p.1 #1Sony 400mm f/4.5 GM vs 600mm f/6.3 GM — Sharpness, AF and real-world comparisons
Sony 400mm f/4.5 GM vs 600mm f/6.3 GM — Sharpness, AF and real-world comparisons
I've been researching the Sony 400mm f/4.5 GM and 600mm f/6.3 GM, particularly how the 400mm + 1.4x TC compares against the native 600mm.
After reading the discussions here and watching several reviews, I'm finding quite a few conflicting conclusions. I thought it might be useful to summarize what I've found and get more opinions from people who have actually used both.
1. Sharpness and image quality
The results seem surprisingly mixed:
Dustin Abbott: Found the 400mm + 1.4x TC marginally sharper than the bare 600mm.
The-Digital-Picture: Their test-chart comparisons seem to favor the 400mm + 1.4x TC slightly in center sharpness. The 600/6.3 has better corrected CA and is sharper outside of the frame center.
Overall, there doesn't seem to be a clear consensus. I'm also wondering how much these differences matter when comparing actual detail resolved on a distant subject rather than pixel-level sharpness.
2. Autofocus performance
This is probably the area I'm most interested in, particularly for birds in flight and lower-light conditions.
Alex Phan: Reported excellent AF with the 600mm in good daylight, but considerable hunting with birds against shaded vegetation. He also found his 300mm f/2.8 + 2x TC acquired focus faster in those conditions.
Fred Miranda owners: Several have reported excellent autofocus with the 400mm + 1.4x TC, although others have noticed some reduction in AF acquisition or tracking performance when using teleconverters.
The question is whether the native 600mm has a meaningful AF advantage over the 400mm + 1.4x TC when both are effectively f/6.3.
Has anyone compared acquisition speed and tracking keeper rates directly, especially with erratic birds or busy backgrounds?
3. Teleconverter performance
The 400mm appears to work exceptionally well with the 1.4x TC, producing 560mm f/6.3 with very little apparent loss of sharpness.
The 2x TC results seem more divided. Some owners report excellent 800mm f/9 performance, while others find the AF penalty significant enough that cropping from 560mm is preferable.
The 600mm also supports a 1.4x TC for 840mm f/9, but owner reports on that combination seem mixed.
In theory on A1ii lenses should not get sharper past f/6.18 (green subject) and f/8.5 (blue subject)
I'd be interested in whether anyone has compared the 400mm + 2x TC against the 600mm + 1.4x TC for both sharpness and AF reliability.
4. Ergonomics and handling
This is another interesting area because the bare lenses weigh almost exactly the same, but adding a TC changes the balance.
MohChee reported taking both combinations on an approximately 15-mile hike with his spouse. Both preferred carrying the bare 600mm, finding that the additional 150–200g and weight distribution of the 400mm + TC were more noticeable than expected.
The 400mm obviously offers the advantage of removing the TC for a brighter, shorter lens, whereas the native 600mm provides more reach without adding any accessories.
5. Value and versatility
The 400mm is more flexible, especially when the subject is close enough to fill the frame at 400mm.
On the other hand, the 600/6.3 seems to be more ergonomic and is lighter compared to the 400/4.5 + TC.
I'd really appreciate more firsthand comparisons from people who have used both lenses, particularly:
Does the 400mm + 1.4x TC genuinely resolve more detail than the bare 600mm, or is the difference mostly limited to test charts?
Is there a noticeable AF acquisition or tracking advantage with the native 600mm?
How well do the 400mm + 2x and 600mm + 1.4x combinations perform in real wildlife photography?
Does the additional weight and different balance of the 400mm + TC make a meaningful difference during prolonged handheld shooting?
For those who have tried both, which would you ultimately keep?
He goes on to say the 600’s advantage at 840mm, vs 400+2X, is actually greater, but still close.
I don’t own the 400, so can’t personally add much here. Except as to your question about how the 600 does with TC’s — for me the 600 does spectacularly well with TC’s on the a1ii, despite concerns about theoretical diffraction limits. My 600 also slightly beats my 300+2X at 600mm… but they are so close it’s effectively a draw.
p.1 #3Sony 400mm f/4.5 GM vs 600mm f/6.3 GM — Sharpness, AF and real-world comparisons
Another thread going on about the actual focal lengths. 560mm is surprisingly close to 600mm.
IMHO, iq difference is negligible or non existent. I don't know if anyone can actually measure AF difference. In theory bare lens should have an advantage. I have only 400. I don't feel it's 'heavy' once TC added. So it's in our mind. If you compare side by side you may feel it
In short you can't go wrong either way. For me 400 was better deal because I'm getting 90% (if not more) of performance for much better price and flexibility of two lenses.
p.1 #4Sony 400mm f/4.5 GM vs 600mm f/6.3 GM — Sharpness, AF and real-world comparisons
kopebuyer wrote:
My 600 also slightly beats my 300+2X at 600mm… but they are so close it’s effectively a draw.
I've seen multiple people say the same thing, I guess I'm in the minority because when I tested my 300+2x TC the 600 6.3 was noticeably better. So much so that I sold the 300 and 2x TC and now shooting just with the 600 6.3 as my only lens.
p.1 #5Sony 400mm f/4.5 GM vs 600mm f/6.3 GM — Sharpness, AF and real-world comparisons
pdog109 wrote: kopebuyer wroteMy 600 also slightly beats my 300+2X at 600mm… but they are so close it’s effectively a draw.I've seen multiple people say the same thing, I guess I'm in the minority because when I tested my 300+2x TC the 600 6.3 was noticeably better. So much so that I sold the 300 and 2x TC and now shooting just with the 600 6.3 as my only lens.