More questiona about the a77 and a99

Started Apr 29, 2013 | Discussions thread
JerryCurtis Veteran Member • Posts: 9,017
Re: When is f/2.8 not f/2.8?

Amateur Sony Shooter wrote:

JerryCurtis wrote:

Amateur Sony Shooter wrote:

Even if they are all F2.8 lens, 70-200 at tele end will receive less light,

Please explain this statement, with references, if you would?

Hi Jerry, I think MediaArchivist explained well in his post. Basically if you try 70-200 at F2.8 for example (fixed ISO), at 70mm and 200mm end, you will see difference in shutter speed. That means you need to let more light in at 200mm end. Cheers!

I've never noticed this, because my 70-400G drops from f/4 to f/5.6 as it zooms, so I've always attributed the change in shutter speed to that.

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Sony V1, H5, A350 and A77... Still learning...
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 JerryCurtis's gear list:JerryCurtis's gear list
Sony Cyber-shot DSC-V1 Sony Cyber-shot DSC-H5 Sony Alpha DSLR-A350 Sony SLT-A77 Sigma 10-20mm F4-5.6 EX DC HSM +9 more
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