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05-29-2016, 12:53 PM   #1
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Lens label

Being new to photography I'm sure theirs an obvious answer to this question: Why does the #2 zoom lens (Q7 5-15mm) label indicate a F/2.8 - 4.5... when in testing this in M mode I can only get as wide as F/3.5?Does it actually open up more in bulb mode or longer exposures?
Thanx in advance

05-29-2016, 12:58 PM   #2
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At what focal length? The maximum aperture varies with focal length on this zoom.
05-29-2016, 01:38 PM   #3
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QuoteOriginally posted by timedriver Quote
Being new to photography I'm sure theirs an obvious answer to this question: Why does the #2 zoom lens (Q7 5-15mm) label indicate a F/2.8 - 4.5... when in testing this in M mode I can only get as wide as F/3.5?Does it actually open up more in bulb mode or longer exposures?
Thanx in advance
At 5mm the widest aperture is F2.8, and as you zoom, the widest selectable aperture will narrow until reaching F4.5 at 15mm.

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05-29-2016, 01:43 PM   #4
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On zooms such as the 5-15 the maximum aperture varies as you zoom. So @ 5mm you get f/2.8 but at 15mm you get f/4.5. Some zooms are constant aperture and would be listed like this: 60-250 f/4. But if you see a range for the aperture that means it is a variable aperture lens and the max will change with focal length.

05-29-2016, 02:39 PM   #5
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QuoteOriginally posted by jatrax Quote
On zooms such as the 5-15 the maximum aperture varies as you zoom. So @ 5mm you get f/2.8 but at 15mm you get f/4.5. Some zooms are constant aperture and would be listed like this: 60-250 f/4. But if you see a range for the aperture that means it is a variable aperture lens and the max will change with focal length.

Thanx so much...it all makes sense now. Yeah I guess I was thrown off by seeing the #6 lens having a constant f/2.8 thru out the whole focal length.
05-31-2016, 11:29 PM - 1 Like   #6
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QuoteOriginally posted by timedriver Quote
Thanx so much...it all makes sense now. Yeah I guess I was thrown off by seeing the #6 lens having a constant f/2.8 thru out the whole focal length.
The speed, low distortion and compression make the 06 my favorite portrait lens. Great bokeh, great subject isolation and great shots.
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