Iris blades not fully retracted

tao · Expire: 2015-03-12

Most lenses I have ever seen had iris blades retracted all the way at the largest aperture setting therefore only little or none at all of the blades can be seen. However my copy of Miranda 52/2.8 has blades that did not fully retracted, as you can see here.

At first I though I had a lemon. However the lens barrel looks new. There are some oil on the blades but this do not appear to interfere with the actuation (the lens is a preset by the way). The iris moves at a reasonable interval between each half stop setting. Therefore I assume that this behavior was by design.

I hope someone could either confirm this or disprove it so that I could have the lens fixed. There are not many info on Miranda, this lens in particular, on the 'net. This also make me wondering if there are any other lenses that leave the blades exposed like this. It is curious that the designer did not make the blade fully retracted so that the lens could be faster.

Anyhow, this aperture configuration results in interesting images. Most star makers produced star bokeh stopped down (e.g. Volna). This Miranda exhibits star-shape specular highlights wide open.

Mos6502 · Joined: 20 Jun 2011 Posts: 960 Location: Austin

If this is the macron lens, then that is how it is supposed to be so far as I know. Do you have a picture of the whole lens?

Attila · Expire: 2025-11-18

I met a few times with similar , I did never care much about that.I don't remember for lenses.

Lightshow · Joined: 04 Nov 2011 Posts: 3666 Location: Calgary

Some lenses you can adjust the iris, for example, my MC PF 85/1.7 has a disk that the iris leaves attach to and that is secured by tightening 3 set screws on the outside of the barrel(under the focus ring) you clock the disk to have the aperture match the aperture ring then lock it down.
It's possible it was your lens was put together incorrectly, has become loose, or was set that way at the factory (like the Super-Tak 55/2 has an f2 disk installed in a f1.8 lens).

tao · Expire: 2015-03-12

I have no idea what is the difference between Miranda Macron and Macro. This one says Macro. It has a double helicoid with magnification down to 1:1. Here's the lens.

Mos6502 · Joined: 20 Jun 2011 Posts: 960 Location: Austin

The Miranda macro lenses usually say "macron" on the front ring. Yours is the first version, so maybe it was made before they started using the "macron" name? The later versions are more common and are 3.5/55mm, the earlier version that you have is very hard to find which is probably why there is so little info about it out there.