Lars
Active member
I picked up a Sigma 50/1.4 EX at the local store the other day. As some of you might recall, I've been a bit curious about its lens because of its nonstandard design. Here are some first impressions.
Price: I paid 3995 SEK including sales tax, or 3196 SEK before tax. For you people across the pound that's today about USD 356 plus sales tax.
Dimensions: This is one big lens! Dimensions and weight almost exactly match my 85/1.4D - just about 5 mm shorter. Filter thread is a whopping 77 mm.
Construction: Focusing is traditional, with the entire lens assembly moving. The lens assembly is one fixed unit contained in an inner metal barrel. The front element is about 62 mm across, so Sigma could have gotten away with using a 67 mm filter thread. Instead, a larger outer barrel size was added, that houses the entire lens assembly. This outer barrel is made of composite material but seems quite substantial, protecting the lens assembly well.
Lens mount bayonet is tight like it should be. The mount is actually oversized compared to Nikon's mounts, allowing the mount screws to be placed further apart, wich in theory would make the construction stronger.
Included lens hood is of sculpted type, and mounts bayonet-style with a positive lock feel to it. The hood could have been slightly longer as there is some margin before any vignetting occurs.
Filter threads are in the outer composite barrel, so it's not metal threads. This is a weak point, care should be taken when mounting filters and it's probably not a good idea to use a screw-in hood as it might rip out the filter threads if you drop the camera.
All in all, with the exception of filter threads the construction inspires confidence. It would seem that Sigma has tried to make a lens that is sturdy and rigid. How well it actually takes a beating remains to be seen.
Focusing: The manual focusing ring has about 90 degrees rotation from endpoints to 45 cm, and feel is OK for an AF lens. MF override is possible in AF mode, or you can turn off AF on the lens. The lens has a built-in AF motor, so it should work with all current Nikon cameras. Focusing speed is good without being stellar - sligthly faster on my old F5 than on my new D700. There is the occasional hunt as the camera/lens combination overshoots. The lens assembly is quite heavy, which can be felt as the focus motor starts and stops. I suspect that it drains the camera battery a bit more than a smaller lens.
Now the optics.
Color and contrast: to my eyes color rendering seems neutral, possibly with an ever so slight warm cast but I'm not quite sure. Overall contrast is moderate, in LF terms more like Rodenstock than Schneider if you can relate to that.
Wide open there is a slight falloff towards edges. The only way to tell is to fire two shots after each other at different apertures and then flip back and forth between them. At f/1.8 any falloff is gone.
Sharpness and microcontrast: At f/1.4 there is a softness just outside the focus plane, and depth of field is so narrow that it's very difficult to nail the focus exactly. For this reason it's easy to dismiss this lens as being soft wide open, when in fact it's not. AF on my D700 is not precise enough, and manual focusing using the viewfinder is even worse (at least with my eyes). Using tripod-mode live view on the D700 I was able to obtain proper focus. Most of this wide-open softness around the focus plane is gone at f/1.6, and completely gone at f/1.8. As with most lenses, resolution drops slightly at f/16 which is the smallest aperture. Resolving power is sufficient for my D700, someone else will have to test on a camera with higher photosite density like D90, D300, D3x.
Towards the extreme corners (the very last 1-2 mm) the image falls apart wide open, with noticeable coma. Getting the corners together requires stopping down to f/8-11. On DX sensor this is not a problem as the inner image circle has good definition at all apertures.
Now on to the interesting part...
Bokeh: So you put the 50 on a body, look through the viewfinder and bokeh seems good, with the limitations of a viewfinder screen. You fire a test shot, look at the display on the D700, and go "Whaaat???" Background bokeh is all cream. Just whipped, thick cream, with sugar added. Foreground is just as creamy and smooth. Transition from focus to blur is exquisite (this is where the wide-open softness comes in). Background specular highlights are rendered as perfect filled circles, with virtually no edge. Bokeh performance is extended through the aperture range, with only the wide-open softness lost. I've only seen this rendering quality in Cooke lenses, that's the closest comparison I can think of.
When discussing this lens, I think it's important to come up with some kind of definition: what is the Sigma 50?
The way I see it, it does at 50 mm what my 85/1.4D does at 85 mm: Render aesthetically pleasing photographs. This reason is enough motivation for me to carry it around despite its huge size and weight.
It's also important to define what it's not:
- It's not your general purpose normal lens - too big and heavy.
- It's probably not the sharpest 50 you can buy. It will compete with most of them I'm sure, but it might not be the sharpest. A comparison would be interesting, but resolution is not the sole reason to use this lens.
So if you are looking for something small and light, or if you are a resolution buff and don't care much about bokeh then this lens is not for you.
If on the other hand you have interest in lenses with that subjective rendering quality, then the Sigma 50 might be of interest. I could also envision this as an interesting portrait lens on 4/3, if its resolving power is sufficient.
