When using this setup from inside to outside,
1. a sigma 10-20mm lens,
2. a 77mm B+W MRC UV filter normal thickness,
3. a 77mm to 82mm step up ring adapter,
4. a cokin 84mm square filter holder,
5. a singh ray 84mm square filter
i got this problem of the filter holder edge coming into the view from 10-13mm,
at 12mm, jpeg small, downsize 25%, saved in jpeg max quality 300DPI,
noticed the left and right wide-end edge
from what i read, there are 3 types of vignetting,
http://en.wikipedia.org/wiki/Vignetting
- Mechanical (or physical) vignetting
- Optical vignetting
- Pixel vignetting
and vignetting refers to a reduction in image brightness in the image periphery compared to the image center.
my confusion is - does vignetting only refers to a reduction in image brightness (i.e. uniform graduated darkening at the corners)? my picture above shows that at 10-13mm, the wide angle will capture undesirable objects in the peripheral field, which includes my filter holder, which is not a reduction in image brightness but a capturing of light and details, including the shape and form of my filter holder. so is that considered a physical vignetting or is it called by another term.
by taking off component by component, i realised that this below setup
1. a sigma 10-20mm lens,
2. a 77mm B+W MRC UV filter normal thickness,
3. a 77mm to 82mm step up filter
does not produce the above problem. but i wonder if i use a thinner UV filter, would it reduce the above problem to may 10-11mm of focal length instead? does the feature of the lens (i.e. the optical vignetting) plays a part in contributing to this kind of problem or are they totally separate issues?
also in another picture, i caught this.
also at 12mm, jpeg small, downsize 25%, saved in jpeg max quality 300DPI,
notice the wave at the top,
if i didn;t rem wrongly, the cokin filter has 3 slots from anterior to posterior for 3 filters at any one time, i put my filter in the farthest and most anterior slot, and i think it cast the filter holder shadow on the filter, causing this wave. i adjusted it to the nearest and most posterior slot, and that disappeared.
i would like to ask those who use other 84mm square filter holder, whether the above problems is a design defect in cokin filter or is it uniform throughout various 84mm square filter holder? can i solve the problem by upgrading on the filter holder?
1. a sigma 10-20mm lens,
2. a 77mm B+W MRC UV filter normal thickness,
3. a 77mm to 82mm step up ring adapter,
4. a cokin 84mm square filter holder,
5. a singh ray 84mm square filter
i got this problem of the filter holder edge coming into the view from 10-13mm,
at 12mm, jpeg small, downsize 25%, saved in jpeg max quality 300DPI,
noticed the left and right wide-end edge
from what i read, there are 3 types of vignetting,
http://en.wikipedia.org/wiki/Vignetting
- Mechanical (or physical) vignetting
- Optical vignetting
- Pixel vignetting
and vignetting refers to a reduction in image brightness in the image periphery compared to the image center.
my confusion is - does vignetting only refers to a reduction in image brightness (i.e. uniform graduated darkening at the corners)? my picture above shows that at 10-13mm, the wide angle will capture undesirable objects in the peripheral field, which includes my filter holder, which is not a reduction in image brightness but a capturing of light and details, including the shape and form of my filter holder. so is that considered a physical vignetting or is it called by another term.
by taking off component by component, i realised that this below setup
1. a sigma 10-20mm lens,
2. a 77mm B+W MRC UV filter normal thickness,
3. a 77mm to 82mm step up filter
does not produce the above problem. but i wonder if i use a thinner UV filter, would it reduce the above problem to may 10-11mm of focal length instead? does the feature of the lens (i.e. the optical vignetting) plays a part in contributing to this kind of problem or are they totally separate issues?
also in another picture, i caught this.
also at 12mm, jpeg small, downsize 25%, saved in jpeg max quality 300DPI,
notice the wave at the top,
if i didn;t rem wrongly, the cokin filter has 3 slots from anterior to posterior for 3 filters at any one time, i put my filter in the farthest and most anterior slot, and i think it cast the filter holder shadow on the filter, causing this wave. i adjusted it to the nearest and most posterior slot, and that disappeared.
i would like to ask those who use other 84mm square filter holder, whether the above problems is a design defect in cokin filter or is it uniform throughout various 84mm square filter holder? can i solve the problem by upgrading on the filter holder?