View previous topic :: View next topic |
Author |
Message |
David
Joined: 13 Apr 2011 Posts: 1869 Location: Denver, Colorado
Expire: 2013-01-25
|
Posted: Tue May 24, 2011 5:56 am Post subject: Mystery Vivitar |
|
|
David wrote:
So I got a Vivitar 75-200 for $13, including shipping, broken the other week. The aperture blades dripped oil and the internal lenses had some dust. After blowing the dust off the lenses with compressed air and cleaning the blades, I decided to keep the lens. Partly because I made a modification internally just to see what would happen.
But I'll get to that in a minute. My big curiosity about this lens is it's background. I tried to look up the info based on the SN, but the online Vivitar resource doesn't list who made lenses starting with "77." The full SN is 77209659.
As for the mod I made on the inside, the aperture range was controlled by a piece of metal on an internal arm. I took the little piece of metal off (it was screwed on) and the lens went from an f4.5 to 22 to an f9 to unknown. The old f22 setting was enormous compared to the pinhole aperture it now has when stopped down. This week I'll take some test shots at the old stop-down level and the new. If it fails miserably, I kept all the parts to undo the mod.
David _________________ http://www.youtube.com/user/hancockDavidM |
|
Back to top |
|
|
walter g
Joined: 20 Feb 2010 Posts: 2463 Location: NC, USA
|
Posted: Tue May 24, 2011 7:12 am Post subject: |
|
|
walter g wrote:
77 is Kobori made. I have a 80-200 made by Kobori that i really like. _________________
Main cameras
Panasonic G5,Nikon J1,Pentax Q10,Sony Nex 6
Minolta MC W SI 2.5/28, MD 2.8/28, MC W SG 3.5/28, MC Celtic 3.5/28, MC W HG 2.8/35, MD Celtic 2.8/35, QE 4/35, Rokkor X 2/45, MC Rokkor X PG 1.4/50, MC Rokkor X PG 1.7/50, MD Rokkor X 1.7/50, MD 2/50, MC Rokkor PF 1.7/55, MC Rokkor PF 1.9/55, Auto Tele Rokkor PG 2.8/135, MC Tele Rokkor QD 3.5/135, TC 4/135, MC Celtic 4/200, MC Tele Rokkor PE 4.5/200
MD 28-70 f3.5-4.8, MD Macro 35-70 f3.5, Md 70-210 f4, MD Rokkor X 75-200 f4.5, MD 100-200 f5.6
Nikon Nikkor 4/20, O Auto 2/35, S Auto 1.4/50..... Miranda Auto 2.8/28, Auto 2.8/35, Auto 1.4/50, Auto EC 1.4/50, Auto 1.8/50, Auto EC 1.8/50,Auto 1.9/50, Auto 3.5/135
Various Soligor,Sun,Fujita,Komura,Spitatone, etc. Lenses
|
|
Back to top |
|
|
Arninetyes
Joined: 24 Jun 2010 Posts: 312 Location: SoCal
Expire: 2013-03-26
|
Posted: Tue May 24, 2011 12:59 pm Post subject: |
|
|
Arninetyes wrote:
So, you've created the world's first pinhole zoom lens? Should be fun! Of course, IQ will be much like any other pinhole cam. _________________ The longer I use autofocus lenses,
The greater my preference for manual focus grows. |
|
Back to top |
|
|
David
Joined: 13 Apr 2011 Posts: 1869 Location: Denver, Colorado
Expire: 2013-01-25
|
Posted: Wed May 25, 2011 7:41 pm Post subject: |
|
|
David wrote:
So I took the modified lens out last night to photograph with. It didn't fit onto my K-7. The mount said P/K, and even fit inside my K1000. So, when I got home (I didn't try it on my K-7 before going into the field... I know,) I was able to modify it to fit.
Most importantly, this demonstrates that Pentax's claim that ALL K-mount lenses will fit on ALL K-mount bodies is untrue. This lens had to be modified to fit. On the K-mount there's a spring-loaded arm that provides aperture interface with the camera. There's also a metal ring next to it for some reason. That ring was undamaged, but shaped differently (photos to come.)
So, the lens now fits. Photos to come later this week. _________________ http://www.youtube.com/user/hancockDavidM |
|
Back to top |
|
|
RioRico
Joined: 12 Mar 2010 Posts: 1120 Location: California or Guatemala or somewhere
|
Posted: Thu May 26, 2011 1:39 pm Post subject: |
|
|
RioRico wrote:
David wrote: |
Most importantly, this demonstrates that Pentax's claim that ALL K-mount lenses will fit on ALL K-mount bodies is untrue. |
I don't think Pentax makes that claim. All PENTAX k-mount lenses will fit; lenses from 3rd-party lensmakers, who reverse-engineered but didn't licence the PK mount, may not fit unmodified. Not all PK interpretations are equal, especially the infamous KR (Ricoh) mount with its nasty pin. Vivitar is well-known for having marketed a few lenses with oversize linkage shields. Don't blame Pentax for what others have done. _________________ Too many film+digi cams+lenses, oh my -- Pentax K20D, K-1000, M42s, more
The simple truth is this: There are no neutral photographs. --F-Stop Fitzgerald |
|
Back to top |
|
|
|
|
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
|