When I set the aperture and shutter speed on my a6000 in manual mode the aperture always changes when I take the photo. I am using a sony 24-240mm lens f/3.5-6.3. It does the same in aperture mode.

Any suggestions.

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    \$\begingroup\$ What focal length are you set at? You might be too far zoomed out to be allowed to shoot at f4.0. what aperture are you getting? \$\endgroup\$
    – thebtm
    Commented Feb 6, 2017 at 16:23
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    \$\begingroup\$ To expand on @thebtm comment, note that for a zoom lens, the low f-number refers to the widest aperture when zoomed out, and the high f-number to the widest aperture when zoomed in. So at e.g. 240mm your lens has a widest aperture of f6.3 ( and f4 is not possible ). \$\endgroup\$ Commented Feb 6, 2017 at 16:27
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    \$\begingroup\$ The usual cause is that you have previously selected Bracketing mode, but have not turned it off. \$\endgroup\$
    – WayneF
    Commented Feb 6, 2017 at 17:21
  • \$\begingroup\$ I think it is the focal length that is the issue. I need to use a faster lens but I don't have the funds for a faster lens. \$\endgroup\$ Commented Feb 6, 2017 at 19:19
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    \$\begingroup\$ The question should be edited to add the missing information, e.g., "the aperture changes when I change the focal length". \$\endgroup\$
    – user29608
    Commented Feb 7, 2017 at 8:36

1 Answer 1


Your Sony 24-240mm f/3.5-6.3 lens is not capable of opening up to f/4 through out its entire focal length range. By the time you zoom all the way to 240mm, the widest possible aperture is f/6.3. Your camera senses that and compensates accordingly.

For more about variable aperture vs. constant aperture zoom lenses, please see:
How do zoom lenses restrict their widest aperture at the telephoto end?
Why does my aperture setting change as I zoom on my DSLR kit lens?
Why do zoom lenses and compact cameras have varied maximum aperture across the zoom range?


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