What is the Basis of the Optimum Viewing Distance?

[xpatUSA]

For example:

"Common theory dictates that the optimal viewing distance for a print is between 1.5 and 2 times the diagonal length of the print."

https://martinbaileyphotography.com/...n-podcast-532/

I hereby expand the title question to include any medium, not just "the print". For example, I view my 24-inch monitor from about 18 inches which is clearly not "optimal"!

Although I am interested in the basis of the above viewing distance factor, I will not be scooting back to 36-48 inches viewing distance just to look at a full-screen image! Working that factor backwards, if I insist on viewing my images at 18 inches, should they be zoomed out to a diagonal of 9-12 inches? ... sounds a bit silly to me!

Anybody?

[Manfred M]

My understanding is that this comes from the world of painting and drawing and has been adopted in the photographic world.

The optimal viewing distance is in theory, the distance that the artist steps back to to see the developing work on their canvas or sketching pad. The entire work can be viewed at that distance and is the minimum target distance the work should be viewed at.

If you get closer, you are not looking at the image in the way the artist intended. Small flaws in brush strokes or pencil / charcoal lines should not impact the overall impression of the work. If the viewer gets closer, they can see how the artist used technique to create something that looks "right" when viewed at proper viewing distance.

All that translates well to a photograph, for very much the same reasons.

[xpatUSA]

My understanding is that this comes from the world of painting and drawing and has been adopted in the photographic world.

The optimal viewing distance is in theory, the distance that the artist steps back to to see the developing work on their canvas or sketching pad ...

Thanks. Would that distance be related to "framing" where the corners of the canvas are aligned as it were with the corners of the intended scene? I'm thinking of the classic movie director's thumb-and-forefinger routine or indeed a camera viewfinder ...

[DanK]

I don't think the concept of oneoptimal distance makes any sense.

One of the criteria people often use is how far you have to be from a display to apprehend the entire display. This is a factor that is bandied about a lot now that many people buy huge televisions. If you sit too close, you have to scan to see the entire screen. And I do think distances can be too short. I have one narrow hallway in which we have hung a bunch of my prints, and with one exception, they are all only 8 x 10 because it's hard to take in anything larger in such a narrow space.

But leaving that aside, I don't think there is any one optimal distance, and I don't believe that the generalization that if you go closer than 1.5-2.0 x, you aren't viewing it as the artist intended. I suspect artists vary in what they intend, and we only sometimes know. And the best for me depends on the nature of the image. For example, when viewing impressionist paintings (one of my favorite genres), I generally stand back to focus on the gestalt rather than the details of the brushwork, and I only go close when I am curious about how an effect was created. In many cases, I'm guessing that was the intent. In contrast, there are many types of paintings and photographs in which detail is part of what makes the image. In those cases, I often find myself walking back and forth--back for the gestalt, forward for the detail. I do this with some of the Dutch masters, for example. I would hope that people would do that with some of my prints.

[xpatUSA]

I don't think the concept of one optimal distance makes any sense.

Agreed and indeed the link postulates a range, not a single value and the range is of ratios not distances.

One of the criteria people often use is how far you have to be from a display to apprehend the entire display. This is a factor that is bandied about a lot now that many people buy huge televisions. If you sit too close, you have to scan to see the entire screen. And I do think distances can be too short. I have one narrow hallway in which we have hung a bunch of my prints, and with one exception, they are all only 8 x 10 because it's hard to take in anything larger in such a narrow space.

But leaving that aside, I don't think there is any one optimal distance, and I don't believe that the generalization that if you go closer than 1.5-2.0 x, you aren't viewing it as the artist intended. I suspect artists vary in what they intend, and we only sometimes know. And the best for me depends on the nature of the image. For example, when viewing impressionist paintings (one of my favorite genres), I generally stand back to focus on the gestalt rather than the details of the brushwork, and I only go close when I am curious about how an effect was created. In many cases, I'm guessing that was the intent. In contrast, there are many types of paintings and photographs in which detail is part of what makes the image. In those cases, I often find myself walking back and forth--back for the gestalt, forward for the detail. I do this with some of the Dutch masters, for example. I would hope that people would do that with some of my prints.

If the basis is not Art, then we still don't know where the 1.5 to 2X diagonal "rule" comes from.

