teardown of the Nikkor-P 105mm f/2.5 lens!

[richardHaw]

http://richardhaw.com/2017/04/17/repair-auto-nikkor-p-105mm-f2-5/

Hello, again APUG! This is my 2nd post here, hope that I can be a productive member of this community!

 

[resummerfield]

Very nice! Thanks for posting!

 

[mooseontheloose]

Nice post - it's definitely a camera I want to add to my collection. (and now following your blog)

 

[Eric Rose]

Major take away - always store lenses mount down so oils don't migrate to iris blades.

 

[richardHaw]

Thanks, guys!
glad you liked it.
there is an old wives' tale about having the aperture mid-way around f/5.6 or f/8 when storing your lens for a long time. I do not know what this was about but I will tall you that when rummaging for junks, the lenses that were stored wide-open or closed all the way tended to be stuck when the blades were rusty. there may be some truth to this but I cannot confirm apart from my experience rummaging at the junk shops here at Tokyo almost everyday

 

[AgX]

I read your "helicoids" part. I taught such myself, but would have enjoyed those graphics before.

However I do not consider a flat screwdriver the best means to make marks. Better would be to use a scriber.
Most comfortable are models that let the needle recess in the shaft for protection.
http://www.schlossereinkauf.de/WebR...157C/A68E/31F5/C0A8/2AB8/C0F0/Reissnadeln.JPG
https://www.qy1.de/img/anreissnadel-311075.jpg

 

[richardHaw]

I read your "helicoids" part. I taught such myself, but would have enjoyed those graphics before.

However I do not consider a flat screwdriver the best means to make marks. Better would be to use a scriber.
Most comfortable are models that let the needle recess in the shaft for protection.
http://www.schlossereinkauf.de/WebR...157C/A68E/31F5/C0A8/2AB8/C0F0/Reissnadeln.JPG
https://www.qy1.de/img/anreissnadel-311075.jpg

Thanks! Was considering that but the added cost is hard to justify for me. I am considering making a video for this in the coming weeks.

 

[Leigh B]

Hi Richard,

Nice write-up.

A suggestion if I may...
When shooting a flat* black subject, increase your exposure by a couple of stops.
This will enhance the subject and make details more obvious.
You don't care if highlights blow out since they're not of interest anyway.

- Leigh

*flat meaning optically non-reflective, not meaning mechanically not rounded

 

[richardHaw]

Hi Richard,

Nice write-up.

A suggestion if I may...
When shooting a flat* black subject, increase your exposure by a couple of stops.
This will enhance the subject and make details more obvious.
You don't care if highlights blow out since they're not of interest anyway.

- Leigh

*flat meaning optically non-reflective, not meaning mechanically not rounded

Thanks, Leigh!!!

Sorry but I lost you on the flat black subjects. Ric

 

[Leigh B]

Sorry but I lost you on the flat black subjects. Ric

The internal parts of the lens are black-anodized aluminum.
They intentionally have a matte finish to reduce light reflections.

Those photograph quite dead at normal exposure.

Over-exposing will bring up subtle differences in tone and texture.
That serves to differentiate the parts visually, so it's easier for the viewer to follow.

- Leigh

 

[richardHaw]

Hello, Leigh!
Yes! I correct the exposure for those sometimes at pshop. I get lazy at times with the iphone eventhough all you need to do is to drag to up the exposure! Ric.

 

[Leigh B]

Yes! I correct the exposure for those sometimes at pshop. I get lazy at times with the iphone eventhough all you need to do is to drag to up the exposure! Ric.

That may or may not work.

Black is, by definition, a lack of photons.

No function in Photoshop can create photons.
Those are what show detail in the subject.
PS can make a uniform black area uniform gray, but that does not convey information.

The only way to increase the amount of information captured is to increase the exposure.
It's best done by increasing the level of illumination. That captures more photons.

- Leigh

 

[richardHaw]

Hello, Leigh.

I can pick up some information from the iphone pic. the problem is balancing what's in the dark and what is not. the thing with these things is most of the time what is in the bright part needs to be exposed properly,too. Ric.

 

[richardHaw]

http://richardhaw.com/2017/05/05/repair-auto-nikkor-p-c-105mm-f2-5/

and here is part 2!!!

 

[Leigh B]

the problem is balancing what's in the dark and what is not.

Of course. That's often a problem in landscape photography.

It's called "gamma", the range of density from highlight to shadow on the negative.
That's controlled by development time.

- Leigh

 

[richardHaw]

Hello, Leigh.
we are really getting off-tangeant with this talk about gammas and mids, if you want to discuss this further can we talk about this in a private message? Please message me instead. Thanks.

 

[Leigh B]

Richard,

I'm talking about the appearance of the photographs in your presentation.

If you don't understand basic photography, I'm sorry.

I have a lot of experience preparing presentations. Just trying to pass it along.

- Leigh

 

[richardHaw]

Thank goodness there is an ignore function here in APUG.

 

[Leigh B]

Thank goodness there is an ignore function here in APUG.

It's amazing how little you will learn by ignoring constructive suggestions.

- Leigh

 

[richardHaw]

you are not being constructive but being obnoxious. read your PM so you won't throw this thread out of tangent.