Plastic is still crap, no matter how you consider it

On 2014-06-28 23:07:28 +0000, RichA said:

http://www.dpreview.com/forums/post/53930590

For an ultra-budget grade lens what do you expect?

I mean, yeah, it's not as good as metal. But the post you link to
starts out with "I bumped my XC 16-50 lens" and I can only guess at the
varying levels of force implied by such an innocuous word as "bumped."

I have bumped the hell out of my EF 50 f/1.8 II and it never gave way
despite the plastic mount, but maybe one man's "bump" is another man's
"slammed into an object with enormous force."

On Sun, 29 Jun 2014 14:20:49 -0700 (PDT), RichA
wrote:

On Sunday, June 29, 2014 5:02:45 PM UTC-4, Oregonian Haruspex wrote:
On 2014-06-28 23:07:28 +0000, RichA said:



http://www.dpreview.com/forums/post/53930590



For an ultra-budget grade lens what do you expect?



I mean, yeah, it's not as good as metal. But the post you link to

starts out with "I bumped my XC 16-50 lens" and I can only guess at the

varying levels of force implied by such an innocuous word as "bumped."



I have bumped the hell out of my EF 50 f/1.8 II and it never gave way

despite the plastic mount, but maybe one man's "bump" is another man's

"slammed into an object with enormous force."

I was in a camera store two years ago and they showed me a box of kit lenses, plastic mounts, that had that kind of damage. Plastic STINKS, especially in a part that is small and meant to hold another, larger part in-place.

It stinks if it is used for a part originally intended to be made in
metal.
--

Regards,

Eric Stevens

On Sun, 29 Jun 2014 21:28:27 -0700 (PDT), RichA
wrote:

I was in a camera store two years ago and they showed me a box of kit lenses, plastic mounts, that had that kind of damage. Plastic STINKS, especially in a part that is small and meant to hold another, larger part in-place.



It stinks if it is used for a part originally intended to be made in

metal.

Agreed. A plastic camera body, while not ideal is fine because it's not providing small-profile critical support for a much heavier component. Using plastic tabs to support an entire lens is not right. In addition to not being strong enough, plastic is abraded easily (as the mount is taken on and off) by the metal camera bayonet screw hole edges (they are sharp) and the black plastic dust gets into the camera and eventually onto the sensor.

You missed my point, and I didn't make it very well.

The bayonet was designed to be made in metal and in my opinion it was
a mistake to substitute a plastic part with mechanical properties
quite different from metal.

There is absolutely no reason why a bayonet system entirely made of
plastic should not be employed but I would expect it to be
significantly different from an equivalent metal component.

--

Regards,

Eric Stevens

On Mon, 30 Jun 2014 00:49:25 -0700 (PDT), RichA
wrote:

On Monday, June 30, 2014 12:52:26 AM UTC-4, Eric Stevens wrote:
On Sun, 29 Jun 2014 21:28:27 -0700 (PDT), RichA

wrote:



I was in a camera store two years ago and they showed me a box of kit lenses, plastic mounts, that had that kind of damage. Plastic STINKS, especially in a part that is small and meant to hold another, larger part in-place.







It stinks if it is used for a part originally intended to be made in



metal.



Agreed. A plastic camera body, while not ideal is fine because it's not providing small-profile critical support for a much heavier component. Using plastic tabs to support an entire lens is not right. In addition to not being strong enough, plastic is abraded easily (as the mount is taken on and off) by the metal camera bayonet screw hole edges (they are sharp) and the black plastic dust gets into the camera and eventually onto the sensor.



You missed my point, and I didn't make it very well.



The bayonet was designed to be made in metal and in my opinion it was

a mistake to substitute a plastic part with mechanical properties

quite different from metal.



There is absolutely no reason why a bayonet system entirely made of

plastic should not be employed but I would expect it to be

significantly different from an equivalent metal component.


Plastic is too weak.

Too weak for what?

Making a bayonet as strong as metal in plastic requires considerable bulk.

It will be bigger in some dimensions - yes.

It's why Sony's NEX-3 was a thicker, bulkier unit than the metal-bodied NEX-5. Once enough bulk is used, the camera will begin to look like something Fisher Price might make for children.

Nonsense. Look at cars. Cars contain up to 30% of their weight as
plastic.

There are some plastics strong enough to do the job, but they are not economical for making cheap cameras, costing more per pound than cast magnesium used in current higher-end cameras.

But magnesium needs machining. Properly designed plastic objects just
clip in place without further machining.
--

Regards,

Eric Stevens

On Wed, 2 Jul 2014 01:09:09 -0700 (PDT), RichA
wrote:

On Monday, June 30, 2014 4:58:37 AM UTC-4, Eric Stevens wrote:
On Mon, 30 Jun 2014 00:49:25 -0700 (PDT), RichA


But magnesium needs machining. Properly designed plastic objects just

clip in place without further machining.

Yes, cast plastic sure is accurate. Metals just keep getting better:

http://phys.org/news/2014-06-world-s...ium-alloy.html

Leaving aside the question of whether or not anyone can manufacture a
camera frame of this materiel, you have to ask could they ever justify
making a camera of it?

