharpness etc when wide open. I try to factor that in and back off the aperture a bit where the other criteria of the shot permit.

[billtils]

I agree with Manfred that it is a matter of taste, however, in the original question you said "....widest aperture" : lets not forget that very few lenses give their best resolution/sharpness etc when wide open. I try to factor that in and back off the aperture a bit where the other criteria of the shot permit.

You beat me to it David! I create Aperture/Sharpness curves for all my lenses; none are/were sharpest fully open and one that I no longer own (and that was responsible to my adopting this practice) was dreadful until stopped down by at least two full stops.

Having said that, all the "wide open" examples in this thread are sharp (other than for DoF fall off in some cases).

[Manfred M]

David / Bill - While that may be true, no one that I know who buys fast lenses does so with the intent of always stopping down to maximize resolution. We buy them so that we can shoot them wide open and frankly they are designed to give good results used that way. We could have saved a lot of money (and weight) opting for a slower lens.

What is a fast lens? For a zoom f/2.8 or faster. For a fixed focal length lens, f/1.4 and faster.

It's not just about resolution, but also low light performance and shallow depth of field. People seem to ignore that and concentrate on resolution.