tzhang4284 wrote: Steve Spencer wrote: tzhang4284 wrote: darrellc wrote:
Maybe Sony released these just to increase the perceived value of the GM lenses. I was really excited about the 40 as my fav focal length but maybe the extra few hundred grams and thousand plus dollars is worth it for the 35 GM rendering, speed and extra sharpness. I have the 24GM and it is a very manageable size and weight, with pleasing IQ making for a really optimal mix of attributes for me.
Lenstip reviews show that the 40mm is very close to the 35mm GM in image quality - comparable to the Sigma 35mm f2 but in a smaller package and better than the Sigma 45mm overall (especially factoring in AF and wide open performance) unless you're looking for "character" or an acceptable country of final assembly.
I wouldn't call what Lenstip reviews image quality. I would call it sharpness. Image quality for me captures a lot more than just sharpness and suppression of CA both lateral and axial are to me important parts of image quality as is bokeh. It is early but it looks to me like the Sony 40 f/2.5 is a very sharp lens but does not suppress axial CA well and does not have a very pleasing bokeh (typical for a smaller lens). The Sigma 45 f/2.8 in contrast isn't as sharp--especially at closer distances--but suppresses axial CA well and has wonderful bokeh. We know with the Sigma 45 f/2.8 this is because it doesn't suppress spherical aberrations (SA), but not suppressing SA means PDAF doesn't work as well, but there is less affect on CDAF. So there are tradeoffs between the lenses. I wouldn't say one has a better image quality. They emphasize different aspects of image quality.
I think we're in subjective rationalization territory here. I had the Sigma 45mm and I came away finding the bokeh unimpressive and the lens soft at 2.8. Great lens when stopped down to f5.6. I look at the Sony 40mm as better wide open and better stopped down with comparable bokeh quality. I also don't see this horrendous CA that you're referring to in any of the sample photos - we're splitting hairs here given the size of these lenses.
I think it isn't so much rationalization, which frankly is a suggestion bordering on being insulting, but rather a difference in preference. The lenses definitely have a different look and different strengths and weaknesses. You might well prefer the Sony 40 f/2.5G, but I prefer the Sigma 45 f/2.8 I series, and that ought to be ok without you suggesting that I am engaging in some sort of rationalization.
Edit: and for clear evidence of axial CA see these pictures posted earlier in the thread:
tzhang4284 wrote: Steve Spencer wrote: tzhang4284 wrote: darrellc wrote:
Maybe Sony released these just to increase the perceived value of the GM lenses. I was really excited about the 40 as my fav focal length but maybe the extra few hundred grams and thousand plus dollars is worth it for the 35 GM rendering, speed and extra sharpness. I have the 24GM and it is a very manageable size and weight, with pleasing IQ making for a really optimal mix of attributes for me.
Lenstip reviews show that the 40mm is very close to the 35mm GM in image quality - comparable to the Sigma 35mm f2 but in a smaller package and better than the Sigma 45mm overall (especially factoring in AF and wide open performance) unless you're looking for "character" or an acceptable country of final assembly.
I wouldn't call what Lenstip reviews image quality. I would call it sharpness. Image quality for me captures a lot more than just sharpness and suppression of CA both lateral and axial are to me important parts of image quality as is bokeh. It is early but it looks to me like the Sony 40 f/2.5 is a very sharp lens but does not suppress axial CA well and does not have a very pleasing bokeh (typical for a smaller lens). The Sigma 45 f/2.8 in contrast isn't as sharp--especially at closer distances--but suppresses axial CA well and has wonderful bokeh. We know with the Sigma 45 f/2.8 this is because it doesn't suppress spherical aberrations (SA), but not suppressing SA means PDAF doesn't work as well, but there is less affect on CDAF. So there are tradeoffs between the lenses. I wouldn't say one has a better image quality. They emphasize different aspects of image quality.
I think we're in subjective rationalization territory here. I had the Sigma 45mm and I came away finding the bokeh unimpressive and the lens soft at 2.8. Great lens when stopped down to f5.6. I look at the Sony 40mm as better wide open and better stopped down with comparable bokeh quality. I also don't see this horrendous CA that you're referring to in any of the sample photos - we're splitting hairs here given the size of these lenses.
I think it isn't so much rationalization, which frankly is a suggestion bordering on being insulting, but rather a difference in preference. The lenses definitely have a different look and different strengths and weaknesses. You might well prefer the Sony 40 f/2.5G, but I prefer the Sigma 45 f/2.8 I series, and that ought to be ok without you suggesting that I am engaging in some sort of rationalization.
Mar 23, 2021 at 12:39 PM
Previous versions of Steve Spencer's message #15541839 « Pre-order Sony G lenses: FE 24mm f/2.8, 40mm f/2.5, 50mm f/2.5 »
