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Doc Sharptail
Joined: 23 Nov 2020
Posts: 1203
Location: Winnipeg Canada
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 Posted: Sat Nov 13, 2021 2:48 am Post subject: How To? |
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Doc Sharptail wrote:
How does one determine if a vintage film era lens is de-centered?
I had a nikkor 50mm F2 turned down by the KEH travelling camera circus, and had no idea.
He shone a powerful little l.e.d. lamp through the glass and gave it back.
The film and a.p.s.c. work that I've done with it appeared normal.
What does one look for in determining de-centered glass?
T.I.A....
-D.S.
_________________
D-810, F2, FTN.
35mm f2 O.C. nikkor
50 f2 H nikkor, 50 f 1.4 AI-s, 135 f3.5 Q,
50 f2 K nikkor 2x, 28-85mm f3.5-4.5 A/I-s, 35-105 3.5-4.5 A/I-s, 200mm f4 Micro A/I, partial list.
"Ain't no half-way" -S.R.V.
"Oh Yeah... Alright" -Paul Simon |
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Lightshow
Joined: 04 Nov 2011
Posts: 3666
Location: Calgary
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| Posted: Sat Nov 13, 2021 6:28 am Post subject: |
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Lightshow wrote:
Did he say it was decentered? Many folks shine a light through to see the cleanliness/condition of the optics, if any dust, oil, haze, fungus is on any element surface it will be very apparent.
I don't know if it's even possible to see decentered elements just by looking at them, assuming realistic amounts.
Here's a rabbit hole for you.
https://www.lensrentals.com/blog/2012/05/testing-for-a-decentered-lens-an-old-technique-gets-a-makeover/
https://www.youtube.com/watch?v=Yy4fbN7-uQY
_________________
A Manual Focus Junky...
One photographers junk lens is an artists favorite tool.
My lens list
http://www.flickr.com/photos/lightshow-photography/
Last edited by Lightshow on Sat Nov 13, 2021 6:58 am; edited 1 time in total |
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Doc Sharptail
Joined: 23 Nov 2020
Posts: 1203
Location: Winnipeg Canada
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| Posted: Sat Nov 13, 2021 6:41 am Post subject: |
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Doc Sharptail wrote:
Yes, he did say it was de-centered.
I tried the same thing myself and was unable to see anything amiss.
The guy was obviously a professional buyer, and turned down the equipment of a lot of other people.
He had quite a pile of Sony cameras by the time I left...
-D.S.
_________________
D-810, F2, FTN.
35mm f2 O.C. nikkor
50 f2 H nikkor, 50 f 1.4 AI-s, 135 f3.5 Q,
50 f2 K nikkor 2x, 28-85mm f3.5-4.5 A/I-s, 35-105 3.5-4.5 A/I-s, 200mm f4 Micro A/I, partial list.
"Ain't no half-way" -S.R.V.
"Oh Yeah... Alright" -Paul Simon |
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Lightshow
Joined: 04 Nov 2011
Posts: 3666
Location: Calgary
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| Posted: Sat Nov 13, 2021 7:00 am Post subject: |
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Lightshow wrote:
He may have been screening or filtering out gear that may not sell quickly.
_________________
A Manual Focus Junky...
One photographers junk lens is an artists favorite tool.
My lens list
http://www.flickr.com/photos/lightshow-photography/ |
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caspert79
Joined: 31 Oct 2010
Posts: 3206
Location: The Netherlands
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| Posted: Sat Nov 13, 2021 7:23 am Post subject: |
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caspert79 wrote:
| Lightshow wrote: |
| He may have been screening or filtering out gear that may not sell quickly. |
Excactly. The decentering story is probably to prevent discussion.
_________________
For Sale:
Minolta MD 24mm f/2.8
Steinheil Auto D Tele Quinar 135mm f/2.8 (Exa)
ISCO Isconar 100mm f/4 (Exa)
Steinheil Cassarit 50mm f/2.8 M39 (Paxette)
I'm always interested in trading lenses! |
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D1N0
Joined: 07 Aug 2012
Posts: 2535
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| Posted: Sat Nov 13, 2021 10:45 am Post subject: |
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D1N0 wrote:
shoot a brick wall wide open and check of all sides/corners are equally soft and de sharp area is centered in the center of the image. Or just some infinity landscape stuff. If one side is fuzzier than the other one the lens is decentered.
You can't check it with a simple led. Lensrentals says it can be tested with a centering collimator which used a projection technique https://thecameraforum.com/test-decentered-lens/ . On a digital camera you can test it on camera through live view as well (explanation in lens rentals link).
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pentaxian
Last edited by D1N0 on Sat Nov 13, 2021 10:54 am; edited 2 times in total |
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tb_a
Joined: 26 Jan 2010
Posts: 3678
Location: Austria
Expire: 2019-08-28
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| Posted: Sat Nov 13, 2021 10:51 am Post subject: |
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tb_a wrote:
Funny topic. If you don't realize any obvious troubles then the lens is most probably in order.
I think it's quite easy to find out decentering with some test pictures. Other than that it's nearly impossible to find out.
_________________
Thomas Bernardy
Manual focus lenses mainly from Minolta, Pentax, Voigtlaender, Leitz, Topcon and from Russia (too many to be listed here). |
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Doc Sharptail
Joined: 23 Nov 2020
Posts: 1203
Location: Winnipeg Canada
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| Posted: Sat Nov 13, 2021 3:39 pm Post subject: |
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Doc Sharptail wrote:
I felt bad for the guy ahead of me in line.
He had a 4 x 5 graflex full kit and got turned down.
The buyer did take a couple of my vivitar lenses though.
I put my f-65 back in the closet as well.
-D.S.
_________________
D-810, F2, FTN.
35mm f2 O.C. nikkor
50 f2 H nikkor, 50 f 1.4 AI-s, 135 f3.5 Q,
50 f2 K nikkor 2x, 28-85mm f3.5-4.5 A/I-s, 35-105 3.5-4.5 A/I-s, 200mm f4 Micro A/I, partial list.
"Ain't no half-way" -S.R.V.
"Oh Yeah... Alright" -Paul Simon |
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Gardener
Joined: 22 Sep 2013
Posts: 950
Location: USA
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| Posted: Thu Nov 18, 2021 1:49 pm Post subject: |
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Gardener wrote:
| Doc Sharptail wrote: |
The buyer did take a couple of my vivitar lenses though.
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Out of curiosity, which and for how much? If you don't mind. |
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Doc Sharptail
Joined: 23 Nov 2020
Posts: 1203
Location: Winnipeg Canada
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| Posted: Fri Nov 19, 2021 5:30 am Post subject: |
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Doc Sharptail wrote:
| Gardener wrote: |
| Doc Sharptail wrote: |
The buyer did take a couple of my vivitar lenses though.
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Out of curiosity, which and for how much? If you don't mind. |
I'm not sure how much he allowed for the vivitars- a 28mm 2.8 and some zoom that I had not used in quite a long time.
There was a bit of a package that I sold including film bodies that were not getting any use.
I got much more than I was expecting, and the check put a bit of a dent into what the D-810 cost me.
I am aware that some of the vivitar wide-angles are still desirable.
-D.S.
_________________
D-810, F2, FTN.
35mm f2 O.C. nikkor
50 f2 H nikkor, 50 f 1.4 AI-s, 135 f3.5 Q,
50 f2 K nikkor 2x, 28-85mm f3.5-4.5 A/I-s, 35-105 3.5-4.5 A/I-s, 200mm f4 Micro A/I, partial list.
"Ain't no half-way" -S.R.V.
"Oh Yeah... Alright" -Paul Simon |
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