Thursday, 7 July 2016

Formats Compared - APSC Mirrorless (Part 2)

A small Mirrorless APSC model can be an excellent travel camera,
 this was shot using a very compact Sony NEX 5n

Today we continue to look at the benefits and deficits of the three core mirrorless formats, APSC is now in the spotlight and in many ways is the best overall compromise, but lets explore a little deeper to see what the format option offers.

APSC:   16 x 24mm nominal frame size but there is some variation from this depending upon the brand of camera, generally we could say the sensor has a surface area of around 380 mm square, which makes it around 45% of the full frame option.

Flexible Format Options

Cropped to M 4/3 a 24mp APSC gives 14mp which is very close to M 4/3 sensors with more framing/cropping flexibility.

Cropped 16 megapixel sensors come back to 9.3 megapixel when cropped to M 4/3 equivalent which is a bit off the pace to be truly practical.


These days we have many wide angle options, including fish eye and quite a few ultra wides, it is unlikely that you could not find something to suit your needs, unless you need to be shooting with a tilt/shift lens in which case short of using a tilt /shift adapter with an ultra wide wide angle lens you have few options.

There are now some extremely good fixed focal length lenses in the format which are economical, focus quickly and provide top class optical performance, basically because they needed to be designed from scratch instead of adapting older pre-digital designs, as often happened with full frame lenses.  The new Sigma 30mm f1.4 is an excellent example of what can be done at a more than reasonable price.

There are also some extraordinary zooms available in the APSC format that can either be used directly on mirrorless or via adapters, the Sigma 18-35mm f1.8 is an excellent example and such a lens would be difficult to implement on full frame and still maintain the same high level of performance. 

These days most kit lenses are quite OK, but generally are not as even performing as M 4/3 kit lenses, that being said the Fuji kit lenses seem to be excellent and a cut above those from other brands.

You can get pancake kit lenses in the APSC format and though they are not great performers they do suit the needs of many consumers and certainly make for a much smaller package for travel etc.

C mounts lenses can give some interesting options ( with a lot of vignetting) and are far more suited to APSC than full frame. Ultimately however if you want to explore C mount lenses an M4/3 camera is a much better starting point.

Generally apertures need to be stopped down just one stop from wide open get adequate or optimal lens performance so practical shutter speeds tend to be a bit faster than FF. 

Aspect Ratio

APSC is easy to crop to any aspect ratio you may desire, however it’s also true that a good many photographers would find that a 4:3 aspect ratio a better starting point.

If you want to work with 16:9 aspect ratio then a 24 megapixel APSC is a very good option, still allowing for plenty of resolution and flexibility.

A 4:3 aspect ratio would actually be a closer match to the print sizes that most people tend to produce when making enlargements, for example 10 by 8s, 5 by 7s, 11 by 14s etc.


Bodies can be very small and light but most full featured bodies are in the 420 to 500g range, there have been a few less full featured sub 300g bodies, which is less than half the lightest full frame body on offer.

Providing you stick with moderate aperture lenses and don't go too telephoto you can keep the total kit weight quite low, generally the extra crop factor of the format means that 200 to 300mm is about as much reach as most people will ever need.  Many of the 55-200mm mirrorless zooms are pretty compact and light, much more so than the FF frame or DSLR style options.


It is still easy to get get very shallow depth of field rendering without spending too much money, in fact almost any full frame lens can be adapted cheaply to MIrrorless APSC and because they can often be used one stop wider open than on Full Frame (basically due to the fact you are using the sharper central core of the lenses image circle) the final result can  effectively look pretty similar.

Noise levels and dynamic range with the latest state of the art APSC sensors are very close to FF, there is a bit of brand difference here and currently the Canon sensor in the M series models lags the rest of field a bit, but nonetheless the performance is fine.


There are some seriously hi spec options in the APSC camp that for all intents and purposes perfectly fulfil the needs of professional photographers without cutting any corners, yet offer considerable cost and weight savings over the full frame options.

IBIS (in body image stabilisation) or lens based stabilisation works very well on the format but M4/3  bodies due to less physical constraints due to sensor size or lens elements still seem to do a little better in this area.

Macro photography is comfortably easier than full frame due to the extra DOF the format offers.

APSC mirrorless is a very flexible format for macro, tilt shift and image stitching, if you make use of the various adapters available to use with legacy lenses or even digital era lenses designed for full frame DSLRs

Almost any lens ever made can operate on APSC via the right adapters, except M4/3 which can work but only at wide open aperture and only if they have a manual focus ring.  It is not generally possible to interchange lenses from other APSC mirrorless formats as the addition of adapter would make it impossible to obtain infinity focus.

Lenses are nicely smaller than FF but longer teles are still quite large. 

There are still no truly excellent pancake zoom options on offer. 

APSC mirrorless is probably the largest sensor size where cross frame clarity can be achieved at a reasonable cost and size/weight balance.

An APSC camera can be dressed up or down depending on what you need, i.e. use compact pancake or small fixed focal length lens of moderate aperture or go the other way and use top drawer heavy fast FF lenses, however the balance of the camera/lens combo will obviously suffer.

There is a wealth of cheap film era lenses to use, many of which are still very good, many film era zooms perform well on APSC mirrorless because the poorly resolved outer field areas are cut off by the format.

There it is, next we will look at the M4/3 option.

No comments:

Post a Comment