The 28mm as a standard lens

<p>This thread is inspired by <a href="../classic-cameras-forum/00aJ6K">this one</a> involving a 28mm lens on a Leica M3.</p>

<p>Years ago I eventually got over the idea of a 'standard lens'. I suppose we can blame Leica, but we can also blame manufacturing costs and culture - so many things go unquestioned in our society, sometimes to the point where reality changes but the dogma does not (e.g. recommending a 50mm as a standard lens for APS-C sensors). The standard lens is one of them.</p>

<p>Back in the day, you'd probably buy your SLR with a 50mm. A lot of fixed-lens RFs had them, too. There are three reasons: history (habit), cost, distortion and aperture width. It's easier and cheaper to get a distortion-free 50/1.8 than a distortion-free 28/2.8 (compare Nikon's 50/1.8 D to their 28/2.8 D). Of course one might prefer a narrower aperture in order to afford a wider lens, but not everyone thinks that way.</p>

<p>There seem to be two main reasons why the 28mm AOV is the default on mobile phones. One, it allows better group shots at dinner tables etc. Two, the perspective is dramatic but not exaggerated. DOF is also increased. Fixed-lens 35mm film compacts used to have 35mm lenses most of the time. Not a useless focal length by any means, but 28mm would have been so much more useful.</p>

<p>FWIW the lens on Apple's iPhone 4S is amazingly good. It has negligible distortion and it's quite sharp.</p>

<p>It's funny how we choose lenses depending on our camera system. I love the 28mm on my phone and I would not have thought that a 28 could be so useful so often. But I wouldn't want to be stuck with that - or any - single focal length. Perhaps it's because for a camera to be sufficiently flexible, you need at least two focal lengths to choose from at any one time - in which case, 'standard lens' becomes 'standard lenses'.</p>

 

<i>Perhaps it's because for a camera to be sufficiently flexible, you need at least two focal lengths to choose from at any one time - in which case, 'standard lens' becomes 'standard lenses'.</i><P>

Perhaps <b>you</b> need at least two focal lengths to choose from at any one time. I do pretty well going out with just a single prime about 85% of the time.

<p>People are spoilt these days and it was decades before I had more than one lens for any of the cameras I owned including the period when I earnt my living taking photos.</p>

<p>If I am shooting cityscape, then I almost always use a 28mm lens. Other than that, it's the usual old 50mm.</p>

<p>There have been a number of wide-angle fixed lens cameras. The Ricoh GR1 springs to mind, and the Fuji GF670W and the Voigtlander III W. Before that in the 1950's you could get the 35mm Walz Wide. There are probably a number of others I have forgotten.</p>

<p>We can blame Leica for a lot of things but I think the idea of wide angle, standard and tele fields of view pre-dates Leitz by a long time - at least to the first cameras - and you would probably need to go back into painting and pre-photography days to see where the standard view evolved. If you go into an art gallery you can see that portrait paintings and still life subjects are usually 'standard' views while landscape paintings are often a wide angle view. </p>

<p>I shoot more MF these days and my medium format gears are very old Ikonta and a Rolleiflex. The lenses are 75mm so it corresponds to the standard '50mm' field of view in 35mm. Not having the option for anything else means I don't yearn for anything else. Yet, when I shoot with the 35mm Bessa R or Oly OL4, it is mostly 35mm on the first and 28mm on the latter. My longer lens work tends to be strictly on digital where a 28mm lens (43mm in full frame equivalent) remains unusued most of the time. I prefer to use a 58mm (83mm) or a 135mm (202mm) most of the time! This is a little complicated but I think the favourite walkaround camera at present is the Ikonta with its 75mm (50mm) lens and I see my world better with that!</p>

<blockquote>

<p>There seem to be two main reasons why the 28mm AOV is the default on mobile phones. One, it allows better group shots at dinner tables etc. Two, the perspective is dramatic but not exaggerated.</p>

</blockquote>

<p>And three, you can hold it at arm's length and get a shot of yourself and a friend. I suspect that's the main motivation. </p>

