My SIgma art 24mm gives me hard time to focus on infinity. I hate this finetuning process of Sigma with docking station. Yet it is powerful, but big minus is that no single copy of the lens is fine tuned out of the box. but tell me, please, how to fine tune for infinity. No target for this.
I will change it for S 24mm. Thank you for reviewing it against Sigma line
Jon Middleton
January 29, 2021 9:29 am
Another fine review, so thank you very much. I bought the 24/1.8G to go along with the D850 a few years ago, well before Nikon brought out the Z line. I already had the D500, the D850 was purchased mostly for landscape both for higher resolution and eliminate the crop factor of the D500. The G is a nice lens, but I was somewhat disappointed with the sharpness in the corners. When the Z system came out I considered adding a Z7 plus the 24/1.8S for landscape, where corner to corner sharpness is most important. However, that would cost roughly $4000. After reading various reviews it seemed that while the 24/1.8S is clearly better than the G, the Zeiss 1.4/25 Milvus is the class leader by a wide margin. Those reviews show insane sharpness across the frame from f/4 to f/11, so I ended up buying one recently on sale for about $2000.
However, comparing those reviews to PL’s is akin to comparing apples to oranges, even though they seem to also use Imatest. So, my question is whether you could or plan to include Zeiss lenses in your lens comparisons. You mentioned in your review of the 85/1.8S that you would be reviewing the Otus, but I don’t see that review as of this date. Clearly, many of the S lenses are excellent, a step up from the F mounts, and perhaps in the same league as the Zeiss lenses. It would be nice to have PL’s reviews of the Zeiss lenses so one could compare apples to apples, or oranges to oranges, if you prefer. Thanks again.
Richard M
May 31, 2020 5:51 am
Thanks again for another well thought out and informative review. I know I am a little late to the thread here but just thought I would add a point I have discovered having now had this lens for a while. I bought this lens on its release and I did extensive testing at night (I primarily bought this for astro work before seeing your review) and at that stage I totally agreed with your coma observations. In fact I took the lens back and was going to move on but the camera store guy mentioned that initial copies from Nikon did have some variants in quality. He gave me a copy from a new batch he had in and said “go try this at night”. I did and I have to say the coma control is amazing, I have kept the copy and never looked back. Just wondered if your review copy may have been like my first lens I picked up as I really think this lens is now brilliant for pinpoint stars even in the corners. Keep up the great work.
There is no suggestion of this with my copy, I do however get ‘angel wings’ at the corners with an old 50mm 1.8 ai that no doubt has been battered over the 40 years of it’s life. I wonder if the earlier examples had an abberation built in?
Don Kelley
March 31, 2020 10:12 am
Thank You… Well Done !!
Don
Petr U
February 25, 2020 6:07 am
Big step up, compared to the 24/1.8G ED. Im shooting with it 2 weeks and its so sharp and fast lens with metallic parts. This year i will change all of my 1.4 and 1.8 AF-S for S lenses. Have a nice day. UP
Venu
February 23, 2020 10:07 pm
No need to be so hard, mate. Sure, you can take the title as best photographer who can photograph with stellar bokehs. I am quite secure with my photography. :)
Or maybe you should read some scientific literature written by academics about optics if you already don’t have that background.
I am aware that some photographers believe that mtf charts don’t tell anything about bokeh, while others believe otherwise. But it is actually more nuanced than what I generalized in my previous reply. I will try to be brief here.
Yes, mtf charts don’t tell the whole story about the bokeh, but they do tell something about bokeh. You need more than mtf charts to conclude the ‘quality’ of bokeh. But mtf charts tell the nature and uniformity of bokeh across the frame from the center. If the Sagittal and Meridional lines are not close to each other, that means the bokeh is not uniform from the center to the edges (remember, this is not precisely the same thing as bokeh quality though). However, quite often, non uniform bokeh across the frame usually is generally non appealing and it’s just a cursory way of looking and having expectations about the bokeh for a given lens.
