If shooting at f/22, is a fast 1.8 lens still considered fast?

Started Apr 17, 2011 | Discussions thread
edwardaneal Veteran Member • Posts: 9,101
dont you ever stop?

you keep posting these ancient diagrams of how a phase detect system might work if it were limited to only one type of sensor, one sensor location, one baffle width on every sensor, - - dont you get it? Seriously any one can look at your symplistic drawing and see how easy it would be to make minor changes that would allow it to work with faster apertures yet still function perfectlly with slower lenses especially in a system that has multiple sensors and can optomize them for more that one paticular aperture, but for some dumb reason you dont think the engineers at Nikon have been smart enough to figure this out.

Nikon has flat out stated that their AF system will in fact focus faster and more accuratly with f/2.8 and f/1.4 lenses. yet here you are hanging desperatly on to the argument

And earlier you called me "hard headed" WOW

Real men admit it when they make a mistake - - - - - Only sore loosers keep making excuses.

I am done here - you are wrong, it is a fact that has been verified by the people at Nikon - - - - deal with it !!!

noirdesir wrote:

DRode wrote:

Thanks for getting this straight from Nikon. I was always told that faster glass benefits the Nijkon AF system. In fact, my own experience would seem to support this. But recently I've read a number of comments that this was not the case. One poster even referred to some kind of "baffles" that would damp the light down to f/5.6 even if the lens were capable of much wider apertures.

These 'baffles' are real (see the green parts below to understand what they do), even Edward has accepted that. He is just of the opinion that Nikon must use both f/2.8 and f/5.6 PD-AF sensors because Canon uses them (and Nikon would be stupid not to use them as well, probably similarly to Nikon using FF sensors prior to 2007 because Canon was using them). And that Nikon has designed its AF system such that a simple test for the existence of f/2.8 AF sensors (which is done by blocking the light to the f/5.6 sensors as indicated in red in the drawing, if there are f/2.8 sensors, the AF should continue working, if there are none, it should not work, which is what is observed) would fail, so the existence of f/2.8 AF sensors in Nikon cameras could be kept secret.

The e-mail from Nikon shows no sign that the person is actually understanding how PD-AF works, otherwise he would be more specific and say that Nikon uses both f/2.8 and f/5.6 AF sensors.

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My kit - D200, 10.5mm f/2.8D, 35mm f/1.8G, 50mm f/1.4G & 70-300VR
SB800, SB600 and other misc lighting equipment

Lenses worth mentioning owned and sold– 12-24 f/4, 17-55 f/2.8, 35-70 f/2.8, 80-200 f/2.8, 20mm f/2.8, 35mm f/2, 50mm f/1.8, 50mm f/1.4D, 60mm f/2.8D, 85mm f/1.8, 105mm f/2D-DC, 180mm f/2.8, 300mm f/4D-ED

 edwardaneal's gear list:edwardaneal's gear list
Sony Alpha NEX-7 Sigma 60mm F2.8 DN Art Carl Zeiss Touit 1.8/32
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