<p>It's a hard choice between the 35mm and the 28mm. I carry both for street Photography that and the 50mm.</p>

<p>What focal length to label as "normal" has a scientific origins:<br>

Normal is all about the human perspective. If you stand before a glass window and with wax pencil, and draw on the glass, outlines of objects seen, the drawing is said to depict the human perspective. It’s a scientific fact that to duplicate view with this perspective , we should view the final image as at contact print size, from a distance about equal to the focal length of the taking lens. If this viewing distance is applicably ignored, distortion creeps in.</p>

<p> Now modern cameras yield tiny negatives and digital chips are also tiny so viewing a life size image from a distant equal to the focal length of the taking lens is impractical. Therefore. we always enlarge the image to view, be it a print on paper, a projected image or on a computer display. Now to achieve an optimized view, the human perspective, the viewing distance becomes focal length used times magnification used.</p>

<p>Studies have shown that people tend to view art and photographs from a distance about equal to the diagonal measure of the displayed rectangle. Now an 8x10 print has a diagonal measure of about 13 inches (330mm). This viewing distance people will gravitate to, hovers around our natural reading distance.</p>

<p>To make an 8x10 from a 35mm negative (24mm x 36mm full frame) the enlargement magnification is about 10x. If we mount a 28mm, the viewing distance to duplicate the human perspective is 28x10=280mm (11 inches). For a 35mm lens -- 35x10=350mm (14 inches. For a 50mm lens -- 50x10=500 (20 inches). </p>

<p>Now all of you know that we are not normally concerned about making images that are geometrically correct however, some knowledge of the basis of the "normal" lens might interest you. One more fact. All lenses look back at the film (chip) and we want this view to be uniform as to brightness and will good definition. Now each lens design has a circle of good definition boundary and that must be large enough to envelope the entire expanse of the film (chip) frame. Generally a lens with a focal length that about equals the diagonal of the format is fitted as the "normal" prime. For the 35mm full frame, this measure is 43.27mm. Such a weird value, opticians round up to 50mm. The difference 43 - 50 is minuscule so don't get carried away by this fact.</p>

<p>If a 43.27mm is mounted, the angle of views are 27⁰ vertical, 40° horizontal, and 47⁰ diagonal. The diagonal angle of view is the one most quoted however I think the other two are the more applicable. Mount a 28mm and the angles are 46.4° vertical, 65.5⁰ horizontal, and 75.4 diagonal.</p>

<p>Wide-angle designs have focal lengths shorter than the diagonal, These lenses must be of special design so that their circle of good definition is expanded to cover the entire rectangle of the format. That's why good wide-angles are somewhat more expensive. </p>

<p>Photography is science and art intertwined, you are free to image as your mind's eye sees the world about you. </p>

<p>I would much prefer that my smartphone not have the equivalent of a 28m lens, personally. For most people using these cameras, it doesn't end up being 28mm anyway, because the pictures are being cropped to square format from a sensor which is 4:3. The ends with the weird exaggerations are being lopped off.</p>

<p>There's a reason 28mm was never a standard on fixed lens cameras (with a few exceptions). It's a specialist focal length which requires extra care in handling to avoid the keystoning that is very easily induced, and it's best used for compositions which have something in the foreground - a fact of which the average person is totally unaware. This is less of a problem with 35mm lenses, and less again with 50mm (speaking in 35mm camera terms).</p>

<p>Conventional wisdom seemed to influence the approximately 40mm focal length (presumably based on the diagonal of the 24x36mm format of "full frame" 35mm film) seen on many fixed lens rangefinders from the 1970s. Cameras like the Canonets, Olympus 35 RC and SP and others of that era seemed to reflect the design quirks of the shutterbug breed. As Marc Bergman observed in <a href="../classic-cameras-forum/00aHMY">this discussion</a>, "It is as if the designers had a freer hand."</p>

<p>But by the 1980s the CW seemed to shift toward 35mm and, later, 28mm lenses for many compact P&S cameras and higher end enthusiast compact cameras. Zooms for miniature digital sensor cameras often begin at the equivalent to 28mm or 35mm on the wide end. </p>

