Sony A7 III - Sigma 150-600 C - MC-11 Review (Part I)

In essence this is the first of several entries to discuss the Sony A7 III.  Particularly, I will be writing about the A7 III with the Sigma 150-600 C lens attached via the Sigma MC-11 adapter.

For those who follow my blog, podcast and YouTube channel, you will know that I have been interested in Sony's line of mirrorless cameras for some time.  I have watched as each new camera launch ushered in a new age of mirrorless  technical features.

Having said all that, I am a Canon photographer.  I have a great deal of money tied up in lenses, flashes, bodies and other accessories.  For me to move to another system like Nikon would mean that I would have to replace everything.  However, that is not true when moving to Sony from Canon.  All I needed was a Sigma MC-11 converter and my Sigma lens could be used.  But, would it be that simple in reality?  That is what I am going to explore of the next several blog entries.

Initial Setup of the Sony A7 III

As with any new camera there are always configurations to perform.  I followed Sony's recommendations for wildlife photography.  They are pretty much as follows:
  • Set Focusing Mode to AF-C (Continuous AF)
  • Set Focus Area set to Flexible Spot 
  • Set Drive Mode to Continuous Hi (8 fps)
  • Set Image to Compressed Raw (uncompressed RAW will fill the buffer up too rapidly) 
  • Make sure the MC-11 Adapter Has the Latest Firmware
  • Make sure the 150-600 has the Latest Firmware
I saved these settings as "1."


  • Megapixels: 24.2
  • Body Style: Magnesium Alloy
  • Autofocus:  Fast Hybrid AF (phase-detection/contrast-detection AF)
  • ISO: 100-51,200
  • Shutter Speed:  30 seconds to 1/8000
  • Viewfinder Coverage: 100%
  • LCD: 2.95 inch with 921,600 dots
  • Drive Modes:  Single, Continuous Hi/Hi+
  • Burst:  8 to 10 FPS depending on drive mode and compression
  • Battery: NP-FZ100 (610 shots)
  • Battery Charging:  Internal with USB cable / External charging available via a charger sold separately

Build Quality and Feel

Right away I noticed how much smaller the A7 III is when comparing it to my Canon EOS 7D Mark II.  My pinky actually dangles off the bottom of the grip. I did not find it uncomfortable though, and both 3rd party grips and a Sony grip can be purchased to make moving to a vertical easier.  The grip will also extend the battery life as it allows me to put two batteries in it.

I found the buttons, for the most part, to be well positioned.  I ended up making the AE-lock button into a back button focus button, since I always shoot with back button focus.  The one button I found hard to get to was the AF-On button.  It is positioned up against the right side of the viewfinder.  By the way, I should also mention that there are numerous buttons the body that can be programmed to whatever the photographer needs. One button I actually think I like better on the Sony is the shutter button, but I am not sure yet. 

Test #1 - Songbird Photography (Day 1)

The first test that any kit has to be able to do for me is to be able to quickly snap into focus when photographing songbirds in a setup studio environment.  I spend a lot of time photographing birds in this scenario and it is an absolute must for me.

In this test, the conditions were quite rough.  It was stormy and heavy cloud cover.  However, it turned out to be a good place to test low light conditions both from a focusing and high ISO perspective.  My ISO ranged from 1000 to 12,800. 

Cottontail Rabbit - High ISO at 12,800!!   The equivalent noise on my 7D Mark II in these conditions would have been 3200 or 6400.

During this test, the focusing of the camera seemed to be hit or miss.  At times it seemed to lock on fine and then suddenly would hunt all the way to infinity and back in a very very slow manner.  It was as if it was switching from phase detect AF to contrast AF and back again.  This was very frustrating to say the least.  On a scale of 1 to 10, one being the worst AF I have ever used and 10 being the best, I would place it at about a 5.  Had it not hunted on many occasions, I would have given it a 7 or better.  It is possible that the "Lock-on" feature will work better.  I have seen some thoughts to that effect online.  I will try that out on day two.

What I did find absolutely amazing was how great the image was at higher ISOs.  That is honestly something I am looking for in my next camera body.  When I am shooting a lens with a minimum aperture of 6.3, I need to have clean shots at 2000 ISO. Right now, with my 7D Mark II that is not possible.  So, I would give it a clear 10 here.  Sony is second to none in image quality.  Below are two test images I took on day one.  I did not have any bird images I thought passed the test on noise and quality.

Sony A7 III - Sigma 150-600 C - MC-11 Converter - f 6.3, ISO 1000, 600 mm, 1/1250, Some cropping done

Roughly 100% Crop of  Original without Additional Sharpening Applied (600mm)

I should also note that the menu system of the Sony is not nearly as complicated as people say it is. Maybe I am just good at navigating menus, but I thought it was quite intuitive and easy to use.  It is just like anything new.  You have to get used to it.

Test #2 - Songbird Photography Day 2 (A MAJOR BREAKTHROUGH)

With somewhat disappointing auto-focus results on day one, I changed my Focus Area strategy to use the Single Point Expand with Lock-on for day 2.  It turned out to be a huge boost to the AF performance.  Sony engineers, it would appear, spent a great deal of time perfecting Lock-on.  For this second day,  it was like shooting with a new camera.  I had increased my keeper rate easily by 75%, and it was actually fun to watch the focusing system stay with the bird.  I could lock on and recompose my images with the confidence that the focusing system would stay right where I locked on (in most cases).

Eastern Bluebird - Lock-on Engaged (this is the secret to using the Sigma 150-600 C) Focus and recompose was easy with Lock-on mode.

However,  the AF was not without issue.  I did notice that it wanted to grab the background on occasion and not let go.  In order to fix this, I had to manually focus back to the general area I wanted to focus in.  This was a disturbing problem, but with such a high keeper rate, it was hard blame the camera too much. After all, this is an adapted lens.  With a Sony native lens, I do not think this would be a problem.

Taking the images back for post processing, I was amazed at the detail of the images with standard AA sharpening applied.  They were sharper, for the most part, than anything out of my Canon 7D Mark II at 600 mm.  It should be noted that some of this was perceived sharpness due to being farther away from the subject and gaining more depth of field.  But, even so, it was a clear winner on sharpness.  Was it better than any other Canon product?  I can't say that for sure.  I think Canon has some amazing full frame sensors out there.  The win might go to Sony on this front as well.  The EOS R has a great sensor though.

100% Crop - Sony A7 III - Sigma 150-600 C - MC-11 Converter - ISO 1000

Common Grackle - Sony A7 III, Sigma 150-600 C, f6.3, 421 mm, ISO 2000, 1/1600

Day 1 and 2 Pros and Cons


  • Amazing image detail and sharpness even with higher ISOs
  • Single point expand with Lock-on blew my mind. 
  • Single point expand made it easy to focus and recompose even in AF-C (continuous tracking)
  • Shutter button was always easy to find and shoot with
  • Built in five way image stabilization
  • Great AF tracking when following birds from branch to branch
  • Easy to "clean up" images in post


  • Unable to use silent shooting due to distortion possible with moving subjects
  • To get good write speeds to the SD card, I had to use compressed RAW.  This gives up data such as high dynamic range.
  • Would like to see a 30 mp sensor size on such a new camera.
  • Seemed to focus much slower when using Non-lock on modes (with MC-11 converter).
  • Limited cropping in post due to 24 mp sensor size
  • AF would grab and hold the background and not let go on several occasions on each day


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