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Comment by nullifidian | Hacker News Reader

I would add that lenses are never going to be the same in that the latest mirror-less full frame lenses, even the higher-end ones (which cost $1000-2500 and more) are increasingly made out of greater proportion of plastic than the DSLR lenses (Canon EF, Nikon F). Even the mount is attached with screws that first go through a plastic frame, which consequently contains at best a partially metal assembly, which was fully metal previously.

I'm not familiar with how well do modern plastics age, but suspect that it's not as well as the old metal lenses (50ies onwards) which are still usable. So it's more of a planned obsolescence trend in my opinion.

And the increasing reliance on digital post processing for correcting optical aberrations like distortion and chromatic aberration. Some Micro Four Thids lenses' raw files are downright unusable without such corrections.

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I don’t understand people’s obsession with plastic vs metal lenses. I have 10+ year old plastic and metal lenses and all are fine. I once dropped a plastic lens and it rolled about 20 feet down a steep gravel and stone driveway. No issues other than some scuffs on the exterior, and I’ve used it for years and years since.

For truly old lenses - 50 years or more like you mention - mildew and fogging seem more likely to be a problem than plastic aging. Plus, lenses of that age are often of limited real-world use anyway given the developments in cameras.

I think the issue is, how well the plastics age. Some over time get brittle and less "flexible", and thus prone to fatigue.

I had a Minolta SLR as a teen (read: late 70s to early 80s). I gave it away 25+ yrs later. I'm not sure about internals, but there was no fears about plastic fatigue. I believe it might still be in use.

I think it’s pretty clear at this point that well made plastic lenses hold up for at least 10-15 years. In my view, the vast majority of use of a typical lens is going to be in the first 10 years or so. After that, if the lenses haven’t been scratched, dropped in the ocean, etc., use is probably going to drop off anyway as better cameras and lenses come along.

A magic drainpipe is a 30 year old lens and is still optically excellent and performant.

Yes! I have one, and wide-open it outresloves the 24MP sensor of my A7ii. It's so sharp that I have to turn down the default sharpening settings in lightroom because then it looks unnaturally sharp.

The reason why it's so good is because it doesn't have in-lens IBIS. It took 15 years to make an IS lens with similar quality to the legendary 80-200!

The lens I use the most is a 70 years old leica lens, it's all metal and glass and looks as if it came out of the factory yesterday. It stills holds up on an m10m sensor (40mpx without bayer array).

Plastic will always be inferior to metal no matter what, both in feel and durability. The only plastic lens I have is also the only lens with helicoid play... it's not even 1/3rd the age of the leica

Plastic will also always be superior to metal in weight, and functionality is all over the map: good lens (for ones purpose) dwarfs enclosure material for that.

It wouldn't be hard to pair you with someone mad at their old-school lens for helicoid play who has no complaints about their plastic. Especially in the last decade, it's not a useful filter, just one of many factors to consider in selecting gear.

Because plastic breaks. Metal is superior in longevity.

Metal breaks too. It entirely depends on how it's engineered. Cheapest plastic sucks a lot more ass than the cheapest metal, but when engineered for permanence, plastics can be superb materials.

I wrote that comment after the plastic buckles on my messenger bag just broke. Perfectly fine, hardly used, but it just broke because it was ten years old. Plastic sucks.

As far as dropping lenses goes, plastic is superior. It bounces back in to shape. Metal bends/dents.

> I don’t understand people’s obsession with plastic vs metal lenses.

It's an issue with perceived quality. So much of the inner workings of things have been replaced with plastic, usually not for the better. When you spend as much money on lenses these days, you don't expect them to cheap out on a small ring.

Also, not all plastic is made equal. I have two lenses made in the last 20 years that have plastic that is starting to deteriorate and become sticky. It's a real shame as those lenses still work and do their job.

Plastic deterioration like this has ruined so many things I liked that are otherwise well designed. I've had it happen with computer mice, umbrellas, knives, camera tripods, shoes, flashlights. I don't know the chemistry behind why, but it's a terrible feeling to have something either disintegrate, or become terribly sticky, or turn into putty.

I agree, I've had both (from Nikon). Plastic tends to bounce, metal bends. The plastic lenses stand up to a bearing very well.

LEGO has pretty good tolerance over time. Perhaps they can keep up with a toy manufacturer if given the right materials.

If you interested in great feeling and great IQ lenses with a small foot print look not further than the Zeiss Loxia line, Sony 24mm F2.8G / 40mm F2.5G and 50mm F2.5G, the new Sigma Contemporary lens line for both E and L mount and Voigtländer lenses for both E and M mount. All of them have metal bodies and some of these are even weather sealed and have AF.

There is some Chinese lenses as well which seem to be very well built.

Great lens resources: https://phillipreeve.net/ https://dustinabbott.net/ and https://www.fredmiranda.com/

If I'm not mistaken Sony G lenses are the greatest offender in terms of the amount of plastic used in the $800-$2000 price range:

https://www.lensrentals.com/blog/2016/04/sony-fe-85mm-f1-4-g... https://www.youtube.com/watch?v=WMXjJxFXRVs

That's one of the reasons I mentioned those three.

I think we have to distinguish between plastic, the one that feels cheap and might crack even when exposed to cold like many of the cheap DSLR lenses. And the "new" kind of plastic that is sturdier and more resistant to drops or scratches. The FE 24-105 is the latter and it does not feel anyhow less quality than more expensive top zooms.

Plastic has its positives as well: it won't scratch as easy as metal and, specially for zooms, its lighter. Imagine a zoom made of metal like a Voigt lens.

Soft plastics on my nikon are an issue. I have noticed that they tend to deteriorate quickly on beach holidays. I suspect it is a combination of Sun, residues of solar cream on the hands and the salt in the air.

You mean the grip? Nikon rubber grips are notorious for falling apart. Which is part of why I sold all my digital Nikon gear when they were tone deaf and peddalled dSLRs and the dumbed down 1 system. Went with the m43. It's not an open standard but it's considerably more open than others.

Do you mean the "rubber textured" plastic on the D50, D70 etc.?

Yes. And the D700, D800 etc. It isn't so much of a problem now with 3d printing and so many materials being available.

The rubber grips are cheap and take 20mins to replace.

This is complete speculation on my part, but doesn't plastic tend to deform more than metal in harsh temperatures? Won't the lack of a metal frame to precisely position all the optical elements cause more aberrations over time?

Over temperature? Nope.

Or to be precise, not well-engineered plastics.

There are a ton of games one can play. For example, one can mix something which expands by 1%, with something which contracts by 1% (which can also mean expanding in the opposite direction). Modern lenses do very well across temperatures.

Over time? At least based on what I've seen, older plastic lenses have not aged well. Of course, that means more sold products. A new lens will blow away an older lens if the older ones is plastic and slightly wobbly. Planned obsolescence.

Not at all. This is actually part of why telephoto lenses use a lot of plastic, you can get a plastic to have ~0 thermal expansion, but that's impossible for a metal, meaning better IQ.

Plastic is used to save weight. I have both new RF lenses and the old EF lenses. The RFs are better in every way like for like and are much lighter. Makes a ton of difference when carrying around.

I don’t think it’s all about cost saving.

Use Fujifilm X, Leica DG or Zeiss lenses if you're discontent with the build quality. Sigma also has a very good quality lens lineup. I only need two, a standard and a 28-30 mm equivalent. Could also do with the wider one. On the Ricoh GRD I never needed anything else.

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