<p>On the one hand, I'd like to believe it's safe to assume there's valid reason for it based on market research into the preferences of actual buyers. On the other hand, I rather like the notion of a rumpled, eccentric designer working in isolation, insisting that, yes, actually, we do want the 43mm focal length and, yes, the film advance lever belongs on the bottom left and the focus wheel belongs under the right index finger and, no, you don't need a self-timer, you heathens.</p>

<p>lex jenkinds is closest for some of the right reasons.<br>

aboutr 43mm is the diagi[onal.<br>

but that is possibly the shortest focal length design that can be used with out a Retrofocus<br>

or Inverter telephoto design. 50 55=and 58 mm normal lenses were ued on early slr's<br>

as the desigh was easier to make and there was a space behind the nenc needed for the<br>

mirror and otjher mechanical parts.<br>

Some of the shorter lengths had some distortion.<br>

and If you took a photo of a girl with a wide angle lebs and she did NOT have a button nose<br>

you would never show her the print.<br>

I know two nice young women and they need a 135mm lens<br>

=straight on. The sharpness of the slightly longer lenses is easier to achieve.,<br>

Something like a 85mm or 105mm lens is even easier.<br>

On the other hand, when taking photos or :"fitting in:" a group. the wide angel lens<br>

had advantages<br>

40 years ago the 35mm lens on a full frame 35mm camera was thought by many to be<br>

a better standard lens. There were only a very few lenses made between 35 and 50.<br>

Possibly there was a 40? made for exactas.</p>

<p>My favorite lens for street photography. Set the aperture to f16, manual focus, then zone focus for a minimum of 3 feet. Gives you enough focus depth that there's no need to worry about focus time when you want to capture that decisive moment.<br>

Bruce Gilden taught me that trick.</p>

<p>I maybe someone special and different to the rest of mankind, I doubt it frankly :-), but when I look at things I do not see what a 50mm AoV lens sees but rather something akin to a 200 or 400mm AoV lens and my excellent perifial viewing makes me aware of what is around the 400mmAoV area. This is about a single key on my keyboard from a distance of about twelve inches [ sitting on my lap] So I dispute Marcus's explanation. The eye is continually moving across the area in front of us but at any one time it actually sees a very narrow area. As a film maker I base the essence of my craft on this behavior of the eye to justify the breaking of a visual presentation into individual shots. It may also explain why I usually see and want to record the result of a moderately long zoom and the wide shot usually has no attraction for me.<br>

The 'normal' lens for a movie camera is the equivalent of a 90mm on full frame 35mm, which helps with this selective 'part of' approach to recording which is often quite missing in still photographers work.</p>

<p>Mr. Uknz,<br /> References I made are the human perspective:<br /> You are referencing angle of view and not perspective. Perspective is how we perceive the distance of objects. If viewed from too close a distance, distortion creeps in. A human face is perceived to have fixed proportions as to the size of nose as compared to the size of the ears. View with too short as lens, the nose appears to swell, the ears shrink. Viewed with too long a lens, the ear to nose ratio is compressed. In still photography the rule-of-thumb is to use a lens 2.5x the diagonal to reproduce the human face are perceived by the individual. This self image is derived from the view in the dressing mirror. Hollywood uses 3x the diagonal because of the magnification on the big screen and the distance the average viewer will sit from the screen. Violations of this rule-of-thumb is OK however, outcries of "I don't photograph well" will be more widespread.</p>

<p>Medical books rate the human eye angle of view as 95° horizontal, 75⁰ down, and 60° up. The pathology and physiology of vision are keys to good photo engineering. That angle of view corresponds to a 12mm lens on a 35mm full frame.</p>

<p>FWIW, examination of the paintings of impressionist painter Gustave Caillebotte, reveal some of his works to have the same angle of view of a 28mm lens on a 35 mm camera. </p>

<p>Look at his paintings, 'The Floor Scrappers', 'Paris Street- Rainy Weather', or 'The Man on the Balcony'</p>

