MF tonality and separation: in the full size image, the airplane is in a clearly different focal plane to the tree and hangar – even though it was shot at f8.
I’ve written previously about what exactly contributes to the ‘medium format look’. However, I think to some degree we also need to both define what constitutes the hallmarks of smaller formats, but more importantly figure out where each format’s strengths lie. Having now shot what I’d consider ‘enough’ with a complete MF system wth lenses ranging from ultra wide (24mm, or 18mm-e) to moderate tele (250mm, or 180mm-e) I think I’ve built up a much more complete picture. No doubt this will change if the recording medium size increase further – with the 54x40mm sensors, for instance – but I think it’s fairly safe to extrapolate based on the differences between subsequent smaller formats.
Compositions like this do not work without extended DOF, but the perspective limits your format size in achieving that.
Depth of field
This is probably the most immediate giveaway: for a given subject magnification, aperture and angle of view, larger formats will appear to have shallower depth of field. Remember that the real focal length and aperture are what determines the degree of background blur; the larger the format, the longer the lens required to cover that angle of view. Even though lenses tend to get slower as the format increases – faster apertures for longer real focal lengths are harder to build – in practice, what we notice is larger formats have some degree of separation between subject and background/foreground planes, where smaller formats may not. However, this may require larger output sizes or resolutions to discern; 1MP web jpegs are almost certainly going to be missing something. It gets a bit more complicated, though: for an ideal lens, the transition between in and out of focus becomes significantly more abrupt as the focal length increases. With a shorter real focal length, that transition might be very gradual – and thus appear to have almost no visual separation at all.
Shallow enough DOF for you?
Angles of view, projection and optical formulae
That said, things get more complicated still: longer lenses are easier to fully correct for, which means optical formula limitations that degrade our perception of sharpness of transition (think of an image ‘sliced into planes’ ) such as coma, longitudinal and lateral chromatic aberration are more easily minimised. When these aberrations don’t ‘eat into’ the edges of the focal plane, we are given the impression of shallower depth of field because the boundary of confusion is much tighter – a subject is either in focus, or it is not.
24mm, and 16mm-e, but no strange edge stretching.
On the reverse side, when engineering for shorter real focal lengths, all sorts of other problems must be taken into account. For instance, if the design requires a relatively long image distance compared to the actual focal length (e.g. Nikon F back flange, ~47mm, focal length, 21mm) then a telecentric design must be used, which contains another set of elements to ‘straighten out’ and extend the ray path so that it might focus the projected image at the correct distance. Even if not, and we are using a system with a short flange back distance – symmetric designs aren’t always ideal because you’re going to land up with very extreme ray angles towards the edges. Since digital sensors are not truly planar but more like a waffle grid, interactions at the edges of the individual photosite can produce both vignetting and purple fringing towards the edges of the sensor. Offset microlenses over the photosites can compensate for this to some degree, but the potential for aberrations to start affecting transitions remains high. This is one of the reasons a lot of fast wide lenses lack the sort of clean transition you’d otherwise expect.
Impossible DOF and perspective for anything but a very, very small sensor. Foreground pipes are barely 20cm from the lens.
But, we’re still not done yet. Even though the perspective (foreground-background) relationships between objects remain the same for a given angle of view, there are practical optical design issues to contend with. In general, the shorter the real focal length and the larger the format, the more projection distortion becomes visible without resorting to very exotic optics: think of squashing a printed balloon onto a glass window, or translating a globe to a flat map. We can represent a map of the world on a 2D surface, but it requires some cutting and/or stretching (which is how we land up with things like the Mercator, Hammer, Panini etc. projections). Stretching is necessary should we want to present a continuous surface, which obviously causes some distortion to the image being projected – we see this as corner smearing or stretching. All lenses have some degree of field (focal plane) curvature, which becomes harder and harder to correct for as the focal length becomes shorter and the angle of view wider.
The wider you get, the worse this becomes. Once you pair that with the inherent difficulties of shorter real focal lengths and physically smaller lenses (i.e. fewer elements, less image circle to work with) – you can probably see why it’s easier to design a 50mm lens with a 60mm back flange distance (~1:1.2, 645 format) than a 30mm one with a 47mm back flange (~1:1.6, 35mm-e), even though they cover the same angle of view. As this ratio gets larger, design becomes exponentially more difficult for reasons previously described. Every time you want to correct for something – telecentricity, field curvature, distortion etc. – you introduce additional elements which must themselves in turn be corrected for.