Venu, I actually don’t care (and don’t know) wether you get your opinions out of coffee grounds or from photo magazines. I’m a big fan of comparisons of pictures. I don’t say the Sigma is an excellent lens, it’s just better than the dated Nikkor 24/1.4 G which also Nasim suggests to get an update. And it’s not “the worst of the bunch” in terms of bokeh: sojujo.smugmug.com/Tests…/n-ts4BVt/
I could repeat the test with two other S-lenses currently at my hands with 24 mm focal length, but both start with f/4 and I will never buy the expensive 24/1.8 S.
It’s just not the first time I compared S-lenses to Sigma Art with F mount. So far the S-lens with better bokeh (which is a matter of taste, no question) still needs to surface. Sharpness: great, corner performance: outstanding, bokeh, hmmmm maybe the 20/1.8 will deliver
I had read where the Nikon lens designers were leaving in more spherical abberarions in the S lenses. This is being done to give smoother bokeh or out of focus areas . Over the years the Nikon lens designers had their “secret sauce “ for certain lenses. Especially in the film days . They would leave in certain aberrations to give a lens a certain character to its image . Sometimes it was only within a certain ( perceived usage) focusing distance and certain f/stops. So many Nikon lenses are not always the best on paper but have certain characteristics within the intended use .
sceptical1
February 23, 2020 3:05 am
Great review and love the sample photos. I will say I applaud Nikon for making great lenses for their Z system. They are criticized for not making “professional” fast primes, but I see little reason for that criticism. I am fine with f1.8 for every use at this point. I shoot outdoors nearly all the time and rarely shoot much below f4, let alone f1.8. Most users, even professionals, are unlikely to pay 2.5x more for f1.4 versions considering how good the F 1.8’s are.
How can you tell about the difference between f/1.4 and f/1.8 if you rarely shoot below f/4? Where do you you get that absurd number of 2.5× the price? Check the prices of the S-line glass and then compare it with real prices of F-lenses, as no f/1.4 S-glass is available.
Patrick
February 22, 2020 12:33 am
Is interesting to see that the 24-70 2.8 isn’t far behind at f2.8. It just show how stellar this zoom lens is
In fact, the 24-70 f/2.8 beats this prime lens at the mid and corners at most apertures, and only very slightly lags behind in the centre. Given the focal length you probably would not be using below f/2.8 anyway. It costs about half the price of the 24-70 f/2.8 in Australia and so probably not worth an additional purchase unless you have very specific needs.
Although actually it seems that difference is only up to f/5.6. Above f/5.6 the prime is slightly better all round. which is good for lanscapes. And the other primes seem to beat out the 24-70 f/2.8 more consistently and significantly at an aperture. So a prime set is probably still the sharpest way to go overall. Just seems to be a slightly weaker prime than the others on the charts.
Pieter Kers
February 21, 2020 3:35 am
Thank you for the review. I have also tested the 24mm 1.8S against the 24mm 1.8G. What i found_ the new lens has a different bokeh- the G-lens is softer as is the bokeh. Coma control is better, contrast is a bit higher, on the S-lens as is the sharpness on the sides when stopping down. – So yes the new one is a bit better, but how i dislike the bad qualities of the focus by wire… Nikon can address some of them in firmware and should, like returning to the old focus point after shutdown. PS the bokeh of the Sigma Art 24mm 1.4 lens is horrible with double images.
“PS the bokeh of the Sigma Art 24mm 1.4 lens is horrible with double images.” Hmm, need to check once more, but double images I also get with S glass (85 especially). Sometimes not easy to tell, depends a lot of aperture and distance between lens, object and background – and how nervoiuse the backgroudn already is.
Did you find the bokeh of Nikkor S less horrible? Wrong question: Is the bokeh of the Nikkor creamy?
Did test the 85mm Nikkor S lens and found it wide open even better than my 85mm Sigma ART. Far less colour faults and purple fringing, more contrast. I have heard that some people find the bokeh of the 85mm S is not so good but i liked it – Did not see the double images you mention, but i have heard that before so it will be true.
about the sigma 24 ART- I disliked the double image bokeh and discovered it is important to me… Yes i like the image of the 24mm 1.8G , only the mechanics are cheap, but it works.
