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	<title>What&#039;s on my mind &#187; available light</title>
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		<title>Sigma 30mm f1.4 EX DC HSM Lens Focusing Problem / High Pitched Noise</title>
		<link>http://www.jonhassall.com/articles/photographs/sigma-30mm-f1-4-focusing-problem-high-pitched-noise/</link>
		<comments>http://www.jonhassall.com/articles/photographs/sigma-30mm-f1-4-focusing-problem-high-pitched-noise/#comments</comments>
		<pubDate>Thu, 23 Jul 2009 20:45:23 +0000</pubDate>
		<dc:creator>Jon Hassall</dc:creator>
				<category><![CDATA[Photographs]]></category>
		<category><![CDATA[30mm]]></category>
		<category><![CDATA[available light]]></category>
		<category><![CDATA[f1.4]]></category>
		<category><![CDATA[long exposure]]></category>
		<category><![CDATA[sigma]]></category>
		<category><![CDATA[USA]]></category>

		<guid isPermaLink="false">http://www.jonhassall.com/articles/?p=123</guid>
		<description><![CDATA[My favourite lens, my Sigma 30mm f1.4, has developed a problem. Frequently it does not respond to auto-focusing, and it makes a high-pitched sound almost like it is struggling to focus]]></description>
			<content:encoded><![CDATA[<p>My favourite lens, my <a href="http://www.sigma-imaging-uk.com/lenses/dclenses/30mm.htm">Sigma 30mm f1.4</a>, has developed a problem. Frequently it does not respond to auto-focusing, and it makes a high-pitched sound almost like it is struggling to focus.</p>
<p>The Sigma 30mm f1.4 lens is my ‘workhorse’ lens, meaning the one I use the most. When I was using a 35mm camera (<a href="http://www.ephotozine.com/article/Pentax-MZS-4183">Pentax MZ-S</a>!), my favourite lens was a 50mm lens. I found a prime/fixed lens encouraged me to move around and experiment with viewpoints rather than be lazy and zoom from a single point.</p>
<p>With a digital APS-C sensor with a 1.6x multiplier, a 30mm lens delivers approximately the same as a 50mm lens on a 35mm film camera.</p>
<div class="wp-caption alignright" style="width: 110px;  border: 1px solid #dddddd; background-color: #f3f3f3; padding-top: 4px; margin: 10px; text-align:center; float: right;"><a href="http://www.jonhassall.com/gallery/tag/usa-2009-gallery/847_public-pay-telephone-in-santa-monica%2C-california.html"><img title="Public pay telephone in Santa Monica, California" src="http://www.jonhassall.com/gallery/preview/l150/847.jpg" alt="Public pay telephone in Santa Monica, California" width="100" height="150" /></a><p style=' padding: 0 4px 5px; margin: 0;'  class="wp-caption-text">Public pay telephone in Santa Monica, California</p></div>
<p>I have been very pleased with the results, being the sharpest out of any lens I have, and the lens hood makes it look formidable. The chromatic aberration was very low, and if anything was visible it has always been easy to remove with Adobe Lightroom’s chromatic aberration correction.</p>
<p>It also works great when taking long-exposure photographs at night. It creates pleasing star effects through its 8 blade octagonal diaphragm:</p>
<div class="wp-caption alignnone" style="width: 160px;  border: 1px solid #dddddd; background-color: #f3f3f3; padding-top: 4px; margin: 10px; text-align:center;"><a href="http://www.jonhassall.com/gallery/tag/night-and-long-exposure/836_street-scene-at-night-in-santa-monica%2C-california.html"><img title="Street scene at night in Santa Monica, California" src="http://www.jonhassall.com/gallery/preview/l150/836.jpg" alt="Street scene at night in Santa Monica, California" width="150" height="100" /></a><p style=' padding: 0 4px 5px; margin: 0;'  class="wp-caption-text">Street scene at night in Santa Monica, California</p></div>
<p>The large maximum aperture of f1.4 is great for low-light and situations requiring high shutter speeds. <a href="http://fstopping.blogspot.com/2009/01/sigma-30mm-f14-low-light-handheld-test.html">F-stopping writes about this</a>. I took this photograph as the passenger of a car travelling around 60mph on a dull English day, and it still came out very usable:</p>
<div class="wp-caption alignnone" style="width: 160px;  border: 1px solid #dddddd; background-color: #f3f3f3; padding-top: 4px; margin: 10px; text-align:center;"><a href="http://www.jonhassall.com/gallery/tag/portraits/22_hunters.html"><img title="Hunters gathering at side of a road in rural Nottinghamshire. Crop of a picture taken at 60mph" src="http://www.jonhassall.com/gallery/preview/l150/22.jpg" alt="Hunters gathering at side of a road in rural Nottinghamshire. Crop of a picture taken at 60mph" width="150" height="100" /></a><p style=' padding: 0 4px 5px; margin: 0;'  class="wp-caption-text">Hunters gathering at side of a road in rural Nottinghamshire. Crop of a picture taken at 60mph</p></div>
<p>A photograph using available light in a bar also came out well:</p>
<div class="wp-caption alignnone" style="width: 160px;  border: 1px solid #dddddd; background-color: #f3f3f3; padding-top: 4px; margin: 10px; text-align:center;"><a href="http://www.jonhassall.com/gallery/tag/portraits/435_people-at-bar-eleven.html"><img title="People at Bar Eleven" src="http://www.jonhassall.com/gallery/preview/l150/435.jpg" alt="People at Bar Eleven" width="150" height="100" /></a><p style=' padding: 0 4px 5px; margin: 0;'  class="wp-caption-text">People at Bar Eleven</p></div>
<p>And finally I found the full-time manual focus very useful. This allowed me to refocus even if autofocus was switched on. Usually if autofocus is activated, a lens doesn’t allow you to manual focus and you can feel the focussing motors giving resistance.</p>
<p>You can find an <a href="http://www.kenrockwell.com/sigma/30mm-f14.htm">in-depth review of the Sigma 30mm f1.4 EX DC HSM at Ken Rockwell’s web site</a>.</p>
<p>I’m going to contact <a href="http://www.sigma-imaging-uk.com/lenses/dclenses/30mm.htm">Sigma Imaging UK</a> support, and fingers crossed they will be able to resolve the issue as I would like to get photographing again <img src='http://www.jonhassall.com/articles/wp-includes/images/smilies/icon_smile.gif' alt=':)' class='wp-smiley' /> </p>
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