Vivitar 28mm focussing problem

Discussion in 'Classic Manual Cameras' started by steve_fay, Mar 3, 2016.

  1. I have a question about a problem with this lens:
    Auto Vivitar Wide-Angle 28mm 1:2.5 No. 22211258
    F-stop range: 2.5-16
    Filter thread: 62mm
    Fixed mount: Konica AR (including "EE" electronic exposure setting on aperture ring)
    Body length (when set at infinity): Approx. 2 9/16 inches

    I recently acquired this lens and was delighted to find it arriving in near-pristine condition, with clean, clear, excellent-looking glass; like-new feel to changing between aperture click stops, very SMOOTH feel to operating the focus ring, and perfectly responsive aperture change when moving the tab on the mount. Except for a couple of light scuffs on the focus ring's grip ridges, the lens could be described as "near mint."
    There is just one perplexing problem that I didn't notice until mounting it on my Konica Autoreflex T -- when I focus on things, the distances they are away from the lens are closer than the lens's distance scale says they should be. At the closest focus end of the range, it might not seem off so very much, but when I focus on something 10-to-12 feet away I find that I am bumping up against the infinity end of the scale ! ! ! The scale says that infinity focus is supposed to be somewhere beyond 30 feet. Due to weather the last couple of days, I didn't take it outside to find out just how out-of-focus things beyond 12 feet away might be.

    Has anyone else had this problem with this (or a similar) lens? I can imagine a problem like this in a lens that looks beat to heck and made grating or rattling sounds like the focus ring had been horsed around or pounded on with a pipe wrench, but how can such a good looking and smooth operating lens have such a problem? Anybody have a clue about how to fix it?

    I have found some decade old and older threads here talking about similar Vivitar f2.5 28mm lenses, but some of them are about a t-mount version, some are about a version with a 2.5-22 f-stop range, and some are about one that takes a 67mm filter. Some say they are made by Kiron, some say Kino.


    *Incidentally, I would have liked to have posted this in the Lenses category of the Equipment section of the forum, but I couldn't find such a category. Still, this Vivitar or its close cousins might be part of many members classic film camera kits either in a fixed mount or t-mount versions), and people with some experience and knowledge about it are who I want to address my question to.
     
  2. As it happens, I have the Minolta edition of this lens, and the focusing scale is the same. The serial number is 224....... (Kino Precision, whose own brand name was Kiron) and it is similar in every way except for being Minolta mount, and going to an aperture of F22. It's nicely made, with a big 62 mm. front end, typical Vivitar of the era, heavy and metallic and smooth as silk. When I focus on something about 15 feet away, the focus ring says 30, and that's near to infinity. When I go out and aim it at a faraway object, the focusing microprisms suggest it's not all the way there.
    I don't think I've ever actually used it, though. My recollection is that some years ago I was making a KEH order, and was under the amount needed for free shipping. The added lens was essentially free by saving me the shipping, which was probably in the range of 11 bucks! My guess is that at that angle and that aperture, perhaps it does not agree with the focusing screen.
    Not long after that, it seems a 28/2.8 Rokkor D lens fell into my lap, and that one has an accurate focus scale, as well as feeling right at home on my X700. On reflection, I'm not sure I've ever actually taken a picture with that one either, but I might have. It's been a while. I'm not crazy about 28 as a focal length on film, and rarely changed from the 50 and 55 normals, which on a Minolta are somewhere between superb and fantastic anyway.
    I think the best solution will be to try it and see if it shoots as well as it looks. A 28 is pretty forgiving.
     
  3. Matthew, thanks for your reply. It's interesting that other seemingly undamaged Vivitar 28mms might have exactly the same problem, suggesting a manufacturing problem--an error calibrating where the focusing scale was fastened into place? ... even an incorrect labeling of the scale? or something else?
    Are you suggesting that the focus on the viewfinder screen and film plane might be different enough to make this problem appear worse than it is? I'm used to thinking that viewfinder focus with an SLR IS accurate for focusing on the film plane, and wouldn't that be a defect of the camera body if it is not?
    I have owned a 28mm m42 prime (not a Vivitar) in the past, and currently own a Tamron 28-70 zoom, and have not noticed a similar problem related to this particular focal length.
    I can see how stopping the lens down might easily bring infinity into focus, and also it is not entirely bad if the camera has a bit closer focus than advertised, but if there is a way to reset the focus ring so that it reads as intended I would try to do that.
    I will try it out on a few of the pictures on a roll of film soon. The problem might not seem to be an issue with some kinds of shots.

    Others, please comment as well if you have observed and otherwise dealt with this problem.
     
