I've used a Sigma 20/1.8 a fair amount and find it useful. Not long ago I did a bunch of work with it underground in a mine, wide open. The results were quite respectable for a fast wide angle. I've certainly seen worse. In my view the quality wide open is better than a pre-aspherical Leica 35/1.4 or a Tamron 24/2.5, for example. The underground images were quite adequate for museum exhibit use in print sizes up to 11x14. Not wonderful, mind you, but certainly good enough not to detract from the usefulness of the images in terms of content.
The extra viewfinder brightness is very useful in poor lighting. In the underground job it allowed me to focus and compose when the brightest illumination was the focus assist beam from a flash. I've also found it very good for shooting public events such as gallery openings using existing light. Closed down a stop or so the results are fine for publication use. I've also used the lens for quick and dirty copy work on large maps. Closed down to f/11, sharpness is extremely close to that of a 60mm Micro Nikkor. I've tested that very carefully. The only flaw is very minor barrel distortion. I wouldn't use it for really high quality publication, but it 's great for doing legible reference copies in a hurry. Overall I'd recommend it as a keeper if you do a lot of hand-held low light work. Hope that helps. John Poirier ----- Original Message ----- From: Amita Guha <[EMAIL PROTECTED]> To: <[email protected]> Sent: Sunday, February 13, 2005 4:15 PM Subject: Sigma 20mm dilemma > Today is Nate's birthday, and I got him the Sigma 20mm f/1.8 because I > thought he wanted it based on samples he'd seen. Turns out he likes it, but > he has that range covered by his Canon 17-40mm, so he can't decide if he > should keep it. The Sigma is faster than the Canon, but that's the only > advantage as far as he can see. Does anyone have the Sigma 20mm or can > anyone think of a reason for him to keep it? I don't mind if he returns it, > but he is really on the fence about this one. > > Meanwhile, I'm eyeing this lens for myself...it's one of those times when I > really wish we were on the same system... > > Amita >
