sticky iris ..

[Ash]

Hi,

I am new to the world of MF lenses. I want to how does sticky iris effect the image quality? On AF lenses, oily blades results in overexposure but logically speaking it should not effect in MF lenses. Whats your opinion?

[ManualFocus-G]

Hi and welcome

As you will be setting the aperture on the lens itself, a sticky aperture simply means it will be slower moving from one stop to another e.g. f1.8 to f4. In real world terms it means you may have to wait a few seconds after changing the aperture before taking the shot.

However, if the blades are actually stuck, then you can't change the aperture at all without taking the lens apart and cleaning the blades. Usually when blades are stuck, they are stuck wide open meaning all your shots will have minimal depth of field.

[martinsmith99]

Welcome to the forum Ash.

Which lens is it that has a sticky iris? Some can be cleaned easily.

[Ash]

Thanks for the replies. I am getting a deal on super takumar 35/3.5 lens with oils on the blades which makes it slow but it is not stuck wide open.

I can get this lens or soligor 35/2.8 (nice condition), Yashinon 35/2.8 (stiff focus), Vivitar 35/2.5 (Tokina make).

I just need to choose one. Please enlighten me

[PaulC]

What is just sticky today may very well be stuck tomorrow, after the oil has dried up just a little bit more. I think it depends on the climate - in the desert where I am, a couple of not-stuck-at-all lenses became completely stuck within a couple of months.

The good news is that they can be cleaned. The bad news is that it involves a lot of skill or a handful of dollars. So price cleaning into any deal.

(Gorgeous avatar, BTW. Very nicely shot.)

[Ash]

Thanks Paul for your suggestion. It seems that best way to go right now is to buy a clean lens. I am a novice and thus dont want to involve into something complicated such as opening the lens and cleaning it.


--- Ash

(Avatar is from a photoshoot of my sister's anniversary flowers )