  4. That does seem strange. I have a Vivitar 24mm lens, but don't remember any focus distance problems. I am pretty sure on the infinity mark it is pretty close.
    Do note that the distance is supposed to be from the film (or sensor) plane, normally marked on the top of the camera as a circle with a line through it. The distance is to the line.
    With rangefinder cameras, I would sometimes use the scale on the lens. With SLRs, it is more usual to focus with the viewing screen. If the camera works right, the view screen should agree with the film/sensor in focus.
    The real test is that infinity is close to right. It is hard to say between 15 and 30.
    Reminds me of a video camera I was using some time ago. I wasn't pointing at anything, and noticed a strange image on the view screen. It was at the widest zoom point, and the AF had focussed on dust on the skylight filter, or at least pretty close to it.
    The main use for the focus scale for SLR lenses is to set an appropriate hyperfocal distance, so you can have an appropriate depth of field and not have to think about focus again. If you want nearby subjects and background both in focus, that is hard to do with AF. Turn the focus ring so it is half way between the foreground focus and background in angular rotation. Sometimes it is easier to do by numbers, but most often it is easier by feel.
     
  5. I also have the same lens in MD mount. I've just checked, and mine is behaving just as it should.
    If I understand what you are saying, is seems that you are focusing on something 10-12 feet away and the distance scale is showing something close to infinity. I just checked with my copy on an XD-11 with a split image rangefinder and I will say that with the lens set to infinity, things that I estimate to be 10-12 feet away appeared very nearly in focus, so things may not be as far off as you might think. As Matthew stated, it may not even cause an issue die to the wide depth of field at 28mm.
    To accurately judge whether a lens is focusing properly, you should check focus at the film plane, as the viewfinder itself may be slightly off. SLR viewfinders can be off a bit, and even a slight variation can have a noticeable effect. With the camera on a tripod, open the back and stretch a piece of frosted tape across the film gate. Set the shutter to bulb or the longest time possible and the lens to wide open. Open the back and use a magnifier to check if the image is in focus when you open the shutter. I use a reversed 50mm lens as a magnifier. Check both infinity and closer distances that you have accurately measured (remember to measure from the film plane).
     
  6. Glen, I can think of one other use for using the lens distance scale, besides figuring hyperfocal range, and that would be to calculate what aperture to use for the distance, when using a manual electronic flash. I will admit that I often make an eyeball guesstimate of the distance, but I am also used to checking that by using the distance scale on the lens, because sometime my guess is wrong.

    Cory, I was just starting to wonder whether I should check the focus on the film plane by using some sort of translucent sheet, like the tape you suggested.
    All responders and readers, there is about 3/8" of distance on the focus scale between the 10-foot mark and the infinity mark, with the 30 mark about 1/4" along the way. Maybe that doesn't actually amount to very much internal movement of the elements involved in focusing.
     
  7. SCL

    SCL

    Steve - Try Cory's suggestion to validate that what you see in the viewfinder as focused is indeed focused at the film plane. If it matches (and does so with other lenses on your camera body), the fact that the scale is off is basically irrelevant for most shots unless you insist on zone focusing using the scale or are using flash. If it doesn't match, then there is a possibility that at some point somebody opened the lens and either didn't reattach at the right point in the helicals....easy for a technician to fix...and then recollimate the lens...which should solve all the issues, or a shim may be missing.
     
  8. Just a wild guess:
    I purchased a very nice used Nikkor MF 50/1.8 which had the same problem. It would not focus to infinity; it hit a "stop" at around 4 meters on the distance scale. I found it was easily possible to fix this problem by moving the position of the "infinity stop".
    I have no idea if the innards of this lens are at all comparable to your Vivitar, but I would be happy to send you an illustrated instruction of how I repaired the Nikkor. Let me know.
     
  9. If you can focus over a reasonable range of distances in the viewfinder, the images will also be sharp on the film (unless the camera has a problem). It could well be that the focusing collar is held on with a few small set-screws (maybe under the rubber focusing grip) that got loose and allowed it to rotate.
    If it isn't focused at infinity when the find shows it in-focus on a distant object (say the moon), then the issue could be the infinity stop or some other collimation method. These are done in different ways on different lenses. Sometimes by rotating the focusing collar with relation to the helical, held by some sort of lock-screw. Sometimes by a selected shim between the optical block and the focusing helical.
     
