Nikkor 300mm 1:4.5 Aperture Stop Down Repair

Cholentpot · Mar 24, 2022

Hi,

I was given a very nice example of a Nikkor 300mm. Only issue is the aperture won't close down. On inspection the reason was obvious. The pin is missing.

Is this a simple fix? Is there a way I can just close it down to something like f/8 and leave it there? 4.5 is nice but it's kind of useless for me on such a long lens.

shutterfinger · Mar 24, 2022

The aperture lever appears to be missing. Remove the 5 screws, lift the mount ring off, take another picture of the rear of the lens and post it.

Cholentpot · Mar 24, 2022

shutterfinger said:
The aperture lever appears to be missing. Remove the 5 screws, lift the mount ring off, take another picture of the rear of the lens and post it.

I can't get the screws out for fear of stripping it. Is there a specific screwdriver I should be using? The glasses repair one can't seem to grip it well enough.

shutterfinger · Mar 24, 2022

Use a #0 JIS or Philips screwdriver. Apply some Acetone around the screw heads and let sit for a few minutes to loosen the threadlocker.

ic-racer · Mar 24, 2022

The screw heads look buggered, so this lens may have been used for parts already. This might be a good lens on which to practice.

shutterfinger · Mar 24, 2022

I tried to remove the screws on mine and only got 1 to come out and its threads were coated with threadlocker.

Cholentpot · Mar 24, 2022

shutterfinger said:
I tried to remove the screws on mine and only got 1 to come out and its threads were coated with threadlocker.

I'll give it a go

ic-racer said:
The screw heads look buggered, so this lens may have been used for parts already. This might be a good lens on which to practice.

If I can't get 'em out this will just be a wide open 300mm lens. Can't really think of what it'll be useful for though...

ic-racer · Mar 24, 2022

Pretend it is a mirror lens

Cholentpot · Mar 24, 2022

ic-racer said:
Pretend it is a mirror lens

f/4.5 is too narrow and too wide at the same time. But yeah, that's what I was planning. And it looks good on a shelf.

reddesert · Mar 28, 2022

Long tele lenses are often useful wide open for getting as fast a shutter speed as possible, and for background blur. A lot of wildlife photos are typically taken at a wide aperture. I use a 300/4.5 occasionally for a technical astro photography application (with d***tal, sorry) and use it wide open for that of course.

The rear screws on Nikon lenses are typically quite tight and you usually need to dissolve thread locker; someone who didn't dissolve the threadlocker probably damaged the screw heads.

Cholentpot · Mar 28, 2022

reddesert said:
Long tele lenses are often useful wide open for getting as fast a shutter speed as possible, and for background blur. A lot of wildlife photos are typically taken at a wide aperture. I use a 300/4.5 occasionally for a technical astro photography application (with d***tal, sorry) and use it wide open for that of course.

The rear screws on Nikon lenses are typically quite tight and you usually need to dissolve thread locker; someone who didn't dissolve the threadlocker probably damaged the screw heads.

I don't do much birding, but I can always try. The screws aren't as bad as they look. I'll try applying some nasty stuff to them and see what happens.

Nikkor 300mm 1:4.5 Aperture Stop Down Repair

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