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
Re: noirdesir - thank you - one more question

As I asked before please tell me why the actual scientific test I posted show that lenses between F/2.8 and f/4 AF the best?

Do you really think that Nikon is not smart enough to place some of the AF sensors in such a way as to take advantage of faster lenses?

Really? - only Canon has ever thought of this?

As a side note - calling names and being insulting does not help you cause

noirdesir wrote:

edwardaneal wrote:

thank you for finally admitting that faster glass can have an advantage in lower light

Thank you for repeatably showing a severe lack of reading comprehension and for actively trying to mislead the others. It just makes me more confident that my earlier judgement about you was absolutely correct.

(For once I did not even say that faster glass makes CD-AF faster, rather that it likely makes AF slower because the additional hunting caused by low DOF is much more important than the reduced signal noise. Secondly, this whole discussion up until your previous post was about PD-AF, so I have not changed my statements regarding PD-AF, I just added a description of a different kind of AF system.)

so one more question

And are you willing to do a very simple thought experiment? (I highly doubt it but I am intrigued whether this is because you are unwilling to do something that might prove you wrong or whether you are simply incapable of doing it.)

if you open up the aperture of a lens doesn't it increase the light evenly across the frame?

if the light is brighter evenly across the frame wouldn't it also be brighter on the windows to the phase detect AF sensors?

If the light were brighter on these windows wouldn't it be easier for these sensors to detect contrast in lower light situations?

If you point two flash lights from different angles at the same spot on your wall, switching both on makes the spot brighter than switching on only one. If you now put a shield between one of the flash lights and the spot on wall but not between the other flashlight and the wall, it will not make any difference for the brightness of the spot on the wall whether the first flashlight is switched on or off.

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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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