November 2014 - Digital Group - Small vs Large Cameras

Meeting Notes March 2009 to 2018.
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spb
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November 2014 - Digital Group - Small vs Large Cameras

Post by spb » Sat Nov 08, 2014 6:25 pm

BEGINNERS TUITION

The Photoshop Elements tuition this month was on the subject of Image Resolution, File Size and Quality. Notes can be downloaded from the Digital Group page of the APS Website.

SMALL CAMERAS, LARGE CAMERAS - does it matter?

At the 2014 Photokina photographic industry bash it was observed that the market for inexpensive point-and-shoot compact cameras is now officially dead - supplanted by mobile phone cameras. Other trends are also very apparent;
- expensive 'Enthusiast Compacts'
- retro-styled cameras (also expensive)
- go-anywhere rugged 'action' cameras
- mirroless system cameras (mini dSLRs)
- photographers fed up with carrying heavy bags of lenses and equipment
- camera sensor sizes growing
- the processing power available in the camera or phone increasing exponentially.

How do these trends affect image quality? Do smaller cameras have disadvantages and if so, are there work-arounds? Should we still be investing in traditional dSLRs?

It so happens that I have in my possession three cameras that represent three market segments relevant to the above debate;
- iPhone 6 Plus smartphone
- Sony RX100 M3 small enthusiast compact
- Nikon D7100 enthusiast dSLR
so I thought that it would be interesting to compare them…..

COST COMPARISON
Interestingly, all three of these very different cameras are currently in the region of £700. Although these are expensive models, they have all won plaudits for very high quality and it would be true to say that the same technology will be widely available at a fraction of the price next year. Indeed last year's models of all three are still on the market at greatly reduced prices. The iPhone 6 Plus camera also comes with a handy phone attached at no extra charge.

IMAGE QUALITY COMPARISON
Image quality is closely related to sensor size and pixel packing density. The Nikon has an APS-C sensor with 24MPx, The Sony a smaller 1" sensor with 20MPx and the iPhone a tiny 1/3" sensor with 8MPx. This results in the Sony having three times the packing density of the Nikon and the iPhone nine times, so we should see more noise and burnt-out highlights as size decreases.

Taking for granted the Nikon image quality, images shown to the meeting demonstrated surprisingly high quality projected and A3-printed colour images from both Sony and iPhone. Certainly suitable for competition - even from the iPhone. The Sony benefits from Raw file availability and greater control of the camera functions but the iPhone quality was surprising. Enlargements from the iPhone showed some JPG artefacts but the images could have been cropped a little and still printed at A3.

In low light, the small sensor of the iPhone created noisy images at ISO 2000, whereas the Sony was clean. However, in practice the iPhone rarely goes beyond ISO 500, preferring to utilise long shutter speeds instead. Without flash ,the optical image stabilisation of the 6 Plus (not available on the 6) enabled pin-sharp hand-held images at 1/4 sec. It is rumoured that Apple process a multi-frame burst in this situation. However it does it, we were surprised and impressed by the results.

The Sony zooms from 24m to 70mm (equiv.) which is a useful range. The iPhone is fixed at 30mm but for wider shots, the panorama setting worked spectacularly well, going anywhere up to 180 deg around with almost flawless stitching and a full resolution of up to 13,600 pixels wide by 3,000 high! Although the iPhone has a digital zoom, the lack of a high quality optical telephoto capability is a serious flaw for portraiture and candids. The in-built Sony panorama feature was less accurate at stitching and only generated a small jpg. However it would be possible to stitch individual shots in Photoshop Elements to produce a very high quality result.

Shots of brick walls revealed almost no distortion from either camera and very little corner softness at any focal length or aperture. This is better than I have come to expect from expensive Nikon zooms! Whether the lack of distortion is a product of post-processing in the camera or a benefit of small lens design is unclear.

In conclusion I believe that image quality should not be a limitation of either small camera although the fixed aperture and focal length of the iPhone do impact the ability to get close to a subject and generate a shallow depth of field.

USABILITY COMPARISON
Clearly, a professional photographer would not dare to take a compact camera or a phone camera to capture a wedding! A dSLR has undoubted gravitas (especially with added battery pack) and it's sheer mass reduces camera shake. Furthermore it can adapt to any situation and produce unquestioned quality. However on the negative side many of us have attracted the unwelcome attention of security staff because we are carrying 'professional' equipment and our bags of heavy equipment seem to become less and less tolerable as the years go by.

Small cameras are, by comparison, discrete, even invisible on the street. And we can always have them with us, in a pocket. A flip screen offers different viewpoints and further candid opportunities. Composing and reviewing on the huge 5.5" HD resolution screen of the iPhone is pure luxury. On the negative side however, the buttons and controls on small cameras can be fiddly and awkward. Both cameras have built-in communications capabilities and high-end features such as rapid burst-mode and HDR.

Most interestingly to me, the small new cameras and especially phones, are part of a vibrant and dynamic software ecosystem that is producing innovative and exciting new photographic possibilities on an almost daily basis. By comparison the dSLR seems stuck in the 20th century. I showed a few examples of these such as;
- the ability to pre-visualise mono images on the camera (both) and yet also generate a full colour raw for post-processing (Sony)
- Hockney-esque joiners from a panned image (IOS App: You Gotta See This!)
- unlimited numbers of creative filters from thousands of phone apps
- image painting apps ( IOS App and Win: Auto Painter)
… none of which may win competitions but help to put the pocketable camera, on the table, at the centre of any social occasion.

CONCLUSIONS
I am convinced that pocketable cameras can't be dismissed and they may have significant advantages in many areas. Image quality is no longer a limitation. Indeed phone cameras have already been used for war reportage because of they are unobtrusive, portable and fairly robust (and ultimately disposable).

Apart from niche areas such as sport and wildlife where the long telephoto is essential, and areas where absolute quality is paramount, I believe that the dSLR is looking rather dated and will need to adapt or die.

Cheers, Steve Brabner

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