Nikkor 24mm 2.8 AI, condensates behind the front lens element

[nikos_k]

<p>My lovely Nikkor 24mm 2.8 (AI mount) has developed some sort of condensate behind the first element. It seems that it has no effect in the image quality, but is it possible to remove the front element and clean it? Is that element glued to others and hence not possible, at least by a non professional like me, to remove and clean it?</p>

[rodeo_joe1]

<p>Condensation within a lens can take some time to clear. I'd just leave it over a gentle source of heat or out in the sun for a while before trying to dismantle it. Then see if the condensation clears on its own.</p>

<p>The 24mm f/2.8 AI is a CRC lens I believe, meaning the front section is separate from the rear and moves independently. I suspect that removal of the front element isn't a simple job in that case. Had it been the 35mm f/2, then the front element practically falls out of that design. None of the elements in the 24mm f/2.8 AI Nikkor are glued to any of the others. They'll all be retained by threaded rings or spacers. See its internal construction diagram here: http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/late70nikkor/wides/retrofocusillus.jpg</p>

<p>BTW, condensation definitely <em>will</em> affect image quality by reducing contrast. And some lenses are more prone to it than others. I have one zoom that mists up quite readily if taken from a cold place to a warmer one, and the result of that misting can easily be seen through the viewfinder.</p>

[nikos_k]

<p>So I guess that I will have to remove the front group and then the front element of that group. It will not be as easy as removing the name plate an then just the front element, is it so?<br>

There is no haze within the lens, just a group of tinny droplets at the periphery of the front of the lens.</p>

[rodeo_joe1]

<p>That symptom sounds like it may be due to loosening of the blacking paint around the rim of the lens. A thing called "Schneideritis", since Schneider lenses were notorious for their black anti-flare paint falling off. The symptoms are little silvery areas shining around the very edge of a lens element. I suppose it might look like beads of liquid in some conditions. </p>

<p>If it is paint loosening, then it won't wipe off. It also won't have much effect on image quality unless it covers a considerable area of the lens rim. To quote Douglas Adams, it's "mostly harmless". My advice, if it ain't bust - don't fix it.</p>

<p> </p>

[nikos_k]

<p>Thank you! It seems to be so. I will follow your advice and leave it as it is. I will do something as soon as I start noticing problems in the image quality. Does that do any permanent damage to the lens' optics?</p>

[rodeo_joe1]

<blockquote>

<p>"Does that do any permanent damage to the lens' optics?"</p>

</blockquote>

<p>Not at all Nikos. Taking the lens apart is likely to do more damage through misalignment when re-assembling, or careless scratching of metalwork or glass.</p>

<p>The black paint is there to prevent unwanted light reflections from the edge of the lens elements - flare in other words. If the loss of paint gets really bad (like maybe 20% of the area or more) then you might see a loss of contrast under certain lighting conditions. The lost paint may also accumulate in the lens and probably show up as flakes settling inside the glass. None of which is irreversible, or even particularly harmful to the image quality. The element can be re-blacked quite easily if removed; with modern permanent-black marker pens doing a very good job of patching up any lost paint. The flakes of old paint can usually be simply blown out of the rest of the lens.</p>