Fred Miranda wrote:
Sony somehow mimicked the 24-70/4 ZA behavior in this aspect but with one important and crucial distinction: The G zoom is sharp to the very corners with minimal astigmatism.
One more thing: looking at Sony's hard to read MTF chart (only MTFF 10 and 30) it looks like there's noticeably more astigmatism (MTF 30) stopped down to f8 at 105mm than wide open. They only show 24mm and 105mm.
Fred Miranda wrote:
Regarding the 35mm corner issue when stopping the lens down. I'm still not 100% sure what's causing it since it could be a combination of things but my best guess is that the main culprit is early signs of diffraction.
Diffraction seems like the obvious answer but looking at the crops you have provided it appears like stopping down induces additional astigmatism rather than just diffraction (this may also be a factor) - the f8 crop to my eye has significantly more astigmatism than the f4 one. Could it be diffraction somehow only occurring on the the tangential lines in the corners? No idea, just a wild guess...
I'd be very interested to understand if this is a copy-specific behaviour or if it's a characteristic of the lens design that all copies will see.
I don’t think it is diffraction at all, unless it is demonstrated that the lens is sharpest in the corners rather than the center, which would be an almost inconceivable performance (assuming a flat field, that is).
Diffraction is first seen in the highest performing part of the field, so the center should be seeing it at lease as soon as the corners.
I suspect that the lens has a complex field curvature to it at that focal length and the field shifts slightly in the far corners as then lens is stopped down. So, basically, astigmatism.
I wonder if this is a result of one of the four aspheric elements in the lens.
Regardless, it looks to be excellent even with that one quirk in the performance.
DavidBM wrote:
One more thing: looking at Sony's hard to read MTF chart (only MTFF 10 and 30) it looks like there's noticeably more astigmatism (MTF 30) stopped down to f8 at 105mm than wide open. They only show 24mm and 105mm.
tzhang4284 wrote:
For those with the lens, how is the handling compared to say a Batis 25 or 24-70mm f4? Is it noticeably heavier and more unwieldy?
So far I find that it balances very nicely and I hardly notice any difference in handling between the 16-35 f4 and the 24-105 f4 even though it is slightly bigger and heavier.
tzhang4284 wrote:
For those with the lens, how is the handling compared to say a Batis 25 or 24-70mm f4? Is it noticeably heavier and more unwieldy?
It handles very nicely. I especially like the new-style knurling on the focus and zoom rings - much better than the old 24-70. I don't mind the extra size and weight at all, considering the drastically better performance.
there have been those that have questioned sample variation. I am very happy with mine. great copy. Also it balances nicely on the a7rii.. TBH I couldn't be happier. My lens performs similarly to freds.
kdrk888 wrote:
Now that I just sold my 24-70 GM, I need a good copy of the 24-105.
I saw that on the B&S board.... Now, what are you going to do with your Batis 135mm ? The spread between the two lenses is not that much.... anymore, relative to the 24-70, that is.
Yes, I'm still not sure but I think it's a combination of factors. I'm starting to think it's not really diffraction since there is still a slight improvement in the center.
Here is what I know so far:
1) It looks like the periphery gets more astigmatic as the lens is stopped down from wide open without refocusing.
2) There is some field curvature at the affected focals lengths.
3) There is no resolution improvement and actually a deterioration in the periphery as the lens is stopped down at the wide range.
4) When focusing on the corner at f/7.1, the corner no longer deteriorates and shows no visible astigmatism. Therefore focus shift plays a role.
It looks like field curvature that is affected by focus shift, perhaps with an increase in astigmatism towards the periphery.
Is this only happening on this copy? I would guess it's a characteristic of this lens but it would be great if someone could run some infinity tests to confirm it. Just use the 35mm focal length (seems to be the most affected), focus at center at f/4 and without refocusing, stop down to f/5.6 and f/8. Check the corners and see if they become more astigmatic.
If this is confirmed to be a lens characteristic, is it bad? I would say it's not.
