Resolution & Megapixels, what actually matters? Can my camera beat up your camera?

In the last couple weeks no category has caused more of a stir than the discussions about megapixels and resolution with the new Sony A7 series.  Most of this controversy starts with lens discussions.  There’s some considerable distinctions between the A7s‘s, 12.2 megapixel sensor, the 24mp on the A7, and the monster 36.3 of the A7r.  The sensors in the three cameras are all considered Full Frame(24×36), each measuring just under the 864 sq. mm. mark.  So what’s the difference between the three, if the sensor is basically the same size?  It’s a great question that confuses lots of people including myself….

Larger sensors tend to have larger pixels, which can translate to lower noise levels, and an increase in dynamic range(Cambridge in Colour article on Sensor size).  More light can be gathered by the larger pixel.  That at least makes sense.  How does this relate to the A7s and why is it the new low light king?   It has 12 really big Megapixels!  The light gathering potential is huge!  It becomes a dream camera for those who want to take low light or fast pictures(action, indoor photography, nights, low lit streets) and astral photography.    Somehow Sony has managed to increase the A7s picture quality by utilizing the unique in-camera processor(Bionz X) combined with the new Exmor CMOS sensor.  Does it have more resolution and capture images as sharp as the higher MP cousins…. no.  What it does do is provide a much sharper picture than the typical 12 megapixel camera (Sony A7s William Brawley’s Shooter report) with much more ISO range.   DXO explains that while the A7s performs better than any other camera tested in low light ISO, it actually looses some Dynamic Range compared to it’s partners(DXO A7 series comparison) after camera applies processing.

FD lens interior-07175
Described by one person as a 36 megapixel digital back, the A7r has few full frame equivalents.

That gets us to the A7 and A7r argument and that megapixels don’t matter.    It’s a complicated process to get an image to the SD card,    As the image zooms through the camera, Sensor size, pixel size, pixel density, processor, sensor type….  range of light/dynamic range… OMG!  –all contribute… Nasim Mansurav,(great articles on sensors etc) and others, refer to segments of this interaction as the “Image Processing Pipeline”(IPP). With the shared Bionz X processor, it’s similar in all three A7 cameras.  Suffice it to say that the largest sensor, with the largest pixels and highest pixel density wins, when the IPP is the same.  It’s starting to make sense why each camera performs the way it does.   Both A7s and A7 have better low light performance in some ranges than the 7r.  The 7r crushes in image quality when used in it’s optimum range.  Some things to ponder when the playground bully says his camera can beat up your camera.

  • About 12,000,000 pixel difference between the A7 resolution, 6024 x 4024,  vs  A7r 7392 x 4920.
  • staggering disparity in pixel density
  • 14 bits of color per pixel vs 12, on A7s and A7.  I think that’s good.
  • NO Anti-Aliasing filter
Lens dust
Ultimate Resolution with the Native FE 55 lens and the A7r.

This information helps resolve why the lens performance on the A7, can seem radically different on the A7r.  Lessor optical quality isn’t realized until placed on the unforgiving 36.3 MP sensor.  On the “R” everything is magnified, good or bad.  It explains why people go to great lengths to defend how good some lenses are!  In the A7 world they are that good.  A bit of a paradox I suppose.

Those of us who live in 7r-ville can hope that the new Loxia lens line, the about to be officially announced FE 16-35 f4 and FE 85 1.8 are capable at 36.3 megapixel levels.

Another good resource for this discussion

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Lens alternatives for the Sony A7r, the worlds preeminent full frame camera!

There are so many soothing lens options for the A7/A7s/A7r until additional FE lenses come out.  I do enjoy playing the villain a bit with the FE lineup.  Yes,  I’ve complained pertinaciously(see definition, fits perfectly), but I do have faith that Sony, Zeiss, perhaps Sigma, or others like Rokinon, Samyang etc. will drop in another hole in one (like the FE 55mm 1.8.),  specifically tailored for the FE Mount.  I’ve composed a pretty good list, which is always subject to debate and taste, of the lenses I use and other standouts.  Most have to take screw in filters.  I photo a lot of water and need polarisers.   I won’t deal with back filters or Lee systems etc.  I’ve seen guys tape tinted glass on their cameras….  not for me.   All lenses on the list have a DXO mark rating of 27 or higher.  27 seems to be the cut off from ordinary.  Finally, full frame capable.  Going to cropped for some extra range is nice at times, but basically want all the picture you can get.

The boys II-6751
Left to right, FE 55mm, “G’ Sony FE 70-200mm, Sigma 85mm 1.4, Sigma 35mm Art, 1.4, Zeiss Distagon 15mm Zf.2, Zeiss Makro Planar 100mm, Zf.2 Adapters, Metabones IV, Zykkor EF to NEX, NIkon to NEX Tilt shift, Novoflex Nikon to Nex

First the wide angles.

The Zeiss Distagon, 15mm 2.8 Cost, $2950…  is considered by many, the best wide angle ever made.  See Ken Rockwell, the Digital Picture, 3d-Kraft.  There is even a M mount version $3900+/-, that’s slightly smaller than the Canon ZE, or Nikon ZF.2.  I believe at this time, only the Canon version, with Metabones or RJcamera smart adapters($269-$399), will show all data in the camera and are full frame compatible.  The filters, $200-$300 ea.  It’s the best, what can you say?

Since the A7’s have come out many people like to throw the 14mm f/2.8 Rokinon/Samyang/Bower, etc  into the mix.   It’s a low price alternative, around $400.  It takes no filters and has high distortion(can be alleviated fairly well in post processing).  Image quality and resolution seem very good.  It weighs less than the Zeiss and looks like a fun lens.  There is a Canon version that will transfer data through the adapter.

