A-mount, 500mm f/4 G and long telephoto lenses

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cocciasik Forum Member • Posts: 75
A-mount, 500mm f/4 G and long telephoto lenses

In one of the many threads about the death of Sony/Minolta A-mount, I was involved in a discussion about the quality of Sony 500mm f/4 G SSM. The availability of good info about this lens is very limited, so I decided to spend some of my spare time to do a pseudo-scientific test that I am going to share with you. I hope you find it useful.

I am lucky enough to have (just for a few days) the following lenses with me:

  • Sony FE 400mm f/2.8 GM OSS (SEL400F28GM)
  • Sony 300mm f/2.8 G SSM II (SAL300F28G2)
  • Sony 500mm f/4 G SSM (SAL500F40G)
  • Minolta AF 300mm f/2.8 G APO HS
  • Minolta AF 300mm f/4 G APO HS
  • Minolta AF 400mm f/4.5 G APO HS
  • Minolta AF 600mm f/4 G APO HS
  • Sony 70-400mm f/4-5.6 G SSM II (SAL70400G2)
  • Tamron SP AF Di VC USD 150-600

and the following teleconverters:

  • Sony Alpha 1.4x Teleconverter (SAL14TC, A-mount)
  • Minolta AF teleconverter 2x II APO (A-mount, it should perform similar to Sony’s version)
  • Sony 1.4x Teleconverter (SEL14TC, E-mount)
  • Sony 2.0x Teleconverter (SEL20TC, E-mount)

What I wanted to test is how the sharpness of the 500mm compares to other lenses. Not AF speed, not chromatic aberrations, not vignetting, not distortion, not weight or size. Just sharpness. I like taking pictures of wildlife, so I find sharpness one of the lens features that I need most (for instance, when you need to crop heavily because the focal length is never enough). Moreover, I am a pixel peeperĀ 

I put a test target at 8 meters from the camera (that is, relatively close focus distance for most of long telephoto lenses, and a realistic distance where your animal could be) as perpendicular as possible to the lens. The target was a ISO 12233 Test Chart, printed with a B/W laser printer at 1200 dpi — not ideal, but more than enough to highlight differences between lenses. The target was very well illuminated with 2x 60w led lights. The focus was manual (with magnified focus peaking) to prevent any AF error. I used A7RII + LA-EA3. However, since LA-EA3 does not work with teleconverters, I had to switch to A99II to test them. In terms of sharpness, I verified that the result coming out from A7RII + LA-EA3 and A99II is exactly the same — you can see it from the files I shared.

I could write several pages about my findings, but it would take too much time. I will share with you just the conclusion. Below you can find a link do download the pictures that I used for the comparison so that you can analyze them independently and draw your own conclusion.

Here it is: if you need to buy a brand new Sony 500mm in 2019, better off switching to E-mount and buy the Sony FE 400mm f/2.8 GM for almost the same price. Add the two teleconverters, and you have plenty of sharpness from 400mm to 800mm. Wide open. If you have the money, it is a no brainer. Plus, it is lighter and has faster AF.

You want to stick to A-mount, there are cheaper alternatives that make the Sony 500mm less attractive. If you can afford it, Sony 500mm is a good lens from multiple points of view. However, it has a major flaw that I personally cannot live with: wide open, it has sharpness and contrast that do not justify the cost. Maybe it is a question of copy variation, but I read multiple comments/reviews and saw several pictures that are perfectly in line with my claim. I do not think my copy is a lemon. I would NEVER use this lens at f/4. I would rather close it to f/4.5 or f/5.0 when I am ok with some resolution loss, but I think I will ALWAYS end up using it at f/5.6 to get all the sharpness that the 42Mpixel sensor of my A99II deserves.

So the question is: why spending thousands of euros/dollars for a lens that delivers sharpness only at f/5.6? There are tons of alternatives that provide comparable sharpness at same aperture or just at 1/3 or 2/3 slower aperture:

  • Minolta AF 400mm f/4.5 G APO HS is an incredible performer despite its age if you are ok with slightly shorter focal length.
  • If you accept to correct some purple fringing in post production (and have big muscles) the Minolta AF 600mm f/4 G APO HS is definitely sharper than the newer Sony and totally usable at f/4!!!
  • The Sony 70-400mm f/4-5.6 G SSM II is absolutely great wide open, a very versatile lens.
  • Sony 300mm f/2.8 G SSM II + Sony Alpha 1.4x is also a good alternative, almost on par with the old Minolta AF 300mm f/2.8 G APO HS + Sony Alpha 1.4x.
  • Maybe, Tamron is the only option to discard when you need sharpness, together with the A-mount 2x teleconverter.

This is the link to my Dropbox account where you have all the test pictures. I didn’t put RAW files because it exceed my account quota. They represent JPEG generated from Capture One from RAWs without any type of adjustment whatsoever. If you know how to share 10GB of RAW files in this forum, please let me know I will gladly do it.


Please also notice that my focus is on the center of the frame. All the lenses of this comparison have pretty homogeneous performance across the frame, so no need to complicate the analysis with corner sharpness. Among them, I only want to show a small crop of the 500mm lens from f/4 to f/5.6 to let you better understand what I am talking about.

Sony 500mm @ f/4

Sony 500mm @ f/4.5

Sony 500mm @ f/5

Sony 500mm @ f/5.6

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