Originally posted by philbaum
Instead of shooting at a narrow DOF like i did at F2 and F2.8, he was shooting at F4 and F5.6, MAKING IT LESS CRITICAL FOR AF TO BE SPOT ON. Not only did that simple change make AF less critical, but it also gives more DOF across the stage getting more action in focus. So what did i need to shoot at smaller apertures, you all know, i needed more ISO. I was ready to buy the Kx to get that ISO capability, may still do that, but at the same time along comes new improvements in software from LR3 and Topaz4 that enable my K20 to get acceptable results at 3200 iso -4000iso like my new Nikon friend. The Nikon guy was not able to make the last dress rehearsal, but the Director didn't notice the difference in IQ because the rest of us are improving our skills.
And you get the prize for explaining one of the biggest myths in the current photography forum meme.
Fast glass is better in low light.
It is, but not for the reasons most people think.
I have had a similar scenario, where I am at a social function with 2 pro photogs, one of whom is internationally renowned. It's actually a kid's birthday party indoors in winter! I took my FA 50/1.4. They shoot ridiculous Nikon and Canon lenses and gear that are worth a fortune.
But they *never, ever, ever* shoot below f/2.8.
Ever.
One guy told me that "Pros never do. There's almost no need, especially for a human subject."
They use 2.8 lenses because they have more headroom when stopped down. They are usually 5.6 shooters with human subjects and the 2.8 constant lenses simply gives them more latitude to get into the lenses sweet spot for sharpness and colour than wide open. Wide open lenses are soft (primes as well) and their contrast is lacking, especially in the corners.
And they know how to focus, just like your summary described. In fact, one guy said he requires sharpness above all (because colour can be dragged out now in PP) and once gone, you can never get it back. Colour fidelity and DR are actually more important to most observers, but there's no consensus with colour. There is with sharpness. So getting an accurate, focus and sharp detail trumps all else. If they want background effects and bokeh, they can PP it (not that I approve, but the point is there and they sell their work to people who do just that, including National Geo.).
They both had to think about whether they owned a lens faster than 2.8, and when they last used it. Neither could remember.
The shallow DOF of sub-2.8 aperture is a recipe for OOF, especially handheld. Sure enough, until I stopped down, my photos looked considerably worse than theirs did. I was using aperture to control light first, DOF second. I had it backwards.
So, the lesson I learned about aperture at a kid's birthday party is that a fast 50 works best at 2.8-4 because of the headroom it brings and I get much better AF stopping down. They were right also about the better colour and definitely sharper images, not just because of the DOF and the lens sweet spot, but also because . I re-learned the lesson about aperture and its limitations and opportunities.
ISO is another kind of latitude. As is flash.