Heavily corrected, but distortion is still visible.
Sensor proprettes
In the earlier article, I also touched upon some of the underlying media differences: no longer do we have the same recording medium in different areas, but physically larger sensors will a) not just have greater spatial resolving power for the same output resolution, but b) generally have larger photo sites and greater spatial resolving power. This leads to significant gaps in dynamic range, noise and in turn, color resolution. On top of that, the potential for greater spatial differentiation leads to much better tonal separation and subtlety: you’ve got a lot more steps to describe the same transition.
These differences must be considered together, mostly because of simple economics: smaller/worse/cheaper vs bigger/better/more expensive. There aren’t any really bad MF lenses because the underlying cost of the main component (sensor) determines the pricing level anyway; however, there aren’t that many good entry level kit lenses for similar reasons. In practice, I believe what this means is that there’s a sweet spot for every format/system; however, this isn’t immediately obvious to most people as few have shot a variety of systems under an equally wide range of conditions. My personal feeling is that there really isn’t a one-size-fits all both because of underlying system characteristics (e.g. small vs large sensors and attendant body features such as AF) and because no one system can give you a sufficiently wide variety of rendering styles. By sensor size, here’s where I think the strengths and weakness lie:
Those impossible compressions…
Compact, phone
Good for: Casual documentary, stealthy documentary, social record. Small size and ubiquity means you are inconspicuous; small sensor means you have almost unlimited depth of field and minimal focusing issues. Fast to use because there are few parameters to control (e.g. changing aperture makes no difference anyway, focus distance only when below a certain range).
Limitations: No DOF separation, restricted dynamic range and poor overall image quality, few options other than a wide FOV.
1″
Good for: I’m struggling a bit here. They’re a bit better than the compacts, but not so much that you’d be happy with one of these for primary output. Rendering of wide options tends to be quite uninspiring and just a bit messy looking: there’s enough depth of field differentiation to make transitions nervous, but not so much DOF that everything is in focus. The biggest strength I can see is for highly compressed telephoto perspectives where everything is in focus – the crop factor means you have much greater DOF than you might think for a given aperture, plus light gathering ability doesn’t become so much of a problem.
Not good for: Similar limitations to compacts and phones, but more lenses available.
M4/3″ and APSC
Good for: Given the lens selections, this isn’t a bad all-round solution for most people. I still haven’t found any wides whose rendering I really like, though – for the all the reasons we previously discussed. I think the main strength is again telephoto work: excellent small lenses with fast apertures (thanks to crop factor) offering enough separation (and not so little you have problems getting enough of the subject in focus) but still the option to get everything in focus if you need to.
Not good for: Wide angle work; a consequence of lens design and simple physics: the wider the field of view, the more spatial information (i.e. resolution) you need to avoid a gritty look.
But sometimes, you might want that gritty look…
35 FF
Good for: General shallow DOF work, moderate wide to moderate tele, supertele with shallow DOF. I think most people have realised by now that to get a wide range of distances in focus with high resolution 35FF bodies, you’ll either need to stop down past the diffraction limit, be shooting pretty wide and/or with subjects constrained beyond a certain distance, or use perspective control (i.e. tilt). Yet because of the completeness of the attendant systems, 35FF remains the all-round choice format: everything from 8-800+mm in a single lens without TCs, plus perspective control and macro.
Not good for: Getting everything in focus outside wides or what tilt shifts are on offer; subtle separation at wide/normal angles of view
50mm, f8, and it’s clearly not even close to all being in focus. Yet the appearance of transition itself is quite natural…
MF digital (44×33, 645-54×40)
Good for: Superwide to moderate telephoto; getting some sort of DOF separation at all distances and focal lengths even with moderate lens speeds
Not good for: Getting everything in focus without the use of tilt shift adaptors or putting the back on a technical camera, telephoto work, anything fast moving
LF
Good for: Full perspective and DOF control, a very ‘flat’ look no matter what the angle of view – minimal distortion and clean projections
Not good for: Anything where you don’t have space for a tripod and several minutes to set up each shot, digital work with the full format area
This kind of tonal subtlety remains the main reason to go larger.
