Re: The new Nikon Z8 vs the Sony A7RV and potential A9III
So I did a little experiment just to approximate the effects of cropping and oversized image circle. If you look at the MTF charts for the two lenses I tested doing so will get you very strong edge to edge sharpness, and little vignetting or other aberrations.
I took some images to see the effect on getting round to as Nikon puts it lemon shaped bokeh balls.
This is very far from an ideal test. Lots of room for criticism. It is not designed to compare these lenses directly to Plena. Too many discrepancies in focal lengths, apertures, zoom/prime etc.. But it does give an idea of what the potential of the larger image circle may be. It also gives a technique to achieve images where the benefits of such cropping might be realized if the image is shot with this intent from the beginning.
I strung up some Christmas lights to provide pinpoint light sources. I used a light stand with a
The first lens is my 50mm f1/2 GM shot at f/1.8 to match the Plena aperture. As you can see the bokeh balls are smooth round and soft. There are just some small misshapen ones very far out to the edges that a very small crop would eliminate. As expected from such a very high optical quality lens.
The second two are from the 70-200 f/2.8 GM II zoom lens. I don't have a 135 FL prime. So, I shot at max aperture where performance is likely the worst. The first image is full frame. You can see that the bokeh balls do suffer distortion out toward the edges. he second shot without touching anything except toggling to crop mode. Overall the bokeh balls are also not as smooth or soft as the 50mm, and do show some onion rings. I think this is expected of even a very high quality zoom. But the cropped image bokeh balls are very nicely shapped and would not be objected to by most.
So, as we can see the benefits of designing a larger image circle in respect to the sensor size are real. This, even in lenses where this concept was not optimized in design. It also seems applicable across focal lengths. It is a technique I will likely try in real shooting when it seems appropriate. Another trick in the bag...
Re: The new Nikon Z8 vs the Sony A7RV and potential A9III
So I did a little experiment just to approximate the effects of cropping and oversized image circle. If you look at the MTF charts for the two lenses I tested doing so will get you very strong edge to edge sharpness, and little vignetting or other aberrations.
I took some images to see the effect on getting round to as Nikon puts it lemon shaped bokeh balls.
This is very far from an ideal test. Lots of room for criticism. It is not designed to compare these lenses directly to Plena. Too many discrepancies in focal lengths, apertures, zoom/prime etc.. But it does give an idea of what the potential of the larger image circle may be. It also gives a technique to achieve images where the benefits of such cropping might be realized if the image is shot with this intent from the beginning.
I strung up some Christmas lights to provide pinpoint light sources. I used a light stand with a
The first lens is my 50mm f1/2 GM shot at f/1.8 to match the Plena aperture. As you can see the bokeh balls are smooth round and soft. There are just some small misshapen ones very far out to the edges that a very small crop would eliminate. As expected from such a very high optical quality lens.
The second two are from the 70-200 f/2.8 GM II zoom lens. I don't have a 135 FL prime. So, I shot at max aperture where performance is likely the worst. The first image is full frame. You can see that the bokeh balls do suffer distortion out toward the edges. he second shot without touching anything except toggling to crop mode. Overall the bokeh balls are also not as smooth or soft as the 50mm, and do show some onion rings. I think this is expected of even a very high quality zoom. But the cropped image bokeh balls are very nicely shapped and would not be objected to by most.
So, as we can see the benefits of designing a larger image circle in respect to the sensor size are real. This, even in lenses where this concept was not optimized in design. It is a technique I will likely try in real shooting when it seems appropriate. Another trick in the bag...
Re: The new Nikon Z8 vs the Sony A7RV and potential A9III
So I did a little experiment just to approximate the effects of cropping and oversized image circle. If you look at the MTF charts for the two lenses I tested doing so will get you very strong edge to edge sharpness, and little vignetting or other aberrations.
I took some images to see the effect on getting round to as Nikon puts it lemon shaped bokeh balls.
This is very far from an ideal test. Lots of room for criticism. It is not designed to compare these lenses directly to Plena. Too many discrepancies in focal lengths, apertures, zoom/prime etc.. But it does give an idea of what the potential of the larger image circle may be. It also gives a technique to achieve images where the benefits of such cropping might be realized if the image is shot with this intent from the beginning.
I strung up some Christmas lights to provide pinpoint light sources. I used a light stand with a
The first lens is my 50mm f1/2 GM shot at f/1.8 to match the Plena aperture. As you can see the bokeh balls are smooth round and soft. There are just some small misshapen ones very far out to the edges that a very small crop would eliminate. As expected from such a very high optical quality lens.
The second two are from the 70-200 f/2.8 GM II zoom lens. I don't have a 135 FL prime. So, I shot at max aperture where performance is likely the worst. The first image is full frame. You can see that the bokeh balls do suffer distortion out toward the edges. he second shot without touching anything except toggling to crop mode. Overall the bokeh balls are also not as smooth or soft as the 50mm, and do show some onion rings. I think this is expected of even a very high quality zoom. But the cropped image bokeh balls are very nicely shapped and would not be objected to by most.
So, as we can see the benefits of designing a larger image circle in respect to the sensor size are real. This, even in lenses where this concept was not optimized in design.
Oct 09, 2023 at 11:24 AM
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