“PS the bokeh of the Sigma Art 24mm 1.4 lens is horrible with double images.” Hmm, need to check once more, but double images I also get with S glass (85 especially). Sometimes not easy to tell, depends a lot of aperture and distance between lens, object and background – and how nervoiuse the backgroudn already is.
Did you find the bokeh of Nikkor S less horrible? Wrong question, let me rephrase: Is the bokeh of the Nikkor creamy?
The wide angle lenses do not have a good bokeh anyway.
But Looking at the mtf charts of nikon 24mm/1.8 S, nikon 24mm/1.8 G and Sigma art 24mm/1.4, it seems to me that Sigma art is the worst of the lot in terms of bokeh. Nikon’s new S line is the better of the lot, followed closely by G.
Glad to see that the Nikon’s new S line lenses are faring better than their F mount counterparts…
If someone judges the bokeh by looking at the MTF charts, that says more about the knowledge of this someone than the lenses he’s talking about without having shot with a single one of it.
Wide angle lenses have historically suffered most from field dependent aberrations. Some of them such as astigmatism are very, very bad for OOF areas as well. Only recently we’ve seen major improvements in that regard and some newer wide angle lenses have much lower field dependent aberrations than their predecessors. The 35 1.8 S may have been the first of this new breed of autofocusing wide angles below $1000 (now there’s the Tamron 35 1.4, maybe even the Sony 20mm 1.8 FE). One cannot precisely determine the amount of one specific aberration (ex : astigmatism) from a MTF chart, but you can reasonably presume that a lens which both sagittal and tangential lines closely follow each others is likely to have a low amount of field dependent aberrations. That’s not always the case, but it often is. The Nikon 24 1.8 Z and Sigma 24 1.4’s MTF curves seem to correspond well to that approach, and it’s fully backed up by actual tests : www.cameralabs.com/sigma…-review/2/ www.cameralabs.com/nikon…-review/2/ There’s a pretty strong correlation between point light sources being deformed into a line (or “wings”) in the corners of the frame (cf. Cameralabs’ nightscapes shots) and the occurence of hard edges in one orientation in OOF areas (cf. Cameralabs’ OOF nightscapes shots). So yes, looking at MTF charts is not an unreasonable first step to start making a number of limited presumptions about OOF areas. Note that this is just about field dependent aberrations. Two lenses with the exact same mix of field dependent aberrations may still have a widely different bokeh because of other factors (LOCA, spherical aberration, onion rings, etc.).
Marcus
February 20, 2020 11:40 pm
Thanks Nasim for uou review and efforts doing that. Somehow I also see all the manufacturers are focus on sharpness from edge to edge, building a perfect lens without personality. But this is the trend of modern lenses and it seams the current request of all of us. But it’s fine we can survive. Please could you tell us exactly which camera you used to test those 24mm lenses? Moreover, when you test the edge part of the lens, do you refocus the lens or you simply focus on the centre and check the centre and edge at the same time? Moreover do you check the focus only at fully aperture or at every closed f stop do you refocus? What about the field curvature if the rested lens? I’m sure in the past you described how you perform the test, but I really appreciate if you remind us. Thanks.
Marcus, it is expected that lenses are going to get sharper, because sensor resolution has also been drastically increasing. There is no point of increasing sensor resolution, if lenses cannot resolve enough detail, which is why lenses are getting bigger and heavier. We have already written about this at PL.
In regards to testing methodologies, the camera used for assessing the sharpness is the Nikon Z7. For Imatest results (and you can read more about how Imatest works on their website), the assessment is always done by focusing in the center of the frame. However, I do manually focus in the corners to see if they get significantly sharper, with the center de-focused. If they do, then I conclude that the lens has field curvature. All lenses exhibit some amounts of it, but some are better than others.
When measuring lens performance, I always refocus with each aperture, because most lenses exhibit focus shift, and this is a good way to assess its impact. I also use a macro rail to move the camera back and forth and shoot at different distances, to make sure that I am providing the best possible results. This takes a lot of time, but this is, in my opinion, the only proper way to provide valid data.
