Converting Pre-AI Lenses to AI

No, this is not an article about the technical  aspects of this. In other words, it's  not a tutorial. Rather, I'm  focusing on  whether the whole thing is worth it. I'll present a  case for and against to  help you draw  your own conclusions and reach a  decision on whether such a process is worth it for you.

Most of you  probably already know what AI and pre-AI lenses are. To spare you the technical details, basically they're two old kinds of Nikkor lenses, with the big difference being that pre-AI lenses cannot be safely used with many modern DSLRs. As a result, owners of pre-AI lenses convert them (or have them converted) to the safe-to-use AI kind.

The thing is, is it worth it?

Some older lenses, like this 200mm f/4 can offer very high optical quality. Still, you should always ask yourself if the trouble is worth it.

Clearly, to  answer that question we need some cost data. Having your lens converted is not very expensive, if you have access to a cheap service point. Here in Finland, I suspect most places would charge you $70 just as you enter their front door; in the USA, I'm sure the situation is better. The part itself (basically just a new aperture ring) costs between $25-40 or something like that. The absolute cheapest "conversion" would be to simply rub off (using a file) a portion of the aperture. Assuming you know how to do it and you have the tools already, it costs nothing and takes 15 mins. BUT, it's not a proper conversion. It's  proper alright in the sense that it's safe to use. But it will decrease the resale value of the lens.

If you want a proper conversion, to estimate whether the cost is worth it,you must compare the price difference between a pre-AI and an AI lens. In many cases, the difference isn't that much. Examples: micro-Nikkor 55mm f/3.5: Pre-AI $60, AI $90. 105mm f/2.8: Pre-AI $75, AI $115. Prices are indicative, and they can vary greatly. Which, in a sense, makes it even LESS worthy to have a pre-AI lens converted. Imagine, having just sent your lens for conversion, you notice the AI model being sold somewhere for the same price!

So, bottom line, I don't favor AI conversions. If you really want an older lens, search for the AI variety, as it will save you the trouble. Of course, if your camera can take a pre-AI lens (check, but basically any entry-level body), you're in luck.