[xpatUSA]

If the basis is not Art, then we still don't know where the 1.5 to 2X diagonal "rule" comes from.

From a Zaire blog comes this to muddy the waters:

"For the vast majority of photographers, the end goal is rather a displayed print that can be scrutinized at close range (theoretically the optimum viewing distance of an image is the same as the diagonal of the print in question, ergo an 8x10” print is optimally viewed at 12.8” from the print)".

I can not help but think that angles rather than distances are involved. For example, there should be an angle subtended by the human eye where the beheld scene can be grasped without the eyes flitting all over the place. I've often thought that might be about one radian or about 60 deg.

Pardon me for mentioning angles in a photographic forum ...

[xpatUSA]

I can not help but think that angles rather than distances are involved. For example, there should be an angle subtended by the human eye where the beheld scene can be grasped without the eyes flitting all over the place. I've often thought that might be about one radian or about 60 deg.

Found this:

"the main point is that only part of the retina processes the main image we see. (The area of main vision is called the cone of visual attention, the rest of what we see is “peripheral vision”). Studies have measured the cone of visual attention and found it to be about 55 degrees wide."

https://petapixel.com/2012/11/17/the...the-human-eye/

Since 55 degrees is very close to one radian, that would be a viewing distance more or less equal to the width and therefore NOT equal to 1.5 or 2 times the diagonal. In other words, it can not be the basis thereof.

So, we still don't know ...

[davidedric]

A few years ago, my left eye developed a macular hole. This is a condition where the fluid in the eye attaches to, and then pulls away the retina ofthe macula, the real centre of vision.

Ther result was rather disconcerting. Whatever I looked at closely with that eye disappeared - but the hole was small. If you were across a room, for example, your head would disappear. Not sure how much this adds to the debate.

Fortunately, an expert ophthalmic surgeon was able to effect a partial repair - I can see, but it's a bit like an inexpertly rendered plaster wall.

Interestingly, the surgery entails filling the eye with gas, which is gradually replaced by fluid produced by the eye. Of course, the fluid accumulates at the bottom of the eyeball, but it appears from the top. Nicely illustrating that our vision really is inverted.

[Manfred M]

I don't think there is a specific numeric value here as to the appropriate viewing distance. The general intent of the "rule" is that the viewer should be able to see the entire image, from edge to edge, not counting any frame.

The aspect ratio is going to be important, if that is the view we are using. A 3:1 panoramic image needs to be viewed differently than a square format image that has the same image area as the pano. Hang the pano vertically, and the viewer will have to be further back still.

Carefully said, one of the "advantages" of viewing on a screen is that the minimum viewing distance will be dictated by the screen size, not the actual image size, and that will be a constant.

[xpatUSA]

A few years ago, my left eye developed a macular hole. This is a condition where the fluid in the eye attaches to, and then pulls away the retina ofthe macula, the real centre of vision.

The result was rather disconcerting. Whatever I looked at closely with that eye disappeared - but the hole was small. If you were across a room, for example, your head would disappear. Not sure how much this adds to the debate.

Fortunately, an expert ophthalmic surgeon was able to effect a partial repair - I can see, but it's a bit like an inexpertly rendered plaster wall.

Interestingly, the surgery entails filling the eye with gas, which is gradually replaced by fluid produced by the eye. Of course, the fluid accumulates at the bottom of the eyeball, but it appears from the top. Nicely illustrating that our vision really is inverted.

Some time back, Dave, my maculae swelled up. Being shortsighted, an unexpected effect was an improvement in my far vision.

Less fun was being injected with stuff into the eye and, yes, although the injection was made at the bottom of the eye, the swirls appeared at the top.

[xpatUSA]

I don't think there is a specific numeric value here as to the appropriate viewing distance. The general intent of the "rule" is that the viewer should be able to see the entire image, from edge to edge, not counting any frame.

Taking that general intent as being offered as the basis for 1.5 to 2X the diagonal, For my myopic self and while gazing at my 24-inch screen, I find 1.5 to 2X to be a bit far ...

The aspect ratio is going to be important, if that is the view we are using. A 3:1 panoramic image needs to be viewed differently than a square format image that has the same image area as the pano. Hang the pano vertically, and the viewer will have to be further back still.

