Sigma Lens Aperture Problem. See link above for more technical details. hw and sw sources. It must have been a purely mechanical issue. since theres no electronic control of the lens aperture. and.
Sigma 1750mm f/2.8 EX DC OS HSM FLD Large Aperture walmart.com
I agree. but it may be a software issue between the 7d and the sigma lens. All other apertures will display an error message. All auto focus camera lenses are wide open until you actually take the photo.
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It must have been a purely mechanical issue. since theres no electronic control of the lens aperture. and. The problem is basically gone from f/4 onwards.
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I wanted to increase sharpness and while in aperture priority. stepped the lens down to f8.0 (for increased sharpness on that sigma lens). If you can see the hexagon type shape of the aperture blades. it means they are not working properly.
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The lens itself doesnt seem to have any obvious mechanical issues like sticky blades. All other apertures will display an error message.
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In comparison tests with comparable lenses. sigma arts tend to come out with the sharpest details. 62mm. and is moderately less expensive.
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Secondly. the art series lenses act like native lenses on the camera body you mount them to. Firstly. the sharpness is really something to drool over.
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Got exact same problem with same lens! With the sigma. i shot approximately 50 photos.
With The Sigma. I Shot Approximately 50 Photos.
That said. the sigma rapidly turned my sharpness test into a nightmare when i realised that the focus point was shifting when changing aperture. Result is that your old 3rd party lens is unable to set aperture so gets error 01 because camera cannot set aperture in lens. The sigma lens produces some vignetting at max.
The Solution To The Aperture Problem Is To Put The Aperture Blades In The Adapter. However This Isnt Ideal For Many Reasons.
I suspect its more like something to do with the electrical connections. but cleaning all the points provided no solution either. Aperture (1ev) but this is still comparatively moderate within the full format test scope. Aperture and the sigma follows this tradition.
Sigma Has Issued A Notice To Customers Concerning Potential Problems With Aperture Operation Of Sigma Lenses On The Sony A33 And A55 Cameras.
Obvious is that f/2 is considerably wider than f/3.5. but for those needing. Lets stay in the sigma i series for the next comparison. looking next at the sigma 24mm f/3.5 dg dn contemporary lens. All other apertures will display an error message.
In Comparison Tests With Comparable Lenses. Sigma Arts Tend To Come Out With The Sharpest Details.
See the full details in sigma’s statement below. Mtf (resolution) macro lenses tend to be stellar performer thanks to a usually very conservative max. I have noticed i am no longer able to access full open f2.8 anymore.
Then That Would Make Some Sense As There Is Some Behavior Pattern You Discovered.
With most modern lenses. the aperture is controlled electronically and the diaphragm may change slightly between shots. even if you are on full manual mode or a fixed aperture. I cant confirm this. but i believe that the 14mm. There is oil on the blades of the sigma. so it is intermittent.