Nasim we area all romantic and think that glass is the mirror of our soul :-) In the past I was more focused on the personality of the lens (yes, I call this personality, like referring to a human), but now, because I’m getting older I need sharpness and cristal clear images. But this is a personal choice, and no discussion here. Going back to our technical discussion, about field curvature, which one exhibits more field curvature and focus shift as well ? Thanks.
Nasim we are all romantic and think that glass is the mirror of our soul :-) In the past I was more focused on the personality of the lens (yes, I call this personality, like referring to a human), but now, because I’m getting older I need sharpness and cristal clear images. But this is a personal choice, and no discussion here. Going back to our technical discussion, about field curvature, which one exhibits more field curvature and focus shift as well ? Thanks.
One more thing regarding lens “personality”. A lens is a lens. It is a piece of plastic that contains glass and metal. It has optical properties, coatings, aberrations, tolerances, variances and a price tag. Lenses don’t have “personalities” or “souls”. If a lens renders a scene one way, while another one does it in a different way, that’s nothing more than differences in optical design. Lenses have changed a lot in the past 10 years, mostly due to the demand for high-resolution sensors. They need to catch up, so they are getting more refined with more corrections. For manufacturers, it is always a balancing game…
Have to agree on that. Sure, tools can adapt to the hands or skills of their owner – but at first, a fountain pen needs a while and a couple of miles of writing to deform it’s tip to the writing of it’s owner. And that’s about it. The only “personality” my lenses have is the pattern of dents or scratches, and they got that over years. But so far as I can see, none of them changed their characteristics much.
In a kind mood, I simply turn my back to people talking about the metaphysical and etherical properties of their glass (it’s always their glass which has characteristics too far out of the reach of every measuring device, but his (no, female photogs usually don’t need this carpet of sheer unexplainability) master’s eye knows the difference). In a less kind mood I try to arrange a comparison of prints.
Hi Nasim, my apologies if I come back after a while, but I still have some doubts because I cannot find this info in your test. Simply, which camera have you used to test 24mm S-line and 24mm AFS? And could you also remind me the camera used during Imatest of the 35mm S-line for Z Camera and the one used with 35 AFS? This very helpful and please write always this technical and boring note at the beginning of each chart. Thanks.
My SIgma art 24mm gives me hard time to focus on infinity. I hate this finetuning process of Sigma with docking station. Yet it is powerful, but big minus is that no single copy of the lens is fine tuned out of the box. but tell me, please, how to fine tune for infinity. No target for this.
I will change it for S 24mm. Thank you for reviewing it against Sigma line
Another fine review, so thank you very much. I bought the 24/1.8G to go along with the D850 a few years ago, well before Nikon brought out the Z line. I already had the D500, the D850 was purchased mostly for landscape both for higher resolution and eliminate the crop factor of the D500. The G is a nice lens, but I was somewhat disappointed with the sharpness in the corners. When the Z system came out I considered adding a Z7 plus the 24/1.8S for landscape, where corner to corner sharpness is most important. However, that would cost roughly $4000. After reading various reviews it seemed that while the 24/1.8S is clearly better than the G, the Zeiss 1.4/25 Milvus is the class leader by a wide margin. Those reviews show insane sharpness across the frame from f/4 to f/11, so I ended up buying one recently on sale for about $2000.
However, comparing those reviews to PL’s is akin to comparing apples to oranges, even though they seem to also use Imatest. So, my question is whether you could or plan to include Zeiss lenses in your lens comparisons. You mentioned in your review of the 85/1.8S that you would be reviewing the Otus, but I don’t see that review as of this date. Clearly, many of the S lenses are excellent, a step up from the F mounts, and perhaps in the same league as the Zeiss lenses. It would be nice to have PL’s reviews of the Zeiss lenses so one could compare apples to apples, or oranges to oranges, if you prefer. Thanks again.
Thanks again for another well thought out and informative review. I know I am a little late to the thread here but just thought I would add a point I have discovered having now had this lens for a while. I bought this lens on its release and I did extensive testing at night (I primarily bought this for astro work before seeing your review) and at that stage I totally agreed with your coma observations. In fact I took the lens back and was going to move on but the camera store guy mentioned that initial copies from Nikon did have some variants in quality. He gave me a copy from a new batch he had in and said “go try this at night”. I did and I have to say the coma control is amazing, I have kept the copy and never looked back. Just wondered if your review copy may have been like my first lens I picked up as I really think this lens is now brilliant for pinpoint stars even in the corners. Keep up the great work.
