Compact lenses, great photos?

Sports and wildlife photographers in particular are famous (or notorious) for investing in and carrying around lenses that are often just huge: large, long, and heavy. Is it possible to take great photos with small, compact lenses, or is an expensive and large lens the only option for a hobbysist photographer who’d want to reach better results?

Winter details, captured with Canon EOS M50, and the kit lens: EF-M 15-45mm f/3.5-6.3 IS STM.

I am by no means an authority in optics or lens design, but I think certain key principles are important to take into consideration.

Perhaps one of the first ones is the style of photography one is engaged with. Are you shooting portrait photos indoors, or even in a studio? Or, are you tripping outdoors, trying to get closeup photos of elusive birds and animals? Or, are you rather a landscape photographer? Or, a street photographer?

Sometimes the intended use of photos is also a factor to consider. Are these party photos, or something that you’ll aim to share mostly among your friends in social media? Or, is this that important photo art project that you aim output into large-format prints, and hang to your walls – or, in to a gallery even?

These days, digital camera sensors are “sharp” enough for pretty much any purpose – one of my smartphones, Huawei Mate 20 Pro, for example, has a 40 megapixel main photo sensor, with 7296 × 5472 native resolution. That is more than what you need for a large poster print (depending on viewing distances and PPI settings, a 4000 x 6000 pixels, or even 2000 x 3000 pixels might be enough for a poster print). There are many professional photographers who took their commercial photos for years with cameras that had only 6 or 8 megapixel sensors. And many of those photos were reproduced in large posters, or in covers of glossy magazines, and no-one complained.

Frozen grass, photographed using Huawei Mate 20 Pro smartphone.

The lens and quality of optics are more of a bottleneck: if the lens is “soft”, meaning that it is not capable of focusing all rays of light in consistent, sharp manner, there is no way of achieving very clear looking images with that. But truth be told, in perhaps 90 % of cases with blurry photos, I blame myself rather than my equipment these days. There are badly focused photos, I had a wrong aperture setting or too long exposure time (and was not using a tripod but shooting handheld) and all that contributes to getting a lot of blurry looking photos.

But it is also true, that if one is trying to achieve very high quality results in terms of optical quality, using a more expensive lens is usually something that many people will do. But actually there are “mainstream” photography situations where a cheap lens will produce results that are just – good enough. It is particularly the more extreme situations, where one is for example trying to get a really lot of light into the lens, to capture really detailed scenes in a very consistent manner, where large, heavy and expensive lenses come to play a role. This is also true of portraiture, where a high-quality lens is also used to deliver good separation of person from the background, and the glass elements, their positioning and the aperture blades are designed to produce particularly nice looking “bokeh” effect (the out-of-focus highlights are blurred in an aesthetically pleasing manner). And of course those bird and wildlife photographers value their well-designed, long telephoto range lenses that also capture a lot of light, thereby enabling the photographer to use short enough exposure times and get sharp images of even moving targets.

A cropped detail, photo taken with SIGMA 150-600 mm f/5-6,3 DG OS HSM Contemporary tele-zoom lens on a dim winter’s day.

In many cases it is actually other characteristics rather than the optical image quality that makes a particular lens expensive. It might be the mechanical build quality, weather-proofing, or the manner the focusing, zooming and aperture mechanisms, and how control rings are implemented that are something a professional photographer might be willing to pay for, in one of their main tools.

In street photography, for example, there are completely different kind of priorities as compared to wildlife photography, or studio portraiture, where using a solid tripod is common. In a street, one is constantly moving, and also trying not to be very conspicuous while taking photos. A compact camera with a compact lens is good for those kinds of reasons. Also, if the targets are people and views on city streets, a “normal range” lens is usually preferable. A long-range telephoto lens, or very wide-angle lens will produce very different kinds of effects as compared to the visual feel and visual experiences that people usually experience as “normal images”. In a 35 mm film camera, or “full-frame” digital camera, a 50 mm lens is usually considered a normal lens, whereas with a camera equipped with a (Canon) “crop” sensor (APS-C, 22.2 x 14.8 mm sensor size) would require c. 30 mm lens to produce similar field of view for the image as a 50 mm in a full-frame camera. Lenses with this kinds of short focal ranges can be designed to be physically smaller, and can deliver very good image quality for their intended purposes, even while being nicely budget-priced. There are these days many such excellent “prime” lenses (as contrasted to more complex “zoom” lenses) available from many manufacturers.

One should note here that in case of smartphone photography, everything is of course even much more compact. A typical modern smartphone camera might have a sensor of only few millimeters in size (e.g. in popular 1/3″ type, the sensor is 4.8 x 3.6 mm), so actual focal length of the (fixed) lens may be perhaps 4.25 mm, but that translates into a 26 mm equivalent lens field-of-view, in a full-frame camera. This is thus effectively a wide-angle lens that is good for many indoor photography situations. Many smartphones feature a “2x” (or even “5x”) sensor-lens combinations, that can deliver a normal range (50 mm equivalent in full-frame) or even telephoto ranges, with their small mechanical and optical constructions. This is an impressive achievement – it is much more comfortable to put a camera capable of high-quality photography into your back pocket, rather than lug it around in a dedicate backbag, for example.

Icy view was taken with Canon EOS M50, and the kit lens: EF-M 15-45mm f/3.5-6.3 IS STM.

Perhaps the main limitation of smartphone cameras for artistic purposes is that they do not have adjustable apertures. There is always the same, rather small hole where rays of light will enter the lens and finally focus on the image sensor. It is difficult to control the “zone of acceptable sharpness” (or, “depth of field”) with a lens where you cannot adjust aperture size. In fact, it is easy to achieve “hyperfocal” images with very small-sensor cameras: everything in image will be sharp, from very close to infinity. But the more recent smartphones have already slighly larger sensors, and there have already even been experiments to implement adjustable aperture system inside these tiny lenses (Nokia N86 and Samsung Galaxy S9 at least have advertised adjustable apertures). Some manufacturers resort to using algorithmic background blurring to create full-frame camera looking, soft background while still using optically small lenses that naturally have much wider depth of field. When you take a look at the results of such “computational photography” in a large and sharp monitor, the results are usually not as good as with a real, optical system. But, if the main use scenario for such photos is to look at them from small-screen, mobile devices, then – again – the lens and augmentation system together may be “good enough”.

All the photos attached into this blog post are taken with either a compact kit lens, or with a smartphone camera (apart from that single bird photo above). Looking at them from a very high resolution computer monitor, I can find blurriness and all kinds of other optical issues. But personally, I can live with those. My use case in this case did not involve printing these out in poster sizes, and I just enjoyed having a winter-day walk, and taking photos while not carrying too heavy setup. I will also be posting the photos online, so the typical viewing size and situation for them pretty much obfuscates maybe 80 % of the optical issues. So: compact cameras, compact lenses – great photos? I am not sure. But: good enough.

More frozen grass, Canon EOS M50, and the kit lens: EF-M 15-45mm f/3.5-6.3 IS STM.

Author: frans

Professor of Information Studies and Interactive Media, esp. Digital Culture and Game Studies in the Tampere University, Finland.