Agreed.

Carefully said, one of the "advantages" of viewing on a screen is that the minimum viewing distance will be dictated by the screen size, not the actual image size, and that will be a constant.

The thread is about the range of optimum viewing distance, though.

My screen is 1920x1200px, just under 3:2. While I normally view at 18", my 'cone of visual attention' does tend to blur out stuff in the corners. Viewing at 24 inches (an oft-stated optimum in the literature) I do "see" more of the image. At 32 inches the blur is more uniform and, at 48 inches, the image is more or less equally blurred due to my myopia. In this context, "viewing" means staring fixedly at the center of the screen.

It would be so nice to hear of some learned paper on human vision which clearly supports the "1.5 to 2X the diagonal" metric but I've yet to find one ...

... to paraphrase Crocodile Dundee in New York - "that would be a basis".

[DanK]

Found this:

"the main point is that only part of the retina processes the main image we see. (The area of main vision is called the cone of visual attention, the rest of what we see is “peripheral vision”). Studies have measured the cone of visual attention and found it to be about 55 degrees wide."

https://petapixel.com/2012/11/17/the...the-human-eye/

Since 55 degrees is very close to one radian, that would be a viewing distance more or less equal to the diagonal and therefore NOT equal to 1.5 or 2 times the diagonal. In other words, it can not be the basis thereof.

So, we still don't know ...

I assumed that something like this was the basis for the viewing distance recommendations for TV screens.

What this doesn't take into account is that people both view and process visual information differently. One would have to take eye-movement patterns into account, I think. People don't stare at something for a long time without moving their eyes. presumably, some people move their area of main vision more than others, and that might be relevant to their optimal distance. People use eye-tracking technologies in all manner of research, and perhaps it could be used for this purpose as well.

[xpatUSA]

I assumed that something like this was the basis for the viewing distance recommendations for TV screens.

What this doesn't take into account is that people both view and process visual information differently. One would have to take eye-movement patterns into account, I think.

Which I assume is why we often see a range in the literature rather than an exact ratio.

People don't stare at something for a long time without moving their eyes.

Which is why I said just now: "In this context, 'viewing' means staring fixedly at the center of the screen.", perhaps while you were typing ...

With no references offered so far apart from in the OP, we still don't have a supported basis for 1.5 to 2X the diagonal.

[DanK]

With no references offered so far apart from in the OP, we still don't have a supported basis for 1.5 to 2X the diagonal.

And I doubt a persuasive one exists.

[xpatUSA]

With no references offered so far apart from in the OP, we still don't have a supported basis for 1.5 to 2X the diagonal.

And I doubt a persuasive one exists.

A bit of research on the TV theory. The first three up in google all said:

1.5 to 2.5X the diagonal for 2K but (grump) 1 to 1.5X for 4K which introduces obfuscation by pixel-pitch. A kinda sorta concensus but both the 2K and the 4K values are different than those in the OP.

More to my taste, human angular vision is introduced here ...

https://www.the-home-cinema-guide.co...-distance.html

... where there is a recommendation for an optimum viewing angle of 36 degrees in the back row of a home theater, um, quite a bit less than the previously-referenced 55 degrees or about 1 radian.

I speculate that there is no known basis for the numbers in the OP other than his own reading and/or his own experience. Therefore, a supportive basis is not found, so let's let sleeping dogs lie ...

[xpatUSA]

I speculate that there is no known basis for the numbers in the OP other than his own reading and/or his own experience. Therefore, a supportive basis is not found, so let's let sleeping dogs lie ...

Waking the dogs for a minute, I did manage to find a credible ( i.e. ITU) standard for TV viewing distances here.

The basis for it's definitions is (guess what) Snellen's eye-test chart criterion of 1 minute of arc and the viewing distance is a single number ** expressed as a factor d times the picture height.

For a 24-inch 1920x1080px computer monitor, said distance comes out to 36.1 inches almost exactly 1.5X the diagonal for what that is worth - still too far for me with my myopic vision.

** Nothing wrong with a single number really - after all, most of us are already familiar with the "sweet" aperture number for lens sharpness - even though it takes good pictures either side. Or the MTF50 number - oft found as the "resolution" of a camera/lens combination.

