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Plastic moulded elements in 28-200?

pdk42

Moderator
In this French interview with Toshiyuki Tsumura from Panasonic, it seems that they’re using plastic elements:


Nous avons utilisé par exemple des lentilles asphériques en plastique moulé, qui permettent d’atteindre un très haut niveau de précision tout en réduisant la taille de ce zoom

In English:

For example, we used aspherical molded plastic lenses, which allow us to achieve a very high level of precision while reducing the size of this zoom.

Not sure how I feel about that!
 
Translated version:
https://phototrend-fr.translate.goo...uto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp

Personally I wouldn't worry much about it. I've had glasses with plastic lenses for a long time: they're lighter, the high refractive index means they can be thinner, and there have never been any signs of deterioration over time.

I'm glad to see he says they regard the S1 series as still being important, but I'm a bit unnerved that he seems to regard sensor shift high resolution modes as being preferable to a higher resolution sensor. That feels a bit too much like the old determination to stick with DFD despite the obvious demand for Phase Detect.
 
Thanks for sharing. But I was more interested in. Other parts of the interview. He mentioned that the upcoming super telephoto will be for ambitious amateurs an pro's. And we should follow the next announcements. That increases my expectations for this lens and I think we will see it soon.
 
Translated version:
https://phototrend-fr.translate.goo...uto&_x_tr_tl=en&_x_tr_hl=en-US&_x_tr_pto=wapp

Personally I wouldn't worry much about it. I've had glasses with plastic lenses for a long time: they're lighter, the high refractive index means they can be thinner, and there have never been any signs of deterioration over time.

I'm glad to see he says they regard the S1 series as still being important, but I'm a bit unnerved that he seems to regard sensor shift high resolution modes as being preferable to a higher resolution sensor. That feels a bit too much like the old determination to stick with DFD despite the obvious demand for Phase Detect.
I suspect the defence of pixel shift was simply to avoid weakness about the lack of a hi res body at the moment. I’m sure the S1ii is coming and that there will be a hi res version.
 
Interesting. They should be able to hit fantastic accuracy and reproducibility with molding. I wonder what resin they use?
I guess I need to modify my thinking about the use of plastics. What should matter is the results, not some bias about “plastic” (which I know is a term that covers a huge range of different materials). For sure, plastic is less dense than glass and it has better thermal properties. And I’m sure moulding rather than grinding should lead, as you say, to better accuracy and reproducibility. I guess it should also eliminate onion ring bokeh.
 
I guess I need to modify my thinking about the use of plastics. What should matter is the results, not some bias about “plastic” (which I know is a term that covers a huge range of different materials). For sure, plastic is less dense than glass and it has better thermal properties. And I’m sure moulding rather than grinding should lead, as you say, to better accuracy and reproducibility. I guess it should also eliminate onion ring bokeh.
I don't think there are major drawback for plastic elements, if it's not the front or back element. Plastic is less hard, so less scratch resistant. But for elements in the inner of the lens, that's no issue. If the optical characteristics of the plastic fit's it's purpose and if they didn't change over time due the influence of light, than I don't see a problem with the use of plastic elements.
 
Nikon has used "hybrid" aspherical elements (i.e. glass and plastic) in some of their lenses for a long time.

I used to own the AF-S 17-35mm f/2.8 D which, according to the spec, has "13 elements in 10 groups inc. 2 ED and 3 aspherical elements (two molded, one hybrid)": OpticalLimits It was their professional wide angle zoom from its release around 2000 up to the announcement of the AF-S 14-24mm f/2.8 G in 2007, and it remained in the range until around 2020.
 
I think plastic elements are much more used as most people think. In high end lenses as well as in cheaper lenses. Most manufacturers don't talk as much about it don't call it plastic, because of the bad reputation. But I think light weight lenses as we see today, are not possible without some kind of plastic elements.
 
The millions and millions of people who wear eyeglasses don't spend time worrying that they are not made of glass, but are plastic. And they have a better product; plastic lenses weigh less and are less apt to break if dropped or mishandled. When a scratch resistant coating is added, plastic lenses are really durable. I remember sitting on a 9th floor balcony with my glasses on a table when a gust of wind blew them off to the ground below. I spent quite a while searching but when I finally found them they weren't broken or scratched, no harm at all really.

In terms of design, there are several suitable plastics with good clarity and with a range of refractive indexes. There is CR-49 (the first plastic eyeglass material), polycarbonate, and a material called High-Index (formulated for high index of refraction). And there are likely quite a few more; each producer will have their own formulatiions. It is easy to see that for high production of complex lenses with multiple groups and multiple elements in each group, plastic would be tempting for some of the complex elements.

The molds for high precision plastic parts are beautiful. They are made of tool steel and have a mirror finish, can be made to very high tolerances, and each is a little machine in itself. If you are a manufacturing geek like me, a tour of the mold shop for plastic camera lenses would be a really great experience.
 
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