Indeed, the "normal" point of a wide lens is usually *not* to use it wide open; bokeh from fast normal and short telephoto lenses is usually much better. McGregNi's posting is on target; the reason to get a fast wide lens is so you can use it at a larger aperture and still get sharp photos, at a higher shutter speed and lower iso. So, instead of f8, perhaps f4 will be very good. There are very few lenses that are sharp wide open; even the ridiculously priced Otus is softer wide open.

Thanks. I have done so, as I indicated in my first posting. "I've looked at the other disassembly instructions on the net for this lens, but there doesn't seem to be a pictorial (or even text) for the preset version of the lens." As far as I can tell, the preset version is not one that is available.

Thanks. I've already repaired a Sigma 24/2.8, a Takumar 50/1.4, a Macro-Takumar 50/4 and a Sigma 28/2.8. So, I have some tools, and some expertise. But it's always useful to find out what I'm in for before tackling an unfamiliar lens. Hopefully, someone out there has already repaired this lens, and can let me know the likely cause of the wobble. Once I understand what it could be, I can then make the determination whether or not I will attempt a fix.

Hi folks,

I have a Takumar 135/3.5 Preset (M42, all black), and it has developed a slight play in the mount section (tube) that telescopes under the focusing barrel. I have removed the back retaining ring, and see two more concentric retaining rings around the back lenses, but they seem tight. The helicoid guides' screws, on either side of the interior barrel, are tight, and the guides slide smoothly, with no wobble. There is enough play that, when mounted, I can, very slightly, move the lens up and down. I've looked at the other disassembly instructions on the net for this lens, but there doesn't seem to be a pictorial (or even text) for the preset version of the lens. It has a 6 digit serial number starting with 799, if that helps for the vintage. The lens works pretty well, even with the slight wobble, but I work in macro with extension tubes, and even a slight bit of wobble is difficult to handle. I haven't attempted to go in through the front, but I'd rather not unless someone can tell me that the back mount tube can be (or must be) tightened from the front. Has anyone done maintenance on this lens enough to know how to tighten the back mount and tube? Thanks for any advice.

Andrew