It seems, as Manfred implied, that screen viewing recommendations can differ considerably from print viewing recommendations, so I withdraw my addition of "any medium" from this discussion, leaving only a desire for a respectable link to an authoritive publication that provides a technical basis for the optimum viewing distance for a print ...

[bralk]

Viewing distance is often one of the parameters in dof calculators. (final viewing distance to print)

Old rule of thump for a tv screen is:
Make a fist and extend your arm. The viewing distance is at the point where your fist
covers the screen. This was developed so you would be able to read subtitles.

[xpatUSA]

Viewing distance is often one of the parameters in dof calculators. (final viewing distance to print)

Interesting, thanks, but I couldn't find a calculator with the "final viewing distance to print" as a parameter. The ones I found only use focusing distance i.e. from the camera to the plane of focus. Do you have a link to one where viewing distance is a parameter? ...

... Unless you are referring to the 8 by 10 inch print held at 10 inches from the nose, often but not always used in DOF calculators in order to determine a Circle of Confusion.

Old rule of thumb for a TV screen is:
Make a fist and extend your arm. The viewing distance is at the point where your fist covers the screen. This was developed so you would be able to read subtitles.

For me, that is a horizontal viewing angle of 12 degrees compared to my usual 48 degrees from where I sit at the computer.

I tried it on my 24-inch monitor and had to step back about 126 inches. In other words, a factor of 5.25 times the diagonal, so I guess that rule of thumb is not the basis of the factors mentioned in the original post.

[DanK]

The old rule of thumb I have long used--which you suggest is about 20% off with your physique--is that a fist held at full extension is about 10 degrees.

That almost works for my TV--it covers perhaps 75% of the horizontal distance when I sit where I normally do. Howeve, it covers less than 25% of my larger monitor. I think that's because we view the two differently. When I watch a movie on TV, I want to apprehend most of the scene in my main vision. That's not how I use my computer screen. I move my eyes from section to section as needed.

In fact--this will be a hint about my age--this is why I switched to computer glasses years go. Normally, I wear progressive lenses. However, I found that unless I used a very small monitor, working on the computer with those glasses made me slightly queasy because I was constantly moving my eyes around, rather than my head, and therefore moving into regions of the lens with a different focus. Instead, I bought cheap line bifocals with the reading area as it normally would be but with the main area a constant focus, set for about 28-30 inches. (You have to make sure that the line on the lens is in the right place relative to the bottom of the monitor.) It was a big relief, and I've used them ever since.

One more reason why a search for one optimal distance may be a pointless search.

[xpatUSA]

The old rule of thumb I have long used--which you suggest is about 20% off with your physique--is that a fist held at full extension is about 10 degrees.

Thanks, I wasn't aware of the nominal angle.

That almost works for my TV--it covers perhaps 75% of the horizontal distance when I sit where I normally do. However, it covers less than 25% of my larger monitor. I think that's because we view the two differently. When I watch a movie on TV, I want to apprehend most of the scene in my main vision. That's not how I use my computer screen. I move my eyes from section to section as needed.

My situation is similar but dictated by the position of furniture in the case of the 40-inch TV and the size of my computer desk in the case of the 24-inch monitor.

One more reason why a search for one optimal distance [factor] may be a pointless search.

The ITU standard I found calculates a single factor for both optimal viewing distance and optimal horizontal viewing angle in Appendix 1 of:

https://www.itu.int/dms_pubrec/itu-r...3-I!!PDF-E.pdf

However the following tells me that TV viewing has little relevance to viewing a print, unfortunately, although it does work for own vision gazing at my own monitor:

...that the following Notes should be regarded as part of this Recommendation:

NOTE 1–For the purpose of this Recommendation the “optimal viewing distance” of a digital image is defined as the viewing distance at which two adjacent pixels of the source image (before it is re-mapped on the display [?]) subtend an angle of 1 arc-min at the viewer’s eye.

NOTE 2–For the purpose of this Recommendation the “optimal horizontal viewing angle” is the horizontal viewing angle under which an image is seen at its optimal viewing distance.

[edit] That standard is confusing in that it defines a minimum viewing distance without always saying so. [/edit]

Which is why it works for my monitor but not for my TV. Duh.