<p><a href="http://www.gustavcaillebotte.org/The-Floor-Scrapers-(study)-I.html">http://www.gustavcaillebotte.org/The-Floor-Scrapers-(study)-I.html</a> </p>

<p><a href="http://www.gustavcaillebotte.org/Paris-Street--Rainy-Weather-1877.html">http://www.gustavcaillebotte.org/Paris-Street--Rainy-Weather-1877.html</a></p>

<p><a href="http://www.gustavcaillebotte.org/The-Man-On-The-Balcony.html">http://www.gustavcaillebotte.org/The-Man-On-The-Balcony.html</a> </p>

<p>Using Caillebote's visual cues one might suggest the 28mm focal length or equivalent provides a 'natural' angle of view.</p>

 

A pair of eyes have a view angle slightly greater than 180 (horizontal) and with practice you can learn to perceive all of it

at once, although acuity falls off greatly off center. We can also concentrate on very narrow fields when needed,

equivalent to at least a 400mm lens if not longer.

 

Most things are considered to be flattered by being viewed or shot at the distance necessary to fill a frame in the 35-85

range because there is a feeling of depth (just another word for a degree of perspective distortion that we consider

pleasing) but not too much perspective distortion. At that distance the cognitive load of correcting the image back to the

spatial relationships we know or expect to be true is not so great as to require conscious effort. Ultra wides are fun

precisely because they invite us not to exert this effort but instead to enjoy the distorted composition for what it is. Long

teles can sometimes do a similar thing but more often are just a second-best alternative to getting closer.

 

A 28 is a good party camera length because you are shooting several people and no one face is close enough to be

overly distorted; if you shoot a group of 5, each face will look like an individual portrait shot with a 100 or so. When it

comes time to shoot 1 or 2 people at the party you are better off backing up and cropping.

<p>From the early days of my 35mm photography I finally determined that a 28mm lens was the fixed focal length lens which fit my way of seeing.</p>

<p>My first was a Soligor 28/2 for my new Canon EF in 1974. Canon didn't have a 28/2 at the time but I got one soon enough (although the Soligor was a very good lens). What today's shooters, particularly those using camera phones and kit lenses miss, is that you have no control over the depth of field which you have with an f2 or faster lens. I can't imagine photography without that control.</p>

<p><em> I can't imagine photography without that control.</em><br>

But it doesn't have to be in-camera. It hardly ever is one of the factors considered in photos I take, but it is a factor in the presentation. I want everything as much is focus as possible so I can make a considered judgement in editing as to if soft focus is needed in any part of the shot. perhaps I should get a Lyto :-)</p>

<p>I think Alan is quite close. "Normal" depends on how you view the print, and any lens of any focal length can be a "normal" lens. If you were actually to photograph the print with the same lens you used to make the original image, and if you were to frame it up perfectly (assuming no croping in the print), then the nodal point of the lens would be the position the viewer should assume in order to view the print "normally." That would imply a very close "normal" viewing distance for a wide angle lens and a much farther "normal" viewing distance for a telephoto.</p>

<p>Put another way, a lens is "normal" when its angle of view is the same as the angle of view used to view the print. And thus "normal" is a matter of convenience and convention. Perhaps younger people have closer viewing distances, so their "normal" would correspond to a shorter focal length lens.</p>

<p>Most of us don't view wide angle shots from a "normal" distance, with our noses in the prints (figuratively speaking), so we see rectilinear distortion in the printed image. This distortion disappears if we move to the "normal" viewing distance. If an ultrawide shot is to be viewed from a greater than normal distance, its appearance is more "normal" in a fisheye geometry. We simply don't realize it. Fisheyes bend straight lines to map them onto a flat surface, but that's actually how our eyes "see" the world. If we stand in the middle of a road and look one direction, the lines of the road converge. If we look the other direction, the lines converge. In the middle, they bow, and if we look straight down at our feet, we can see this bowing to either side. The reason that we don't perceive the lines bowing is that our brains do not interpret the information thusly.</p>