There are three ways of approaching this: either select the format that will give you the greatest coverage of the kinds of things you normally shoot; restrict yourself to one format that produces results of the kind you want to produce; or, have multiple systems (or a system that allows for some interchangeability of lenses and sensor sizes, e.g. Nikon 1/CX, Nikon APSC and Nikon FX: three bodies, one set of lenses). I’ve gone down the multiple system route because I found the the adaptations simply don’t work that well – it usually isn’t a limitation of optics, but the whole thing just becomes very clunky in use. But of course, we also must remember that doing something differently with unconventional formats almost always yields unusual (and sometimes quite aesthetically pleasing) results…MT
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Ming Thein | Photographer 
By far, this must be the most thought provoking article I have read on photography. I read this a times over the last few weeks to make sure I understood all the points. It should be a must read article in photography class.
Thanks.
Very interesting article and comments. Your blog is a real enrichment for the photography community and beyond. I’m still struggling to understand certain points you make and have a few questions. I’d be very grateful to read your opinion. I realise that you speak from experience and observations and in no way I want to disclaim your findings. It’s just that certain of your points seem to negate some theoretical concepts I have of optics. I too do think that larger formats render differently, but maybe for fewer reasons that you mention.
– You say that “the transition between in and out of focus becomes significantly more abrupt as the focal length increases”. That’s true, but I don’t think it has any effect on the final image. Let’s say you compare two images at the same output size taken from the same spot of the same subject with two different formats. To achieve the same field of view you choose a shorter focal length on the smaller format and a longer focal length on the larger format. To equalise depth of field you close down the aperture on the longer lens. Will the transition between in and out of focus still be more abrupt in the image taken with the larger format? The depth of field is the same. From there, circles of confusion should be of the same size right to the blur discs created from distant highlights, at least according to the laws of optics and assuming ideal lenses. Nothing predicts a more abrupt transition in the large format image. Maybe the apparent abruptness is only due to smaller aberrations in longer vs. shorter real, i.e. non-ideal lenses and if a shorter lens would be as well corrected as a longer lens, the difference would vanish?
– You say that longer “lenses tend to project flat rather than spherically”. Is this the same as saying that longer lenses tend to have less field curvature? If so, is this really true or just a consequence of the narrower field of view of longer lenses for a given format? The closer you look at something curved, the flatter it appears. If you use the longer lens on a larger format, you capture a larger portion of the field curvature. Consider the same situation as above. Does the field curvature really appear smaller on the larger format image?
– In your article ‘That medium format ‘look’: what is it?’ you say that “a lens that covers a very wide angle of view on a larger format just feels less ‘wide’ (usually characterized by geometric distortion, think edge stretching) than the same angle of view on a smaller format”. In this article you show two images, one taken with an H6D “24mm, and 16mm-e, but no strange edge stretching” and one taken with a RX100 “Heavily corrected, but distortion is still visible”. Again, considering the same situation as above and ideal lenses, the smaller and larger format images would surely be identical with respect to geometric distortion/edge stretching, wouldn’t they? If the larger format image appears or feels less wide, it has to be because the longer less is better corrected for distortion. It’s certainly easier to correct a longer lens for distortion, but there some extremely well corrected short lenses for small formats that are at least as well corrected as equivalent lenses for larger formats, invalidating this argument in these specific cases.
Up until now and taking aside the points you make regarding sensor properties I would venture and claim that the only reason different formats render differently is that longer lenses are easier to correct and consequently lenses for larger formats are on average much better corrected than lenses for smaller formats.
– Theoretically it should be possible to mimic the look of larger formats on smaller formats by using the Brenizer method (when applicable).
– You mention that the small sensor wide in the Ricoh GR renders exceptionally well. Is this in regard to distortion or to the abruptness of out of focus transition or both? In your review of the GR you write that “the lens doesn’t slice things crisply into planes like the Nikon Coolpix A’s does” or like other modern Leica ASPH designs. Or is it only in regard to tonal separation where the GR truly excels at?
– Are the differences noticeable between adjacent formats, e.g. between APC-S and FF or between FF and 44x33mm? Surely they must be huge between any of the digital MF and 4×5″.
– Incidentally, do you still have and use your ArcaSwiss F? I’d love to see some new images taken with it!