  10. I did put a piece of frosty tape across the film mask opening, and checked to see whether I had infinity focus there. It was as bit nasty outside so I just stood at window. Unfortunately, with the overcast sky, the results didn't seem conclusive. It was a bit hard to find something bright out beyond 30 feet, or a sharp contrasty line to look at -- dark gray branches don't make sharp silhouettes against light gray skies! The power line pole made a bit better subjects, although even they looked tiny at that distance, so I used a 10x magnifier to look at their image on the tape. They may have been close to sharp. Panning around, looking at the images on the frosty tape without the magnifier, most of what was between 8 feet to infinity looked pretty sharp.
    Looking again through the viewfinder and focusing on the screen above the mirror, the real frustration came when I tried to focus on a clump of grass about 12-13 feet from my vantage inside the window. Before I could get the blades of grass as sharp as I thought they ought to be I was up against the infinity stop. Still, the edges of a nearby outbuilding, about 25 feet away, seemed reasonably sharp through the viewfinder at the same setting. It could be that stopped down one or two stops, anything from about 7 feet to infinity is going to look pretty sharp...depending on the enlargement size, perhaps.
    It could be as Mike and John are suggesting that the infinity stop slipped, or that something else is in the wrong relationship with it. I think, I will need to take some pictures with the lens, and see how the problem affects images it can make in practice. Perhaps, meanwhile someone who knows more about the construction this lens might happen by this thread with suggestions. I can see, some tiny set screws that might help with the problem, but I would hesitate to just start loosening things to see what happens. Long ago, I took apart a very cheap lens that I knew I would never use again. At one point tiny ball bearing, appearing out of nowhere, went careening across the table top! I don't know if I found them all. Good thing I wasn't planning on putting that lens back together.
     
  11. Can you get focus at infinity? If you can and you don't rely on zone or hyperfocal, I wouldn't worry about it.

    Do other lenses behave normally on that camera?
     
  12. Andy, it's sunny today so I've tried again, checking with frosty tape across the film plane. Beyond 30ft to infinity does look pretty sharp, though the graininess of the tape frostiness interferes with telling it it is dead sharp or just close. No, I haven't noticed anything like this with other lenses that work on that camera body. That trying to focus on things not far beyond 10 feet hits the stop, when the scale on the lens says that can't happen until you are focusing on things beyond 30 feet, can't help but raise questions and be kind of frustrating if that mid-distance object doesn't look perfectly sharp in the viewfinder. If the hyperfocal scale is correct, just stopping down to f8 would throw everything from 5ft to infinity into focus, so in practice seeing perfect focus in the viewfinder might not cause much of an issue on the film, unless the lens is wide open and something intended to be in focus isn't.

    Everyone, I thought I should post some pics of the lens, since there may have been at least 3 Vivitar 28mm/f2.5 variations back within not so many years of this one and it might matter which one this one is, and since seeing what set screws or access points are present might affect a posters' suggestions.
    Picture one -- this shows the ONE set screw in the focusing ring. Since the textured grip is made of deep, sharp metal grooves and not a rubber or leatherette sleeve, there is nothing to pull up to look for more set screws in the focusing ring. Also, right below the Made in Japan, is one of the three screws that hold the hyperfocal scale ring in place. The narrow textured ring is the aperture adjuster, and it has no screws that can be seen on the outside.
    [​IMG]

    Picture two -- this shows the screws at the mount end of the lens.
    [​IMG]
    Picture three -- How the blazes did I get so much dust on the front element!!!!?!!! I'm usually way more fastidious. I guess, because I really wasn't taking pictures, just fiddling with the lens on an empty body. Strong window light to one side really lit up the dust, and the lighter scuffs in pict two that really are not apparent when handling the lens.
    [​IMG]
     
  13. The forum interface won't let me edit my previous post to get the images to either appear or show as clickable links. I don't know why. Even though somebody can copy the direct link address from between the IMG tags and paste them in an address line to get to the images, I thought I would try to get them to display in this post...in the same order as they are introduced above:
    [​IMG]
    [​IMG]
    [​IMG]
    That seemed to work...
     
  14. I was given a Nikon mount Vivitar 28mm f2.8 lens which I have never used. The front lens surround says " Vivitar 28MM MC CLOSE FOCUS WIDE ANGLE NO. 28302954 dia 49MM. After reading the above comments, I tried focusing this lens mounted on a Nikon FM. Infinity appears to occur at about 27 feet from the subject, being the edge of a door, so as to get a clear distinction in the split image viewfinder. Viewing a truck parked across the road (about 100 feet away) appears blurry and out of focus. I don't think I will be using this lens based on what I have just found out.
     
  15. The images above look just like the Minolta one I have. Alas, if I had a digital camera on which this couls be used, or I'd just go ahead and test it and have an answer, but I can do that only with Nikon mount lenses. Oh poor poor me.
     
