Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
10-29-2009, 11:32 PM   #1
Junior Member




Join Date: Jan 2009
Location: Utah
Posts: 36
Vivitar 28mm F2 aperture blades

Hey guys/gals,

I just got this lens off ebay and it looks and feels awesome for the price i paid. Or, at least I think

Only problem seems to be that the aperture blades will not move when turning the aperture ring, only when you physically press on the lever do they move. The blades look clean and snappy, I think something isn't connected or something. Is there a way to repair this by removing the mount and looking for anything in particular? Any help such as a website or personal experience would be much appreciated.

I haven't put it on the camera yet but I'm pretty sure the blades should move in or out when turning the aperture ring, at least my other manual lenses do.

The lens is a Vivitar 28mm F2 s/n 22**** and is a auto-wide? Not sure exactly what that means because it sure looks like every other manual lens I've seen.

Thanks for looking and any suggestion left
Steve

10-30-2009, 12:18 AM   #2
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,195
I don't know how much you know about M42 lens so please forgive me if I state the obvious....

I assume the lens in question is similar to this lens (it was my lens sold recently).

Please try this:

1. At the rear (near the camera when mounted) of the lens, there is a switch that toggles to show either M or A. Move the switch so that the M is shown (see photo #2 of the eBay listing).

2. Turn the aperture ring. Observe the aperture blades. Do they close/open according to the setting of the aperture ring? If they don't, the lens has a problem.

3. Change the switch setting so that the A is shown.

4. Turn the aperture ring. Observe the aperture blades. Do they close/open according to the setting of the aperture ring? (they should remain fully open).

5. Set the aperture ring to 16, push the little pin at the rear of the lens in. Do you see the aperture blades close down from fully open? (they should).

6. Repeat #5 with different settings of the aperture ring (11, 8, ...).

And report back.

Fortunately, this lens is pretty simple to fix.
10-30-2009, 04:36 AM   #3
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,345
it might be something in the aperture (dried out oil).

I just picked up my mother's old Nikon F2 and the vivitar 24mm F2 lens with it is stuck wide open.

Took the lens mount off, and found that the aperture is really sticky, you can close it but it is so stiff the spring there can't do it. can't easily see how to get the rear element out to gain access to the blades, but I suspect the oil has gone a littly gummy
10-30-2009, 05:22 AM   #4
Inactive Account




Join Date: Nov 2008
Location: USA
Posts: 924
Could be he has the K mount version.

10-30-2009, 07:47 AM   #5
Junior Member




Join Date: Jan 2009
Location: Utah
Posts: 36
Original Poster
Thank you for the suggestions, help and your time, I should've mentioned it is a K-mount sorry.

Please don't stop with your suggestions.
10-30-2009, 11:48 AM   #6
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,195
The lens mentioned in my post above is M42 mount, but I used to own (and repair) the Vivitar K-mount 28mm F/2 and the K-mount 24mm F/2. They are of the same construction as the M42 counterparts (but the lenses bearing "Kiron" mark have totally different construction).

Try this:

Grab the front part of the lens with one hand and the rear part of the lens with another, twist them apart like you are opening a jar. The lens should separate into two parts. The aperture blades are on the rear part, fully exposed.






Removing the rear optical part of the lens is not difficult. But I don't remember exactly the steps. If you post photos of the rear part of the lens, they may bring back my memory.

Here's an old photo of the Vivitar K-mount 28mm F/2 after I cleaned its aperture blades. Unfortunately, I don't have any other photo of its construction:

10-30-2009, 12:08 PM   #7
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,345
when you say twist, how much force, my 24 is worse that a jam jar with the lid stuck on.

quick edit update

using a considerable effort, and a rubber pad designed to open jar lids, I managed to get teh front group off.

if the aperture is like mine, it will be stuck wide open, and you will need to take the lens mount off also. there, you shold find a spring that pulls the blades shut, and a little lever that it connects to. Carefully move this lever and close down the aperture, so that you can take the oil off it.

Clean the blades with isopropanol, and if there is any residue on the front of the rear element clean this too. blow out al the dust and you should be good to go. it worked on my Nikkor version any way.

Last edited by Lowell Goudge; 10-30-2009 at 12:38 PM.
10-30-2009, 12:22 PM   #8
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,195
QuoteOriginally posted by Lowell Goudge Quote
when you say twist, how much force, my 24 is worse that a jam jar with the lid stuck on.
Not much force based on my experience with several lenses of the same construction.