– You say that “the transition between in and out of focus becomes significantly more abrupt as the focal length increases”. That’s true, but I don’t think it has any effect on the final image. Let’s say you compare two images at the same output size taken from the same spot of the same subject with two different formats. To achieve the same field of view you choose a shorter focal length on the smaller format and a longer focal length on the larger format. To equalise depth of field you close down the aperture on the longer lens. Will the transition between in and out of focus still be more abrupt in the image taken with the larger format? The depth of field is the same. From there, circles of confusion should be of the same size right to the blur discs created from distant highlights, at least according to the laws of optics and assuming ideal lenses. Nothing predicts a more abrupt transition in the large format image. Maybe the apparent abruptness is only due to smaller aberrations in longer vs. shorter real, i.e. non-ideal lenses and if a shorter lens would be as well corrected as a longer lens, the difference would vanish?
Yes, but unless you’re working off a tripod all the time, in practice, you tend not to stop down enough to compensate fully. This looks different and is the main contributing factor I see in most larger format images.
– You say that longer “lenses tend to project flat rather than spherically”. Is this the same as saying that longer lenses tend to have less field curvature? If so, is this really true or just a consequence of the narrower field of view of longer lenses for a given format? The closer you look at something curved, the flatter it appears. If you use the longer lens on a larger format, you capture a larger portion of the field curvature. Consider the same situation as above. Does the field curvature really appear smaller on the larger format image?
Field curvature is not the same thing as projection – the former is a curved focal plane; the latter is to do with projecting a sperhical image onto a flat surface (think a globe). You can have one without the other or both together or neither.
– In your article ‘That medium format ‘look’: what is it?’ you say that “a lens that covers a very wide angle of view on a larger format just feels less ‘wide’ (usually characterized by geometric distortion, think edge stretching) than the same angle of view on a smaller format”. In this article you show two images, one taken with an H6D “24mm, and 16mm-e, but no strange edge stretching” and one taken with a RX100 “Heavily corrected, but distortion is still visible”. Again, considering the same situation as above and ideal lenses, the smaller and larger format images would surely be identical with respect to geometric distortion/edge stretching, wouldn’t they? If the larger format image appears or feels less wide, it has to be because the longer less is better corrected for distortion. It’s certainly easier to correct a longer lens for distortion, but there some extremely well corrected short lenses for small formats that are at least as well corrected as equivalent lenses for larger formats, invalidating this argument in these specific cases.
See previous.
Up until now and taking aside the points you make regarding sensor properties I would venture and claim that the only reason different formats render differently is that longer lenses are easier to correct and consequently lenses for larger formats are on average much better corrected than lenses for smaller formats.
Yes, that’s largely true.
– Theoretically it should be possible to mimic the look of larger formats on smaller formats by using the Brenizer method (when applicable).
Yes, because thats’s effectively using a larger sensor and a ‘better’ lens.
– You mention that the small sensor wide in the Ricoh GR renders exceptionally well. Is this in regard to distortion or to the abruptness of out of focus transition or both? In your review of the GR you write that “the lens doesn’t slice things crisply into planes like the Nikon Coolpix A’s does” or like other modern Leica ASPH designs. Or is it only in regard to tonal separation where the GR truly excels at?
And also consistency across the frame.
– Are the differences noticeable between adjacent formats, e.g. between APC-S and FF or between FF and 44x33mm? Surely they must be huge between any of the digital MF and 4×5″.
Yes and no, depends on relative difference in size. 4×5 is many times larger than 645, but FF isn’t vs APSC.
– Incidentally, do you still have and use your ArcaSwiss F? I’d love to see some new images taken with it!
Sorry – sold it and never got around to scanning the few images I did shoot.
Thank you a lot for these clarifications! Much appreciated.
Thanks a lot, Ming, for this concise and enlightening article. I no more feel “stuck” in the equivalency paradigm. It’s a kind of a revelation.
– Do small sensors have real advantages for macro ? For a given depth of field, they can gather more light, does it need to be considered ?
– How to factor sensor performance and lens quality with the general considerations you describe? I mean a “mediocre” lens with an average bigger sensor may not be overall “better” than a very good smaller sensor system ?
– Could you show us some examples illustrating the phenomena you describe, with the same image taken with various sensor sizes in equivalent conditions ? I remember that you did something like that to compare sensor performance.
Thanks again and warm congratulations for your brillant work.
“– Do small sensors have real advantages for macro ? For a given depth of field, they can gather more light, does it need to be considered ?”
