[Lowell Goudge]

Thanks, I'll give it a try when I get home. Do you just remove the three screws and lift off the collar? I made the mistake of taking some close up test shots before adjusting for infinity focus and really liked how they came out. Here's one of my "tool of destruction", wide open, of course.

Yes, remove the screws totally, and watch out for the little washers, they are what actually does the locking as they bdrige the gap between the focusing mechanism and collar.

You might wish to try a little nail polish to stick them to the focusing collar if they are not already stuck.

If you take them all out, the collar lifts off,

Attach the washers to the screws with nail polish and let dry before re-assembling, to make it easier. the little screws are hard enough to deal with without loose washers

[slick100d]

Ok, I pulled off the focus collar. There is just one pin on the body hidden under the ring with the depth of field gauge:



The bottom of the focusing collar is cut lower around 70% of the way around so the stops are when either of the ends hits the pin.



So, buy cutting away more I can extend the range. I'm thinking about leaving only a small section. I suppose you could remove it altogether, then you could go more than 360 degrees. I'm not sure that's a good idea though.

I hope to have time tomorrow to do some grinding.

[mjkwee]

I have a Vivitar Series 1 105mm f2.5 macro telephoto lens that I can't focus at infinity. Base on the serial number this is a Kiron lens. Has anyone have a similar problem and have they found a way to adjust it? Or do you know if this has a similar 3 screws? Attached are a photos of the lens. There is a single screw on the side. Does this open the top front cover w/ hood?

[Just1MoreDave]

I have this lens in Kiron version. It has been sitting around forever; I think I'm afraid to put it together and find out I screwed up. On this lens, I think what you need to do is unscrew the ring that says "1:1 Macro Telephoto". Beneath that are three screws that probably adjust infinity focus. Loosen them, focus a bit, retighten, something like that. I can't tell you exactly because my lens is still in pieces.

You might think that removing the single Phillips screw would allow you to remove that ring. It's a good theory. On the Kiron, it gets you nowhere. The ring is threaded on and thread-locker is used to glue it in place. I had to drill holes in the ring and use a strap wrench to get enough leverage to get it off. I hate having to drill holes but at least I was right in this case. It wasn't coming off any other way.

[mjkwee]

Just1MoreDave, Thanks for the input. I am not equipped with a strap wrench you suggested. It sounds far more involved than what I am capable of doing at this time. I suffered a stroke that left my right side paralyzed. I was hoping for a much straight forward procedure that I may attempt to do. Thanks a lot for giving me a feel and be able to assess the job required.

I wish you luck in putting your Kiron lens back. Michael

[Ratmagiclady]

To the original topic, here is another method for infinity focus adjustment. Two rings with square slots for a lens spanner surround the front element. Arrows mark the spanner slots. One ring is a locking ring, the other screws a carrier for the front element in or out. Sometimes lacquer locks the rings also. I've seen this on zooms only. Some examples are the Pentax-F 70-210 and its Takumar-F relatives, the Takumar-A 70-200/4 and its twins under Cosmicar and other brands, the Pentax-A 80-200mm, and the Pentax-F 100-300.

Hrm, this is interesting: I've got this Kiron 80-200 f4 for my old Canons that won't focus quite to infinity. (Someone had this one apart for cleaning, (not well, at that, it'd seem) and in the process seems to have mucked up that setting.

Interestingly, there's an outer bezel comprising the top end of the barrel, (perhaps not all that unlike the little primes depicted, I suppose we're about to find out, ) and it's quite possible it's all that simple. Let's see if there's enough light left to me here. )

Edit: An hour or so later, hrm. Ha. I have infinity focus. (I think the bigger part of the problem was just the whole front group not being seated fully, actually: most of the mechanism in there seems pretty non-negotiable, at least if you're in the right place to start with) but I had to have it apart, regardless, to try and clean those elements properly. *sigh.* Putting white gloves on the shopping list. Gonna have to go back in tomorrow after a rest. )

Oh, thanks for the motivation, guys.