Then there is single-crystal magnesium. Much stronger again. But who
wants it?
--

Regards,

Eric Stevens

On 6/29/14 4:20 PM, in article
, "RichA"
wrote:

On Sunday, June 29, 2014 5:02:45 PM UTC-4, Oregonian Haruspex wrote:
On 2014-06-28 23:07:28 +0000, RichA said:



http://www.dpreview.com/forums/post/53930590



For an ultra-budget grade lens what do you expect?



I mean, yeah, it's not as good as metal. But the post you link to

starts out with "I bumped my XC 16-50 lens" and I can only guess at the

varying levels of force implied by such an innocuous word as "bumped."



I have bumped the hell out of my EF 50 f/1.8 II and it never gave way

despite the plastic mount, but maybe one man's "bump" is another man's

"slammed into an object with enormous force."

I was in a camera store two years ago and they showed me a box of kit lenses,
plastic mounts, that had that kind of damage. Plastic STINKS, especially in a
part that is small and meant to hold another, larger part in-place.

Mister Robinson would NOT have liked you, Rich A...

On 2014-07-02 14:48:05 +0000, George Kerby said:

On 6/29/14 4:20 PM, in article
, "RichA"
wrote:
On Sunday, June 29, 2014 5:02:45 PM UTC-4, Oregonian Haruspex wrote:
On 2014-06-28 23:07:28 +0000, RichA said:

http://www.dpreview.com/forums/post/53930590

For an ultra-budget grade lens what do you expect?

I mean, yeah, it's not as good as metal. But the post you link to
starts out with "I bumped my XC 16-50 lens" and I can only guess at the
varying levels of force implied by such an innocuous word as "bumped."

I have bumped the hell out of my EF 50 f/1.8 II and it never gave way
despite the plastic mount, but maybe one man's "bump" is another man's
"slammed into an object with enormous force."

I was in a camera store two years ago and they showed me a box of kit lenses,
plastic mounts, that had that kind of damage. Plastic STINKS, especially in a
part that is small and meant to hold another, larger part in-place.

Mister Robinson would NOT have liked you, Rich A...

I believe the career advice given to Ben at the party came from another
guest, not Mr. Robinson.
From imdb.com:
Mr. McGui I just want to say one word to you. Just one word.
Benjamin: Yes, sir.
Mr. McGui Are you listening?
Benjamin: Yes, I am.
Mr. McGui Plastics.
Benjamin: Exactly how do you mean?

--
Regards,

Savageduck

On Mon, 30 Jun 2014 10:06:06 +1200, Eric Stevens
wrote:

On Sun, 29 Jun 2014 14:20:49 -0700 (PDT), RichA
wrote:

On Sunday, June 29, 2014 5:02:45 PM UTC-4, Oregonian Haruspex wrote:
On 2014-06-28 23:07:28 +0000, RichA said:



http://www.dpreview.com/forums/post/53930590



For an ultra-budget grade lens what do you expect?



I mean, yeah, it's not as good as metal. But the post you link to

starts out with "I bumped my XC 16-50 lens" and I can only guess at the

varying levels of force implied by such an innocuous word as "bumped."



I have bumped the hell out of my EF 50 f/1.8 II and it never gave way

despite the plastic mount, but maybe one man's "bump" is another man's

"slammed into an object with enormous force."

I was in a camera store two years ago and they showed me a box of kit lenses, plastic mounts, that had that kind of damage. Plastic STINKS, especially in a part that is small and meant to hold another, larger part in-place.

It stinks if it is used for a part originally intended to be made in
metal.

I take that back. It stinks if the component isn't properly designed
for the material it is to be made of. But here is an example which
shows that under the right circumstances plastic _can_ be successfully
substituted for metal:
http://news.yahoo.com/sogefi-audi-de...--finance.html

or http://tinyurl.com/nt6wwk4
--

Regards,

Eric Stevens

On 7/2/14 11:05 AM, in article
2014070209050085350-savageduck1@REMOVESPAMmecom, "Savageduck"
wrote:

On 2014-07-02 14:48:05 +0000, George Kerby said:

On 6/29/14 4:20 PM, in article
, "RichA"
wrote:
On Sunday, June 29, 2014 5:02:45 PM UTC-4, Oregonian Haruspex wrote:
On 2014-06-28 23:07:28 +0000, RichA said:

http://www.dpreview.com/forums/post/53930590

For an ultra-budget grade lens what do you expect?

I mean, yeah, it's not as good as metal. But the post you link to
starts out with "I bumped my XC 16-50 lens" and I can only guess at the
varying levels of force implied by such an innocuous word as "bumped."

I have bumped the hell out of my EF 50 f/1.8 II and it never gave way
despite the plastic mount, but maybe one man's "bump" is another man's
"slammed into an object with enormous force."

I was in a camera store two years ago and they showed me a box of kit
lenses,
plastic mounts, that had that kind of damage. Plastic STINKS, especially in
a
part that is small and meant to hold another, larger part in-place.

Mister Robinson would NOT have liked you, Rich A...

I believe the career advice given to Ben at the party came from another
guest, not Mr. Robinson.
From imdb.com:
Mr. McGui I just want to say one word to you. Just one word.
Benjamin: Yes, sir.
Mr. McGui Are you listening?
Benjamin: Yes, I am.
Mr. McGui Plastics.
Benjamin: Exactly how do you mean?

Ahhh! My Bad.

But... If I had said "Mr. McGuire would NOT have liked you, RichA...", would
it have meant anything?!?

Maybe it didn't, anyway...