Yes, but they also hit diffraction limits much earlier for a given resolution. In my experience, DOF gains are faster than diffraction losses though, so there’s still an overall advantage – unless you downsample from much larger/higher resolution sensors.
“– How to factor sensor performance and lens quality with the general considerations you describe? I mean a “mediocre” lens with an average bigger sensor may not be overall “better” than a very good smaller sensor system ?”
This is not a straightforward question, and depends a lot on pixel pitch. I would personally prefer the better smaller sensor system because the output appears more crisp and will upscale better; the larger sensor images will appear soft (but assuming all else is equal, you’ll probably gain DR and color advantages). Of course, larger sensors have decent cheap lens options, and good small sensor lenses are still expensive, so this may be an academic question.
“– Could you show us some examples illustrating the phenomena you describe, with the same image taken with various sensor sizes in equivalent conditions ? I remember that you did something like that to compare sensor performance.”
When I get some time, this has to be a scientific and controlled test…
I’m a great fan of the large format look but can’t say I understand the physics or even what visually makes the look. I’m not up for the cost or inconvenience of large format but I’d really like to understand what makes the look.
‘LF: Good for: Full perspective and DOF control, a very ‘flat’ look no matter what the angle of view – minimal distortion and clean projections’
Could you expand on ‘very flat look … clean projections’. Does the flat look come from more parallell light hitting the sensor? Grasping at straws here.
It comes from the real focal length used being longer than ‘normal’ (50mm or thereabouts) for practically any angle of view – this means the lenses tend to project flat rather than spherically, as with wides for smaller formats. ‘Normal’ for my 4×5″ was 150mm!
But “normal” focal lengths are different for each format, because the angle of view is what determines what looks similar to “normal” human vision. And AOV is determined by the format size for a given focal length. So a 50mm is only a “normal” lens on FF 35mm. But it’s telephoto on 16mm and wide angle on 6×7. I think people get confused by assigning wide/normal/tele descriptors to focal lengths when they should be assigned to AOVs. Especially if one is jumping between formats. And it’s also confusing for people to refer to f-stops and aperture size interchangeably, when they’re not the same thing. F-stop is a ratio of the focal length divided by the actual aperture diameter. As far as the physics is concerned, the only difference between larger and smaller formats is DOF. And that is only because at the same f-stop on a shorter lens has a smaller actual aperture that that f-stop on a longer lens on the larger format which would give the same AOV and thus image size in the frame.
So what you’re really talking about has nothing to do with format, it has to do with lens design, as you mention in your blog post. With some of the lenses for larger formats being simpler designs that are better corrected for distortion. People often read the description of “very flat look … clean projections” or similar phrases and think that larger formats change the rendering of depth and perspective. But the only thing that changes perspective is moving the camera. So it’s confusing to people who then assign those characteristics to the format itself. When the physics doesn’t work that way.
I know that you understand these things. I’m just clarifying for readers because there is so much confusion about the difference between formats
Hi Ming,
Wonderful as always, especially for communicating the aesthetic ramifications of technical choices. About those 1″ sensors. I wonder, though, if they might not also be useful at the extreme wide end of the focal range as well? Stopped down a little, they might lose their nervousness and be nice instruments for wide angle work. I’ve been eyeing a Nikon DL18-50 as a pocket rocket since proposes a relatively unique combination of field of view and portability. I’d be interested to see you take one for a whirl if/when they become available. Thoughts?
Small sensor wides generally don’t render well, with only one exception I can think of – the GR.
No interest in the DL18-50, sorry.
Very interesting article, thanks. I especially like the shot of the scaffolding poles above taken with a smartphone, never really thought about what a phone can do vs what a larger sensor cannot achieve.
🙂
Hello Ming,
I read your article which is so interesting as usual. According to your explanation: the more sensor is large, the more feeling of wideness decrease given a field of view. This is always been also my personal judgement comparing 35mm on FF vs 17mm on micro4/3 (and I prefer the look of 35mm on FF much more).
However, this morning I made a home test comparing an Iphone shot vs my FF Canon at the matching focal lenght (~30mm) and I was surprised when I saw that the background on the iphone shot feel closer to the main subject in the foregroung compared to FF..
It’s just the effect of “everything in focus” or there is something I’m not considering? Can you help me understanding?
