28 2.8 AIS Dissassebmly help

[fraser_darwent]

<p>I cannot unscrew the ring with the lens info on (the front ring)<br>

even after removing the 2 grub screws on either side, it is still VERY stuck. any help ? thanks</p>

 

[ellis_vener_photography]

Find the largest, heaviest hammer you can find and give it a few whacks.

[jose_angel]

<p>Do you have the right tool?</p>

[mike_halliwell]

<p>Ellis, to quote from Good Morning Vietnam..</p>

 

<blockquote>

<p>''Oh you are going straight to hell for that one'!</p>

 

</blockquote>

<p>I take it you don't like 28mm 2.8 AISs, did you have a bad experience once?</p>

<p> </p>

[thirteenthumbs]

<p>Apply a small amount of Acetone (nail polish remover) around the edge of the threads and wait 5+ minutes and try again.<br>

Use a lens spanner to fit the ring.<br>

Hold the lens barrel in a lens vise or a strap wrench.</p>

[kari_oinonen]

<p>I have the model they are selling still as new a 28/2.8, but mine is 20+ years old.<br>

Sometimes the rings are tight, especially if you take a too firm grip thus pressing the ring too much. That results in more sticking. A strap wrench (improvised) or a grippy flat piece of material (rubber) could help too. Set the lens nose down on the piece of that material and turn. This trick is used for stuck filters if needed. <br>

As I can see there is no place to apply a solvent and I'd be very careful with asetone as a drop on the lens element will surely hurt the coating.<br>

The crc-system is tricky to get back in tune if you open the three screws under the nose ring. You may see the effect of 1/3 mm change in position easily.</p>

[ellis_vener_photography]

Yes. Optically I t's an overhyped (by Ken Rockwell) PoS compared to modern lenses. Forty years ago? Great lens. today,

not even close. Bad coma, and chromatic aberration.

[roy_ramavarapu1]

<h1 ><em>non-AI Nikkor-P 180mm/f2.8 conversion to AI with Nikon factory ring</em></h1>

<p>posted on 17 Oct 2013<br>

This posting may have relevant information/experience that I documented in a similar situation: I was dismantling this lens only for AI conversion, and started out with the wrong set of tools. The Japanese camera equipment need JIS (Japan Industrial Standard, I think) type Philips screwdrivers. Regular Philips screwdrivers will ruin the screws; using acetone is ok but use a Q-tip (touch only) and don't let the acetone seep into the lens. Hope this posting helps. I FINALLY completed my task of AI conversion.</p>

[luke_kaven]

<p>"Nikon 28/2.8 AIs sample variation demonstrated"</p>

<p>http://www.16-9.net/lens_tests/28mm_2.html</p>

<p>When they're good, they're very very good; when they're bad...etc.</p>

[John Seaman]

<p>If all else fails in this situation I have carefully drilled two small holes opposite each other in the nameplate ring (not with this particular lens) and used a pair of metal dividers to engage the holes and twist it off.</p>

[jose_angel]

<p>Again, without the right tools it could be an impossible task. It can be done without the needed knowledge, maybe (someone could tell you how to do it), but without specific tools it will be a huge botch. First, the tools.</p>

 

[fraser_darwent]

<p>Many thanks for the responses.<br>

Im curious what tools people are talking about ? On my 55 2.8 Micro AIS and 28 2.0 AIS , after removing the grub screws i could simple unscrew the filter ring by hand</p>

[kari_oinonen]

<p>Tools: a stronger hand perhaps. If that does not help see the previous posts ;-)<br /> Solvent and two kinds of aids/tools are already suggested to get a better leverage in screwing the nose piece off.</p>

<p>I like that lens. I believe that yours is worth the servicing!</p><div></div>

[fraser_darwent]

<p>Just to be absolutely 100% sure,<br /> the only thing keeping it in place are 2 grubs screws 180 degrees apart right ?<br>

Thats the case with all my other AIS lenses, just want to make sure there's nothing extra holding it in place before i take a vice to it - carefully<br>

Thanks again all</p>

 

[kari_oinonen]

<blockquote>

<p>Just to be absolutely 100% sure,<br /> the only thing keeping it in place are 2 grubs screws 180 degrees apart right ?</p>

</blockquote>

<p>Who knows if somebody has applied clue or thread lock. But other that that no mechanical item is locking the nose part. I am talking now the Nikkor 28 f2.8 ai-s lens with min focus distance 0.2 meters.<br>

(Actually the nose part of micro Nikkor 55 f2.8 ai-s has not even a single one grubs screws to hold it in its place.)</p>

<p>Please take a note if you want a good result:</p>

<blockquote>

<p>The crc-system is tricky to get back in tune if you open the three screws under the nose ring. You may see the effect of 1/3 mm change in position easily.</p>

</blockquote>

<p>With live view the tuning is however straightforward. It is possible to adjust the CRC -element when the lens is on the camera. The three screws are then accessible while the nose piece is not yet in place - as you may know already.</p>

[fraser_darwent]

<p>I know thanks , I had a 28 2.0 with the CRC which I had to re-adjust, took a while but it went fine.<br>

This is the offending lens</p><div></div>

[kari_oinonen]

<p>Fraser, it seems that you have got the SIC coated version, not the older NIC one.</p>

<p>Looking this far away it seems that the nose ring has got a hit to the right side in the image. If so, check that first as it might be the offending factor.</p>

[keith_b1]

<p>"Optically I t's an overhyped (by Ken Rockwell) PoS compared to modern lenses. Forty years ago? Great lens. today, not even close. Bad coma, and chromatic aberration."<br>

Apparently, the sample variation on this lens is pronounced. Who knows how many you'd have to go through to get a "good" one.<br>

I think my copy is somewhere between the extremes; it's blurry on the sides until about f/5.6.</p>

 

 

 

 

 

 

 

[fraser_darwent]

<p>Kari,<br>

The nose ring has in fact been dented and I am aware of this, however as far as I can tell it is only the filter thread and does not go back further although this my in fact be the problem.<br>

As I am wanting access to the focus ring helicals as the focusing is stiff, besides this is there anye other way to access them ? Thanks</p><div></div>

[kari_oinonen]

<p>Fraser, there is a possibility that the "CRC-guide" is sticking. Slip the rubber grip away and apply suitable grease to the groove- very sparingly ;-). I did even tape a piece of suitably thin metal over the groove for protection. These might help and you may avoid openig the whole lens. </p>

[fraser_darwent]

<p>Kari,<br>

Will try this many thanks. Real bummer as this lens is otherwise fantastic , even compared to my 55 2.8 micro</p>