There is no suggestion of this with my copy, I do however get ‘angel wings’ at the corners with an old 50mm 1.8 ai that no doubt has been battered over the 40 years of it’s life. I wonder if the earlier examples had an abberation built in?
Thank You… Well Done !!
Don
Big step up, compared to the 24/1.8G ED. Im shooting with it 2 weeks and its so sharp and fast lens with metallic parts. This year i will change all of my 1.4 and 1.8 AF-S for S lenses. Have a nice day. UP
No need to be so hard, mate. Sure, you can take the title as best photographer who can photograph with stellar bokehs. I am quite secure with my photography. :)
Or maybe you should read some scientific literature written by academics about optics if you already don’t have that background.
I am aware that some photographers believe that mtf charts don’t tell anything about bokeh, while others believe otherwise. But it is actually more nuanced than what I generalized in my previous reply. I will try to be brief here.
Yes, mtf charts don’t tell the whole story about the bokeh, but they do tell something about bokeh. You need more than mtf charts to conclude the ‘quality’ of bokeh. But mtf charts tell the nature and uniformity of bokeh across the frame from the center. If the Sagittal and Meridional lines are not close to each other, that means the bokeh is not uniform from the center to the edges (remember, this is not precisely the same thing as bokeh quality though). However, quite often, non uniform bokeh across the frame usually is generally non appealing and it’s just a cursory way of looking and having expectations about the bokeh for a given lens.
The above comment is for Joachim’s reply..
Venu, I actually don’t care (and don’t know) wether you get your opinions out of coffee grounds or from photo magazines. I’m a big fan of comparisons of pictures. I don’t say the Sigma is an excellent lens, it’s just better than the dated Nikkor 24/1.4 G which also Nasim suggests to get an update. And it’s not “the worst of the bunch” in terms of bokeh: sojujo.smugmug.com/Tests…/n-ts4BVt/
I could repeat the test with two other S-lenses currently at my hands with 24 mm focal length, but both start with f/4 and I will never buy the expensive 24/1.8 S.
It’s just not the first time I compared S-lenses to Sigma Art with F mount. So far the S-lens with better bokeh (which is a matter of taste, no question) still needs to surface.
Sharpness: great,
corner performance: outstanding,
bokeh, hmmmm maybe the 20/1.8 will deliver
I had read where the Nikon lens designers were leaving in more spherical abberarions in the S lenses. This is being done to give smoother bokeh or out of focus areas . Over the years the Nikon lens designers had their “secret sauce “ for certain lenses. Especially in the film days . They would leave in certain aberrations to give a lens a certain character to its image . Sometimes it was only within a certain ( perceived usage) focusing distance and certain f/stops.
So many Nikon lenses are not always the best on paper but have certain characteristics within the intended use .
Great review and love the sample photos.
I will say I applaud Nikon for making great lenses for their Z system. They are criticized for not making “professional” fast primes, but I see little reason for that criticism. I am fine with f1.8 for every use at this point. I shoot outdoors nearly all the time and rarely shoot much below f4, let alone f1.8. Most users, even professionals, are unlikely to pay 2.5x more for f1.4 versions considering how good the F 1.8’s are.
How can you tell about the difference between f/1.4 and f/1.8 if you rarely shoot below f/4? Where do you you get that absurd number of 2.5× the price? Check the prices of the S-line glass and then compare it with real prices of F-lenses, as no f/1.4 S-glass is available.
Is interesting to see that the 24-70 2.8 isn’t far behind at f2.8. It just show how stellar this zoom lens is
In fact, the 24-70 f/2.8 beats this prime lens at the mid and corners at most apertures, and only very slightly lags behind in the centre. Given the focal length you probably would not be using below f/2.8 anyway. It costs about half the price of the 24-70 f/2.8 in Australia and so probably not worth an additional purchase unless you have very specific needs.
