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04-04-2011, 01:44 PM   #16
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I own the Sigma 20mm F1.8 EX. My copy is very soft and lacks contrast (compared to my FA43 and FA77).

The minimum focusing distance is amazing as is the razor thin DOF when focusing close at F1.8.

04-04-2011, 06:12 PM   #17
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QuoteOriginally posted by heasley Quote
I own the Sigma 20mm F1.8 EX. My copy is very soft and lacks contrast (compared to my FA43 and FA77). The minimum focusing distance is amazing as is the razor thin DOF when focusing close at F1.8.
Thanks heasley..so,do you think that 14mm is better than the 20mm?
04-04-2011, 06:38 PM   #18
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QuoteOriginally posted by basikal_kusayang Quote
Thanks heasley..so,do you think that 14mm is better than the 20mm?

I may just have a bad copy of the 20mm but the photographs I've seen taken with the 14 F2.8 at F4 are far better (sharp/contrasty) than F4 on the Sigma 20mm.

Having said that you may have a need for the close focus and narrow DOF. Sigma makes the only mass production F1.8 20mm lens in existence.
04-04-2011, 06:46 PM   #19
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QuoteOriginally posted by heasley Quote
I may just have a bad copy of the 20mm but the photographs I've seen taken with the 14 F2.8 at F4 are far better (sharp/contrasty) than F4 on the Sigma 20mm. Having said that you may have a need for the close focus and narrow DOF. Sigma makes the only mass production F1.8 20mm lens in existence.
thanks heasley....i think i need to do a LOT of reading about the lenses and make my mind.quick...tq

04-04-2011, 07:21 PM   #20
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QuoteOriginally posted by basikal_kusayang Quote
yeah, i know, but i found both of the lenses at the same price. so,i dont realy know which lens should i buy.
Both, the focal lengths are significantly different. 14 is considered wide on digital. 20, not so much (less than the kit even). OK, since the Sigma may be a dog, consider the DA 21 or something else. Personally I would say a used 12-24 is a good choice.
04-04-2011, 07:23 PM   #21
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QuoteOriginally posted by SpecialK Quote
Both, the focal lengths are significantly different. 14 is considered wide on digital. 20, not so much (less than the kit even).
yeah,i know,i just want a wide prime that can give me a great bokeh..
04-04-2011, 08:38 PM   #22
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QuoteOriginally posted by basikal_kusayang Quote
yeah,i know,i just want a wide prime that can give me a great bokeh..
not gonna happen. there's a direct relationship between DOF and FL.

moving away from those 50 f/1.4 and f/1.2 you get very little DOF, and there's not a bright enough lens to get it back.
04-04-2011, 09:02 PM   #23
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QuoteQuote:
moving away from those 50 f/1.4 and f/1.2 you get very little DOF, and there's not a bright enough lens to get it back.
Worded backward :-) Just clarifying...Wide angle has more DOF, and no wides are fast enough to minimize it with a big aperture, like 0.5 :-)

04-04-2011, 09:53 PM   #24
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QuoteQuote:
Heasley: Having said that you may have a need for the close focus and narrow DOF. Sigma makes the only mass production F1.8 20mm lens in existence.

Yes, which must be the reason why the Sigma still gets a 4-Star rating @ Photozone for price & performance. 4 stars is better than a lot of lenses get there. I think Photozone is trying to say something here. The lens, in their words is, a "very ambitious" one.
04-04-2011, 10:20 PM   #25
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Yeah but the IQ rating is only 1.5 stars, in other words it is only slightly better than the bottom of a coke bottle.
04-04-2011, 10:50 PM   #26
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QuoteOriginally posted by SpecialK Quote
Worded backward :-) Just clarifying...Wide angle has more DOF, and no wides are fast enough to minimize it with a big aperture, like 0.5 :-)
yep, totally backward lol.
04-05-2011, 01:26 AM   #27
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QuoteOriginally posted by basikal_kusayang Quote
yeah,i know,i just want a wide prime that can give me a great bokeh..
That will be difficult, but also depends on what the subject is and how close, how balanced the DOF and the bokeh.

I tend to use the distance to get the whole object in focus, not only part of it, to get the max impact of 3D effect on an image. Wide primes give 'sharper' bokeh and larger DOF, unless the subject is close, but then we have to deal with distortion, especially human portraits. The wider the more difficult to balance these properties.
04-05-2011, 02:43 AM   #28
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QuoteOriginally posted by basikal_kusayang Quote
yeah,i know,i just want a wide prime that can give me a great bokeh..
At F1.8 the 20mm produces decent bokeh for a wide angle lens. Just do a search of Flickr and you'll see plenty of examples. But it is definitely a specialty lens.
04-05-2011, 04:50 AM   #29
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QuoteOriginally posted by selar Quote
Or the DA 21 Limited. The FA* 24/2 is overrated. Its worth it if you're shooting film but not otherwise.
I assume you haven't owned one then.
It's definitely not overrated. I'd say it's a great lens well worth it's * designation.
21 is a good lens but has more distortion but less CAs than 24. And of course, 21/3.2 will give you even more DOF than 24/2
04-05-2011, 09:36 AM   #30
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QuoteOriginally posted by selar Quote
Yeah but the IQ rating is only 1.5 stars, in other words it is only slightly better than the bottom of a coke bottle.
Again, you confirm my point--Photozone gives it an overall score of 4. It does this because, if you want 20mm & f 1.8, this is the best lens out there. It is that simple!

The optical score has everything to do with the fact that the lens is a rare, ambitious attempt at a difficult combination, which is judged against all other lenses with more modest efforts. Given its credentials, it is relatively inexpensive too. None of the lenses are actually bad, it is just that they all are so good, with some better than others.

Your "bottom of a coke bottle" comment leads me to believe you never shot with the lens. All the lenses @ Photozone are capable, especially in the right hands. Lens making these days has gotten so good that none are truly bad; rather, some are better than others. Of course, even the best ones, can produce a bad apple in the batch now and then.

To keep this in perspective, I've seen fantastic photography done with 60 year old, and older lenses--were they optically better than the Sigma 20mm f 1.8??? The shooter makes the shot. On that note, when you get a second, have a look at some of the excellent work done in here Full-size sample photos from Sigma 20mm F/1.8 with the Sigma 20mm f 1.8.
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