Topic: Spiratone 400/6.3 - Dismantle

I very recently acquired this long thin telephoto - manual 12-bladed (!) diaphragm, Nikon T mount. Anyway, the rearmost element is pretty cloudy, so I'd like to see if I can take it out and clean it. taking the T mount off doesn't really gain me anything - the element is recessed about 2" in. The only place where I might gain some entry are three small screws situated just forward of the aperture ring, and just behind the focus ring. I suspect that loosening these will allow me to either slide off or unscrew the rear half of the lens barrel. I've never dismantled a lens before, and this seems like a good place to start - didn't really cost me anything. Has anyone taken one of these apart, and if so, where to start? Failing that, anyone have any general advice foe opening up a long telephoto? Thanks in advance. DC.

Nikon F3HP, F4S, FM, D70S. MF Nikkor 24/2.8,35/2.0,50/1.8,85/2.0,105/2.5,180/2.8,200/4.0,AF Nikkor 18-70/3.5-4.5,70-300/4.0-5.6,AF Sigma 105/2.8 macro.
Olympus OM-4T. Zuiko 28/2.8,35/2.8,50/1.4,50/3.5 macro,85/2.0,200/4.0,35-70/3.6,65-200/4.0.
Contax 137MA+Yashica 50/2.0.
Currently outfitting new darkroom (plumbing).

Re: Spiratone 400/6.3 - Dismantle

mine unscrews underneath the tripod mount.  loosen & remove tripod mount then grasp front & rear sections, unscrew...

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Re: Spiratone 400/6.3 - Dismantle

Here's less than half an answer, but maybe better than nothing.  I have a 400/6.3 Spiratone but have never had to take it apart, so I just started poking around with it for the first time.  There were more than one version of this lens, so this may apply only to the series I have, which was new in 1979:

If you grab the barrel in front of and behind the tripod mounting collar, and twist, the lens barrel will unscrew at this point.  The rear 2 elements come off with the rear end of the barrel, and the diaphragm is accessible to the front (the 3 set screws you mentioned will then probably remove the diaphragm from the rest of the lens if you need to clean it).

The construction of the cell with the 2 rear elements in it is a surprise: the inner part of the barrel, including the screw threads, the surface where the tripod ring clamps down and the flanges over the edges of the elements themselves, is not aluminum but molded plastic, it looks like Delrin.  It appears to be all one piece, and it looks like it may have been molded in place with the inner lens cell and the outer aluminum barrel as inserts in the mold.  I do not see any way to remove the individual elements, or to get any closer to the rear element than you can get just by removing the T mount.  If you have to clean the front surface of the second element, you'll be able to reach that. 

The lens is a pretty respectable performer, especially if you take its cost into consideration (I think mine was $67 new with multicoating).... not a Nikkor certainly, but vastly better than the low priced mirror lenses that became popular a bit later on.

on top of all my other medical problems, now they tell me i have hypochondria .....

http://www.flickr.com/photos/26262745@N08/

Re: Spiratone 400/6.3 - Dismantle

Excellent - thank you both - the barrel unscrewed at the tripod collar just as you described. The rear element is right there - have to go out now, but I'll investigate cleaning the elements later (assuming not many beers on board). Cheers. DC.

Update - anyway, I unscrewed the rear half of the barrel - this part is just "tube" - no glass in it. The rear element protruded ~1" out from the front half of the lens. Held in place by a threaded lockring that was seriously torqued down. I put on a pair of nitrile gloves for grip, and went at it - got it unscrewed without mishap. The element is ~30mm diameter and 2-3 mm thick. From the weight and ground edges, I'm sure it's glass. Anyway, it cleaned up easily and went back into the lens clear and spotless - I have no idea what the haze was, but it was quite severe. Lens reassembled easily. I've never used as long a lens as this - time to try it out before I ebay it. Thanks again. DC.

Last edited by Litespud (2009-05-26 03:59:24)

Nikon F3HP, F4S, FM, D70S. MF Nikkor 24/2.8,35/2.0,50/1.8,85/2.0,105/2.5,180/2.8,200/4.0,AF Nikkor 18-70/3.5-4.5,70-300/4.0-5.6,AF Sigma 105/2.8 macro.
Olympus OM-4T. Zuiko 28/2.8,35/2.8,50/1.4,50/3.5 macro,85/2.0,200/4.0,35-70/3.6,65-200/4.0.
Contax 137MA+Yashica 50/2.0.
Currently outfitting new darkroom (plumbing).

Re: Spiratone 400/6.3 - Dismantle

Very good!  Yes, the elements will certainly be glass.  Yours is different in construction from mine, probably earlier manufacture... in mine, the glass comes out in the rear part of the barrel and as far as I can tell it cannot be removed - there are not threaded rings, only what appears to be a plastic molded-in-place flange holding a 2-element cell in place.  Yours is the better idea of the two, and should give good service indefinitely.

I think you will find the lens to be worth keeping.  I have found that, at the distances it's most likely to be used at, sharpness is more affected by atmospherics (heat waves, etc) than by any unsharpness in the lens itself.  When you're to that point, paying more for a better lens is likely to return less on your investment than you might have hoped for.  Of course, there are times when the air is clear, temperatures are uniform and/or you're shooting pretty close ... for bird-watching, where distances are fairly short and sharpness is usually hyper-critical, a better lens would be called for.  You will certainly not do better than this for anything like the same money, though, the next meaningful step up is a good lump of cash.  Well worth it if you're serious, not so much if you just want to play with it and get a few good pics.

on top of all my other medical problems, now they tell me i have hypochondria .....

http://www.flickr.com/photos/26262745@N08/