Although actually it seems that difference is only up to f/5.6. Above f/5.6 the prime is slightly better all round. which is good for lanscapes. And the other primes seem to beat out the 24-70 f/2.8 more consistently and significantly at an aperture. So a prime set is probably still the sharpest way to go overall. Just seems to be a slightly weaker prime than the others on the charts.
Thank you for the review.
I have also tested the 24mm 1.8S against the 24mm 1.8G.
What i found_ the new lens has a different bokeh- the G-lens is softer as is the bokeh.
Coma control is better, contrast is a bit higher, on the S-lens as is the sharpness on the sides when stopping down.
– So yes the new one is a bit better, but how i dislike the bad qualities of the focus by wire…
Nikon can address some of them in firmware and should, like returning to the old focus point after shutdown.
PS the bokeh of the Sigma Art 24mm 1.4 lens is horrible with double images.
“PS the bokeh of the Sigma Art 24mm 1.4 lens is horrible with double images.” Hmm, need to check once more, but double images I also get with S glass (85 especially). Sometimes not easy to tell, depends a lot of aperture and distance between lens, object and background – and how nervoiuse the backgroudn already is.
Did you find the bokeh of Nikkor S less horrible? Wrong question: Is the bokeh of the Nikkor creamy?
Did test the 85mm Nikkor S lens and found it wide open even better than my 85mm Sigma ART.
Far less colour faults and purple fringing, more contrast.
I have heard that some people find the bokeh of the 85mm S is not so good but i liked it – Did not see the double images you mention, but i have heard that before so it will be true.
about the sigma 24 ART- I disliked the double image bokeh and discovered it is important to me… Yes i like the image of the 24mm 1.8G , only the mechanics are cheap, but it works.
“PS the bokeh of the Sigma Art 24mm 1.4 lens is horrible with double images.” Hmm, need to check once more, but double images I also get with S glass (85 especially). Sometimes not easy to tell, depends a lot of aperture and distance between lens, object and background – and how nervoiuse the backgroudn already is.
Did you find the bokeh of Nikkor S less horrible? Wrong question, let me rephrase: Is the bokeh of the Nikkor creamy?
The wide angle lenses do not have a good bokeh anyway.
But Looking at the mtf charts of nikon 24mm/1.8 S, nikon 24mm/1.8 G and Sigma art 24mm/1.4, it seems to me that Sigma art is the worst of the lot in terms of bokeh. Nikon’s new S line is the better of the lot, followed closely by G.
Glad to see that the Nikon’s new S line lenses are faring better than their F mount counterparts…
If someone judges the bokeh by looking at the MTF charts, that says more about the knowledge of this someone than the lenses he’s talking about without having shot with a single one of it.
Wide angle lenses have historically suffered most from field dependent aberrations. Some of them such as astigmatism are very, very bad for OOF areas as well. Only recently we’ve seen major improvements in that regard and some newer wide angle lenses have much lower field dependent aberrations than their predecessors. The 35 1.8 S may have been the first of this new breed of autofocusing wide angles below $1000 (now there’s the Tamron 35 1.4, maybe even the Sony 20mm 1.8 FE). One cannot precisely determine the amount of one specific aberration (ex : astigmatism) from a MTF chart, but you can reasonably presume that a lens which both sagittal and tangential lines closely follow each others is likely to have a low amount of field dependent aberrations. That’s not always the case, but it often is. The Nikon 24 1.8 Z and Sigma 24 1.4’s MTF curves seem to correspond well to that approach, and it’s fully backed up by actual tests :
www.cameralabs.com/sigma…-review/2/
www.cameralabs.com/nikon…-review/2/
There’s a pretty strong correlation between point light sources being deformed into a line (or “wings”) in the corners of the frame (cf. Cameralabs’ nightscapes shots) and the occurence of hard edges in one orientation in OOF areas (cf. Cameralabs’ OOF nightscapes shots).
So yes, looking at MTF charts is not an unreasonable first step to start making a number of limited presumptions about OOF areas.
