2014 Camera Kit-Part 2

The next step in figuring out a possible lens kit that will work with the Sony A7 / A7r is to look at primes.

With only 3 lenses available for the FE (Full Frame E-mount), if a complete kit is needed then we have to go with adapters.   Once that decision is made, a whole lot of very good lenses get eliminated.  The reason is that with a dumb adapter, an aperture ring is required.  So most high quality Canon and Nikon options just will not work.  What does work are the Zeiss and Voightlander manual lenses for Leica (M-mount) and Nikon (Zeiss ZF.2 mount).  There are reasonably priced Metabones and other high quality adapters for both of these readily available.

There are some other things to consider when thinking about making the jump from APS-C to Full Frame sensors.

- Roughly a stop difference in depth of field.  f/2.8 on APS-C gives a similar DOF to f/4.0 on a full frame. 

- For the same resolution, FF will have better ISO performance than APS-C.  bigger photo sites on the sensor make a difference, again roughly a full stop.

- Everything costs more on Full Frame.  And especially with higher resolution cameras, whether Nikon, Sony or Canon, glass that takes full advantage of the camera's capabilities is going to be more expensive.

Plus we have to consider that all things are not equal between brands.  Sony may be a leader in innovation, but Nikon manages to squeeze out slightly better ISO performance on the same sensor.  They must have a better processing algorithm for that.  But the mirror less Sony will run at a faster frame rate when you need to capture action.  You have to pick what works for your particular style.  It's not like any of the major manufacturers are generations ahead of the other guys, the race is still close.

For backpacking photography size and weight are an important consideration.  So I decided to make up a chart of likely candidates.

Click for more readable size

A few things jump out when looking at the stats.  The M-mount glass is much smaller and lighter.   From the early reports, the 35mm and higher choices work great on the A7r.  Once below 35mm vignetting is an issue.  It's a problem even on the Leica body.  Fixable, with a little extra processing, but something to think about.  It may be the bigger Nikon mount lenses will work better in ultra wides since they were designed for an SLR style body and the slant of light coming into sensor is less severe.  I haven't seen tests with the Zeiss Nikon mount glass on the A7 or even the Nex-7, so that theory remains unproven.  

My quick calculation is that the total weight of the Voightlander 15mm, 21/1.8, 50/1.5, 75/1.8 and Zeiss 35/2 comes to 1440 grams.  Compare that to the Zeiss 24-70 for A-mount at 984 grams and the difference is 456 grams, almost exactly 1 lb.  There are certainly lighter 24-70 lenses out there but I don't think the differences will be great at similar quality.

There is a big difference in price.  That selection of Voightlander and Zeiss primes comes to more than $4400, compared to $2000 for the top quality Zeiss 24-70, or $1200 for the FE mount 24-70 f/4 lens.  That's a take your breath away difference.   It also make the cost of even an expensive camera body look less important.  And any body we buy today will be long gone before those lenses wear out.  

That's a lot to think about.  A big flexible zoom or a bag full of light and small primes.