Your lens may have a different construction. Kiron changed to a different design and, if the few lenses I attempted are any indication, started hiring gorillas to work in the assembly line

The later design uses ball bearings. Somewhere around the rear element of the lens is a ring of about 60 ball bearings (1.6mm diameter based on the few lenses I worked on). Let's say that I haven't successfully repaired any lens of this construction yet.

10-30-2009, 12:47 PM   #9
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,345
QuoteOriginally posted by SOldBear Quote
Not much force based on my experience with several lenses of the same construction.

Your lens may have a different construction. Kiron changed to a different design and, if the few lenses I attempted are any indication, started hiring gorillas to work in the assembly line

The later design uses ball bearings. Somewhere around the rear element of the lens is a ring of about 60 ball bearings (1.6mm diameter based on the few lenses I worked on). Let's say that I haven't successfully repaired any lens of this construction yet.
your's may have not been too bad but mine was really tight, it did open up eventually, with force, and as noted above is all back together and working now. Thanks,

Now if the OP can have the same success!

by the way, mine is a nikon AI mount, and the interest I have is to use it with my N AI - PK adaptor as a trial, and perhaps in the long run, change lens mounts using a flanged M42 to PK adapotor. F2 at 24mm is nice to have.
10-30-2009, 12:54 PM   #10
Junior Member




Join Date: Jan 2009
Location: Utah
Posts: 36
Original Poster
Great advice thank you...Gorillas is right...I think I need to hit the gym or something because this this is on good ...I'll let ya know how things go
10-30-2009, 01:47 PM   #11
Junior Member




Join Date: Jan 2009
Location: Utah
Posts: 36
Original Poster
Thanks for everyones help much appreciated...bad news...it's outside my expertise for sure and has gone to the trash.

Guess Im gonna have to keep my eyes open for another lens... dang the bad luck.

Thanks so much for the help pictures and all the directions.
Steve
10-30-2009, 02:03 PM   #12
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,345
QuoteOriginally posted by zoeybird Quote
Thanks for everyones help much appreciated...bad news...it's outside my expertise for sure and has gone to the trash.

Guess Im gonna have to keep my eyes open for another lens... dang the bad luck.

Thanks so much for the help pictures and all the directions.
Steve
throw it our way and maybe we can recover it?
10-30-2009, 02:29 PM   #13
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,195
zoeybird, check your PM.
10-30-2009, 03:25 PM   #14
Pentaxian




Join Date: Feb 2009
Location: Alameda, CA
Posts: 3,195
QuoteOriginally posted by Lowell Goudge Quote
by the way, mine is a nikon AI mount, and the interest I have is to use it with my N AI - PK adaptor as a trial, and perhaps in the long run, change lens mounts using a flanged M42 to PK adapotor. F2 at 24mm is nice to have.
If the lens has no sentimental value to you, I suggest selling it and get a "proper" K-mount lens instead. Look at what I sold recently: Kiron 28mm 1:2 Nikon AI mount
10-30-2009, 10:03 PM   #15
Junior Member




Join Date: Jan 2009
Location: Utah
Posts: 36
Original Poster
Man, that lens looked awesome...

I replied to your PM...

After checking the inside of mine to figure out what was up or going on inside causing the aperture blades not to open...I didn't find the oil on the blades but it looked like the lens was recently worked on because things kinda just came apart when I started to dismantle it...I've never taken apart a lens before but some of the parts just didn't seem to fit in like they should and I knew I was over my head with it.

Thanks again for your help suggestions and the repairs
Steve
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
28mm, aperture, blades, f2, k-mount, lens, move, pentax lens, slr lens, vivitar, vivitar 28mm f2
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Why are aperture blades always black? mikemike Photographic Technique 20 08-23-2010 06:05 PM
Vivitar 75-205mm f3.8 1 touch zoom lens Aperture blades cleaning Take-5-JB Pentax SLR Lens Discussion 6 08-12-2010 08:53 PM
Oil on aperture blades dgaies Pentax SLR Lens Discussion 2 08-10-2010 07:41 AM
Question about aperture blades on my fa 31 ltd skawi Pentax SLR Lens Discussion 6 07-15-2008 01:25 PM
Aperture blades sticky? Toshi Pentax SLR Lens Discussion 7 04-13-2007 12:02 PM



All times are GMT -7. The time now is 07:50 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top