Thanks a lot,
Impossible to say without knowing which lens you used, and how that particular lens renders – in one of the other comments I explain why this is the case with wides based on concave or convex field curvature and projection…
I used an old 20-35 3.5-4.5 usm…Therefore I understand that it’s not only the sensor size but also the way a lens is corrected, right?
Ming, I take the opportunity to ask you what is the behaviour (relative of this characteristic) of Leica Q’s 28mm, compared also to M-mount 28 f2 Summicron. What do you mean in another article that Leica Q 28 is good for cinematic style?
Thanks again, I really like not only your photos and blog, but also the way you manage interaction with readers!
“…it’s not only the sensor size but also the way a lens is corrected, right?”
Yes.
“Ming, I take the opportunity to ask you what is the behaviour (relative of this characteristic) of Leica Q’s 28mm, compared also to M-mount 28 f2 Summicron. What do you mean in another article that Leica Q 28 is good for cinematic style?”
The Q’s 28mm appears to have the same kind of field curvature that makes for slightly soft corners at wider apertures, but better separation from the background because the focal plane isn’t flat. I didn’t see it on the M 28/2.
Good article!
I’ve found a nice “matching” dual system to be the Hasselblad X1D and the Ricoh GR set to 4:3 in camera.
ACG
The GR is actually a pretty good companion camera to anything – not just because IQ is ‘good enough’ and it can ride in a pocket until needed, giving you quick draw ability alongside a more specific tool.
Thanks for brining this issue to light, Ming. This is a seriously underreported aspect of photogaphy technique.
I have used every format on your list at one point or another, and I agree with your findings. I’ve ways thought there was more to how formats render besides the angle of view/depth of field characteristics. There is just something more pleasant about how larger formats render in the wide to normal range. Back when I shot Micro 4/3, there was always something vaguely uncomfortable about the wides/normals. It just never felt right to shoot with a 20-25mm lens with normal angle of view. APS-C has the same feeling, though to a lesser extent. Being a wide/normal shooter I feel like the 35mm format or larger is a must to keep a pleasant projection. When I switched from APS-C to full frame as my primary camera my images just started “feeling” better.
I even feel like different lenses I’ve had over the years, even in the same focal length/format have had different projection characteristics. Aren’t there even some of the older specialized Nikkor fisheyes that are made specifically for different projection types?
Its vague and difficult to quantify, but it makes a big difference as far as the “feel” of the image. Its why 4×5 landscapes have an inherent beauty about them, and why close up iPhone portraits always feel somehow weird. Sometimes I wonder if there is just something visually less pleasant about how focal lengths below ~24mm project on any format. The more sensitive I become to projection distortion the more I find myself avoiding anything below 28mm on FF.
I’ve found that paying attention to these characteristics for each piece of gear I own (and consequently keeping the size of my kit down) has greatly helped my images. Its easy to previsualize and to produce consistant images when you fully understand how your gear “sees” the world.
“I even feel like different lenses I’ve had over the years, even in the same focal length/format have had different projection characteristics.”
They definitely do. The Zeiss 2/28 Distagon, for instance, projects very differently from the 1.4/28 Otus, and to be honest – whilst the Otus is technically better, I prefer the pictorial feel of the Distagon.
“Aren’t there even some of the older specialized Nikkor fisheyes that are made specifically for different projection types?”
Yes, and this is a good example – fisheyes come in rectangular, circular etc.
Close up iPhone portraits feel weird because you’re using 28mm-e – it’s just not a flattering FL for people. 28mm-e even on larger formats still looks odd.
Conversely though: longer lenses are great on smaller formats (and much more convenient from a size and achievable DOF standpoint, too) 🙂
Despite being a 35FF user, I’d probably say APSC hits the sweet spot. For wide, question is how wide do most people need? 28mm equiv with the GR is plenty wide enough for most and well we know how good that is….
I’ve never been as comfortable with the way lenses render on APSC as with FF or 44×33 or M4/3; I have no idea why that is. The GR is an exception, though it seems that longevity of these things isn’t that great (I know of at least half a dozen people whose cameras have just died for one reason or another that appears to be related to wear rather than trauma).
Strange… I’ve always felt the same way. Everything alway felt a little “weird” on my old D7000 compared to full frame, but I’ve always loved the way my Coolpix A renders. Perhaps another advantage of matched lens/sensor combo?