I'll follow up with some sample shots over the weekend. (Please tell me what kind of setups you would like to see.)
Lars
Price: I paid 3995 SEK including sales tax, or 3196 SEK before tax. For you people across the pound that's today about USD 356 plus sales tax.
Dimensions: This is one big lens! Dimensions and weight almost exactly match my 85/1.4D - just about 5 mm shorter. Filter thread is a whopping 77 mm.
Construction: Focusing is traditional, with the entire lens assembly moving. The lens assembly is one fixed unit contained in an inner metal barrel. The front element is about 62 mm across, so Sigma could have gotten away with using a 67 mm filter thread. Instead, a larger outer barrel size was added, that houses the entire lens assembly. This outer barrel is made of composite material but seems quite substantial, protecting the lens assembly well.
Lens mount bayonet is tight like it should be. The mount is actually oversized compared to Nikon's mounts, allowing the mount screws to be placed further apart, wich in theory would make the construction stronger.
Included lens hood is of sculpted type, and mounts bayonet-style with a positive lock feel to it. The hood could have been slightly longer as there is some margin before any vignetting occurs.
Filter threads are in the outer composite barrel, so it's not metal threads. This is a weak point, care should be taken when mounting filters and it's probably not a good idea to use a screw-in hood as it might rip out the filter threads if you drop the camera.
All in all, with the exception of filter threads the construction inspires confidence. It would seem that Sigma has tried to make a lens that is sturdy and rigid. How well it actually takes a beating remains to be seen.
Focusing: The manual focusing ring has about 90 degrees rotation from endpoints to 45 cm, and feel is OK for an AF lens. MF override is possible in AF mode, or you can turn off AF on the lens. The lens has a built-in AF motor, so it should work with all current Nikon cameras. Focusing speed is good without being stellar - sligthly faster on my old F5 than on my new D700. There is the occasional hunt as the camera/lens combination overshoots. The lens assembly is quite heavy, which can be felt as the focus motor starts and stops. I suspect that it drains the camera battery a bit more than a smaller lens.
Now the optics.
Color and contrast: to my eyes color rendering seems neutral, possibly with an ever so slight warm cast but I'm not quite sure. Overall contrast is moderate, in LF terms more like Rodenstock than Schneider if you can relate to that.
Wide open there is a slight falloff towards edges. The only way to tell is to fire two shots after each other at different apertures and then flip back and forth between them. At f/1.8 any falloff is gone.
Sharpness and microcontrast: At f/1.4 there is a softness just outside the focus plane, and depth of field is so narrow that it's very difficult to nail the focus exactly. For this reason it's easy to dismiss this lens as being soft wide open, when in fact it's not. AF on my D700 is not precise enough, and manual focusing using the viewfinder is even worse (at least with my eyes). Using tripod-mode live view on the D700 I was able to obtain proper focus. Most of this wide-open softness around the focus plane is gone at f/1.6, and completely gone at f/1.8. As with most lenses, resolution drops slightly at f/16 which is the smallest aperture. Resolving power is sufficient for my D700, someone else will have to test on a camera with higher photosite density like D90, D300, D3x.
Towards the extreme corners (the very last 1-2 mm) the image falls apart wide open, with noticeable coma. Getting the corners together requires stopping down to f/8-11. On DX sensor this is not a problem as the inner image circle has good definition at all apertures.
Now on to the interesting part...
Bokeh: So you put the 50 on a body, look through the viewfinder and bokeh seems good, with the limitations of a viewfinder screen. You fire a test shot, look at the display on the D700, and go "Whaaat???" Background bokeh is all cream. Just whipped, thick cream, with sugar added. Foreground is just as creamy and smooth. Transition from focus to blur is exquisite (this is where the wide-open softness comes in). Background specular highlights are rendered as perfect filled circles, with virtually no edge. Bokeh performance is extended through the aperture range, with only the wide-open softness lost. I've only seen this rendering quality in Cooke lenses, that's the closest comparison I can think of.
When discussing this lens, I think it's important to come up with some kind of definition: what is the Sigma 50?
The way I see it, it does at 50 mm what my 85/1.4D does at 85 mm: Render aesthetically pleasing photographs. This reason is enough motivation for me to carry it around despite its huge size and weight.
It's also important to define what it's not:
- It's not your general purpose normal lens - too big and heavy.
- It's probably not the sharpest 50 you can buy. It will compete with most of them I'm sure, but it might not be the sharpest. A comparison would be interesting, but resolution is not the sole reason to use this lens.
So if you are looking for something small and light, or if you are a resolution buff and don't care much about bokeh then this lens is not for you.
If on the other hand you have interest in lenses with that subjective rendering quality, then the Sigma 50 might be of interest. I could also envision this as an interesting portrait lens on 4/3, if its resolving power is sufficient.
I'll follow up with some sample shots over the weekend. (Please tell me what kind of setups you would like to see.)
Lars
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