If you’re a Leica fan, and I’d love to try this lens, the Leica 21mm f/3.4 Super Elmar M Lens $2995.    It does take filters(46mm), it’s the most lightweight of the three.  You will need an M to Sony NEX adapter.  Manual focus only.

 The 3 DXO wide angel lens specs.

The 35mm range

The Sigma, Art 35mm 1.4 DG, So far,  in limited use this lens is crisp.   In larger landscapes you sacrifice some DOF by topping out at F16, as the Cape Flattery shot illustrates.  I’ve seen some incredible shallow DOF shots in the forums.  The three following shots at our new restaurant, highlight the lens capabilities wide open.

sigma 35 f16-01253
Cape Flattery WA, Sigma 35mm A F/1.4 DG @ f16
Planter box 35mm 1.4-01460
Sigma 35mm A 1.4, shot @ 1.4 1/400 sec, hand held. The detail in the middle of the planter is fantastic. That’s not distortion, the board is very warped.
Sigma 35mm 1.4 A  90% crop
Andy 35mm 1.4-01465
Andy, our contractors Golden, resting, Sigma 35mm @ 1.4

 

It’s not a light lens @ 665 grams.  Cost $900, takes 67mm filters.  It has a very good price to quality value.  You can buy any Sigma lens with a Sony A mount, which when coupled with the La-e4 adapter has excellent AF.

Next on the list has to be the Native, Zeiss Sony 35mm, FE Sonnar T*, 2.8 ZA.  This lens would have been a slam dunk choice if it had the quality of the Sonnar 55mm.  It rates significantly lower than the Sigma, 33 to 43, although it is a very high quality performer.  It’s still a moderately fast lens, and weighs next to nothing @ 4.23 ounces.  Only…$800

Several manual focus gems are out there and if anyone would like to loan one to me…. the Voigtlander 35mm F1.2 Nokton Leica, Leica Summilux-M 35 mm f/1.4 ASPH or the Leica-Summicron M 35mm f/2 Asph. Read the Gear Patrol review on 35mm lenses for additional info.

I can’t drive 55…mm

Thanks Sammy Hagar.  The 55mm, FE Sonnar T* 1.8 ZA pretty much ends this conversation about 55mm lenses for the A7’s.  Best auto focus 55mm ever tested according to DXO, SonyAlphaRumors.  Shoots outstanding video with all three cameras.  The only lens better is the OTUS, 55mm.  The Otus is a tank(3 1/2 times the size of the FE), has close to perfect optics and is manual focus.  In four Sony Facebook Groups, only 55 talked about… is the FE.

 Macro lenses….  oh soo close…up

There’s too much territory to cover in great detail in this class, but here are some awesome choices!

Flash Macro 100mm-00840
Wonderful transitions in focus on the Zeiss, 100mm Makro Planar T*, ZF.2. Flash, our Black Lab sitting on the bed….

Carl Zeiss Makro-Planar T* 100mm f/2 ZF2  $1850

Carl Zeiss Apo Sonnar T* 2/135 ZE  $1600

Sigma 85mm 1.4 EX DG Canon  $970

Canon EF 100mm f/2.8 L USM   $970

Minolta Maxxum 100mm f/2.8 Macro $400 used,  See Ken Rockwell review.

Leica TS-APO-ELMAR-S 120 mm f/5.6 ASPH$7300++

I’m lucky enough to own three of these lenses.  My backup camera is a 5D mk III and two of them fit that camera too.  Today on a budget I’d track down a Minolta.  It was produced in a Sony E mount and should be a rock star on the A7r with a Le-a4 adapter.

Can we get some Zoomage please!

This is by far the hardest category and the most controversial.   Forum wars with comments near a 100 per thread, are common.  This series started out over disappointment in the Native 28-70 FE kit lens, and the Zeiss Sony 24-70 Vario Tessar T* FE F4.  The 24-70 Tessar is damn good in the center, comparable with any of the lenses.  It just loses clarity on the edges, which is really bad for a landscape photographer!

Hope springs eternal on the about to be released FE 16-35mm F4.  Sony did well in their “G” 70-200 FE lens(see DXO comparison of these native FE lenses).  It’s good edge to edge, has excellent resolution, and AF on the A7s & A7 is fast.  It’s certainly worthy of leaving the other macro lenses at home and getting great shots if you want to go light.  For now I’ve put my money into a Sony Vario-Sonnar T* 16-35mm F2.8 ZA SSM, $1600, plus the La-e4 adapter.   The Sonnar T* design really shines edge to edge.  It will arrive Thursday and hopefully I will report nothing but rave reviews!

Several other zooms have to be considered.  The Canon EF 16-35mm f/2.8L II USM  $1400
which I’ve used extensively on the 5D Mk III, is a wonderful lens.  It looks like the most popular lens in the Sony Forums as well.  Price to value is very good.  

Another choice that is more budget friendly is the Sigma 17-35mm F2.8-4 EX DG Aspherical HSM, $350

Conclusions and final thoughts!

There are many other lens options that work very well on this system.  One forum going pointed out that the old Canon FD lens with adapter are another wonderful choice.  They are expensive in the open market, but if you run into one, grab it and get the Canon FD to Nex adapter(there are several inexpensive alternatives).   The optics from what I’ve researched are outstanding and there is a variety of focal lengths.

I don’t talk much about Nikon glass.  Until someone puts out a Nikon “smart” adapter, they remain manual focus with no information transferred to the camera.  Nikon’s best lenses are well known, ez to research and are great choices in many cases.

Right as I was winding down this post, a couple sources said that 5 of the  ZM mount, manual focus, Zeiss lenses are going to be re-released with the FE mount.   Hopefully so!