Voigtlander 58mm Nocton f/1.4

[kenneth_smith7]

<p>I have a used version, and it's astounding in all ways, but I was just curious about the non-symmetrical iris. Or is this just mine? I've never even seen such an oddly shaped iris. Everything seems to be working just fine. I don't even have to make any exposure compensations, as I was informed a 2/3 overexposure was common with this lens. Mine exposes the same as any lens. But what's up with this mis-shaped iris?</p>

[andylynn]

I've owned two of these. Neither had an asymmetrical iris. But I ended up selling them because both times the images I

was getting weren't quite what I wanted.

[rodeo_joe1]

<p>Any pictures of this misshapen iris Ken? Does the hole look pear-shaped?<br>

It sounds like one of the blades has stuck or popped out of its pivot. If so it needs fixing before the misplaced blade damages the other ones or falls onto the glassware.</p>

[kenneth_smith7]

<p>Sorry no pictures. My eyes are screaming this morning, too stressed for macro work. The iris works fine, and smoothly, so I don't know if there's any cause for alarm. I would say one blade just seems higher up that the others. Wondering what Andy didn't like about the images. So far I'm bowled over with the superb sharpness combined with a very full bodied rendering.</p>

[kenneth_smith7]

<p>Here's a picture.</p>

[kenneth_smith7]

<p>Sorry, trouble uploading. Try this. Looks oddball to me.</p><div></div>

[roland_vink]

<p>A lot of lenses have a slightly asymmetric opening as shown here, especially at the smallest aperture which is where variations in the aperture blades are most apparent. Open up one or two stops and the problem usually goes away.</p>

[clive_murray_white]

<p>I've just checked mine and its just like yours, which may mean that it's normal for this lens, though a sample of 2 isn't enough to make that claim - and I'm very happy with mine too, <em>I'm bowled over with the superb sharpness combined with a very full bodied rendering</em> - I agree, that's a very good description of this little beauty.<br>

<br>

Maybe there's a lesson to be learned here - I think we are just assuming that symmetry is necessary.</p>

[kenneth_smith7]

<p>It's a peculiar shape even opened up. I've never seen anything like it. It takes on a slightly different shape, all asymmetric, at each aperture. Wonderful lens, I just wanted to make sure things were OK, given that I bought it used and was surprised to see this shape. Thanks for the responses all.</p>

[clive_murray_white]

<p>Mine also - so nothing to worry about, I bought mine new.</p>

[ChrisSpeaker]

<p>Mine appears (bought new) to look just like yours. Question. Does the "non-symmetrical iris" follow around as you spin the lens in your hand? I think what your seeing is just a optical illusion when looking though the back lens at a angle. HTH.</p>

[kenneth_smith7]

<p>Chris, Well I'm pretty sure it's not an optical illusion, ( unless everything is ) I've looked it over pretty closely under bright lights. There's one blade that seems to remain flatter because it is advanced into the circle more. When opening up, the circle does not merely expand, it actually gets a bit oblong and tilts to one side. Open a little more and it achieves a more normal looking circle.<br>

Thanks Clive, I'm done worrying it.</p>

[al_derickson]

<p>I just checked mine and it is also oblong and it is not an optical illusion.</p>

<p>Al</p>