I have been considering this lens for backpacking landscapes and it seems that, while many people really like it, others have complained about "mushy" corners, especially in the lower half of the zoom. Presumably due to the high vignetting?
So, here are my questions -
1). Of those of you who have this lens, are "mushy" corners a problem?
2). Is this a case of sample variation?
3). How many of you have had to go through more than one copy to get one you are satisfied with?
There's a 20-70/4 image thread here, might need search to pull it from "archive." These would be user samples. Also, a DPreview thread with full res images. I did a Google search using this, "dpreview sony 20-70/4 image thread full resolution" to get results. Mine there are A7Riv shots and getting them to load/share at full res/size seems to be troublesome. My impression is these would all be "share" type shots so perhaps edited for sharing not technical lens evaluation.
1)? Not that I've noticed. With the caveat of a combination of my vision, how well my glasses do, "progressive lenses," subject choices, etc. quite often I crop to 16:9 for sharing and go to 3840x2160. Combine that with perhaps less critical expectations, not shooting for perfection nor having a set of suitable long term use highest end lenses to have used and be able to compare.
2)? Maybe? I get a feel that some of the complaints are more out of a desire to complain and perhaps misplaced expectations. I don't know how critically some evaluated or over-critically evaluated in respect to what might be appropriate user cases and expectations. It's a $1200 G lens, not a $2500 GM or GMii for example. There does seem to be some discussion of variation and/or field curvature.
I am not obsessive with pixel peeping so I really could not tell you if my copy is a "good" or a "bad" one. Shooting on A7IV with the same res as your A7CII I don't know how big you have to print to notice if the corners are smeared. My complaints for the lens is really that it relies on optical correction in software to deal with distortion at the wide end. But it does go unusually wide for a standard zoom that its understandable. And I brought it in place of carrying a wide prime for a recent trip and having the wide end at 20 worked great.
It’s a great lens perfect for backpacking and I love mine. My copy is the first and only one I purchased brand new from B&H and it’s tack sharp edge to edge at f/8 and f/11 which are generally the apertures I use for landscapes. It’s lightweight and easy to carry. I use mine often with the A7CR and find it balances well. Sometimes I’ll pair it with a Batis 135 for something telephoto or even pair it with the Tamron 28-200. Lots of overlap between those two lenses but that zoom combo works well and covers 20-200 and not too heavy really. Another combo I will use for backpacking or long hikes is Tamron 28-200 + 20mm f/1.8 G especially if I’m doing any astrophotography. I just recently got the Viltrox 14mm Air and I may pair the Tamron with that too depending on where I’m going. But If I were just bringing one lens though it would be the 20-70 for certain. It also makes for a great skiing lens too.
I bought the 20-70 f/4 a little over 1.5 years ago. I suddenly needed to hike for nearly every photograph I get. Sometimes the hikes are pretty far on fairly primitive trails that require using hands and and feet to traverse obstacles. And I'm old. The weight of my previous system became a huge issue.
Since image quality is irrelevant if you can't get your camera to where the pictures are, I was prepared to make some sacrifices. My goal was to get the best IQ I could carry to the places I want to go.
I use the 20-70 with a Sony A7R-V that I got at the same time. I contemplated the A7CR but opted for a bit more weight, better EVF, and some other features I use that the A7CR doesn't have. At around the same time a friend in the US did get the A7CR along with a 20-70 f/4 for multi-day backpacking trips and other general photography. Both of us got and kept a single copy of the lens. Both of us independently compared our copy under reasonably controlled circumstances against the Canon 24-70 f/2.8 L II, which both of us also have. The tests were done using the Sony cameras with a Sigma MC-11 adapter for the Canon lenses.
The short answer is that the Sony 20-70 has image quality well beyond its price range. My friend thinks his 20-70, at f/8, is a bit better than his Canon 24-70 L-II at all focal lengths they have in common. I think the Sony 20-70 lens is a little better than my Canon lens at the longer focal lengths and a little worse toward the corners at 24mm.
I did no comparisons at focal lengths wider than 24mm, but from "just looking" at ridiculous photos of brick walls and such at actual pixels, the Sony 20-70 is more than "good enough". Some softness can be seen in the corners if you look for it, but based on other lenses I've owned it's "acceptable". Also, I don't tend to use such wide focal lengths as often as many others do. If the lens is going to live between 20mm and 24mm you might want a different lens. I'd stress that it takes some painful pixel peeping to see any differences, and my results were not completely repeatable.
IMO, the "corner problem" is not due to "bad" optics. The lens is small and lightweight specifically because they allow the distortion to get crazy at the widest focal lengths. I think it's the correction of that distortion by software that creates some corner softness. For me it's better than carrying a large and heavy lens long distances on difficult trails. Unless your hobby is looking at image corners through a microscope, it's probably a non-issue.
Doug, I have the FE 20-70 F4 and have used the lens on multi day hiking trips, travel, and landscape back at home. I must admit that at first I was sceptical about the 20-70, not expecting too much from it, but the FE 20-70 has exceeded all my expectations and I'm very happy with the performace of the lens.
Sure it is not a perfect lens and my manual primes (Zeiss Loxia) can be a little bit sharper in the edges and corners and maybe have a nicer rendering overall but overall the 20-70 holds up very good and I find the overall IQ very good. I have no complaints at all, and I do consider myself critical for IQ/sharpness.
The versatility is simply great, 20-70 is a great focal range for a one lens solution, and also the magnification/close-focus distance is very usable. For the size and weight it is just a very nice lens in my opinion.
I was maybe fortunate to not have to go through several copies, I bougt mine new almost 2.5 years ago and after brick-wall testing confirmed it was well centered and corners/edges good enough to keep the lens.
It is my main lens now for travel and landscape and I have just purchased the FE 70-200 F4 G2 Macro to supplement is. I think they make a great pairing.
I don't realy notice mushy cornes in my real life images. Sure, sometimes I have a shot where the cornes could be a bit better, but not at the level that it bothers me.
For what ut is worth, I had the great FE 35 F1.4 GM and compared it with against the FE 20-70 and to be honest I couldn't see a meaningfull enough difference. The GM holds a bit better into extreme corners but in center/midframe they are very close in typical landscape apertures (f/5.6 - F/11). I sold the 35 GM since I also have 2 other 35mm primes (Loxia 35 and FE 35 F2.8 Zeiss).
The majority of the images in my Sarek 2024 Album on flickr are taken with FE 20-70, apart from the Northern light images and some telephoto images taken with Loxia 85.
My experience with my 20-70 f/4 G has been excellent. As others have said, it punches above it's price point. I have been more than happy with it's sharpness even at 20mm. If I need really wide I do carry a 16mm f1.8G as well and pair the two of those with a 70-200mm f/4 G II macro. That trio does pretty much everything I need for landscape photography as is still pretty light when paired with a A7R5.