  16. John, if mine had focus ring travel out to 27 feet, I probably would have never suspected a problem. If I knew I had the problem your lens has, I might not worry about it so much unless I wanted to shoot the lens wide open.
    Matthew, I can't afford the adapter that would let this Konica AR mount lens fit on my Pentax K110D dslr, so I can do any quick image tests either. Ha, ha!
     
  17. Okay, so I'm thinking that I might try loosening the set screw on the focus ring, and then move it slightly one way or the other, and tighten it back down. Then I would check to see if that changed anything.

    If that does seem to make progress toward lessening the problem, then I would try the same thing again. But if it doesn't, then I will put the ring back were it was, and instead try moving the front part of the lens body under the ring...if there is a way to do that.
    But before I try either of those things, I would be be very happy to listen to any suggestions about alternative approaches or considerations.
     
  18. Steve, If the lens I have achieves "infinity" focus at 27 feet at f2.8, then I believe I would need to stop the lens down to at least f8 in order to cover infinity at "infinity". The viewfinder (at f2.8) then appears very fuzzy making composition difficult. Depth of Field stop-down to f8 only darkens the viewfinder, again making composition difficult.
     
  19. I seem to have made some progress. I have adjustable focus for things well beyond 12 or 13 feet away (I didn't have that before). Things at infinity aren't perfectly sharp, however -- a pole about 200 feet away is slightly askew at the split image line in my Konica Autoreflex TC's viewfinder. Keep in mind that the lens's focus scale has very little space between the 30-foot mark and the infinity mark. Things 40-80 feet out, look pretty sharp. I've tried several things to try to improve the infinity focus, but I don't really know what I'm doing and don't want to break something. The closer-up marks on the focus ring are reading far more accurately than before.
    I'll include the lens in some shots on a roll of Kodak 100Tmax I have now in the TC.. We'll see how the scans of the negs turn out. There will be some delay before I can report back with those.
     
  20. Steve,
    The basic nature of your problem seems rather straightforward to me. Unfortunately I do not have the specific solution for your lens.
    The first thing to keep in mind is that the ring inscribed with the distance scale (lens focus scale) is physically separate from the focusing adjustment (helicoid). The focus scale ring incorporates the so called "infinity stop" and, when the proper fixing screws are loosened, it can be moved independently from the focusing adjustment.
    What needs to be done is to free the focus scale ring and change its position so that the infinity stop no longer prevents (blocks) rotation of the focus adjustment from achieving sharp focus on objects at infinity. Pole at about 100 feet is a perfect test and should line up perfectly in the split image finder. Once that is accomplished, and being very careful not to alter the focus adjustment, you can re-position the focus scale ring so that the infinity mark is lined up with the index and then fix it in position.
    Good luck.
    PS: Looking at your earlier post with photos:
    Also, right below the Made in Japan, is one of the three screws that hold the hyperfocal scale ring in place.​
    My guess is that these three screws can be loosened (not removed) to allow the scale ring to rotate freely.
     
  21. Mike, I tired your suggestion. Originally, I didn't try this, because the top of that ring, having the aperture selection mark and the focus selection mark, as well as the hyperfocal range and infrared focus marks, is supposed to be oriented with the main focus and aperture selection marks centered at the top. But if I only had to turn that ring an eighth or sixteenth of an inch, in order to get the infinity focus zeroed in, that wouldn't be such a terrible aesthetic sacrifice.
    So, I loosened the three screws, putting some tape over the heads so that they couldn't fall out. This allowed me turn that ring freely in either direction. Unfortunately, adjusting this ring didn't allow turning the focus ring any closer to infinity. The infinity focus stop must not be attached to or in any other way affected by that ring. Great suggestion, though. At least I ruled that out.
     
  22. Steve
    My guess now is that the infinity stop must be buried somewhere beneath the focus scale ring and some further disassembly is needed to get at. Sorry I can't help with that.
     
  23. If the hyperfocal scale is right, stopping down to f8 will bring everything from 5 feet to infinity into focus. when focused on some point about halfway between them on the focus scale. I would guess that f5.6 would bring infinity into focus if I was focused nearly on it. So if I am really trying to have infinity in focus it shouldn't be very hard. It might actually be harder to throw infinity out of focus, though focusing on something very near in the foreground with the lens wide open at f2.5 that might be reasonably possible. It is much better than it was. In fact if it was this close to correct, I might not have noticed a problem for some time.

    I have an old Vivitar zoom I might try to take apart sometime,---if I ever egt around to it--- to clean out the fungus. The design is entirely different, but if that task went very, very well, it might give me the courage to work on this one again, performing deeper surgery.
     

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