<p>The facts are; normal is based on magnification used to make the display print and focal length used.<br>

The ideal portrait focal length is about 2.5x the diagonal measure of the format.</p>

<p>Example: If a 50mm is used on a full frame 24mm by 36mm with a diagonal measure of 43mm, (50mm is the traditional "normal", to make an 8x10 requires 10x magnification. 24 x 10 = 240mm ---- 36 x 10 = 360mm. The image size as so magnified is 9.4 inches x 14.17 inches. The viewing distance to perceive the finished image by way of the human perspective is 50 x 10 = 500mm = 20 inches (about natural reading distance).</p>

<p>If you use a compact digital, the format size is 16mm by 24mm with a diagonal of 30mm, the "normal" focal length is 30mm. To discover the crop (magnification factor) 50 ÷ 30 = 1.6. The crop factor 1.6 tells us that if we mount a 30mm on the compact digital it will replicate the angle of view of a 30 x 1.6 = 48mm mounted on a full frame camera.</p>

<p>If we make an 8x10 for display the magnification needed will be 13x(8 inch = 203mm 16mm = 12.6 (rounded up to 13). Now the viewing distance for this size display made using a 30mm lens is 30 x 13 = 390mm = 15 inches. Thus the 30mm on the compact is equivalent to a 50mm on a full frame i.e. the viewing distances are about the same to replicate the human perspective.</p>

<p>Why is a 105mm (43 x 2.5) mounted on a full frame conceded the optimal focal length for portraiture? Likely, an 8x10 print will be made; likely, that print will sit on a mantel or on a desk and the viewing distance will lengthen to about 1 meter or 3 feet. We mount a 105mm, we make an 8x10 at magnification 10. The viewing distance is 105 x 10 = about 1 meter and this mimics the human perspective.</p>

<p> For the compact digital, that's 30 x 2.5 = 75mm. The compact digital format is 16mm by 24mm. To make an 8x10 requires about 13x magnification. We mount a 75mm. The viewing distance becomes 75 x 13 = 975mm or about 3 feet. </p>

<p>Now I know this is all gobbledygook so that's all folks. </p>

<p><em>But it doesn't have to be in-camera.</em><br>

<em><br /></em><br>

Well, yes it does.</p>

<p>To the extent you do not understand what is going on with your lens or camera, and you just kick the can down the road to Photoshop, you are just a manipulator of unexpected images and not a photographer.<em><br /></em></p>

<p>LOL Micheal Linn ... But hang in there and enjoy your photography while I enjoy mine.</p>

<p>Personally I view the wider angle lens advocated here with considerable distaste. It is the attitude of the snap shooter who has not learnt to select the essential element of a subject so they just point the camera and shoot. The 'photographer' appreciates selection and uses the longer lens to help them confine the photograph to the essense of the subject material.<br>

A side issue are the DSLR users who do because they can shoot wide with the excuse it is so they can crop to whatever format is subsequently required. To me this is button pushing at a high level. Most of my life I have shot with smaller formats and the way to achieve excellence is to work out what is the essential and shoot only that. I'm sure that there are valid commercial reasons for shooting wide but that is not proper photography but business dominating the work resulting from a lack of adequate communication between client and photographer prior to the shoot as to what is required. <br>

So the wider lens may well be how the eye sees things but it is recording the undisciplined jumble of life as opposed to creative selection. Editing helps in the selective process when it was not possible to achieve that with the camera. In esoterical terms my endeavour is to achieve in-camera a file which can be handled in editing to produce the result required.</p>

<i>The 'photographer' appreciates selection and uses the longer lens to help them confine the photograph to the essense of the subject material. . . . Most of my life I have shot with smaller formats and the way to achieve excellence is to work out what is the essential and shoot only that.</i><P>

There are plenty of very-skilled and accomplished photographers using wide angle lenses who can 1.) "convey the essence of the subject material" without substantial cropping and 2.) coordinate and balance different elements within the frame without having to make their photo about a singular subject. Not mastering the effective use of wide angles doesn't mean that you are a superior photographer.