[Just1MoreDave]

... but I had to have it apart, regardless, to try and clean those elements properly. *sigh.* Putting white gloves on the shopping list. Gonna have to go back in tomorrow after a rest. )

Oh, thanks for the motivation, guys.

It's pretty satisfying when it all works out.

I can add a new way that manufacturers adjust for infinity focus. I have a couple of Auto-Takumars that apparently use shims (thin metal washers) when they build the lens. As long as the shims are reinstalled, there is no adjustment required after reassembly.

[Lowell Goudge]

Just1MoreDave, Thanks for the input. I am not equipped with a strap wrench you suggested. It sounds far more involved than what I am capable of doing at this time. I suffered a stroke that left my right side paralyzed. I was hoping for a much straight forward procedure that I may attempt to do. Thanks a lot for giving me a feel and be able to assess the job required.

I wish you luck in putting your Kiron lens back. Michael

I think it is really lens dependant.

for my 2 wide angle kirons, the collar around the outer barrel is not held onl tightly. The one set screw locks it in place on the beauty ring. removing the one set screw the collar just threads off.

It may be Kist1MoreDave is thinking about removing the entire lens group at the front. That is very very tight and requires a strap wrench. But you don't need to remove the group to adjust infinity focus, only the outer collar.

The reason most threads get into removing the group is that is how you clean oil off the aperture blades, which is a common problem with the kirons. Oil leaks oout of the grease used in the focusing helix and gets into the aperture.

the screws we access to adjust the focusing helix are just used to attach the focusing ring to the helix and the connection is the thrust load of the screw on the washer.

[Just1MoreDave]

I think it is really lens dependant.

for my 2 wide angle kirons, the collar around the outer barrel is not held onl tightly. The one set screw locks it in place on the beauty ring. removing the one set screw the collar just threads off.

It may be Just1MoreDave is thinking about removing the entire lens group at the front. That is very very tight and requires a strap wrench. But you don't need to remove the group to adjust infinity focus, only the outer collar.

It's a macro, so it's different. You can see from this photo, the ring with the lens name on it isn't wide enough to touch that screw, and construction is completely different.



That ring covers up the three screws that are needed for infinity focus adjustment. Like I said, on my lens it was glued on with thread-locker, and did not come off until I forced it. Once you get it off, the adjustment is easy.

The reason most threads get into removing the group is that is how you clean oil off the aperture blades, which is a common problem with the kirons. Oil leaks out of the grease used in the focusing helix and gets into the aperture.

The 105/2.8 macro mostly comes apart from the back, and is one of those lenses where the aperture mechanism can be easily removed. On my lens, I believe the grease dried out too much and the lens became really difficult to focus. Eventually forcing the focusing ring hard caused the connection between ring and helix to shift, so the adjustment was wrong. But to avoid the issue in the future, I have to completely disassemble it, regrease both sets of threads, then reassemble.

[mjkwee]

Looking closely at my beauty ring, it has 3 screws about 1 mm in diameter (see picture for one screw). I wonder if the Vivitar cover is held by these three screws? The smallest screw driver I have is 1.5mm and it is so much wider than the hole and screw. I read that these screws are very delicate and I need the proper tool with the proper size head otherwise I can easily strip these screws and may no longer unscrew them. Any recommendationwhere I can get really small precision screw drivers?

Update May 6, 2010

I finally, got the proper screwdriver set and began to attempt removing the beauty ring (see picture below- there are 3 screws around). Underneath the beauty ring are the three screws to the focus ring. When I loosen these 3 screws that did not allow me to adjust the focus ring to infinity. However, loosening the screw on the side (see the second photo above) allowed me to adjust the focus ring to infinity (with infinity marking off). Tightening this screw back (won't go all the way in) prevents the focusing ring from moving. It appears that this screw stops the focus ring from going beyond a certain point. So I kept this screw loose so I can move the focus ring pass the infinity marking and focus at infinity (w/c I desire) but I do not know what the long term effect of the screw floating. Tested the lens this morning with good results. I hope this is helpful to others.