Architect1776 Loc: In my mind

What ever distance floats your boat is normal or optimal then.

selmslie Loc: Fernandina Beach, FL, USA

That’s not much help.

Maybe it would be better to watch the public at a museum. I suspect the people who get close are just looking at details and not the print as a whole.

Architect1776 Loc: In my mind

Getting close is optimal for them .
Just like all the pixel peepers here in UHH.

Longshadow Loc: Audubon, PA, United States

Do pixel peepers take a magnifying glass to gallery shows?

rlv567 Loc: Baguio City, Philippines

Just an interesting observation - I have had prior to this question: You seem always - commendably - to answer questions in a reasonable, logical, practical way!!!

Loren - in Beautiful Baguio City

selmslie Loc: Fernandina Beach, FL, USA

When they get close they can't see the entire image, just the details. That's the same as pixel peeping, not normal.

Pixel peeping at 100% is abnormally anal, like taking a magnifying glass to a museum.

gvarner Loc: Central Oregon Coast

The viewer selects their preferred distance. They’re not going to be held to standing on a line.

Longshadow Loc: Audubon, PA, United States

Thanks Loren, I like to try.

selmslie Loc: Fernandina Beach, FL, USA

You might not be able to do that. The Mona Lisa (30x21 inches) is protected by a barrier that won't let you get that close.

Considering what the climate change protesters have been doing lately you are probably going to see more barriers and nervous guards, even for less valuable images.

Longshadow Loc: Audubon, PA, United States

Fotoartist Loc: Detroit, Michigan

One thing not mentioned is that less detailed images don’t need to be viewed close to appreciate. But in general I like the straight diagonal distance as the best general guide.

SalvageDiver Loc: Huntington Beach CA

The resolving power of the human eye with 20/20 vision is 60 arc-seconds, which is the basis for the standard eye charts in the doctors office. At a viewing distance of 24" the minimum spacial separation between two lines that can be resolved by the eye is 0.007". Therefore a minimum print resolution of 143dpi is needed to provide the illusion of a continuous tone to an observer with 20/20 vision. 286dpi would be needed for someone with 20/10 vision. Just simple HS trig to derive.

Based on the above, you can easily evaluate the adequacy of any of the above rules of thumb, theories, urban legends or make up your own easily remembered rule to get you close.

selmslie Loc: Fernandina Beach, FL, USA

That's pretty close to the other calculation based on 300ppi at 10 inches (about 2x as many ppi for people with superior acutance).

But is still leaves open the question about how far away you might normally view a full print or image.

I think that Fotoartist pointed out the key to the conundrum, that is depends on whether the presence of detail draws you closer.

There were also some good points in the post and the provided links from dpullum regarding how close we can comfortably get to an image and the fact that this increases as we age.

We need to consider that the viewing distance for a print smaller than 8x10 is not going to keep going down. It's just not easy to take in a small print from the "normal" viewing distance from much closer than we consider comfortable for reading text.

Architect1776 Loc: In my mind

Most likely.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

My experience is in creating portraits and commercial industrial images for public and decorative display so I am somewhat concerned with viewing distances. The as per Cambridge Color is somewhat correct but there are caveats.

As an example, I had to photograph a number of former and sitting mayors of my city for a permanent display at the city hall. Some of the older existing portraits we oil paintings and were 3/4-length images of the subjects. Someof the portraits, that I made previously, were in that kind of pose and all of them were 30x40 inches. I worked out viewing distances as per the said formula and the available backup space in the hallway where the display is mounted. One of the soon-retiring mayors wanted to use a headshot (head and shoulders image) I shot for him for other purposes and did not feel like sitting for another shoot! I had to diplomatically explain that a 30x40 "headshot" would be grotesque seeing the viewing distance of the corridor where the display is hanging. It would look like those enormous portraits of Mao Zedong that are displayed in public squares in China. So the subject and pose in a portrait also factor in larger-than-life headshots that are problematic.

On the other side of the coin, I have made images of heavy excavation and construction equipment shot for mural-sized images in trade show booth displays. I have to come up with a size and perspective that gave the viewer the impression that they standing on a construction site.

Yet another aspect of viewing distance has to do with image quality and detail. The requirements for a 24x30 display print and a highway-size billboard are different.

There is another theory as to PERSPECTIVE. For example, THEORATICALLY, a landscape image shot with a wide-angle lens with an exaggerated foreground would seem more "normal" or more compressed if viewed at 2" away Or, an image shot with a long lens from a distance, where the backgron is very compressed, would seem "normal" if viewed from a block away. This seems hyperbolic but as one can imagine both cases are not practical. The prescribed math doesn't always fit the circumstances.

Practically speaking, 8x10 portraits, 10 or 11-inch images in a wedding album, commercial images in a catalog, or brochure all are gonna be viewed at about arm's lenght- most foks will not examine prints with a magnifying glass or from yards away. Larger prints, murals, billboards? Common sense dictates they will be viewed from a practical distance to be properly appreciated.