Non-SLR wides always have a rendering advantage because they generally don’t require the telecentric rear group, which can do strange things to the way the lens projects…
I actually took one apart that failed due to me taking a pretty good fall coming down a mountain side ( I was lucky enough not to suffer serious damage myself). Anyway the lens-sensor packaging in a very small space is a pretty remarkable feat of engineering, I really don’t see how you could greatly improve on the build of lens mechanism, without a significant size increase. The real question would be do the film models, which also had a collapsible lens, and are also remarkably compact, have significantly better longevity?
My most useful camera for travel that I’ve ever had is the Ricoh GR-21. It’s the old film version with such a good 21 mm FF lens that they made an separate Leica interchangeable lens from the formula! I’m still (hopelessly) waiting for an digital version. I only use an 21mm focal length lens when traveling because of the need to ‘take it all in’ on narrow streets and large architecture. And I’m on my fold-up bike so small is best. Please Ricoh, make a APSC 14mm GR model or better yet, FF 21mm Digital GR. (I’ve never been happy the the 28FF angle of view, no matter what the formate and I’ve tried 645 & 67 in it as well. Everyone sees differently.)
I’m still using my GR-21 film camera because there is nothing like it in digital. It’s going strong.
FWIW, Ricoh made a screw mount version of the 28mm too, I think.
The GW3 21mm converter for the GR is really excellent, though not quite as pocketable as the naked camera as it doesn’t collapse.
They had other issues – very temperamental LCDs for a start…
Another great article,Ming. < Thanks
Could express your views on pixel size, as well? There must be an optimum size for the different sensor sizes, from a practical users' point of view! For example when the pixels get too small, to prevent blur becomes almost impossible! < I don't know it that statement is correct or not. That's why I'm asking you. Thanks.
Maybe this is why there are so many 35mm FF stalwarts out there: you can control depth-of-field on demand with a minimum of fuss. Which is why I still enjoy my old Nikon 50mm f/1.8 pancake lens (except when I am in post and have to try and clear the terrible axial CA!)
Good insight as always.
There does appear to be a sweet spot between DOF and angle of view for the 35mm format…anything much larger requires some focal plane gymnastics to get everything in focus.
Again you explained the technical background in a very understandable way, which makes your conclusions easy to follow.
Thanks a lot!
Glad it makes sense 🙂
The only article I have every come across which makes the differences plain to see. Many thanks, Ming.
No problem.
ming, this is a great article which
the issue of “projection” is the most subtle – given advances in computerized optical design, do you think it would/will be possible to design a “wide angle” lens for DX or FX that matches the geometric performance of a large format lens… or is physics just too much against us here? at least some of the distortion (“perspective”) are really only a function of subject distance, right? I know in the 3D visualization world, the concept of “format” or sensor size ONLY affects depth of field, not the geometric projection…
as an aside, I realized while reading this article that I’m sitting almost exactly in the spot you took one of the photos – on street at montgomery in San Francisco. funny coincidence!
It’s definitely possible, and it isn’t the physics that’s the problem: it’s the cost 🙂
Now that DJI has acquired Hasselblad maybe you should have included a note on which format is best for aerial perspective.
I’m not sure how corporate finance and commercial transactions are relevant to creative choices…
Vilem Flusser’s excellent “Towards a Philosophy of Photography” is a good place to start understanding how corporate finance structures creative choices.
I worked in finance for ten years prior to photography. And it’s possible to relate anything to anything, but my point here was that it really has nothing to do with me (nor do I have any information or control) – I can’t figure out why at least 60 people yesterday thought it did. If I had that much influence, I wouldn’t be a photographer 🙂
Maybe I’m missing something but how does DJI’s (for now rumored) acquisition of Hasselblad suddenly change anything from a creative/equipment choice perspective?
Also, I recall Ming has an entire previous article devoted to shooting out of airplanes and helicopters. (not using drones though) You may find that article useful.
I may be wrong about the article but I know he has several photoessays where he touches on some of the technical aspects of shooting out of planes/helicopters.
Thanks for your comprehensive and very informative article, Ming. I use MF (Pentax 645Z and 645Nii, 35mm (Leica M) and M4/3 (Olympus OMD). I have been very impressed with the Olympus OMD system which I have found to be excellent at, in particular, close up and macro work, in a light tent. The pro series of lenses is sublime, as is the 75mm f 1.8. Not really for landscapes but excellent for portraits, black and white conversions and so forth. I very rarely use the in-camera special effects programmes. My only gripe would be the sheer complexity of the programmes but, once that learning curve is mastered and some presets have been stored, you are ready to go. A nice touch would be a 2x teleconverter rather than the 1.4x version. Coupled with the excellent 40-150mm pro zoom lens that would be a killer combo. For most general purpose work I am happy to go with Leica M and for landscapes I use the Pentax 645Z.
