Wednesday, August 28, 2013

The Sony Diaries #4: High ISO? no worries with the Sony a99

There has never been a free lunch with high ISO's. Using high ISOs (ISO1600 and higher) meant putting up with noise/grain, colour shifts, and overall image degradation. Back in the film days, rating an ISO400 film at ISO800 was, literally, pushing it. In digital, as sensor technology (and size) evolved, the high ISO quality boundaries expanded; still, an image taken at ISO3200 shows image degradation in comparison to one taken at ISO400 (a difference of 3 stops).
I knew that, in theory,  a well exposed image may be taken at high ISO's without noticeable or significant image deterioration. I never had much success with this theory so I kept my ISO rating at ISO800, maybe ISO1600 for dark reception venues, even with my full frame Canon 5d2.
Enter the Sony a99. This is a full frame camera with what I think is (shared by reviewers across the internet universe)  the best, unsurpassed, AWB and light metering implementation ever. Coupled with Sony's SLT technology, with its phase detect LIVE VIEW (on the industry's highest resolution EVF OLED finder and matching screen) which means what-you-see-is-what-the-sensor-gets-exactly (along with the thumb wheel for instant +/- EV adjustment), my images are almost always well-exposed!
I have now taken to using the AUTO ISO setting (ISO50-ISO6400) when I am on either Aperture Priority or Shutter Priority Mode. My images are almost always well-exposed and colour-balanced.
Here are samples of what I mean (as well as showcasing the Sony a99's micro-adjust feature):
Zeiss 24-70f2.8 at 50mm, 1/60@f3.2, ISO2500, full-frame 24MP
detail area from above, cropped to 1.5MP
Zeiss 24-70f2.8 at 50mm, 1/60@f3.2, ISO2500, full-frame 24MP
detail area from above, cropped to 2.1MP
Tamron 70-200f2.8 at 200mm, 1/125@f3.5, ISO6400, full-frame 24MP
detail area from above, cropped to 1.0MP
The image taken with the Tamron is note-worthy in that this lens was a so-so lens when used with the Sony a65 and Sony a57, consumer-oriented cameras without a micro-adjust feature. I was prepared to live with this since this Tamron is priced at less than half of what the Sony G version and the equivalent Canon and Nikon offerings go for. What I didn't realize is that the lens is actually innately very sharp; the a99 allowed me to micro adjust the focus plane so that the Tamron potential is realized!
Needless to say, I'm a Sony fan!

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