• Panasonic Cameras

  AF100 Zooming Image Gets Darker ? ?

  Posted by Henry Panniell on April 15, 2013 at 9:24 pm

  Took my AF100 on a test drive, using Nikon DX 18-55mm, f/3.5(off of my Nikon D5100) and as I zoomed in on my subjects the image got darker. Zoomed out it got lighter. Been looking at Barry Green’s DVD, maybe i have not gotten to this section yet . . . any suggestions as to what is going on.
  Thanks in advance

  God Bless – Henry

  Allan Klingler replied 12 years, 11 months ago 5 Members · 5 Replies
• 5 Replies

• 

  Erik Naso

  April 16, 2013 at 2:56 am

  As you zoom in your going to loose light. Even ENG lenses act like that.

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• 

  Noah Kadner

  April 16, 2013 at 6:24 am

  Also if it’s not a fixed focal length zoom it will change f-stop as you zoom through if you’re wide open. i.e. don’t be surprised…

  Noah

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• 

  Matthew Sonnenfeld

  April 16, 2013 at 2:47 pm

  That lens specifically is a f3.5-f5.6. I.E., as you zoon from 18mm to 55mm the aperture closes from an f3.5 at the wide end, to a f5.6 at the long end. This is roughly a stop and a half of light loss.

  While it is happening on your Nikon as well, you notice is more on your AF100 because sensors are more sensitive to varying stops than your eye is. As in, your eye has such great dynamic range that a stop and a half of light loss doesn’t really matter to it, but to a sensor with roughly 11 stops of dynamic range (being generous), a stop and a half is a BIG difference. That’s why you see it in the EVF and on the LCD of your AF100, but not through the optical pentaprism of your Nikon.

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• 

  Henry Panniell

  April 17, 2013 at 2:32 am

  Are you saying I have to stop asking for my money back ! ! ! – Seriouly . . . Thanks everyone for the replies and explanation. Sound correct to !

  Thanks – God Bless

  Henry
• 

  Allan Klingler

  June 12, 2013 at 9:46 pm

  I have observed the same phenomenon with my AG-AF100A, it can be an abrupt change in the darkness level. The same can happen with abrupt scenery pans.

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