Uneven aperture blades?

[Snoweagle]

Depends on the lens too. Most of my lenses maintain a circular shape till about f/5.6, but after that the aperture blades remain in a fairly symmetrical shape

That's what i meant when i said at smaller apertures, it will not be in such a perfect shape.

 

[Snoweagle]

Snoweagle, do you have any additional info that backs up your statement?

The lenses speak for itself.

 

[H4lcyon]

I have seen more than 20 of this lens.
Most of them got uneven aperture blades

There's no problem with your lens

Thanks fatigue and the rest of you for clarifying. I don't have that many lenses (yet ;p) so no experience before hehe

 

[calebk]

That's what i meant when i said at smaller apertures, it will not be in such a perfect shape.

Actually, what Rashkae meant is that even past f/5.6, the shape is still regular, just not circular.

 

[zzyzx]

Actually, what Rashkae meant is that even past f/5.6, the shape is still regular, just not circular.

yeah i think so too. it should be regular but not circular since there is only that few blades.

if this is so, then the TS's lens is got problem or not? as i notice the blade at 7 O'clock position didn't close as much as the rest of the blades...

 

[Snoweagle]

Actually, what Rashkae meant is that even past f/5.6, the shape is still regular, just not circular.

That's what i meant by saying perfect shape but at smaller apertures e.g. f/8 and smaller, it's not that regular.

 

[Zeisser]

Basically it's the construction of the lens whereby the blades overlapped each other to
form the aperture and the irregular opening is normal.

 

[Spectrum]

Most 35mm format lenses aperture blade more or less inherent such problem. But yet, I hardly encounter such problem happen in those 120mm format lenses aperture blade.;p
Maybe I'm wrong too.

 

[fatigue]

Problem with the construction? Or design issue?

I believe it's more on making the lens affordable rather than design problem.
Having a regular aperture shape means tighter parts specs, perhaps additional QC/QA process which only translates to additional cost.
These lens makers can produce perfect aperture shapes if they want to, but it will be costly.

Thanks fatigue and the rest of you for clarifying. I don't have that many lenses (yet ;p) so no experience before hehe

I don't have much lenses as well. My hobby/part-time gives me the opportunity to try and test several lenses.