I'm just testing the lens and checking the corners at 1:1 and 2:1. I noticed this behavior but doubt it would be very noticeable in real images.
How to avoid it? I'm still not sure since this seems to be a bit more complex than just field curvature. I would say focus the lens at f/5.6 and forget about it.
AGeoJO wrote:
I saw that on the B&S board.... Now, what are you going to do with your Batis 135mm ? The spread between the two lenses is not that much.... anymore, relative to the 24-70, that is.
Good question, Joshua. I think I will get the 24-105 in a couple months, I don't have much use for that lens in the winter. I may sell the Batis 135 after I get the 24-105. Hope there will be a native 180mm or 200mm....Maybe Sigma MC-11 + Canon 200mm f2.8 II? I just sold the MC-11 too
Anyone here able to comment performances compared to the Sigma ART equivalent?
I know for weight/dimension (but price also) but really curios for sharpness.
scalanc2 wrote:
Anyone here able to comment performances compared to the Sigma ART equivalent?
I know for weight/dimension (but price also) but really curios for sharpness.
I believe Roger at LensRentals will run a comparison test soon.
This is very interesting,Fred.
Now Imaging resource is no longer testing tenses, Lenstip is rarely testing Sony lenses, DXO is thesting smatphones while Photozone tests onle few lenses.
Therefore Lensrentals remain one of the most important testing site WW.
Ok Fred ran your test on my lens today. At 35 mm my corners did not show any deterioration from f4 to f8. However the corners did not improve either. On my copy at every focal length the corners looked the same at f4 f5.6 and f8. That was with 2:1 magnification in Lightroom. Can't speak for others but for my copy it's about as sharp as it's gonna get wide open and that's pretty sharp. Obviously stopping down will improve depth of field on my copy but not sharpness. Also, my copy seems excellent at 105 mm. I need to test it more but I think mine might be a tad sharper at the long end than the short end and I was pretty happy with the wide end
Went out yesterday afternoon into evening for some real work. I wasn't totally sold on the around the yard stuff. But. . on real world out there work from 24-105, I am getting some stunningly sharp images. Even on 105 at f9, the area in focus, edge to edge sharp, center 2/3's very sharp. At 2:1 the detail of the image isn't deteriorating. I also am enjoying the 105 over the longest end of my 24-70L II. I would say that 90% of my type of work right now is covered with this. I have the 70-200 f4 IS Canon on my A7RII but not using it as much but there when needed. Contrast is also very good without giving a false character to the image. Shooting directly into the sun, just a touch of flair, and sometimes none and stopped down, the nice sunburst/ray effect.
An odd thing with this lens and the A7RIII is that if you use continuous focus mode, if you set the camera on an image but don't have any movement, for me anyway, there is focus hunting but with a little movement it gets the focus right. With my Canon stuff, it will lock focus on continual and of course refocus as I move but it doesn't require that there be any movement as it doesn't hunt and throw the focus off if there is no movement. Unlike the previous 24-105 that I sent back, single shot now works great with no focus shift.
Another thing I notice is that I still do not find that Sony work for me as well as Canon IS. Even Canon lenses on the III or II is better than the 24-105 Sony.
C_n_red_again wrote:
Ok Fred ran your test on my lens today. At 35 mm my corners did not show any deterioration from f4 to f8. However the corners did not improve either. On my copy at every focal length the corners looked the same at f4 f5.6 and f8. That was with 2:1 magnification in Lightroom. Can't speak for others but for my copy it's about as sharp as it's gonna get wide open and that's pretty sharp. Obviously stopping down will improve depth of field on my copy but not sharpness. Also, my copy seems excellent at 105 mm. I need to test it more but I think mine might be a tad sharper at the long end than the short end and I was pretty happy with the wide end...Show more →
Can you post some 1:1 crops showing the edges at f/4 and f/8?
? The spread between the two lenses is not that much.... anymore, relative to the 24-70, that is.