Note that this is just about field dependent aberrations. Two lenses with the exact same mix of field dependent aberrations may still have a widely different bokeh because of other factors (LOCA, spherical aberration, onion rings, etc.).
Thanks Nasim for uou review and efforts doing that. Somehow I also see all the manufacturers are focus on sharpness from edge to edge, building a perfect lens without personality. But this is the trend of modern lenses and it seams the current request of all of us. But it’s fine we can survive.
Please could you tell us exactly which camera you used to test those 24mm lenses?
Moreover, when you test the edge part of the lens, do you refocus the lens or you simply focus on the centre and check the centre and edge at the same time? Moreover do you check the focus only at fully aperture or at every closed f stop do you refocus? What about the field curvature if the rested lens?
I’m sure in the past you described how you perform the test, but I really appreciate if you remind us. Thanks.
Marcus, it is expected that lenses are going to get sharper, because sensor resolution has also been drastically increasing. There is no point of increasing sensor resolution, if lenses cannot resolve enough detail, which is why lenses are getting bigger and heavier. We have already written about this at PL.
In regards to testing methodologies, the camera used for assessing the sharpness is the Nikon Z7. For Imatest results (and you can read more about how Imatest works on their website), the assessment is always done by focusing in the center of the frame. However, I do manually focus in the corners to see if they get significantly sharper, with the center de-focused. If they do, then I conclude that the lens has field curvature. All lenses exhibit some amounts of it, but some are better than others.
When measuring lens performance, I always refocus with each aperture, because most lenses exhibit focus shift, and this is a good way to assess its impact. I also use a macro rail to move the camera back and forth and shoot at different distances, to make sure that I am providing the best possible results. This takes a lot of time, but this is, in my opinion, the only proper way to provide valid data.
Nasim we area all romantic and think that glass is the mirror of our soul :-)
In the past I was more focused on the personality of the lens (yes, I call this personality, like referring to a human), but now, because I’m getting older I need sharpness and cristal clear images. But this is a personal choice, and no discussion here.
Going back to our technical discussion, about field curvature, which one exhibits more field curvature and focus shift as well ? Thanks.
Nasim we are all romantic and think that glass is the mirror of our soul :-)
In the past I was more focused on the personality of the lens (yes, I call this personality, like referring to a human), but now, because I’m getting older I need sharpness and cristal clear images. But this is a personal choice, and no discussion here.
Going back to our technical discussion, about field curvature, which one exhibits more field curvature and focus shift as well ? Thanks.
One more thing regarding lens “personality”. A lens is a lens. It is a piece of plastic that contains glass and metal. It has optical properties, coatings, aberrations, tolerances, variances and a price tag. Lenses don’t have “personalities” or “souls”. If a lens renders a scene one way, while another one does it in a different way, that’s nothing more than differences in optical design. Lenses have changed a lot in the past 10 years, mostly due to the demand for high-resolution sensors. They need to catch up, so they are getting more refined with more corrections. For manufacturers, it is always a balancing game…
Have to agree on that. Sure, tools can adapt to the hands or skills of their owner – but at first, a fountain pen needs a while and a couple of miles of writing to deform it’s tip to the writing of it’s owner. And that’s about it. The only “personality” my lenses have is the pattern of dents or scratches, and they got that over years. But so far as I can see, none of them changed their characteristics much.
In a kind mood, I simply turn my back to people talking about the metaphysical and etherical properties of their glass (it’s always their glass which has characteristics too far out of the reach of every measuring device, but his (no, female photogs usually don’t need this carpet of sheer unexplainability) master’s eye knows the difference). In a less kind mood I try to arrange a comparison of prints.
Hi Nasim, my apologies if I come back after a while, but I still have some doubts because I cannot find this info in your test.
Simply, which camera have you used to test 24mm S-line and 24mm AFS? And could you also remind me the camera used during Imatest of the 35mm S-line for Z Camera and the one used with 35 AFS? This very helpful and please write always this technical and boring note at the beginning of each chart. Thanks.
Marcus, all the tests were performed on the Z7, same camera. The F mount lenses were used with FTZ adapter.
Sorry, but I’m not going to publish this info on each lens review, because there is literally one person who asked for it, and it is you…