Great article. What interests me in particular is wide angle distortion. In theory there should be no difference between symmetrical and telecentric designs. Circle will always get more elongated toward edges. What`s your opinion on this?. Another thing is projection of image. Our vision is projected on a semicircular plane of eye and then corrected in the brain. As far I know there`s a filter from DxO that corrects flat projection.. Plainly speaking it gradually compresses the picture from the edges toward center. The effect is of course dependent on distance. Landscapes need it less then close-midrange objects. Do you use it?
Theoretically no, but in practice, theoretically perfect is too expensive to achieve.
The flat projection vs spherical projection issue is precisely why some wides appear wider – some lenses correct with the sphere, some against. It’s impossible to fully correct, more so when lenses must be designed to a budget. Curved sensors might be an interesting solution to this.
No, I don’t use lens correction beyond the ACR profiles. Never needed it…
I must be incredibly stupid or stubborn — or both — but I’ve arguing for years that the optimal shape for a sensor is concave. That portion of a sphere which is the inverse of a simple lens. Lens design could then be made much less intricate and less inexpensive, with minimal correction needed. Whenever I bring up that idea I’m told it’s simply impossible; the manufacturing process requires that sensors be flat. Well, hell — so was the earth at one point. I mean, eveyone agreed it had to be flat. Until it wasn’t.
Looking for concave sensor my friend ? Get hold of one of those panoramic cams like russian Horizont or japanese Widelux. They are already here. Right, but film is a kind of photon sensitive sensor, isn`t it.
Concave in one axis only 🙂 Are the lenses also cylindrical? I’ve never had a chance to examine one of these things close up.
About cylindrical lenses. There`s one aspect that haven`t be touched upon. Anamorphics! Pity no lens maker tried to do one for still camera, say 50mm . Imagine a 25mm panoramic wide with 50mm DOF! Yes there`re plenty for film use but they are huge and bloody expensive.
I think some of the low end cine lens makers are actually doing ‘cheap’ anamorphics (cheap being relative of course…)
Neither; I completely agree with you. The problem is making a concave sensor is something else…though I believe Canon and others are trying.
Ming, what are your thoughts on 4:3 aspect ratio versus 3:2, has that affected the way you employ medium format versus 35mm format? Being a m4/3 user myself, I have always felt 4:3 aspect gives more freedom especially in portrait orientation. There is also a notable difference what the angle of view appears to be when compared to 3:2 aspect. Crop factor is calculated from sensor diagonal after all, so with “equivalent” lenses the lateral FoV and vertical FoV are somewhat different between aspect ratios. For example, the Panasonic 15mm doesn’t feel like a 30mm equivalent and certainly nowhere close to a 28mm equivalent. If anything, it feels more like a 35mm to me.
I was always comfortable with 3:2, since most of the time I’ll trim one axis anyway to better balance off my subject – regardless of what the original capture aspect ratio was. But yes, I do feel more comfortable with 4:3 – there just seems to be a bit less wastage overall, especially with portraits (as you’ve rightly pointed out).
I suspect the projection of the wide also has a lot to do with how ‘wide’ it feels – the Hasselblad 24 and 28 are fairly flat, which makes them feel not-so-wide – even though the 28 is a 21mm-e and the 24 is something like 18.5mm. My theory is if there’s a strong central bulge, it feels longer because the edges are compressed and the geometric distortion hidden; if there’s central compression then it feels wider as the edges of the frame are stretched, which emphasises geometric distortion.
Educational and entertaining as always, Ming. I’ve been meaning to rent a 24 tiltshift for maximum dof with my 35 mm dslr and do some experimenting.
Just remember to properly zero out the tilt axis to avoid unintended movements… 🙂
Hi Ming, Thank you! Your article puts the issue of format choice in perspective. I was never happy with the results of M4/3 wide angle compared to FF35mm. Now I understand it! I really appreciate your in depth analysis.
No problem.
Thanks for a great article. Appreciate the depth of information.
Pleasure!