httivals wrote:
Mark: How accurate is the focusing of the Sigma 50mm f1.4 (or your Sigma 50mm f1.4) on a Canon 5D? Thanks, Howard
At dpreview.com, user Chez Wimpy posted extensively about this lens
and mentioned that autofocus worked fine with this lens on his 20D.
A number of the shots he posted from AI Servo mode looked good.
Thanks Mark to share your insight on this lens, sorry I once more have to leave a critical comment about it
These are not bokeh samples, these are OOF blur disc samples, it doesnt tell a lot about the quality of the bokeh, maybe it tells something about the character of the bokeh though. Curvature of field may just be too different to any other lenses to compare them the way you have done it.
I believe that the reason some lenses do not fully correct CA wide open, is that you have shaped OOF discs and not the IMO boring blobs of the Sigma. Again some people may like it others dont and it is certainly a lens with some appeal to people who want to replace the Canon 1.4
It's amusing that for years around here we've heard people complain about the busy bokeh of Canon lenses and rave about the smooth bokeh of other makes of lenses. Now that Sigma seems to have put out a lens with smooth bokeh, some complain that its bokeh is not busy enough.
Perhaps Sigma needs to launch a luxury brand, ala Lexus.
CKrueger wrote:
It's amusing that for years around here we've heard people complain about the busy bokeh of Canon lenses and rave about the smooth bokeh of other makes of lenses. Now that Sigma seems to have put out a lens with smooth bokeh, some complain that its bokeh is not busy enough.
Perhaps Sigma needs to launch a luxury brand, ala Lexus.
You missed the point.
we have no idea how the full image looks like, where the focus sits, how much the blobs are out of focus, the distance to the background, the scale of the image
Andi Dietrich wrote:
You missed the point.
we have no idea how the full image looks like, where the focus sits, how much the blobs are out of focus, the distance to the background, the scale of the image.
The point is that all four lenses were placed under identical conditions; the comparative difference is the point.
I'm not sure that posting the full frame will tell you anything more meaningful than the crops, but here it is anyway: the Sigma at f4. Distance to focal plane (subject centre frame) was about 1m. Distance to bokeh samples ranged from about 15cm to 1.5m. As stated previously, all these are background rather than foreground samples. http://www.16-9.net/raw/bokeh_ff_f4.jpg
I will be looking at the bokeh in other settings but I'm not interested in shooting an unrealistically contrived set: for me, bokeh only becomes an issue when it's either too busy, draws ugly light discs, or has prominent CA – so I'll be seeking out scenes that tell me something I want to know.
If anyone wants to see samples of different areas at different scales or apertures, just shout.
Andi Dietrich wrote:
Does the EXIF allow lens corrections in DPP? This may be a possibility if Sigma adapter the same settings of the EF50mm
I just got my Sigma 50 tonight. Yes, it allows lens corrections in DPP.
I'm not sure how relevant this is, since the geometric distortion is very
well controlled on this lens, and I haven't seen much CA with it.
I also noticed that Peripheral Illumination correction vastly over-corrected
the vignetting, if I used the standard amount (100).
Fast, quiet, generally accurate. I'm getting about the same AF accuracy with
the Siggy on my 30D that I get with Canon lenses on this body: which is to say
good, but not perfect. When it misses, it generally front-focuses a little, but I
think this is as much the body's fault as anything. This lens seems about as
accurate in AF as my EF 100 f/2.
The build quality is very nice on this Sigma. When focusing from minimum
distance out to long distance, it is smooth and pretty fast, with a really nice
quality feel to the focus motor. There is fairly heavy glass to move, and the
HSM is up to the task. When focusing over a smaller range, around 8 to 10 meters
out, you can sometimes feel a little clunk in the mechanism, as it is moving and
stopping very quickly.
Overall, the lens feels very much like a slightly larger Sigma 30/1.4
I think they have optimized this lens for bokeh and uniformity across the full frame.
Distortion is minimal. Straight lines look straight. No visible vignetting on 1.6x crop
body -- even wide open. Colors are fantastic.
It is still possible to get low contrast with the lens, when shot in dim, soft light,
but I think it's still better wide open than the EF 50/1.4 or the CZ 50/1.4 Planar.
Tim
Edited by trumpet_guy on Jul 02, 2008 at 02:46 AM GMT
The bokeh question is a matter of taste, and I am well aware that few share my bad taste. I like my bokeh to look more interesting than this lens makes it. Whether smooth, Leica-style bokeh kills 3D effect or not, I don't know, but I don't think it's impossible that there is a connection between sharp edged image circles, extended depth of field, 3D effect, and edge sharpness.
In hubsands sample of the tassle thingy hanging off the table, all the lenses draw a beautiful mysterious object which clearly has a pattern of strong points of light in it. On the Sigma it's just mush, so the lens is telling me less about the scene.
One of the reasons I am not always very enthusiastic about Leica glass is that in seeking creamy bokeh, 3D effect often seems to be lost. I accept that this is purely conjectural, so I probably won't stand by it if someone can challenge it or has counterexamples.
Ultimately I don't think busy has to mean ugly. Sharp-edged bokeh can still be smooth, even if it is also well-defined.
As always, thanks Mark for sharing your data so generously.
